AsfiledwiththeSecuritiesandExchangeCommissiononNovember 4,2021

RegistrationNo.333-

UNITEDSTATES

SECURITIESANDEXCHANGECOMMISSION

WASHINGTON,D.C.20549

FORM S-3

REGISTRATIONSTATEMENT

UNDER

THE SECURITIES ACT OF 1933

GALECTO, INC.

(Exactnameofregistrantasspecifiedinitscharter)

Delaware	37-1957007
(Stateorotherjurisdictionofincorporation)	(I.R.S. EmployerIdentificationNo.)

75 State Street, Suite 100

Boston,Massachusetts,02109

Ole Maaloes Vej 3

DK-2200 Copenhagen N

Denmark

(Address of principal executive offices, including zip code)

(+45) 70 70 52 10

(Address,includingzipcode,andtelephonenumber,includingareacode,ofregistrant’sprincipalexecutiveoffices)

Jonathan Freve

Chief Financial Officer

Galecto, Inc.

75 State Street, Suite 100

Boston,Massachusetts,02109

(+45) 70 70 52 10

(Name,address,includingzipcode,andtelephonenumber,includingareacode,ofagentforservice)

Copiesto:

Edwin M. O’Connor

Goodwin Procter LLP

620 8th Avenue

New York, NY 10018

(212) 813-8800

Approximate date of commencement of proposed sale to the public: From time to time after the effective date of this Registration Statement.

If the only securities being registered on this Form are being offered pursuant to dividend or interest reinvestment plans, please check thefollowingbox:☐

If any of the securities being registered on this Form are to be offered on a delayed or continuous basis pursuant to Rule 415 under the SecuritiesActof1933,other thansecuritiesofferedonlyinconnectionwithdividendorinterestreinvestmentplans,checkthefollowing box:☒

If this Form is filed to register additional securities for an offering pursuant to Rule 462(b) under the Securities Act, please check the followingboxandlisttheSecuritiesActregistrationstatementnumberof theearliereffectiveregistration statementforthesameoffering:☐

If this Form is a post-effective amendment filed pursuant to Rule 462(c) under the Securities Act, check the following box and list the SecuritiesActregistrationstatementnumberoftheearliesteffectiveregistration statement forthesameoffering:☐

If this Form is a registration statement pursuant to General Instruction I.D. or a post-effective amendment thereto that shall become effective uponfilingwiththe Commissionpursuant toRule 462(e) under theSecurities Act,checkthefollowingbox.☐

If this Form is a post-effective amendment to a registration statement filed pursuant to General Instruction I.D. filed to register additionalsecuritiesor additionalclassesofsecuritiespursuant toRule 413(b)underthe SecuritiesAct,checkthefollowingbox.☐

Indicate by check mark whether the registrant is a large accelerated filer, an accelerated filer, a non-accelerated filer, a smaller reporting company,or an emerging growth company. See the definitions of “large accelerated filer,” “accelerated filer,” “smaller reporting company” and “emerging growthcompany”in Rule12b-2 oftheExchangeAct. (Checkone):

Largeacceleratedfiler	☐	Acceleratedfiler	☐
Non-acceleratedfiler	☒	Smallerreportingcompany	☒
		Emerginggrowth company	☒

If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying withanynew orrevisedfinancialaccounting standardsprovided pursuanttoSection7(a)(2)(B)ofthe SecuritiesAct.☐

CALCULATIONOFREGISTRATIONFEE

Title of Each Class ofSecuritiestobeRegistered(1)	Amount to be Registered (1)(2)	ProposedMaximumOfferingPricePer Security(3)	ProposedMaximumAggregateOffering Price(3)	Amount of RegistrationFee(4)
Common Stock, $0.00001 par value
Preferred Stock, $0.00001 par value
Debt Securities
Warrants
SubscriptionRights
Units
Total	$200,000,000	N/A	$200,000,000	$18,540

(1) There is being registered hereunder an indeterminate number of shares of (a) common stock, (b) preferred stock, (c) debt securities, (d) warrants to purchase common stock, preferred stock or debt securities of the Registrant, (e) subscription rights to purchase common stock, preferred stock or debt securities of the Registrant, and (f) units, consisting of some or all of these securities in any combination, as may be sold from timeto time by the Registrant. Any securities registered hereunder may be sold separately or as units with other securities registered hereunder. Thereare also being registered hereunder an indeterminate number of shares, at indeterminate prices, of common stock, preferred stock and debtsecurities as shall be issuable upon conversion, exchange or exercise of any securities that provide for such issuance or pursuant to the anti-dilution provisions of any such securities. In no event will theaggregateofferingpriceofalltypesofsecuritiesissuedbytheRegistrantpursuanttothisregistrationstatementexceed$200.0million.

(2) Pursuant to Rule 416(a), this registration statement also covers any additional securities that may be offered or issued in connection with any stock split,stockdividend or similartransaction.

(3) Estimated solely for purposes of computing the registration fee. The proposed maximum offering price per share and proposed maximumaggregate offering price for each type of security will be determined from time to time by the Registrant in connection with the issuance by the Registrantofthe securities registered hereunder and, pursuant to General Instruction II.D, is not specified as to each class of security.

(4) CalculatedpursuanttoRule457(o)undertheSecuritiesActof1933, as amended.

The Registrant hereby amends this registration statement on such date or dates as may be necessary to delay its effective date until theRegistrant shall file a further amendment which specifically states that this registration statement shall thereafter become effective inaccordance with Section 8(a) of the Securities Act of 1933, as amended, or until the registration statement shall become effective on such date as the Securities and Exchange Commission,acting pursuant tosaid Section8(a), maydetermine.

EXPLANATORY NOTE

Thisregistrationstatementcontainstwoprospectuses:

• a base prospectus, which covers the offering, issuance and sale by us of up to a maximum aggregate offering price of $200,000,000 of ourcommon stock,preferred stock,debtsecurities,warrantstopurchaseourcommon stock,preferred stockordebtsecurities,subscriptionrightstopurchaseourcommon stock,preferred stock ordebtsecuritiesand/orunitsconsistingofsomeorallofthesesecurities;and

• a sales agreement prospectus covering the offering, issuance and sale by us of up to a maximum aggregate offering price of $50,000,000 of our common stock that may be issued and sold under an Open Market Sale AgreementSM, or Sales Agreement, dated November 4, 2021withJefferiesLLC, orJefferies.

The base prospectus immediately follows this explanatory note. The specific terms of any securities to be offered pursuant to the base prospectus will be specified in a prospectus supplement to the base prospectus. The sales agreement prospectus immediately follows the base prospectus. The $50,000,000 of common stock that may be offered, issued and sold under the sales agreement prospectus is included in the $200,000,000 of securities that may beoffered, issued and sold by us under the base prospectus. Upon termination of the Sales Agreement with Jefferies, any portion of the $50,000,000included in the sales agreement prospectus that is not sold pursuant to the Sales Agreement will be available for sale in other offerings pursuant to thebase prospectus, and if no shares are sold under the Sales Agreement, the full $50,000,000 of securities may be sold in other offerings pursuant to thebaseprospectus and an accompanying prospectussupplement.

The information in this prospectus is not complete and may be changed. We may not sell these securities until the registration statement filed with theSecurities and Exchange Commission is effective. This prospectus is not an offer to sell these securities, and it is not soliciting an offer to buy thesesecurities,in any jurisdictionwherethe offer or saleis not permitted.

SUBJECTTOCOMPLETION,DATEDNOVEMBER 4,2021

PROSPECTUS

$200,000,000

Common Stock

Preferred Stock

Debt Securities

Warrants

Subscription Rights

Units

From time to time, we may offer up to $200,000,000 aggregate dollar amount of shares of our common stock, preferred stock, debt securities,warrants to purchase our common stock, preferred stock or debt securities, subscription rights to purchase our common stock, preferred stock or debtsecurities and/or units consisting of some or all of these securities, in any combination, together or separately, in one or more offerings, in amounts, atprices and on the terms that we will determine at the time of the offering and which will be set forth in a prospectus supplement and any related freewriting prospectus. We may also offer securities as may be issuable upon conversion, redemption, repurchase, exchange or exercise of any securitiesregisteredhereunder,includinganyapplicableanti-dilutionprovisions.

This prospectus provides a general description of the securities we may offer. Each time we offer securities, we will provide specific terms of the securities offering in a supplement to this prospectus. We may also authorize one or more free writing prospectuses to be provided to you in connection with these offerings. The prospectus supplement and any related free writing prospectus may also add, update or change information contained in this prospectus. The total amount of these securities will have an initial aggregate offering price of up to $200,000,000.

You should read this prospectus, the information incorporated, or deemed to be incorporated, by reference in this prospectus, and any applicable prospectus supplement and any related free writing prospectus carefully before you invest.

This prospectus may not be used to offer and sell any securities unless accompanied by a prospectus supplement.

Our common stock is traded on the Nasdaq Global Select Market under the symbol “GLTO” On November 3, 2021, the last reported sales price for our common stock was $3.39 per share. None of the other securities we may offer are currently traded on any securities exchange. The applicable prospectus supplement and any related free writing prospectus will contain information, where applicable, as to any other listing on the Nasdaq Stock Market or any securities market or exchange of the securities covered by the prospectus supplement and any related free writing prospectus.

Aninvestmentinoursecuritiesinvolvesahighdegreeofrisk.Youshouldcarefullyconsidertheinformationunder theheading“RiskFactors”beginningonpage5ofthisprospectusbeforeinvestinginoursecurities. We may include additional risk factors in supplements to this prospectus under the heading "Risk Factors."

Common stock, preferred stock, debt securities, warrants, subscription rights and/or units may be sold by us to or through underwriters ordealers, directly to purchasers or through agents designated from time to time. For additional information on the methods of sale, you should refer to the section titled “Plan of Distribution” in this prospectus and in the applicable prospectus supplement. If any underwriters, dealers or agents are involved in the sale of any securities with respect towhich this prospectus is being delivered, the names of such underwriters or agents and any applicable fees, discounts or commissions, details regardingover-allotment options, if any, and the net proceeds to us will be set forth in a prospectus supplement. The price to the public of such securities and thenetproceeds weexpecttoreceive from suchsalewillalso besetforthinaprospectus supplement.

NeithertheSecuritiesand Exchange Commissionnoranystatesecuritiescommissionhasapprovedordisapprovedofthesesecuritiesordeterminedifthis prospectusis truthfulorcomplete.Anyrepresentation tothe contraryis acriminaloffense.

Thedateofthisprospectusis                         ,2021

TABLEOFCONTENTS

	Page
ABOUT THIS PROSPECTUS	1
PROSPECTUS SUMMARY	2
RISK FACTORS	5
SPECIAL NOTE REGARDING FORWARD LOOKING STATEMENTS	6
USE OF PROCEEDS	8
PLAN OF DISTRIBUTION	9
DESCRIPTION OF CAPITAL STOCK	11
DESCRIPTION OF DEBT SECURITIES	15
DESCRIPTION OF WARRANTS	21
DESCRIPTION OF SUBSCRIPTION RIGHTS	23
DESCRIPTION OF UNITS	24
LEGAL MATTERS	27
EXPERTS	27
WHERE YOU CAN FIND MORE INFORMATION	27
INCORPORATION OF CERTAIN INFORMATION BY REFERENCE	27

ABOUTTHISPROSPECTUS

This prospectus is part of a registration statement on Form S-3 that we filed with the Securities and Exchange Commission, or the SEC, using a “shelf” registration process. Under this shelf registration process, from time to time, we may sell any combination of the securities described in this prospectus in one or more offerings, up to a total dollar amount of $200.0 million. In this prospectus, we have provided a general description of the securities we may offer.

Each time we sell securities under this shelf registration process, we will provide a prospectus supplement that will contain specific information about the terms of the offering. We may also add, update or change any of the information contained in this prospectus in a prospectus supplement. To the extent there is a conflict between the information contained in this prospectus and the prospectus supplement, you should rely on the information in the prospectus supplement; provided that, if any statement in one of these documents is inconsistent with a statement in another document having a later date—for example, a document incorporated by reference in this prospectus or any prospectus supplement—the statement in the document having the later date modifies or supersedes the earlier statement. You should read both this prospectus and any prospectus supplement together with additional information described under the heading “Where You Can Find More Information.”

You should rely only on the information contained in or incorporated by reference into this prospectus or any applicable prospectus supplement.

No dealer, salesperson or any other person is authorized to give any information or to make any representation other than the information and representations contained in or incorporated by reference into this prospectus or any applicable prospectus supplement. If different information is given or different representations are made, you may not rely on that information or those representations as having been authorized by us. You may not imply from the delivery of this prospectus and any applicable prospectus supplement, nor from a sale made under this prospectus and any applicable prospectus supplement, that our affairs are unchanged since the date of this prospectus and any applicable prospectus supplement or that the information contained in any document incorporated by reference is accurate as of any date other than the date of the document incorporated by reference, regardless of the time of delivery of this prospectus and any applicable prospectus supplement or any sale of a security. This prospectus and any applicable prospectus supplement may only be used where it is legal to sell the securities.

THISPROSPECTUSMAYNOTBEUSEDTOOFFERANDSELLSECURITIESUNLESSITISACCOMPANIEDBYAPROSPECTUSSUPPLEMENT.

In this prospectus, unless the context otherwise requires, the terms “Galecto,” the “Company,” “we,” “us,” and “our” refer to Galecto, Inc. and its and its subsidiaries, taken as a whole, unless otherwise noted. “Galecto” and all product candidate names are our commonlaw trademarks. This prospectus and the information incorporated herein by reference contains additional trade names, trademarks and service marks ofother companies, which are the property of their respective owners. We do not intend our use or display of other companies’ trade names, trademarks or servicemarks toimplya relationshipwith, orendorsementor sponsorshipofusby,theseother companies.

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PROSPECTUSSUMMARY

This summary highlights information contained in other parts of this prospectus or incorporated by reference in this prospectus from ourAnnual Report on Form 10-K for the year ended December 31, 2020, any subsequent Quarterly Reports on Form 10-Q and our other filings with the SEC listed below under the heading“Incorporation of Certain Information by Reference.” This summary may not contain all the information that you should consider before investing in our securities. You should read the entire prospectus, the applicable prospectus supplement and any related free writing prospectus and theinformation incorporated by reference in this prospectus and any prospectus supplement carefully, including the information under the heading “Risk Factors” and the financial data and related notes and otherinformationincorporated by reference,before makingan investmentdecision.

CompanyOverview

We are a clinical-stage biotechnology company developing therapeutics that are designed to target the biological processes that lie at the heart of fibrosis and cancer. While our initial focus has been on the development of small-molecule inhibitors of galectin-3 and the collagen cross-linking enzyme lysyl oxidase-like 2, or LOXL2, which play key roles in regulating fibrosis, we are also advancing our compounds for the treatment of cancer (initially in non-small cell lung cancer, or NSCLC, and myelofibrosis). We believe our product candidates are distinct from the current generation of antifibrotic and anti-cancer agents and have the potential to significantly improve patients’ clinical outcomes and enhance their quality of life.

Our most advanced product candidate, GB0139, is an inhaled small molecule inhibitor of galectin-3. We are developing GB0139 for the treatment of severe fibrotic lung diseases such as idiopathic pulmonary fibrosis, or IPF, a life-threatening progressive fibrotic disease of the lung. While there are currently two approved therapies for the treatment of lung fibrosis, they have only been shown to have a modest impact on the progression of the disease, and both therapies have been associated with significant side effects leading to poor therapeutic adherence. In our clinical trials completed to date, we found orally inhaled GB0139 to be generally well-tolerated and that the compound inhibited galectin-3 in the lungs, in a dose-dependent manner, and that it decreased levels of a range of plasma biomarkers, such as YKL-40 and PDGF, that have been linked to mortality, severity and/or progression in IPF.

GB0139 is in Phase 2b clinical development, and our other current product candidates and research initiatives are in earlier stages of clinical and preclinical development. Our ability to generate revenue from product sales sufficient to achieve profitability will depend heavily on the successful development and eventual commercialization of one or more of our product candidates. Our operations to date have been financed primarily from our initial public offering, the issuance of convertible preferred shares and convertible notes. Since inception, we have had significant operating losses. Our net loss was $12.7 million and $38.3 million for the three and nine months ended September 30, 2021, respectively. Our net loss was $11.7 million and $23.3 million for the three and nine months ended September 30, 2020, respectively. As of September 30, 2021, we had an accumulated deficit of $142.7 million and $127.6 million in cash, cash equivalents and marketable securities.

Accordingly, we will continue to require additional financing to advance our current product candidates through clinical development, to develop, acquire or in-license other potential product candidates and to fund operations for the foreseeable future. We will continue to seek funds through equity offerings, debt financings or other capital sources, including potentially collaborations, licenses and other similar arrangements. However, we may be unable to raise additional funds or enter into such other arrangements when needed on favorable terms or at all. If we raise additional capital through public or private equity offerings in the future, the ownership interest of our existing stockholders will be diluted, and the terms of these securities may include liquidation or other preferences that adversely affect our stockholders’ rights. If we raise additional capital through debt financing, we may be subject to covenants limiting or restricting our ability to take specific actions, such as incurring additional debt, making capital expenditures or declaring dividends. Any failure to raise capital as and when needed could have a negative impact on our financial condition and on our ability to pursue our business plans and strategies. If we are unable to raise capital, we will need to delay, reduce or terminate planned activities to reduce costs. We will need to generate significant revenues to achieve profitability, and we may never do so.

TheSecuritiesWeMayOffer

With this prospectus, we may offer common stock, preferred stock, debt securities, warrants to purchase our common stock, preferred stock or debt securities, subscription rights to purchase our common stock, preferred stock or debt securities, and/or units consisting of some orallofthesesecuritiesinanycombination.Theaggregateofferingpriceofsecuritiesthatweofferwiththisprospectuswill notexceed $200.0million.Eachtimeweoffersecuritieswiththisprospectus,wewillprovideoffereeswithaprospectussupplementthatwill containthespecifictermsofthesecuritiesbeingoffered.Thefollowing isasummaryofthesecuritieswemayofferwiththisprospectus.

Common Stock

Wemayoffersharesofourcommon stock,parvalue $0.00001pershare.

Preferred Stock

We may offer shares of our preferred stock, par value $0.00001per share, in one or more series. Our board of directors or a committee designatedby the board will determine the dividend, voting, conversion and other rights of the series of shares of preferred stock being offered. Each series of preferred stock will be more fully described in the particular prospectus supplement that will accompany this

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prospectus,includingredemptionprovisions,rightsintheeventofourliquidation,dissolutionorthewindingup,votingrightsandrightstoconvertintocommonstock.

DebtSecurities

We may offer general obligations, which may be secured or unsecured, senior or subordinated and convertible into shares of our common stock or preferred stock. In this prospectus, we refer to the senior debt securities and the subordinated debt securities together as the “debtsecurities.”Ourboard ofdirectorswilldeterminetheterms ofeachseriesofdebt securitiesbeingoffered.

We will issue the debt securities under an indenture between us and a trustee. In this document, we have summarized general features of the debt securities from the indenture. We encourage you to read the indenture, which is an exhibit to the registration statement of which thisprospectus isapart.

Warrants

We may offer warrants for the purchase of debt securities, shares of preferred stock or common stock. We may issue warrantsindependentlyortogetherwithothersecurities.Ourboard ofdirectorswill determinethetermsofthewarrants.

Subscription Rights

Wemayoffersubscriptionrightsforthepurchaseofcommon stock,preferred stockordebtsecurities.Wemayissuesubscriptionrightsindependentlyortogetherwithothersecurities.Ourboardofdirectorswilldeterminethetermsofthesubscriptionrights.

Units

Wemayofferunitsconsistingofsomeorallofthesecuritiesdescribedabove,inanycombination,includingcommon stock,preferred shares, warrants and/or debt securities. The terms of these units will be set forth in a prospectus supplement. The description of the terms of these units in the related prospectus supplement will not be complete. You should refer to the applicable form of unit and unit agreement for completeinformationwith respectto theseunits.

CorporateInformation

We were formed under the laws of the State of Delaware in October 2019. Subsequently, shares in Galecto Biotech AB, a Swedish operating company, were exchanged at a one-to-one ratio for shares in Galecto, Inc. On December 31, 2019, we consummated a purchase agreement by and among Galecto, Inc., PK Merger Sub, Inc., and PharmAkea, Inc., or PharmAkea, whereby we acquired PharmAkea in principally an all-stock transaction. As of September 30, 2021, our wholly-owned subsidiaries were Galecto Biotech AB, PharmAkea and Galecto Securities Corporation, and Galecto Biotech ApS, a Danish operating company, was a wholly-owned subsidiary of Galecto Biotech AB.

Our principal US executive offices are located at 75 State Street, Suite 100, Boston, MA 02109 and our principal international executive offices are located at Ole Maaloes Vej 3, DK-2200 Copenhagen N, Denmark, and our telephone number is (+45) 70 70 52 10. Our website address is http://www.galecto.com. The information contained on, or that can be accessed through, our website is not a part of this prospectus. We have included our website address in this prospectus solely as an inactive textual reference.

We use various trademarks and trade names in our business, including without limitation our corporate name and logo. All other trademarks or trade names referred to in this prospectus are the property of their respective owners. Solely for convenience, the trademarks and trade names in this prospectus may be referred to without the ® and ™ symbols, but such references should not be construed as any indicator that their respective owners will not assert, to the fullest extent under applicable law, their rights thereto.

ImplicationsofBeinganEmergingGrowthCompanyandaSmallerReportingCompany

We are an “emerging growth company,” as defined in the Jumpstart Our Business Startups Act, or the JOBS Act, enacted in April 2012. Forso long as we remain an emerging growth company, we are permitted and intend to rely on certain exemptions from various public companyreporting requirements, including an exemption from the requirement to include an attestation report on internal control over financial reporting issued by ourindependent registered public accounting firm pursuant to Section 404(b) of the Sarbanes-Oxley Act of 2002, reduced disclosure obligationsregarding executive compensation in our periodic reports and proxy statements, and exemptions from the requirements of holding a nonbindingadvisory vote on executive compensation and any golden parachute payments not previously approved. In particular, in this prospectus, we havenot included or incorporated by reference all of the executive compensation-related information that would be required if we were not an emerging growth company. Accordingly, the information contained herein may be different than the information you receive from other public companies inwhichyouhold stock.

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We will remain an emerging growth company until the earlier to occur of (1) the last day of the fiscal year (a) following the fifth anniversaryof the date of the closing of our initial public offering, (b) in which we have total annual gross revenues of at least $1.07 billion or (c) in which wearedeemedtobea“largeacceleratedfiler,”undertherulesoftheSEC,whichmeans themarketvalueofourequitysecuritiesthatisheldby non-affiliates exceeds $700 million as of June 30^th of the prior year, and (2) the date on which we have issued more than $1.0 billion in non-convertible debtduring theprior three-year period.

In addition, the JOBS Act provides that an emerging growth company can take advantage of an extended transition period for complyingwithneworrevisedaccountingstandards.Thisprovisionallowsanemerginggrowthcompanytodelaytheadoptionofsomeaccountingstandards until those standards would otherwise apply to private companies. We have elected to use this extended transition period for complying with newor revised accounting standards that have different effective dates for public and private companies until the earlier of the date we (i) are no longer an emerging growth company or (ii) affirmatively and irrevocably opt out of the extended transition period provided in the JOBS Act. As a result,we are not subject to the same new or revised accounting standards as other public companies that are not emerging growth companies, and ourfinancial statements may not be comparable to other public companies that comply with new or revised accounting pronouncements as of publiccompany effective dates. We may choose to early adopt any new or revised accounting standards whenever such early adoption is permitted forprivatecompanies.

We arealsoa “smallerreportingcompany,”meaningthat the market valueof ourstockheld bynon-affiliates isless than$700million andour annual revenue was less than $100 million during our most recently completed fiscal year. We may continue to be a smaller reporting company if either (i) the market value of our stock held by non-affiliates is less than $250 million or (ii) our annual revenue was less than $100 millionduring the most recently completed fiscal year and the market value of our stock held by non-affiliates is less than $700 million. If we are a smaller reporting company at the time we cease to be an emerging growth company, we may continue to rely on exemptions from certain disclosurerequirements that are available to smaller reporting companies. For so long as we remain a smaller reporting company, we are permitted and intendto rely on exemptions from certain disclosure and other requirements that are applicable to other public companies that are not smaller reportingcompanies.

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RISKFACTORS

An investment in our securities involves a high degree of risk. The prospectus supplement applicable to each offering of securities will contain adiscussion of the risks applicable to an investment in our securities. Prior to making a decision about investing in our securities, you should carefullyconsider the specific factors discussed under the heading “Risk Factors” in the applicable prospectus supplement, together with all of the otherinformation contained or incorporated by reference in the prospectus supplement or appearing or incorporated by reference in this prospectus. Youshould also consider the risks, uncertainties and assumptions discussed in our most recent Annual Report on Form 10-K, in any subsequent QuarterlyReport on Form 10-Q and any other filings we make with the SEC from time to time, which are incorporated herein by reference in this prospectus, and may be amended, supplemented or superseded from time to time by other reports we file with the SEC in the future. The risks and uncertainties we have described are not the only ones we face. Additional risks and uncertainties not presently known to us or that we currently deem immaterial may alsoaffectour operations.

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SPECIALNOTEREGARDINGFORWARD-LOOKINGSTATEMENTS

This prospectus and documents incorporated by reference herein and therein contain “forward-looking statements” within the meaning of theSection 27A of the Securities Act of 1933, as amended, or the Securities Act, and Section 21E of the Securities Exchange Act of 1934, as amended, orthe Exchange Act. We intend that such forward-looking statements be subject to the safe harbors provided by the Private Securities Litigation Reform Act of 1995. These forward-looking statements involve a number of risks and uncertainties. We caution readers that any forward-lookingstatement is not a guarantee of future performance and that actual results could differ materially from those contained in the forward-looking statement.Thesestatements arebasedon currentexpectationsof futureevents.

Suchstatements include,butarenotlimited to,statements about:

• the success, cost and timing of our product development activities and planned initiation and completion of clinical trials of our lead product candidate, GB0139, including our ability to enroll patients in our ongoing Phase 2b clinical trial of GB0139 at anticipated rates and our ability to complete such trial with fewer dosage groups, as well as our other current product candidates and any future product candidates;

• the success, cost and timing of our product development activities and planned initiation and completion of our clinical trials;

• our need to raise additional funding before we can expect to generate any revenues from product sales;

• our ability to obtain regulatory approval for our current or future product candidates that we may identify or develop, including our expectation that the FDA or other regulatory agencies would agree with our belief that our Phase 2b clinical trial of GB0139 may be registrational;

• our ability to ensure adequate supply of our current or future product candidates;

• our ability to maintain third-party relationships necessary to conduct our business;

• our heavy dependence upon the success of our research to generate and advance additional product candidates;

• our ability to establish an adequate safety or efficacy profile for our current or future product candidates that we may pursue;

• the implementation of our strategic plans for our business, our current or future product candidates we may develop and our technology;

• our intellectual property position, including the scope of protection we are able to establish and maintain for intellectual property rights covering our product candidates and technology;

• the rate and degree of market acceptance and clinical utility for our current or future product candidates we may develop;

• our estimates about the size of our market opportunity;

• our ability to use the capital we have raised in ways that increase the value of your investment;

• our expectations related to the use the capital we have raised, and estimates of our expenses, future revenues, capital requirements and our needs for additional financing;

• our ability to establish and maintain collaborations;

• our financial performance and liquidity;

• our ability to effectively manage our potential growth;

• developments relating to our competitors and our industry, including the impact of government regulation;

• our ability to retain the continued service of our key professionals and consultants and to identify, hire and retain additional qualified professionals;

• the effect of the COVID-19 pandemic, including mitigation efforts and economic effects, on any of the foregoing or other aspects of our business operations and those of our collaborators, service providers and other vendors;

• our ability to maintain adequate internal controls over financial reporting; and

• other risks and uncertainties, including those listed under the section titled “Risk Factors.”

Any statements about our expectations, beliefs, plans, objectives, assumptions or future events or performance are not historical facts and may be forward-looking. You can find many of these statements by looking for words like “believes,” “expects,” “anticipates,” “estimates,” “may,” “might,” “should,” “will,” “could,”, “should,” “plans,” “intends,” “projects,” “predicts,” “potential,” “continue,” “seek” or similar expressions, or the negative of these terms, in this prospectus and the documents incorporated by reference herein and in any free writing prospectus. Any forward-looking statements are qualified in their entirety by reference to the factors discussed throughout this prospectus, and in particular those factors referenced in the section “Risk Factors.”

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These forward-looking statements are based on the current beliefs and expectations of our management and are subject to significant risks and uncertainties. If underlying assumptions prove inaccurate or unknown risks or uncertainties materialize, actual results may differ materially from current expectations and projections. Factors that might cause such a difference include those discussed in our most recent Annual Report on Form 10-K and any subsequent Quarterly Report on Form 10-Q, as well as those discussed in this prospectus and in the documents incorporated by reference into this prospectus. You are cautioned not to place undue reliance on these forward-looking statements, which speak only as of the date made. We anticipate that subsequent events and developments will cause our views to change. However, while we may elect to update these forward-looking statements at some point in the future, we have no current intention of doing so except to the extent required by applicable law. You should, therefore, not rely on these forward-looking statements as representing our views as of any date subsequent to the date of this prospectus.

This prospectus and the documents incorporated by reference also contain estimates, projections and other information concerning our industry, our business, and the markets for certain diseases, including data regarding the estimated size of those markets, and the incidence and prevalence of certain medical conditions. Information that is based on estimates, forecasts, projections, market research or similar methodologies is inherently subject to uncertainties and actual events or circumstances may differ materially from events and circumstances reflected in this information. Unless otherwise expressly stated, we obtained this industry, business, market and other data from reports, research surveys, studies and similar data prepared by market research firms and other third parties, industry, medical and general publications, government data and similar sources.

All subsequent written or oral forward-looking statements attributable to us or any person acting on our behalf are expressly qualified in their entirety by the cautionary statements contained or referred to in this section. We do not undertake any obligation to release publicly any revisions to these forward-looking statements to reflect events or circumstances after the date of this prospectus or to reflect the occurrence of unanticipated events, except as may be required under applicable U.S. securities law. If we do update one or more forward-looking statements, no inference should be drawn that we will make additional updates with respect to those or other forward-looking statements.

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USEOFPROCEEDS

We will retain broad discretion over the use of the net proceeds to us from the sale of our securities under this prospectus. Unless otherwiseprovided in the applicable prospectus supplement, we intend to use the net proceeds from the sale of securities under this prospectus for generalcorporate purposes, which may include, but are not limited to, funding research and development and clinical development costs to support the advancement of our potential product candidates and the expansion of our research and development programs, increasing our working capital, acquisitions or investments in businesses, products or technologies that are complementary to our own and capital expenditures. We will set forth in the applicable prospectus supplement our intended use for the net proceeds received from the sale of any securities. We may temporarily invest the net proceeds in a variety of capital preservation instruments, including investment grade, interest bearing instruments and U.S. government securities, or may hold such proceeds as cash, untiltheyareusedfortheirstatedpurpose.Wehavenotdeterminedtheamountofnetproceedstobeusedspecificallyforsuchpurposes.

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PLANOFDISTRIBUTION

We may sell the securities covered by this prospectus to one or more underwriters for public offering and sale by them, and may also sell thesecurities to investors directly or through agents. We will name any underwriter or agent involved in the offer and sale of securities in the applicableprospectus supplement. We have reserved the right to sell or exchange securities directly to investors on our own behalf in jurisdictions where we areauthorizedtodo so.We may distributethesecuritiesfromtimetotimein one ormoretransactions:

• at a fixed price or prices, which may be changed;

• at market prices prevailing at the time of sale;

• at prices related to such prevailing market prices; or

• at negotiated prices.

We may directly solicit offers to purchase the securities being offered by this prospectus. We may also designate agents to solicit offers to purchase the securities from time to time. We will name in a prospectus supplement any agent involved in the offer or sale of our securities. Unless otherwise indicated in a prospectus supplement, an agent will be acting on a best efforts basis, and a dealer will purchase securities as a principal for resale at varying prices to be determined by the dealer.

If we utilize an underwriter in the sale of the securities being offered by this prospectus, we will execute an underwriting agreement with the underwriter at the time of sale and we will provide the name of any underwriter in the prospectus supplement that the underwriter will use to make resales of the securities to the public. In connection with the sale of the securities, we, or the purchasers of securities for whom the underwriter may act as agent, may compensate the underwriter in the form of underwriting discounts or commissions. The underwriter may sell the securities to or through dealers, and those dealers may receive compensation in the form of discounts, concessions or commissions from the underwriters or commissions from the purchasers for whom they may act as agent.

We will provide in the applicable prospectus supplement any compensation we pay to underwriters, dealers, or agents in connection with the offering of the securities, and any discounts, concessions or commissions allowed by underwriters to participating dealers. Underwriters, dealers and agents participating in the distribution of the securities may be deemed to be underwriters within the meaning of the Securities Act, and any discounts and commissions received by them and any profit realized by them on resale of the securities may be deemed to be underwriting discounts and commissions. We may enter into agreements to indemnify underwriters, dealers and agents against civil liabilities, including liabilities under the Securities Act, and to reimburse them for certain expenses. We may grant underwriters who participate in the distribution of our securities under this prospectus an option to purchase additional securities to cover any over-allotments in connection with the distribution.

The securities we offer under this prospectus may or may not be listed through the Nasdaq Stock Market or any other securities exchange. To facilitate the offering of securities, certain persons participating in the offering may engage in transactions that stabilize, maintain or otherwise affect the price of the securities. This may include short sales of the securities, which involves the sale by persons participating in the offering of more securities than we sold to them. In these circumstances, these persons would cover such short positions by making purchases in the open market or by exercising their option to purchase additional securities. In addition, these persons may stabilize or maintain the price of the securities by bidding for or purchasing securities in the open market or by imposing penalty bids, whereby selling concessions allowed to dealers participating in the offering may be reclaimed if securities sold by them are repurchased in connection with stabilization transactions. The effect of these transactions may be to stabilize or maintain the market price of the securities at a level above that which might otherwise prevail in the open market. These transactions may be discontinued at any time.

We may engage in at the market offerings into an existing trading market in accordance with Rule 415(a)(4) under the Securities Act. In addition, we may enter into derivative transactions with third parties, or sell securities not covered by this prospectus to third parties in privately negotiated transactions. If the applicable prospectus supplement indicates, in connection with those derivatives, the third parties may sell securities covered by this prospectus and the applicable prospectus supplement, including short sale transactions. If so, the third party may use securities pledged by us or borrowed from us or others to settle those sales or to close out any related open borrowings of stock, and they may use securities received from us in settlement of those derivatives to close out any related open borrowings of stock. The third party in these sale transactions will be an underwriter and will be identified in the applicable prospectus supplement. In addition, we may otherwise loan or pledge securities to a financial institution or other third party that in turn may sell the securities short using this prospectus. The financial institution or other third party may transfer its economic short position to investors in our securities or in connection with a concurrent offering of other securities.

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We will file a prospectus supplement to describe the terms of any offering of our securities covered by this prospectus. The prospectus supplement will disclose:

• thetermsof theoffer;

• thenamesofanyunderwriters,includinganymanagingunderwriters,aswellasanydealersoragents;

• thepurchasepriceofthesecuritiesfromus;

• thenetproceedstousfromthesaleof thesecurities;

• anydelayeddeliveryarrangements;

• anyover-allotmentorotheroptionsunderwhichunderwriters,ifany,maypurchaseadditionalsecuritiesfromus;

• anyunderwritingdiscounts,commissionsorotheritemsconstitutingunderwriters’compensation,andanycommissionspaidtoagents;

• in a subscription rights offering, whether we have engaged dealer-managers to facilitate the offering or subscription, including their nameornames and compensation;

• anypublicofferingprice;and

• otherfactsmaterialtothetransaction.

Wewillbearallorsubstantiallyallofthecosts,expensesandfeesinconnectionwiththeregistrationofoursecuritiesunderthisprospectus.Theunderwriters,dealersandagentsmayengageintransactionswithus,orperformservicesforus,intheordinarycourseof business.

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DESCRIPTIONOFCAPITAL STOCK

The following description of our capital stock and provisions of our amended and restated certificate of incorporation and bylaws are summaries of material terms and provisions and are qualified by reference to our amended and restated certificate of incorporation and bylaws.

General

Our authorized capital stock consists of 300,000,000 shares of common stock, par value $0.00001 per share, and 10,000,000 shares of preferred stock, par value $0.00001 per share, all of which shares of preferred stock are undesignated.

As of September 30, 2021, we had 25,261,832 shares of common stock outstanding and no outstanding shares of preferred stock. As of September 30, 2021, we had outstanding options to purchase 3,923,728 shares of our common stock, with a per share weighted-average exercise price of $6.57.

Common Stock

Holders of our common stock are entitled to one vote for each share of common stock held of record for the election of directors and on all matters submitted to a vote of stockholders. Except as described under “Anti-Takeover Effects of Delaware Law and Provisions of Our Amended and Restated Certificate of Incorporation and Bylaws” below, a majority vote of the holders of common stock is generally required to take action under our amended and restated certificate of incorporation and bylaws. Holders of our common stock are entitled to receive dividends ratably, if any, as may be declared by our board of directors out of legally available funds, subject to any preferential dividend rights of any preferred stock then outstanding. Upon our dissolution, liquidation or winding up, holders of our common stock are entitled to share ratably in our net assets legally available after the payment of all our debts and other liabilities, subject to the preferential rights of any preferred stock then outstanding. Holders of our common stock have no preemptive, subscription, redemption or conversion rights and no sinking fund provisions are applicable to our common stock. The rights, preferences and privileges of holders of common stock are subject to, and may be adversely affected by, the rights of the holders of shares of any series of preferred stock that we may designate and issue in the future.

Preferred Stock

Our board of directors is authorized, without action by the stockholders, to designate and issue up to an aggregate of 10,000,000 shares of preferred stock in one or more series. Our board of directors may designate the rights, preferences and privileges of the shares of each series and any of its qualifications, limitations or restrictions. Our board of directors may authorize the issuance of preferred stock with voting or conversion rights that could adversely affect the voting power or other rights of the holders of common stock. The issuance of preferred stock, while providing flexibility in connection with possible future financings and acquisitions and other corporate purposes could, under certain circumstances, have the effect of restricting dividends on our common stock, diluting the voting power of our common stock, impairing the liquidation rights of our common stock, or delaying, deferring or preventing a change in control of us, which might harm the market price of our common stock. See also “—Anti-Takeover Effects of Delaware Law and Provisions of Our Amended and Restated Certificate of Incorporation and Bylaws—Provisions of our amended and restated certificate of incorporation and bylaws—Undesignated preferred stock” below.

Registration Rights

Holders of 7,628,196 shares of our common stock or their permitted transferees, which we refer to as our registrable securities, are entitled to rights with respect to the registration of these securities under the Securities Act. These rights are provided under the terms of the Amended and Restated Investors’ Rights Agreement among the Company and certain of its stockholders, dated September 25, 2020, or the Investors’ Rights Agreement. The Investors’ Rights Agreement includes demand registration rights, short-form registration rights and piggyback registration rights. All fees, costs and expenses incurred in connection with registrations under the Investors’ Rights Agreement, will be borne by us, and all selling expenses, including underwriting discounts and selling commissions, will be borne by the holders of the shares being registered.

Demand registration rights

The holders of our registrable securities are entitled to demand registration rights. Under the terms of the Investors’ Rights Agreement, we will be required, upon the request of holders of at least a majority of our outstanding registrable securities, to file a registration statement and effect the registration with respect to at least forty percent (40%) of the registrable securities then outstanding (or a lesser percent if the anticipated aggregate offering price, net of expenses related to the offering, would exceed $10 million) having an anticipated aggregate offering price, net of expenses related to the offering, of at least $5 million for public resale, unless our board of directors decides in good faith that such registration would be materially detrimental to us and our stockholders under the circumstances. We are required to effect up to two registrations pursuant to this provision of the Investors’ Rights Agreement.

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Short form registration rights

The holders of our registrable securities are also entitled to short form registration rights. Pursuant to the Investors’ Rights Agreement, if we are eligible to file a registration statement on Form S-3, upon the request of holders of at least 25% of our outstanding registrable securities to sell registrable securities with an anticipated aggregate offering amount of at least $3.0 million net of certain expenses related to the offering, we will be required to effect a registration of such shares, unless our board of directors decides in good faith that such registration would be materially detrimental to us and our stockholders under the circumstances. We are required to effect up to two registrations in any twelve-month period pursuant to this provision of the Investors’ Rights Agreement.

Piggyback registration rights

The holders of our registrable securities are entitled to piggyback registration rights. If we register any of our securities either for our own account or for the account of other security holders, the holders of our outstanding registrable securities are entitled to include their shares in the registration. Subject to certain exceptions contained in the Investors’ Rights Agreement, we and the underwriters may limit the number of shares included in the underwritten offering if the underwriters determine that marketing factors require a limitation of the number of shares to be underwritten.

Indemnification

The Investors’ Rights Agreement contains customary cross-indemnification provisions, under which we are obligated to indemnify holders of registrable securities in the event of material misstatements or omissions in the registration statement attributable to us, and they are obligated to indemnify us for material misstatements or omissions attributable to them.

Expenses of registration

We will pay the registration expenses, subject to certain limited exceptions contained in the Investors’ Rights Agreement, of the holders of the shares registered pursuant to the demand, short form and piggyback registration rights described above, including the expenses of one counsel for the selling holders.

Expiration of registration rights

The registration rights granted under the Investors’ Rights Agreement will terminate upon the earlier of (i) a deemed liquidation event, as defined in our amended and restated certificate of incorporation or certain other events constituting our sale, (ii) on a holder-by-holder basis, at such time after our initial public offering when a holder’s registrable securities could be sold under Rule 144 of the Securities Act or a similar exemption without limitation during a three-month period without registration or (iii) the third anniversary of our initial public offering.

Anti-Takeover Effects of Delaware Law and Provisions of Our Amended and Restated Certificate of Incorporation and Bylaws

Certain provisions of the Delaware General Corporation Law, or DGCL, and of our amended and restated certificate of incorporation and could have the effect of delaying, deferring or discouraging another party from acquiring control of us. These provisions, which are summarized below, are expected to discourage certain types of coercive takeover practices and inadequate takeover bids and, as a consequence, they might also inhibit temporary fluctuations in the market price of our common stock that often result from actual or rumored hostile takeover attempts. These provisions are also designed in part to encourage anyone seeking to acquire control of us to first negotiate with our board of directors. These provisions might also have the effect of preventing changes in our board of directors or management. It is possible that these provisions could make it more difficult to accomplish transactions that stockholders might otherwise deem to be in their best interests. However, we believe that the advantages gained by protecting our ability to negotiate with any unsolicited and potentially unfriendly acquirer outweigh the disadvantages of discouraging such proposals, including those priced above the then-current market value of our common stock, because, among other reasons, the negotiation of such proposals could improve their terms.

Delaware takeover statute

We are subject to the provisions of Section 203 of the DGCL. In general, Section 203 prohibits a publicly held Delaware corporation from engaging in a “business combination” with an “interested stockholder” for a three-year period following the time that this stockholder becomes an interested stockholder, unless the business combination is approved in a prescribed manner. Under Section 203, a business combination between a corporation and an interested stockholder is prohibited unless it satisfies one of the following conditions:

• before the stockholder became interested, our board of directors approved either the business combination or the transaction which resulted in the stockholder becoming an interested stockholder;

• upon consummation of the transaction which resulted in the stockholder becoming an interested stockholder, the interested stockholder owned at least 85% of the voting stock of the corporation outstanding at the time the transaction commenced, excluding for purposes of determining the voting stock outstanding, shares owned by persons who are directors and also officers, and employee stock plans, in some instances, but not the outstanding voting stock owned by the interested stockholder; or

• at or after the time the stockholder became interested, the business combination was approved by our board of directors and authorized at an annual or special meeting of the stockholders by the affirmative vote of at least two-thirds of the outstanding voting stock which is not owned by the interested stockholder Section 203 defines a business combination to include:

• any merger or consolidation involving the corporation and the interested stockholder;

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• any sale, transfer, lease, pledge, exchange, mortgage or other disposition involving the interested stockholder of 10% or more of the assets of the corporation;

• subject to exceptions, any transaction that results in the issuance or transfer by the corporation of any stock of the corporation to the interested stockholder;

• subject to exceptions, any transaction involving the corporation that has the effect of increasing the proportionate share of the stock of any class or series of the corporation beneficially owned by the interested stockholder; or

• the receipt by the interested stockholder of the benefit of any loans, advances, guarantees, pledges or other financial benefits provided by or through the corporation.

In general, Section 203 defines an interested stockholder as any entity or person beneficially owning 15% or more of the outstanding voting stock of the corporation and any entity or person affiliated with or controlling or controlled by the entity or person.

Provisions of our amended and restated certificate of incorporation and bylaws

Our amended and restated certificate of incorporation and bylaws include a number of provisions that may have the effect of delaying, deferring or discouraging another party from acquiring control of us and encouraging persons considering unsolicited tender offers or other unilateral takeover proposals to negotiate with our board of directors rather than pursue non-negotiated takeover attempts. These provisions include the items described below.

Board composition and filling vacancies. In accordance with our amended and restated certificate of incorporation, our board is divided into three classes serving staggered three-year terms, with one class being elected each year. Our amended and restated certificate of incorporation also provides that directors may be removed only for cause and then only by the affirmative vote of the holders of not less than two thirds or more of the shares then entitled to vote at an election of directors. Furthermore, any vacancy on our board of directors, however occurring, including a vacancy resulting from an increase in the size of our board, may only be filled by the affirmative vote of a majority of our directors then in office even if less than a quorum.

No written consent of stockholders. Our amended and restated certificate of incorporation provides that all stockholder actions are required to be taken by a vote of the stockholders at an annual or special meeting, and that stockholders may not take any action by written consent in lieu of a meeting. This limit may lengthen the amount of time required to take stockholder actions and would prevent the amendment of our bylaws or removal of directors by our stockholder without holding a meeting of stockholders.

Meetings of stockholders. Our amended and restated bylaws provide that only a majority of the members of our board of directors then in office may call special meetings of stockholders and only those matters set forth in the notice of the special meeting may be considered or acted upon at a special meeting of stockholders. Our amended and restated bylaws limit the business that may be conducted at an annual meeting of stockholders to those matters properly brought before the meeting.

Advance notice requirements. Our amended and restated bylaws establish advance notice procedures with regard to stockholder proposals relating to the nomination of candidates for election as directors or new business to be brought before meetings of our stockholders. These procedures provide that notice of stockholder proposals must be timely given in writing to our corporate secretary prior to the meeting at which the action is to be taken. Generally, to be timely, notice must be received at our principal executive offices not less than 90 days or more than 120 days prior to the first anniversary date of the annual meeting for the preceding year. The notice must contain certain information specified in our amended and restated bylaws.

Amendment to certificate of incorporation and bylaws. As required by the DGCL, any amendment of our amended and restated certificate of incorporation must first be approved by a majority of our board of directors, and if required by law or our amended and restated certificate of incorporation, must thereafter be approved by a majority of the outstanding shares entitled to vote on the amendment, and a majority of the outstanding shares of each class entitled to vote thereon as a class, except that the amendment of the provisions relating to stockholder action, directors, limitation of liability and the amendment of our amended and restated certificate of incorporation must be approved by not less than two thirds of the outstanding shares entitled to vote on the amendment, and not less than two-thirds of the outstanding shares of each class entitled to vote thereon as a class. Our bylaws may be amended by the affirmative vote of a majority vote of the directors then in office, subject to any limitations set forth in the bylaws; and may also be amended by the affirmative vote of at least two thirds of the outstanding shares entitled to vote on the amendment, voting together as a single class.

Undesignated preferred stock. Our amended and restated certificate of incorporation provides for 10,000,000 authorized shares of preferred stock. The existence of authorized but unissued shares of preferred stock may enable our board of directors to render more difficult or to discourage an attempt to obtain control of us by means of a merger, tender offer, proxy contest or otherwise. For example, if in the due exercise of its fiduciary obligations, our board of directors were to determine that a takeover proposal is not in the best interests of us or our stockholders, our board of directors could cause shares of preferred stock to be issued without stockholder approval in one or more private offerings or other transactions that might dilute the voting or other rights of the proposed acquirer or insurgent stockholder or stockholder group. In this regard, our amended and restated certificate of incorporation grants our board of directors broad power to establish the rights and preferences of authorized and unissued shares of preferred stock. The issuance of shares of preferred stock could decrease the amount of earnings and assets available for distribution to holders of shares of common stock. The issuance may also adversely affect the rights and powers, including voting rights, of these holders and may have the effect of delaying, deterring or preventing a change in control of us.

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Exclusiveforum.OuramendedandrestatedbylawsprovidethattheCourtofChanceryoftheStateofDelawareshallbethesoleandexclusiveforumforanystatelawclaimsfor:(i)anyderivativeactionorproceedingbroughtonourbehalf,(ii)anyactionassertingaclaimofbreachofafiduciarydutyowedbyanyofourdirectorsorofficerstousorourstockholders,(iii)anyactionassertingaclaimagainstusarisingpursuanttoanyprovisionoftheDGCLorourcertificateofincorporationorbylaws,(iv)anyactiontointerpret,apply,enforce,ordeterminethevalidityofourcertificateofincorporationorbylaws,or(v)anyactionassertingaclaimagainstusgovernedbytheinternalaffairsdoctrine.ThisexclusiveforumprovisionwillnotapplytoanycausesofactionarisingundertheSecuritiesActortheExchangeActoranyotherclaimforwhichthefederalcourtshaveexclusivejurisdiction.Unlessweconsentinwritingtotheselectionofanalternateforum,theUnitedStatesDistrictCourtfortheDistrictofDelawareshallbethesoleandexclusiveforumforresolvinganycomplaintassertingacauseofactionarisingundertheSecuritiesAct,asweareaDelawarecorporation.Althoughouramendedandrestatedbylawscontainthechoiceofforumprovisiondescribedabove,itispossiblethatacourtcouldrulethatsuchprovisionsareinapplicableforaparticularclaimoractionorthatsuchprovisionsareunenforceable.

Transfer Agent and Registrar

The transfer agent and registrar for our common stock is Computershare Trust Company, N.A. The transfer agent and registrar’s addressis250 Royall Street, Canton, MA 02021.

TheNasdaqGlobalSelectMarket

Our common stock is listed on the Nasdaq Global Select Market under the symbol “GLTO.”

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DESCRIPTIONOFDEBTSECURITIES

This section describes the general terms and provisions of our debt securities that we may issue from time to time. We may issue debt securities, in one or more series, as either senior or subordinated debt or as senior or subordinated convertible debt. While the terms we have summarized below will apply generally to any future debt securities we may offer under this prospectus, the applicable prospectus supplement or free writing prospectus will describe the specific terms of any debt securities offered through that prospectus supplement or free writing prospectus. The terms of any debt securities we offer under a prospectus supplement or free writing prospectus may differ from the terms we describe below. Unless the context requires otherwise, whenever we refer to the “indentures,” we are also referring to any supplemental indentures that specify the terms of a particular series of debt securities.

We will issue any senior debt securities under the senior indenture that we will enter into with the trustee named in the senior indenture. We will issue any subordinated debt securities under the subordinated indenture that we will enter into with the trustee named in the subordinated indenture. We have filed forms of these documents as exhibits to the registration statement, of which this prospectus is a part, and supplemental indentures and forms of debt securities containing the terms of the debt securities being offered will be filed as exhibits to the registration statement of which this prospectus is a part or will be incorporated by reference from reports that we file with the SEC.

The indentures will be qualified under the Trust Indenture Act of 1939, as amended, or the Trust Indenture Act. We use the term “trustee” to refer to either the trustee under the senior indenture or the trustee under the subordinated indenture, as applicable.

The following summaries of material provisions of the senior debt securities, the subordinated debt securities and the indentures are subject to, and qualified in their entirety by reference to, all of the provisions of the indenture applicable to a particular series of debt securities. We urge you to read the applicable prospectus supplement or free writing prospectus and any related free writing prospectuses related to the debt securities that we may offer under this prospectus, as well as the complete applicable indenture that contains the terms of the debt securities. Except as we may otherwise indicate, the terms of the senior indenture and the subordinated indenture are identical.

General

We may offer under this prospectus up to an aggregate principal amount of $200.0 million in debt securities, or if debt securities are issued at adiscount, or in a foreign currency, foreign currency units or composite currency, the principal amount as may be sold for an aggregate public offeringprice of up to $200.0 million. Unless otherwise specified in the applicable prospectus supplement, the debt securities will represent our direct, unsecured obligationsand will rank equally with allof ourotherunsecured indebtedness.

We may issue the debt securities in one or more series with the same or various maturities, at par, at a premium, or at a discount. We will describe the particular terms of each series of debt securities in a prospectus supplement relating to that series, which we will file with the SEC. The prospectus supplement relating to the particular series of debt securities being offered will specify the particular amounts,prices and terms of those debt securities. We have filed a copy of the form of indenture as an exhibit to the registration statement in which thisprospectusis included.Theseterms may include:

• thetitleoftheseries;

• theaggregateprincipalamount,and,ifaseries,thetotalamountauthorizedandthetotalamountoutstanding;

• theissuepriceorprices,expressedasapercentageoftheaggregateprincipalamountofthedebtsecurities;

• anylimitontheaggregateprincipalamount;

• thedateordatesonwhichprincipalispayable;

• theinterestrateorrates(whichmaybefixedorvariable)or,ifapplicable,themethodusedtodeterminesuchrateorrates;

• thedateordatesfromwhichinterest, ifany,willbepayableandanyregularrecorddatefortheinterestpayable;

• theplaceorplaceswhereprincipaland,ifapplicable,premiumandinterest,ispayable;

• thetermsandconditionsuponwhichwe may,ortheholdersmayrequireusto,redeem orrepurchasethedebtsecurities;

• the denominations in which such debt securities may be issuable, if other than denominations of $1,000 or any integral multiple of thatnumber;

• whetherthedebtsecuritiesaretobeissuableintheformofcertificatedsecurities(asdescribedbelow)orglobalsecurities(asdescribedbelow);

• the portion of principal amount that will be payable upon declaration of acceleration of the maturity date if other than the principal amountofthedebtsecurities;

• thecurrency ofdenomination;

• the designation of the currency, currencies or currency units in which payment of principal and, if applicable, premium and interest, will bemade;

• if payments of principal and, if applicable, premium or interest, on the debt securities are to be made in one or more currencies or currency unitsotherthanthecurrencyofdenomination, themanner inwhichtheexchangeratewithrespectto suchpaymentswillbedetermined;

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• ifamountsofprincipaland,ifapplicable,premiumandinterestmaybedeterminedbyreferencetoanindexbasedonacurrency or currencies or by reference to a commodity, commodity index, stock exchange index or financial index, then the manner in which such amountswillbedetermined;

• theprovisions,ifany,relatingtoanycollateralprovidedforsuchdebtsecurities;

• anyadditiontoorchangeinthecovenantsand/ortheaccelerationprovisionsdescribedinthisprospectusorintheindenture;

• anyeventsofdefault,if nototherwisedescribed belowunder “Eventsof Default”;

• thetermsandconditions,ifany,forconversionintoorexchangeforcommon stockorpreferred stock;

• anydepositaries,interestratecalculationagents,exchangeratecalculationagentsorotheragents;and

• thetermsandconditions,ifany,uponwhichthedebtsecuritiesshallbesubordinatedinrightofpaymenttoourotherindebtedness.

We may issue discount debt securities that provide for an amount less than the stated principal amount to be due and payable upon acceleration ofthe maturity of such debt securities in accordance with the terms of the indenture. We may also issue debt securities in bearer form, with or withoutcoupons. If we issue discount debt securities or debt securities in bearer form, we will describe material U.S. federal income tax considerations and othermaterialspecialconsiderationswhichapplytothesedebt securitiesin theapplicableprospectussupplement.

We may issue debt securities denominated in or payable in a foreign currency or currencies or a foreign currency unit or units. If we do, we will describe the restrictions, elections, and general tax considerations relating to the debt securities and the foreign currency or currencies or foreigncurrencyunit orunitsintheapplicableprospectussupplement.

Debt securities offered under this prospectus and any prospectus supplement may be subordinated in right of payment to certain of our then outstanding senior indebtedness.

RegistrarandPaying Agent

The debt securities may be presented for registration of transfer or for exchange at the corporate trust office of the security registrar or at any other office or agency that we maintain for those purposes. In addition, the debt securities may be presented for payment of principal, interest and any premium at the office of the paying agent or at any office or agency that we maintain for those purposes.

Conversion or Exchange Rights

Debt securities may be convertible into or exchangeable for common stock. The terms and conditions of conversion or exchange will be stated in the applicable prospectus supplement. The terms will include, among others, the following:

• theconversionor exchangeprice;

• theconversionor exchange period;

• provisionsregardingtheconvertibilityorexchangeabilityofthedebtsecurities,includingwhomayconvertorexchange;

• eventsrequiringadjustmenttotheconversionorexchangeprice;

• provisionsaffectingconversionorexchangeintheeventofourredemptionofthedebtsecurities;and

• anyanti-dilutionprovisions,ifapplicable.

Registered Global Securities

If we decide to issue debt securities in the form of one or more global securities, then we will register the global securities in the name of the depositary for the global securities or the nominee of the depositary, and the global securities will be delivered by the trustee to the depositary for credit to the accounts of the holders of beneficial interests in the debt securities.

The applicable prospectus supplement will describe the specific terms of the depositary arrangement for debt securities of a series that are issued in global form. None of us, the trustee, any payment agent or the security registrar will have any responsibility or liability for any aspect of the records relating to or payments made on account of beneficial ownership interests in a global debt security or for maintaining, supervising or reviewing any records relating to these beneficial ownership interests.

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No Protection in the Event of Change of Control

The form indenture does not have any covenants or other provisions providing for a put or increased interest or otherwise that would afford holders of our debt securities additional protection in the event of a recapitalization transaction, a change of control or a highly leveraged transaction. If we offer any covenants or provisions of this type with respect to any debt securities covered by this prospectus, we will describe them in the applicable prospectus supplement.

Covenants

Unless otherwise indicated in this prospectus or the applicable prospectus supplement, our debt securities will not have the benefit of any covenants that limit or restrict our business or operations, the pledging of our assets or the incurrence by us of indebtedness. We will describe in the applicable prospectus supplement any material covenants in respect of a series of debt securities.

Merger, Consolidation or Sale of Assets

The form of indenture provides that we will not consolidate with or merge into any other person or convey, transfer, sell or lease our properties and assets substantially as an entirety to any person, unless:

• we are the surviving person of such merger or consolidation, or if we are not the surviving person, the person formed by the consolidation or into or with which we are merged or the person to which our properties and assets are conveyed, transferred, sold or leased, is acorporation organized and existing under the laws of the U.S., any state or the District of Columbia or a corporation or comparable legalentity organized under the laws of a foreign jurisdiction and has expressly assumed all of our obligations, including the payment of theprincipalof and,premium,ifany, andinterest onthedebt securitiesand theperformanceoftheothercovenantsunder theindenture; and

• immediately before and immediately after giving effect to the transaction on a pro forma basis, no event of default, and no event which, afternotice orlapseoftime orboth, wouldbecomeanevent ofdefault, hasoccurredandis continuingundertheindenture.

Events of Default

Unless otherwise specified in the applicable prospectus supplement, the following events will be events of default under the indenture with respect to debt securities of any series:

• wefailtopayanyprincipalorpremium,ifany,whenitbecomesdue;

• wefailtopayanyinterestwithin30daysafteritbecomesdue;

• we fail to observe or perform any other covenant in the debt securities or the indenture for 60 days after written notice specifying thefailure from the trustee or the holders of not less than 25% in aggregate principal amount of the outstanding debt securities of that series; and

• certaineventsinvolvingbankruptcy,insolvencyorreorganizationofusoranyofoursignificantsubsidiaries.

The trustee may withhold notice to the holders of the debt securities of any series of any default, except in payment of principal of or premium, ifany, or interest on the debt securities of a series, if the trustee considers it to be in the best interest of the holders of the debt securities of that series to doso.

If an event of default (other than an event of default resulting from certain events of bankruptcy, insolvency or reorganization) occurs, and iscontinuing, then the trustee or the holders of not less than 25% in aggregate principal amount of the outstanding debt securities of any series mayaccelerate the maturity of the debt securities. If this happens, the entire principal amount, plus the premium, if any, of all the outstanding debt securities of the affected series plus accrued interest to the date of acceleration will be immediately due and payable. At any time after the acceleration, but before a judgment or decree based on such acceleration is obtained by the trustee, the holders of a majority in aggregate principal amount of outstanding debtsecuritiesof suchseriesmayrescindand annul suchacceleration if:

• alleventsofdefault(otherthannonpaymentofacceleratedprincipal,premiumor interest)havebeencuredorwaived;

• alllawfulinterestonoverdueinterestandoverdueprincipalhasbeenpaid;and

• therescissionwould notconflict withanyjudgmentor decree.

In addition, if the acceleration occurs at any time when we have outstanding indebtedness that is senior to the debt securities, the payment of theprincipal amount of outstanding debt securities may be subordinated in right of payment to the prior payment of any amounts due under the seniorindebtedness, in which case the holders of debt securities will be entitled to payment under the terms prescribed in the instruments evidencing the senior indebtedness and the indenture.

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If an event of default resulting from certain events of bankruptcy, insolvency or reorganization occurs, the principal, premium and interest amount with respect to all of the debt securities of any series will be due and payable immediately without any declaration or other act on the part of the trusteeorthe holders ofthedebtsecurities ofthatseries.

The holders of a majority in principal amount of the outstanding debt securities of a series will have the right to waive any existing default orcompliance with any provision of the indenture or the debt securities of that series and to direct the time, method and place of conducting anyproceedingfor any remedyavailabletothetrustee,subjecttocertain limitationsspecified intheindenture.

No holder of any debt security of a series will have any right to institute any proceeding with respect to the indenture or for any remedy under the indenture, unless:

• theholdergivestothetrusteewrittennoticeofacontinuingeventofdefault;

• theholdersofatleast25%inaggregateprincipalamountoftheoutstandingdebtsecuritiesoftheaffectedseriesmakeawrittenrequestandoffer reasonableindemnitytothetrusteeto institutea proceeding astrustee;

• thetrusteefailstoinstituteaproceedingwithin60daysaftersuchrequest;and

• the holders of a majority in aggregate principal amount of the outstanding debt securities of the affected series do not give the trustee a directioninconsistentwith such request during such60-dayperiod.

These limitations do not, however, apply to a suit instituted for payment on debt securities of any series on or after the due dates expressed in the debt securities.

We will periodically deliver certificates to the trustee regarding our compliance with our obligations under the indenture.

Modification and Waiver

From time to time, we and the trustee may, without the consent of holders of the debt securities of one or more series, amend the indenture or the debt securities of one or more series, or supplement the indenture, for certain specified purposes, including:

• to provide that the surviving entity following a change of control permitted under the indenture will assume all of our obligations under the indentureand debt securities;

• toprovideforcertificateddebtsecuritiesinadditiontouncertificateddebtsecurities;

• tocomplywithanyrequirementsoftheSECundertheTrustIndentureAct;

• toprovide forthe issuanceof andestablishtheformandtermsandconditions ofdebtsecurities ofanyseriesas permittedby theindenture;

• to cure any ambiguity, defect or inconsistency, or make any other change that does not materially and adversely affect the rights of anyholder;and

• toappointasuccessortrusteeundertheindenturewithrespecttooneormoreseries.

From time to time, we and the trustee may, with the consent of holders of at least a majority in principal amount of an outstanding series of debtsecurities, amend or supplement the indenture or the debt securities series, or waive compliance in a particular instance by us with any provision of the indenture or the debt securities. We may not, however, without the consent of each holder affected by such action, modify or supplement the indentureorthe debtsecuritiesor waive compliancewith any provisionoftheindentureor thedebtsecurities inorderto:

• reduce the amount of debt securities whose holders must consent to an amendment, supplement, or waiver to the indenture or such debt security;

• reduce the rate of or change the time for payment of interest or reduce the amount of or postpone the date for payment of sinking fund or analogousobligations;

• reducetheprincipaloforchangethestated maturityofthedebtsecurities;

• makeanydebt securitypayableinmoneyother thanthatstatedinthedebtsecurity;

• change the amount or time of any payment required or reduce the premium payable upon any redemption, or change the time before which nosuch redemptionmaybemade;

• waiveadefaultinthepaymentof theprincipalof,premium, ifany, orinterestonthedebtsecuritiesora redemptionpayment;

• waivearedemptionpaymentwithrespecttoanydebtsecuritiesorchangeanyprovisionwithrespecttoredemptionofdebtsecurities;or

• takeanyotheractionotherwiseprohibitedbytheindenturetobetakenwithouttheconsentofeachholderaffectedbytheaction.

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Defeasance of Debt Securities and Certain Covenants in Certain Circumstances

The form indenture permits us, at any time, to elect to discharge our obligations with respect to one or more series of debt securities by following certain procedures described in the indenture. These procedures will allow us either:

• to defease and be discharged from any and all of our obligations with respect to any debt securities except for the following obligations(whichdischarge isreferredtoas “legaldefeasance”):

• toregisterthetransferorexchangeofsuchdebtsecurities;

• toreplacetemporaryormutilated,destroyed,lostorstolendebtsecurities;

• tocompensate and indemnifythe trustee; or

• tomaintainanofficeoragencyinrespectofthedebtsecuritiesandtoholdmoniesforpaymentintrust;or to be released from our obligations with respect to the debt securities under certain covenants contained in the indenture, as well as any additional covenants which may be contained in the applicable supplemental indenture (which release is referred to as “covenantdefeasance”).

Inordertoexerciseeitherdefeasanceoption,wemustirrevocablydepositwiththetrusteeorotherqualifyingtrustee,intrustforthatpurpose:

• money;

• U.S. Government Obligations (as described below) or Foreign Government Obligations (as described below) that through the scheduledpaymentofprincipaland interest inaccordancewiththeir termswillprovide money;or

• a combination of money and/or U.S. Government Obligations and/or Foreign Government Obligations sufficient in the written opinion ofanationally-recognizedfirmofindependent accountants to providemoney;

that, in each case specified above, provides a sufficient amount to pay the principal of, premium, if any, and interest, if any, on the debt securities of theseries,onthescheduled due datesor onaselected dateofredemptioninaccordancewith thetermsof theindenture.

Inaddition,defeasancemaybeeffectedonlyif,amongotherthings:

• in the case of either legal or covenant defeasance, we deliver to the trustee an opinion of counsel, as specified in the indenture, stating that as a result of the defeasance neither the trust nor the trustee will be required to register as an investment company under the InvestmentCompanyAct of1940, as amended;

• in the case of legal defeasance, we deliver to the trustee an opinion of counsel stating that we have received from, or there has beenpublished by, the Internal Revenue Service a ruling to the effect that, or there has been a change in any applicable federal income tax lawwith the effect that (and the opinion shall confirm that), the holders of outstanding debt securities will not recognize income, gain or lossforU.S.federalincometaxpurposessolelyasaresultofsuchlegaldefeasanceandwillbesubjecttoU.S.federalincometaxonthesameamounts, in the same manner, including as a result of prepayment, and at the same times as would have been the case if legal defeasancehadnot occurred;

• in the case of covenant defeasance, we deliver to the trustee an opinion of counsel to the effect that the holders of the outstanding debtsecurities will not recognize income, gain or loss for U.S. federal income tax purposes as a result of covenant defeasance and will besubject to U.S. federal income tax on the same amounts, in the same manner and at the same times as would have been the case if covenantdefeasance hadnotoccurred;and

• certainotherconditionsdescribedintheindenturearesatisfied.

If we fail to comply with our remaining obligations under the indenture and applicable supplemental indenture after a covenant defeasance of theindenture andapplicablesupplementalindenture,andthedebtsecuritiesaredeclareddueandpayablebecauseoftheoccurrenceofanyundefeasedevent of default, the amount of money and/or U.S. Government Obligations and/or Foreign Government Obligations on deposit with the trustee could be insufficient to pay amounts due under the debt securities of the affected series at the time of acceleration. We will, however, remain liable in respect ofthesepayments.

The term “U.S. Government Obligations” as used in the above discussion means securities that are direct obligations of or non-callableobligations guaranteed by the United States of America for the payment of which obligation or guarantee the full faith and credit of the United States of Americaispledged.

The term “Foreign Government Obligations” as used in the above discussion means, with respect to debt securities of any series that aredenominated in a currency other than U.S. dollars, (1) direct obligations of the government that issued or caused to be issued such currency for thepayment of which obligations its full faith and credit is pledged or (2) obligations of a person controlled or supervised by or acting as an agent orinstrumentality of such government the timely payment of which is unconditionally guaranteed as a full faith and credit obligation by that government,whichin either caseunderclauses (1)or (2),arenotcallableorredeemable attheoptionof theissuer.

Regarding the Trustee

We will identify the trustee with respect to any series of debt securities in the prospectus supplement relating to the applicable

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debtsecurities.Youshouldnotethatifthetrusteebecomesacreditorofours,theindentureandtheTrustIndentureActlimittherightsofthetrusteetoobtainpaymentofclaimsincertaincases,ortorealizeoncertainpropertyreceivedinrespectofanysuchclaim,assecurityorotherwise.Thetrusteeanditsaffiliatesmayengagein,andwillbepermittedtocontinuetoengagein,othertransactionswithusandouraffiliates.If,however,thetrusteeacquiresany“conflictinginterest”withinthemeaningoftheTrustIndentureAct,itmusteliminatesuchconflictorresign.

The holders of a majority in principal amount of the then outstanding debt securities of any series may direct the time, method and place ofconducting any proceeding for exercising any remedy available to the trustee. If an event of default occurs and is continuing, the trustee, in the exerciseof its rights and powers, must use the degree of care and skill of a prudent person in the conduct of his or her own affairs. Subject to that provision, thetrustee will be under no obligation to exercise any of its rights or powers under the indenture at the request of any of the holders of the debt securities,unlessthey haveoffered tothe trusteereasonableindemnityorsecurity.

NoIndividualLiabilityofIncorporators,Shareholders,OfficersorDirectors

Each indenture provides that no incorporator and no past, present or future shareholder, officer or director of our company or any successor corporation in those capacities will have any individual liability for any of our obligations, covenants or agreements under the debt securities or such indenture.

Governing Law

The indentures and the debt securities will be governed by, and construed in accordance with, the laws of the State of New York, except to the extent that the Trust Indenture Act is applicable.

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DESCRIPTIONOFWARRANTS

The following description, together with the additional information we may include in any applicable prospectus supplements, summarizes thematerial terms and provisions of the warrants that we may offer under this prospectus and the related warrant agreements and warrant certificates. While the terms summarized below will apply generally to any warrants that we may offer, we will describe the particular terms of any series of warrants inmoredetailintheapplicableprospectus supplement. Ifweindicate in theprospectus supplement,the terms of anywarrantsofferedunderthatprospectus supplement may differ from the terms described below. Specific warrant agreements will contain additional important terms and provisionsandwillbeincorporatedbyreferenceasanexhibitto theregistrationstatement, which includesthisprospectus.

General

We may issue warrants for the purchase of our debt securities, preferred stock, common stock, or any combination thereof. Warrants may be issued independently or together with our debt securities, preferred stock or common stock and may be attached to or separate from any offeredsecurities. Each series of warrants will be issued under a separate warrant agreement to be entered into between us and a bank or trust company, aswarrant agent. The warrant agent will act solely as our agent in connection with the warrants. The warrant agent will not have any obligation orrelationship of agency or trust for or with any holders or beneficial owners of warrants. This summary of certain provisions of the warrants is notcomplete. For the terms of a particular series of warrants, you should refer to the prospectus supplement for that series of warrants and the warrantagreementforthatparticular series.

DebtWarrants

The prospectus supplement relating to a particular issue of warrants to purchase debt securities will describe the terms of the debt warrants,including thefollowing:

• thetitleofthedebtwarrants;

• theofferingpricefor thedebtwarrants, ifany;

• theaggregatenumberofthedebtwarrants;

• thedesignationandtermsofthedebtsecurities,includinganyconversionrights,purchasableuponexerciseofthedebtwarrants;

• ifapplicable,thedatefromandafterwhichthedebtwarrantsandanydebtsecuritiesissuedwiththemwillbeseparatelytransferable;

• the principal amount of debt securities that may be purchased upon exercise of a debt warrant and the exercise price for the warrants,whichmay be payable in cash,securitiesor otherproperty;

• thedatesonwhichtherighttoexercisethedebtwarrantswillcommenceandexpire;

• ifapplicable,the minimumormaximumamount ofthe debtwarrantsthatmay beexercised atanyonetime;

• whetherthedebtwarrantsrepresentedbythedebtwarrantcertificatesordebtsecuritiesthatmaybeissueduponexerciseofthedebtwarrantswillbeissued inregistered orbearer form;

• informationwithrespecttobook-entryprocedures,ifany;

• thecurrency orcurrencyunitsin whichthe offeringprice,ifany,and theexerciseprice arepayable;

• ifapplicable,adiscussionofmaterialU.S.federalincometaxconsiderations;

• theantidilutionprovisionsofthedebtwarrants,ifany;

• theredemptionorcallprovisions,ifany,applicabletothedebtwarrants;

• any provisions with respect to the holder’s right to require us to repurchase the debt warrants upon a change in control or similar event; and

• any additional terms of the debt warrants, including procedures and limitations relating to the exchange, exercise, and settlement of the debt warrants.

Debt warrant certificates will be exchangeable for new debt warrant certificates of different denominations. Debt warrants may be exercised at thecorporate trust office of the warrant agent or any other office indicated in the prospectus supplement. Prior to the exercise of their debt warrants, holdersof debt warrants will not have any of the rights of holders of the debt securities purchasable upon exercise and will not be entitled to payment ofprincipalor any premium,ifany,or interestonthe debt securitiespurchasableupon exercise.

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EquityWarrants

The prospectus supplement relating to a particular series of warrants to purchase our common stock or preferred stock will describe the terms of thewarrants, including the following:

• thetitleofthewarrants;

• theofferingpricefor the warrants,ifany;

• theaggregatenumberofwarrants;

• thedesignationandtermsofthecommon stockorpreferred stockthatmaybepurchaseduponexerciseofthewarrants;

• if applicable, the designation and terms of the securities with which the warrants are issued and the number of warrants issued with each security;

• ifapplicable,thedatefromandafterwhichthewarrantsandanysecuritiesissuedwiththewarrantswill beseparatelytransferable;

• the number of common stock or preferred stock that may be purchased upon exercise of a warrant and the exercise price for thewarrants;

• thedatesonwhichtherighttoexercisethewarrantsshallcommenceandexpire;

• ifapplicable,theminimumormaximumamountofthewarrantsthatmaybeexercisedatanyone time;

• thecurrency orcurrencyunitsin whichthe offeringprice,ifany,and theexerciseprice arepayable;

• ifapplicable,adiscussionofmaterialU.S.federalincometaxconsiderations;

• theantidilutionprovisionsofthewarrants,ifany;

• theredemptionorcallprovisions,ifany,applicabletothewarrants;

• anyprovisionswithrespecttoaholder’srighttorequireustorepurchasethewarrantsuponachangeincontrolorsimilarevent;and

• any additional terms of the warrants, including procedures and limitations relating to the exchange, exercise and settlement of thewarrants.

Holdersofequitywarrantswillnotbeentitled:

• tovote,consent,orreceivedividends;

• receivenoticeasshareholderswithrespecttoanymeetingofshareholdersfortheelectionofourdirectorsoranyothermatter;or

• exerciseanyrightsasshareholders.

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DESCRIPTIONOFSUBSCRIPTIONRIGHTS

We may issue subscription rights to purchase our common stock, preferred stock or debt securities. These subscription rights may be offeredindependently or together with any other security offered hereby and may or may not be transferable by the shareholder receiving the subscription rightsin such offering. In connection with any offering of subscription rights, we may enter into a standby arrangement with one or more underwriters or otherpurchasers pursuant to which the underwriters or other purchasers may be required to purchase any securities remaining unsubscribed for after suchoffering.

The prospectus supplement relating to any subscription rights we offer, if any, will, to the extent applicable, include specific terms relating to theoffering,including some orall ofthefollowing:

• theprice,ifany,forthesubscription rights;

• theexercisepricepayableforourcommon stock,preferred stockordebtsecuritiesupontheexerciseofthesubscriptionrights;

• thenumberofsubscriptionrightstobeissuedtoeachshareholder;

• thenumberandtermsofourcommon stock,preferred stockordebtsecuritieswhichmaybepurchasedpereachsubscriptionright;

• theextentto which thesubscriptionrightsaretransferable;

• any other terms of the subscription rights, including the terms, procedures and limitations relating to the exchange and exercise of the subscriptionrights;

• thedateonwhichtherighttoexercisethesubscriptionrightsshallcommence,andthedateonwhichthesubscriptionrights shallexpire;

• the extent to which the subscription rights may include an over-subscription privilege with respect to unsubscribed securities or an over-allotmentprivilegeto theextentthesecurities are fullysubscribed;and

• if applicable, the material terms of any standby underwriting or purchase arrangement which may be entered into by us in connection withtheofferingof subscriptionrights.

The description in the applicable prospectus supplement of any subscription rights we offer will not necessarily be complete and will be qualified in its entirety by reference to the applicable subscription rights certificate, which will be filed with the SEC if we offer subscription rights. We urge you toreadtheapplicablesubscriptionrights certificateandanyapplicableprospectussupplement intheirentirety.

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DESCRIPTIONOFUNITS

We may issue units comprised of common stock, debt securities and warrants in any combination. We may issue units in such amounts and in asmany distinct series as we wish. This section outlines certain provisions of the units that we may issue. If we issue units, they will be issued under one or more unit agreements to be entered into between us and a bank or other financial institution, as unit agent. The information described in this section may not be complete in all respects and is qualified entirely by reference to the unit agreement with respect to the units of any particular series. The specificterms of any series of units offered will be described in the applicable prospectus supplement. If so described in a particular supplement, the specificterms of any series of units may differ from the general description of terms presented below. We urge you to read any prospectus supplement related toany series of units we may offer, as well as the complete unit agreement and unit certificate that contain the terms of the units. If we issue units, forms of unit agreements and unit certificates relating to such units will be incorporated by reference as exhibits to the registration statement, which includes thisprospectus.

Each unit that we may issue will be issued so that the holder of the unit is also the holder of each security included in the unit. Thus, the holder of a unit will have the rights and obligations of a holder of each included security. The unit agreement under which a unit is issued may provide that thesecurities included in the unit may not be held or transferred separately, at any time or at any time before a specified date. The applicable prospectussupplement maydescribe:

• the designation and terms of the units and of the securities comprising the units, including whether and under what circumstances thosesecurities may beheldortransferredseparately;

• anyprovisions ofthe governing unitagreement;

• thepriceorpricesatwhichsuchunitswillbeissued;

• theapplicableUnitedStatesfederalincometaxconsiderationsrelatingtotheunits;

• anyprovisionsfortheissuance,payment,settlement,transferorexchangeoftheunitsorofthesecuritiescomprisingtheunits;and

• anyothertermsoftheunitsandofthesecuritiescomprisingtheunits.

The provisions described in this section, as well as those described under “Description of Share Capital,” “Description of Debt Securities” and“DescriptionofWarrants”willapplytothesecuritiesincludedineachunit,totheextentrelevantandasmaybeupdatedinanyprospectussupplements.

IssuanceinSeries

We may issue units in such amounts and in as many distinct series as we wish. This section summarizes terms of the units that apply generally to allseries.Mostofthefinancialandotherspecifictermsofaparticularseriesofunitswillbedescribedintheapplicableprospectussupplement.

UnitAgreements

We will issue the units under one or more unit agreements to be entered into between us and a bank or other financial institution, as unit agent. We may add, replace or terminate unit agents from time to time. We will identify the unit agreement under which each series of units will be issued and theunitagent under thatagreementin theapplicableprospectussupplement.

Thefollowingprovisionswill generallyapplytoallunitagreementsunlessotherwisestatedintheapplicableprospectussupplement:

ModificationWithoutConsent

Weandtheapplicableunitagentmayamendanyunitorunitagreementwithouttheconsentofanyholder:

• tocureanyambiguity;anyprovisionsofthegoverningunitagreementthatdifferfromthosedescribedbelow;

• tocorrectorsupplementanydefectiveorinconsistentprovision;or

• to make any other change that we believe is necessary or desirable and will not adversely affect the interests of the affected holders inanymaterialrespect.

We do not need any approval to make changes that affect only units to be issued after the changes take effect. We may also make changes that do not adversely affect a particular unit in any material respect, even if they adversely affect other units in a material respect. In those cases, we do not need to obtain the approval of the holder of the unaffected unit; we need only obtain any required approvals from the holders of the affected units.

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Modification with Consent

We may not amend any particular unit or a unit agreement with respect to any particular unit unless we obtain the consent of the holder of that unit,ifthe amendmentwould:

• impair any right of the holder to exercise or enforce any right under a security included in the unit if the terms of that security requiretheconsentoftheholdertoanychangesthatwouldimpairtheexerciseorenforcementofthatright;or

• reduce the percentage of outstanding units or any series or class the consent of whose holders is required to amend that series or class,or theapplicableunitagreementwith respectto thatseriesor class,asdescribedbelow.

Anyotherchangetoaparticularunitagreementandtheunitsissuedunderthatagreementwouldrequirethefollowingapproval:

• If the change affects only the units of a particular series issued under that agreement, the change must be approved by the holders ofamajority ofthe outstandingunits ofthatseries;or

• If the change affects the units of more than one series issued under that agreement, it must be approved by the holders of a majority of all outstanding units of all series affected by the change, with the units of all the affected series voting together as one class forthispurpose.

These provisions regarding changes with majority approval also apply to changes affecting any securities issued under a unit agreement, as thegoverningdocument.

Ineachcase,therequiredapproval mustbegivenbywrittenconsent.

Unit Agreements Will Not Be Qualified Under Trust Indenture Act

Nounitagreementwillbequalifiedasanindenture,andnounitagentwillberequiredtoqualifyasatrustee,undertheTrustIndentureAct. Therefore,holdersofunitsissuedunderunitagreementswillnothavetheprotections oftheTrustIndentureActwithrespecttotheirunits.

MergersandSimilarTransactionsPermitted;NoRestrictiveCovenantsorEventsofDefault

The unit agreements will not restrict our ability to merge or consolidate with, or sell our assets to, another corporation or other entity or to engagein any other transactions. If at any time we merge or consolidate with, or sell our assets substantially as an entirety to, another corporation or otherentity, the successor entity will succeed to and assume our obligations under the unit agreements. We will then be relieved of any further obligationundertheseagreements.

The unit agreements will not include any restrictions on our ability to put liens on our assets, nor will they restrict our ability to sell our assets. The unitagreements also will notprovide foranyevents ofdefaultor remedies upontheoccurrenceof anyeventsofdefault.

Governing Law

TheunitagreementsandtheunitswillbegovernedbyNewYorklaw.

Form, Exchange and Transfer

We will issue each unit in global—i.e., book-entry—form only. Units in book-entry form will be represented by a global security registered in the name of a depositary, which will be the holder of all the units represented by the global security. Those who own beneficial interests in a unit will do so through participants in the depositary’s system, and the rights of these indirect owners will be governed solely by the applicable procedures of thedepositary and its participants. We will describe book-entry securities, and other terms regarding the issuance and registration of the units in theapplicableprospectussupplement.

Each unit and all securities comprising the unit will be issued in the same form.

If we issue any units in registered, non-global form, the following will apply to them.

The units will be issued in the denominations stated in the applicable prospectus supplement. Holders may exchange their units for units of smallerdenominationsor combinedintofewerunitsoflargerdenominations,aslongas thetotal amountisnot changed.

• Holders may exchange or transfer their units at the office of the unit agent. Holders may also replace lost, stolen, destroyed ormutilatedunitsatthatoffice.Wemayappointanotherentitytoperformthesefunctionsorperformthemourselves.

• Holders will not be required to pay a service charge to transfer or exchange their units, but they may be required to pay for any taxor other governmental charge associated with the transfer or exchange. The transfer or exchange, and any replacement, will be madeonly if our transfer agent is satisfied with the holder’s proof of legal ownership. The transfer agent may also require an indemnitybeforereplacinganyunits.

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• If we have the right to redeem, accelerate or settle any units before their maturity, and we exercise our right as to less than all those units or other securities, we may block the exchange or transfer of those units during the period beginning fifteen (15) days beforethe day we mail the notice of exercise and ending on the day of that mailing, in order to freeze the list of holders to prepare themailing. We may also refuse to register transfers of or exchange any unit selected for early settlement, except that we will continueto permit transfers and exchanges of the unsettled portion of any unit being partially settled. We may also block the transfer orexchangeofanyunitinthis manner ifthe unitincludes securitiesthatareormaybeselected forearlysettlement.

Onlythedepositarywillbeentitledtotransferorexchangeaunitin globalform, sinceitwillbethe soleholderoftheunit.

Payments and Notices

In making payments and giving notices with respect to our units, we will follow the procedures as described in the applicable prospectussupplement.

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LEGALMATTERS

Certain legal matters in connection with this offering will be passed upon for us by Goodwin Procter LLP, Boston, Massachusetts. Any underwriters or agents will be advised about legal matters relating to any offering by their own counsel, which will be named in the applicable prospectus supplement.

EXPERTS

The consolidated financial statements of Galecto Inc. appearing in Galecto, Inc.'s Annual Report on Form 10-K for the year ended December 31,2020, have been audited by EY Godkendt Revisionspartnerselskab, independent registered public accounting firm, as set forth in their report thereon, included therein, and incorporated herein by reference. Such consolidated financial statements are incorporated herein by reference in reliance upon such report given on the authority of such firm as experts in accounting and auditing

WHEREYOUCANFINDMOREINFORMATION

This prospectus is part of a registration statement we filed with the SEC. This prospectus does not contain all of the information set forth in the registration statement and the exhibits to the registration statement. For further information with respect to us and the securities we are offering under this prospectus, we refer you to the registration statement and the exhibits and schedules filed as a part of the registration statement. You should rely only on the information contained in this prospectus or incorporated by reference. We have not authorized anyone else to provide you with different information. We are not making an offer of these securities in any jurisdiction where the offer is not permitted. You should not assume that the information in this prospectus is accurate as of any date other than the date on the front page of this prospectus, regardless of the time of delivery of this prospectus or any sale of the securities offered by this prospectus.

We are subject to the informational requirements of the Exchange Act and are required to file annual, quarterly and other reports, proxy statements and information with the SEC. The SEC maintains an Internet site (http://www.sec.gov) that contains reports, proxy and information statements, and various other information about us.

Information about us is also available at our website at http://www.galecto.com. However, the information contained on, or that can beaccessed through, our website is not a part of this prospectus or any accompanying prospectus supplement and is not incorporated by reference into this prospectus.

INCORPORATIONOFCERTAININFORMATIONBYREFERENCE

The SEC allows us to “incorporate by reference” information that we file with the SEC, which means that we can disclose important informationto you by referring you to those other documents. The information incorporated by reference is an important part of this prospectus, and information we file later with the SEC will automatically update and supersede this information. We incorporate by reference the documents listed below, other thanthosedocuments orportionsofthosedocumentsdeemed to befurnished andnotfiledin accordancewithSECrules:

• OurAnnualReporton Form 10-KfortheyearendedDecember31,2020filedwiththeSEConMarch29,2021;

• Our Quarterly Reports on Form 10-Q for the quarters ended March 31, 2021, June 30, 2021 and September 30, 2021 and filed with the SEC on May 4, 2021, August 5, 2021 and November 4, 2021;

• Our Current Reports on Form 8-K filed on January 8, 2021, May 28, 2021 and July 6, 2021;

• Our Definitive Proxy Statement on Schedule 14A, filed with the SEC on April 14, 2021 (but only with respect to information required by Part III of our Annual Report on Form 10-K for the year ended December 31, 2020, which information shall update and supersede information included in Part III of our Annual Report on Form 10-K for the year ended December 31, 2020); and

• The description of our common stock in our Registration Statement on Form 8-A (No. 001-39655) filed with the SEC on October 23, 2020, and including any other amendments or reports filed for the purpose of updating such description.

We also incorporate by reference any future filings we make with the SEC under Section 13(a), 13(c), 14, or 15(d) of the Exchange Act (in eachcase, other than current reports furnished under Item 2.02 or Item 7.01 of Form 8-K and exhibits filed on such form or that are related to such items)between the date of the initial registration statement and the effectiveness of the registration statement and following the effectiveness of the registration statement until the offering of the securities under the registration statement is terminated or completed. These documents include, without limitation,AnnualReportsonForm10-K,QuarterlyReportsonForm10-Q, CurrentReportsonForm8-K, aswellasproxy statements, and any amendments thereto.

Upon written or oral request, we will provide without charge to each person, including any beneficial owner, to whom this prospectus is delivered, a copy of any or all of such information that has been incorporated herein by reference (other than exhibits to such documents unless such exhibits arespecifically incorporated by reference into the documents that this prospectus incorporates). Written or oral requests for copies should be directed toGeneral Counsel, Galecto, Inc., 75 State Street, Suite 100, Boston, MA 02109, Attention: General Counsel. See the section of this prospectus titled “Where You Can Find More Information” for information concerning how toreadandobtain copiesofmaterialsthatwefilewiththeSEC.

27

Anystatementcontainedinthisprospectus,orinadocumentalloraportionofwhichisincorporatedbyreference,shallbemodifiedorsupersededforpurposesofthisprospectustotheextentthatastatementcontainedinthisprospectus,anyprospectussupplementoranydocumentincorporatedbyreferencemodifiesorsupersedessuchstatement.Anysuchstatementsomodifiedorsupersededshallnot,exceptassomodifiedorsuperseded,constituteapartofthisprospectus.

28

Common Stock

Preferred Stock

Debt Securities

Warrants

Subscription Rights

Units

PROSPECTUS

,2021

29

The information in this prospectus is not complete and may be changed. We may not sell these securities until the registration statement filed with the Securities and Exchange Commission is effective. This prospectus is not an offer to sell these securities, and it is not soliciting an offer to buy thesesecurities,in any jurisdictionwherethe offer or saleis not permitted.

SUBJECTTOCOMPLETION,DATEDNOVEMBER 4,2021

PROSPECTUS

Upto$50,000,000

Common Stock

We have entered into an Open Market Sale AgreementSM, or Sales Agreement, with Jefferies LLC, or Jefferies, relating to common stockoffered by this prospectus. In accordance with the terms of the Sales Agreement, we may offer and sell common stock having an aggregate offering priceofup to $50.0million fromtimetotimethrough Jefferies, actingasour sales agent.

Our common stock is listed on the Nasdaq Global Select Market under the symbol “GLTO.” On November 3, 2021, the last sale price of our common stockreported onNasdaqwas$3.39pershare.

Upon delivery of a placement notice, and subject to our instructions in that notice and the terms and conditions of the Sales Agreement generally, Jefferies may sell common stock by any method permitted by law deemed to be an “at the market offering” as defined by Rule 415(a)(4) promulgatedunder the Securities Act of 1933, as amended, or the Securities Act. Jefferies is not required to sell any specific number or dollar amount of securities,but will act as a sales agent using commercially reasonable efforts consistent with its normal trading and sales practices, on mutually agreed termsbetween Jefferies and us, to sell on our behalf all of the common stock requested to be sold by us. There is no arrangement for funds to be received inanyescrow,trust orsimilararrangement.

Jefferies will be entitled to compensation at a fixed commission rate of up to 3.0% of the gross sales price per share of common stock sold under the Sales Agreement. In connection with the sale of common stock on our behalf, Jefferies will be deemed to be an “underwriter” within the meaning of theSecurities Act, and the compensation of Jefferies will be deemed to be underwriting commissions or discounts. We have also agreed to provideindemnification and contribution to Jefferies with respect to certain liabilities, including liabilities under the Securities Act and the Securities Exchange Actof1934,asamended.See“PlanofDistribution”foradditionalinformation regardingthe compensationtobe paidtoJefferies.

Investinginourcommon stockinvolvesahighdegreeofrisk.Beforemakinganinvestmentdecision,pleaseread “Risk Factors” beginning on page S-7 of this prospectus, page 5 of the accompanying base prospectus and in thedocumentsincorporatedbyreferenceinthisprospectusandtheaccompanyingbaseprospectus.

NeithertheSecuritiesandExchangeCommissionnoranystatesecuritiescommissionhasapprovedordisapprovedofthesecuritiesbeingoffered by this prospectus or accompanying base prospectus, or determined if this prospectus or accompanying base prospectus is truthful orcomplete.Anyrepresentation tothe contraryis acriminaloffense.

Jefferies

Thedateofthisprospectusis               ,2021

TABLEOFCONTENTS

	Page
ABOUTTHISPROSPECTUS	S-1
SPECIALNOTEREGARDINGFORWARD-LOOKINGSTATEMENTS	S-2
PROSPECTUSSUMMARY	S-4
THEOFFERING	S-6
RISKFACTORS	S-7
USEOFPROCEEDS	S-9
MATERIALU.S.FEDERALINCOMETAXCONSEQUENCESFORU.S.HOLDERS	S-10
PLANOFDISTRIBUTION	S-13
LEGALMATTERS	S-14
EXPERTS	S-14
WHEREYOUCANFINDMOREINFORMATION	S-14
INCORPORATIONOFCERTAININFORMATIONBYREFERENCE	S-14

We are responsible for the information contained and incorporated by reference in this prospectus, in any accompanying prospectus, and in any related free writing prospectus we prepare or authorize. We have not authorized anyone to give you any other information, and we take no responsibility for any other information that others may give you. If you are in a jurisdiction where offers to sell, or solicitations of offers to purchase, the securities offered by this documentation are unlawful, or if you are a person to whom it is unlawful to direct these types of activities, then the offer presented in this document does not extend to you. The information contained in this document speaks only as of the date of this document, unless the information specifically indicates that another date applies. Our business, financial condition, results of operations and prospects may have changed since those dates.

ABOUTTHISPROSPECTUS

This prospectus is part of a registration statement that we have filed with the Securities and Exchange Commission, or SEC, utilizing a “shelf”registration process, and relates to the offering of our common stock. Before buying any of the common stock that we are offering, we urge you tocarefully read this prospectus, the accompanying base prospectus and all of the information incorporated by reference herein and therein, as well as theadditional information described under the headings “Where You Can Find More Information” and “Incorporation of Certain Information by Reference.” These documents containimportantinformation thatyou shouldconsiderwhen makingyour investmentdecision.

We provide information to you about this offering of our common stock in two separate documents that are bound together: (1) this prospectus,which describes the specific details regarding this offering; and (2) the accompanying base prospectus, which provides general information, some ofwhich may not apply to this offering. Generally, when we refer to this “prospectus,” we are referring to both documents combined. If information in thisprospectus is inconsistent with the accompanying base prospectus, you should rely on this prospectus. To the extent there is a conflict between theinformation contained in this prospectus, on the one hand, and the information contained in any document incorporated by reference in this prospectus,on the other hand, you should rely on the information in this prospectus, except as provided in the following sentence. If any statement in one of thesedocuments is inconsistent with a statement in another document having a later date—for example, a document incorporated by reference in thisprospectus—thestatementinthedocument havingthelaterdatemodifies orsupersedesthe earlierstatement.

You should rely only on the information contained or incorporated by reference in this prospectus and the accompanying base prospectus orcontained in any free writing prospectus prepared by or on our behalf. We have not, and Jefferies has not, authorized anyone to provide you withdifferent information. The distribution of this prospectus and the accompanying base prospectus and sale of these securities in certain jurisdictions maybe restricted by law. We are not, and Jefferies is not, making an offer to sell these securities in any jurisdiction where the offer or sale is not permitted.You should assume that the information appearing in this prospectus, the accompanying base prospectus, the documents incorporated by reference inthis prospectus and the accompanying base prospectus, and in any free writing prospectus that we have authorized for use in connection with thisoffering, is accurate only as of the date of those respective documents. Our business, financial condition, results of operations and prospects may havechangedsincethose dates.

Unless the context indicates otherwise, as used in this prospectus, the terms “Company,” “Galecto,” “Registrant,” “we,” “us” and “our” refer toGalecto, Inc. and its subsidiaries, taken as a whole, unless otherwise noted. “Galecto” and all product candidate names are our commonlaw trademarks. This prospectus and the information incorporated herein by reference contains additional trade names, trademarks and service marks ofother companies, which are the property of their respective owners. We do not intend our use or display of other companies’ trade names, trademarks or servicemarks toimplya relationshipwith, orendorsementor sponsorshipofusby,theseother companies.

S-1

SPECIALNOTEREGARDINGFORWARD-LOOKINGSTATEMENTS

This prospectus, the accompanying base prospectus and the documents incorporated by reference herein and therein contain “forward-lookingstatements” within the meaning of the Section 27A of the Securities Act of 1933, as amended, and Section 21E of the Securities Exchange Act of 1934, as amended, or the Exchange Act. We intend that such forward-looking statements be subject to the safe harbors provided by the Private Securities Litigation Reform Act of 1995. These forward-looking statements involve a number of risks and uncertainties. We caution readers that any forward-looking statement is not a guarantee of future performance and that actual results could differ materially from those contained in the forward-lookingstatement.Thesestatementsarebasedon currentexpectationsoffutureevents.

Suchstatements include,butarenotlimited to,statements about:

• the success, cost and timing of our product development activities and planned initiation and completion of clinical trials of our lead product candidate, GB0139, including our ability to enroll patients in our ongoing Phase 2b clinical trial of GB0139 at anticipated rates and our ability to complete such trial with fewer dosage groups, as well as our other current product candidates and any future product candidates;

• the success, cost and timing of our product development activities and planned initiation and completion of our clinical trials;

• our need to raise additional funding before we can expect to generate any revenues from product sales;

• our ability to obtain regulatory approval for our current or future product candidates that we may identify or develop, including our expectation that the FDA or other regulatory agencies would agree with our belief that our Phase 2b clinical trial of GB0139 may be registrational;

• our ability to ensure adequate supply of our current or future product candidates;

• our ability to maintain third-party relationships necessary to conduct our business;

• our heavy dependence upon the success of our research to generate and advance additional product candidates;

• our ability to establish an adequate safety or efficacy profile for our current or future product candidates that we may pursue;

• the implementation of our strategic plans for our business, our current or future product candidates we may develop and our technology;

• our intellectual property position, including the scope of protection we are able to establish and maintain for intellectual property rights covering our product candidates and technology;

• the rate and degree of market acceptance and clinical utility for our current or future product candidates we may develop;

• our estimates about the size of our market opportunity;

• our ability to use the capital we have raised in ways that increase the value of your investment;

• our expectations related to the use the capital we have raised, and estimates of our expenses, future revenues, capital requirements and our needs for additional financing;

• our ability to establish and maintain collaborations;

• our financial performance and liquidity;

• our ability to effectively manage our potential growth;

• developments relating to our competitors and our industry, including the impact of government regulation;

• our ability to retain the continued service of our key professionals and consultants and to identify, hire and retain additional qualified professionals;

• the effect of the COVID-19 pandemic, including mitigation efforts and economic effects, on any of the foregoing or other aspects of our business operations and those of our collaborators, service providers and other vendors;

• our ability to maintain adequate internal controls over financial reporting; and

• other risks and uncertainties, including those listed under the section titled “Risk Factors.”

Any statements about our expectations, beliefs, plans, objectives, assumptions or future events or performance are not historical facts and may beforward-looking. You can find many of these statements by looking for words like “believes,” “expects,” “anticipates,” “estimates,” “may,” “might,”“should,” “will,” “could,”, “should,” “plans,” “intends,” “projects,” “predicts,” “potential,” “continue,” “seek” or similar expressions, or the negative ofthese terms, in this prospectus, the accompanying base prospectus and the documents incorporated by reference herein and in any free writingprospectus. Any forward-looking statements are qualified in their entirety by reference to the factors discussed throughout this prospectus, the accompanying base prospectus and the documents incorporated byreferencehereinandtherein, andinparticularthosefactorsreferencedinthesection “RiskFactors.”

These forward-looking statements are based on the current beliefs and expectations of our management and are subject to significant

S-2

risksanduncertainties.Ifunderlyingassumptionsproveinaccurateorunknownrisksoruncertaintiesmaterialize,actualresultsmaydiffermateriallyfromcurrentexpectationsandprojections.FactorsthatmightcausesuchadifferenceincludethosediscussedinourmostrecentAnnualReportonForm10-KandanysubsequentQuarterlyReportonForm10-Q,aswellasthosediscussedinthisprospectus,theaccompanyingbaseprospectusandthedocumentsincorporatedbyreferencehereinandtherein.Youarecautionednottoplaceunduerelianceontheseforward-lookingstatements,whichspeakonlyasofthedatemade.Weanticipatethatsubsequenteventsanddevelopmentswillcauseourviewstochange.However,whilewemayelecttoupdatetheseforward-lookingstatementsatsomepointinthefuture,wehavenocurrentintentionofdoingsoexcepttotheextentrequiredbyapplicablelaw.Youshould,therefore,notrelyontheseforward-lookingstatementsasrepresentingourviewsasofanydatesubsequenttothedateofthisprospectus.

This prospectus and the documents incorporated by reference also contain estimates, projections and other information concerning our industry, our business, and the markets for certain diseases, including data regarding the estimated size of those markets, and the incidence and prevalence of certain medical conditions. Information that is based on estimates, forecasts, projections, market research or similar methodologies is inherently subject to uncertainties and actual events or circumstances may differ materially from events and circumstances reflected in this information. Unless otherwise expressly stated, we obtained this industry, business, market and other data from reports, research surveys, studies and similar data prepared by market research firms and other third parties, industry, medical and general publications, government data and similar sources.

All subsequent written or oral forward-looking statements attributable to us or any person acting on our behalf are expressly qualified in their entirety by the cautionary statements contained or referred to in this section. We do not undertake any obligation to release publicly any revisions to these forward-looking statements to reflect events or circumstances after the date of this prospectus or to reflect the occurrence of unanticipated events, except as may be required under applicable U.S. securities law. If we do update one or more forward-looking statements, no inference should be drawn that we will make additional updates with respect to those or other forward-looking statements.

S-3

PROSPECTUSSUMMARY

This summary highlights certain information about us, this offering and selected information contained elsewhere in or incorporated by reference into this prospectus and the accompanying base prospectus. This summary is not complete and does not contain all of the information that you shouldconsider before deciding whether to invest in our common stock. For a more complete understanding of our company and this offering, we encourageyou to read and consider carefully the more detailed information in this prospectus, including the information incorporated by reference in thisprospectus and the accompanying base prospectus, and the information included in any free writing prospectus that we have authorized for use inconnection with this offering, including the information under the heading “Risk Factors” in this prospectus on page S-7 and under similar headings inthedocumentsincorporatedbyreferenceinto this prospectusand theaccompanying baseprospectus.

Overview

We are a clinical-stage biotechnology company developing therapeutics that are designed to target the biological processes that lie at the heart of fibrosis and cancer. While our initial focus has been on the development of small-molecule inhibitors of galectin-3 and the collagen cross-linking enzyme lysyl oxidase-like 2, or LOXL2, which play key roles in regulating fibrosis, we are also advancing our compounds for the treatment of cancer (initially in non-small cell lung cancer, or NSCLC, and myelofibrosis). We believe our product candidates are distinct from the current generation of antifibrotic and anti-cancer agents and have the potential to significantly improve patients’ clinical outcomes and enhance their quality of life.

Our most advanced product candidate, GB0139, is an inhaled small molecule inhibitor of galectin-3. We are developing GB0139 for the treatment of severe fibrotic lung diseases such as idiopathic pulmonary fibrosis, or IPF, a life-threatening progressive fibrotic disease of the lung. While there are currently two approved therapies for the treatment of lung fibrosis, they have only been shown to have a modest impact on the progression of the disease, and both therapies have been associated with significant side effects leading to poor therapeutic adherence. In our clinical trials completed to date, we found orally inhaled GB0139 to be generally well-tolerated and that the compound inhibited galectin-3 in the lungs, in a dose-dependent manner, and that it decreased levels of a range of plasma biomarkers, such as YKL-40 and PDGF, that have been linked to mortality, severity and/or progression in IPF.

GB0139 is in Phase 2b clinical development, and our other current product candidates and research initiatives are in earlier stages of clinical and preclinical development. Our ability to generate revenue from product sales sufficient to achieve profitability will depend heavily on the successful development and eventual commercialization of one or more of our product candidates. Our operations to date have been financed primarily from our initial public offering, the issuance of convertible preferred shares and convertible notes. Since inception, we have had significant operating losses. Our net loss was $12.7 million and $38.3 million for the three and nine months ended September 30, 2021, respectively. Our net loss was $11.7 million and $23.3 million for the three and nine months ended September 30, 2020, respectively. As of September 30, 2021, we had an accumulated deficit of $142.7 million and $127.6 million in cash, cash equivalents and marketable securities.

Accordingly, we will continue to require additional financing to advance our current product candidates through clinical development, to develop, acquire or in-license other potential product candidates and to fund operations for the foreseeable future. We will continue to seek funds through equity offerings, debt financings or other capital sources, including potentially collaborations, licenses and other similar arrangements. However, we may be unable to raise additional funds or enter into such other arrangements when needed on favorable terms or at all. If we raise additional capital through public or private equity offerings in the future, the ownership interest of our existing stockholders will be diluted, and the terms of these securities may include liquidation or other preferences that adversely affect our stockholders’ rights. If we raise additional capital through debt financing, we may be subject to covenants limiting or restricting our ability to take specific actions, such as incurring additional debt, making capital expenditures or declaring dividends. Any failure to raise capital as and when needed could have a negative impact on our financial condition and on our ability to pursue our business plans and strategies. If we are unable to raise capital, we will need to delay, reduce or terminate planned activities to reduce costs. We will need to generate significant revenues to achieve profitability, and we may never do so.

CompanyInformation

We were formed under the laws of the State of Delaware in October 2019. Subsequently, shares in Galecto Biotech AB, a Swedish operating company, were exchanged at a one-to-one ratio for shares in Galecto, Inc. On December 31, 2019, we consummated a purchase agreement by and among Galecto, Inc., PK Merger Sub, Inc., and PharmAkea, Inc., or PharmAkea, whereby we acquired PharmAkea in principally an all-stock transaction. As of September 30, 2021, our wholly-owned subsidiaries were Galecto Biotech AB, PharmAkea and Galecto Securities Corporation, and Galecto Biotech ApS, a Danish operating company, was a wholly-owned subsidiary of Galecto Biotech AB.

Our principal US executive offices are located at 75 State Street, Suite 100, Boston, MA 02109 and our principal international executive offices are located at Ole Maaloes Vej 3, DK-2200 Copenhagen N, Denmark, and our telephone number is (+45) 70 70 52 10. Our website address is http://www.galecto.com. The information contained on, or that can be accessed through, our website is not a part of this prospectus. We have included our website address in this prospectus solely as an inactive textual reference.

S-4

Implications of Being an Emerging Growth Company and a Smaller Reporting Company

We are an “emerging growth company,” as defined in the Jumpstart Our Business Startups Act, or the JOBS Act, enacted in April 2012. For solong as we remain an emerging growth company, we are permitted and intend to rely on certain exemptions from various public company reportingrequirements, including an exemption from the requirement to include an attestation report on internal control over financial reporting issued by our independentregistered public accounting firm pursuant to Section 404(b) of the Sarbanes-Oxley Act of 2002, reduced disclosure obligations regarding executivecompensation in our periodic reports and proxy statements, and exemptions from the requirements of holding a nonbinding advisory vote on executive compensation and any golden parachute payments not previously approved. In particular, in this prospectus, we have not included or incorporated byreference all of the executive compensation-related information that would be required if we were not an emerging growth company. Accordingly, theinformationcontained hereinmay bedifferentthan theinformationyou receivefromotherpublic companiesin which youholdstock.

We will remain an emerging growth company until the earlier to occur of (1) the last day of the fiscal year (a) following the fifth anniversary of the date of the closing of our initial public offering, (b) in which we have total annual gross revenues of at least $1.07 billion or (c) in which we are deemed to be a “large accelerated filer,” under the rules of the SEC, which means the market value of our equity securities that is held by non-affiliates exceeds $700 million as of  June 30^th of the prior year, and (2) the date on which we have issued more than $1.0 billion in non-convertible debt during the prior three-year period.

In addition, the JOBS Act provides that an emerging growth company can take advantage of an extended transition period for complying with new or revised accounting standards. This provision allows an emerging growth company to delay the adoption of some accounting standards until those standards would otherwise apply to private companies. We have elected to use this extended transition period for complying with new or revised accounting standards that have different effective dates for public and private companies until the earlier of the date we (i) are no longer an emerging growth company or (ii) affirmatively and irrevocably opt out of the extended transition period provided in the JOBS Act. As a result, we are not subject to the same new or revised accounting standards as other public companies that are not emerging growth companies, and our financial statements may not be comparable to other public companies that comply with new or revised accounting pronouncements as of public company effective dates. We may choose to early adopt any new or revised accounting standards whenever such early adoption is permitted for private companies.

We are also a “smaller reporting company,” meaning that the market value of our stock held by non-affiliates is less than $700 million and our annual revenue was less than $100 million during our most recently completed fiscal year. We may continue to be a smaller reporting company if either (i) the market value of our stock held by non-affiliates is less than $250 million or (ii) our annual revenue was less than $100 million during the most recently completed fiscal year and the market value of our stock held by non-affiliates is less than $700 million. If we are a smaller reporting company at the time we cease to be an emerging growth company, we may continue to rely on exemptions from certain disclosure requirements that are available to smaller reporting companies. For so long as we remain a smaller reporting company, we are permitted and intend to rely on exemptions from certain disclosure and other requirements that are applicable to other public companies that are not smaller reporting companies.

S-5

THEOFFERING

Common stock offeredby us	Common stock having an aggregate offering price of up to $50.0 million.
Common stock to be outstanding immediately after this offering	Up to 39,480,121 shares, assuming sales of 14,218,289 shares of our common stock in this offering at an offering price of $3.39 per share, which was the last reported sale price of our common stock on the Nasdaq Global Select Market on November 3, 2021. The actual number of shares issued will vary depending on the sales prices under this offering.
Mannerofoffering	“At-the-market” offering that may be made from time to time through or to our sales agent,Jefferies.See“PlanofDistribution”onpageS-20ofthisprospectus.
Useofproceeds	Because there is no minimum offering amount required as a condition to this offering, the actualtotal public offering amount, commissions and proceeds to us, if any, are not determinable at thistime. We intend to use the net proceeds from this offering for general corporate purposes. See “UseofProceeds”on page S-9ofthisprospectus.
NasdaqGlobalSelectMarketsymbol	“GLTO”
Riskfactors	See the “Risk Factors” section on page S-7 of this prospectus and the accompanying baseprospectus for a discussion of factors you should carefully consider before deciding to invest in ourcommon stock.

The number of shares of common stock shown above to be outstanding after this offering is based on 25,261,832 shares of common stock outstanding as of September 30, 2021, and excludes as of that date:

•     2,512,427 shares of our common stock issuable upon the exercise of options outstanding under the 2020 Stock Option and Grant Plan, at a weighted-average exercise price of $4.54 per share;

•     1,411,301 shares of our common stock issuable upon the exercise of options outstanding under the 2020 Equity Incentive Plan, or the 2020 Plan, at a weighted-average exercise price of $10.18 per share; and

• 1,476,632 shares of our common stock reserved for future issuance under the 2020 Plan.

S-6

RISKFACTORS

An investment in our common stock involves a high degree of risk. Before deciding whether to invest in our common stock, you should consider carefully the risks described below and the risks, uncertainties and assumptions discussed in our most recent Annual Report on Form 10-K and anysubsequent Quarterly Reports on Form 10-Q, which are incorporated by reference in this prospectus and any free writing prospectus with respect tothis offering filed by us with the SEC, as well as any amendment or update to our risk factors reflected in subsequent filings with the SEC, together with other information in this prospectus, the accompanying base prospectus, and the information and documents incorporated by reference that we haveauthorized for use in connection with this offering. The risks and uncertainties described below and incorporated by reference herein are not the onlyones we face. Additional risks and uncertainties that we are unaware of or that we deem immaterial may also become important factors that adverselyaffect our business. If any of these risks actually occur, our business, financial condition, results of operations or cash flows could be seriously harmed. This could cause the trading price of our common stock to decline, resulting in a loss of all or part of your investment. Please also read carefully thesectiontitled“SpecialNote Regarding Forward-LookingStatements.”

RisksRelatedtoThisOffering

Managementwillhavebroaddiscretionastotheuseoftheproceedsfromthisoffering,andmaynotusetheproceedseffectively.

Because we have not designated the amount of net proceeds from this offering to be used for any particular purpose other than general corporate purposes, our management will have broad discretion as to the application of the net proceeds from this offering and could use them for purposes other than those contemplated at the time of the offering. You will not have the opportunity, as part of your investment decision, to assess whether theseproceeds are being used appropriately. Our management may use the net proceeds for corporate purposes that may not improve our financial condition or market value.

Pending their use, we plan to invest the net proceeds from this offering in short- and intermediate-term, interest-bearing obligations, investment-grade instruments, certificates of deposit or direct or guaranteed obligations of the U.S. government. These investments may not yield afavorablereturntoour stockholders.

Purchasersinthisofferingmayexperiencedilutioninthebookvalueoftheirinvestment.

The shares sold in this offering, if any, will be sold from time to time at various prices. However, the offering price of our common stock may be higher than the net tangible book value per share of our outstanding common stock. After giving effect to the saleof common stock in the aggregate amount of $50.0 million at an assumed offering price of $3.39 per share, the last reported sale price of our common stock on November 3, 2021 on the Nasdaq Global Select Market, and after deducting commissions and estimated offering expenses, our as adjusted net tangible book value as ofSeptember 30, 2021 would have been approximately $177.8 million or approximately $4.50 per share.

In addition to this offering, subject to market conditions and other factors, we may pursue additional equity financings in the future, includingfuture public offerings or future private placements of equity securities or securities convertible into or exchangeable for equity securities. Further, theexercise of outstanding stock options, the exercise of stock options issued in the future, or the vesting of restricted stock units could result in furtherdilution to investors and any additional shares issued in connection with acquisitions, should we choose to pursue any, will result in dilution to investors. In addition, themarketprice ofour common stockcouldfall as a result of resales of shares of common stock due to an increased number of shares available for sale in the market. For a further description of the dilutionthatyouwillexperienceimmediately afterthisoffering,seethesection inthis prospectustitled“Dilution.”

Because we do not intend to declare cash dividends on our common stock in the foreseeable future, shareholders must rely on appreciation of thevalueof our common stockforany return on theirinvestment.

We have never declared or paid cash dividends on our common stock. We currently anticipate that we will retain future earnings for thedevelopment, operation and expansion of our business and do not anticipate declaring or paying any cash dividends in the foreseeable future. Inaddition, the terms of any future debt agreements may preclude us from paying dividends. As a result, we expect that only appreciation of the price of ourcommon stock,ifany,willprovidea returnto investors inthisoffering forthe foreseeablefuture.

The common stock offered hereby will be sold in “at the market” offerings, and investors who buy common stock at different times will likely paydifferentprices.

Investors who purchase shares of our common stock in this offering at different times will likely pay different prices, and so may experiencedifferent levels of dilution and different outcomes in their investment results. We will have discretion, subject to market demand, to vary the timing,prices, and numbers of common stock sold in this offering. In addition, subject to the final determination by our board of directors, there is nominimum or maximum sales price for common stock to be sold in this offering. Investors may experience a decline in the value of the common stocktheypurchasein this offeringasaresultof salesmade at prices lowerthantheprices theypaid.

S-7

TheactualnumberofshareswewillissueundertheSalesAgreement,atany onetimeorintotal,isuncertain.

Subject to certain limitations in the Sales Agreement entered into by us with Jefferies and compliance with applicable law, we have the discretion to deliver a placement notice to Jefferies at any time throughout the term of the Sales Agreement. The number of shares that are sold by Jefferies afterdeliveringaplacementnoticewillfluctuatebasedonthemarketpriceofthecommon stockduringthesalesperiodandlimitswesetwithJefferies. Because the price per share of each share sold will fluctuate based on the market price of our common stock during the sales period, it is not possible atthisstageto predictthenumberofshares thatwillbeultimately issuedor theresulting grossproceeds.

S-8

USEOFPROCEEDS

We may issue and sell common stock having aggregate sales proceeds of up to $50.0 million from time to time. Because there is no minimumoffering amount required as a condition to this offering, the actual total public offering amount, commissions and proceeds to us, if any, are notdeterminable at this time. There can be no assurance that we will sell any shares under or fully utilize the Sales Agreement with Jefferies as a source offinancing.

We currently intend to use the net proceeds from this offering payable to us for general corporate purposes, including expenditures aimed atgrowing our business and research and development expenditures focused on product development. We do not currently have specific plans orcommitments with respect to the net proceeds from this offering and, accordingly, are unable to quantify the allocation of such proceeds among thevarious potential uses. We will have broad discretion in the way that we use the net proceeds of this offering. Pending our use of the net proceeds, if any, from this offering, we intend to invest the net proceeds in a variety of capital preservation investments, including short-term, investment grade,interestbearing instrumentsandU.S. government securities.

S-9

MATERIALU.S.FEDERALINCOMETAXCONSEQUENCESFORU.S.HOLDERS

The following discussion is a summary of certain U.S. federal income tax considerations applicable to non-U.S. holders (as defined below) with respect to their ownership and disposition of shares of our common stock issued pursuant to this offering. For purposes of this discussion, a non-U.S. holder means a beneficial owner of our common stock that is for U.S. federal income tax purposes:

• a non-resident alien individual;

• a foreign corporation or any other foreign organization taxable as a corporation for U.S. federal income tax purposes; or

• a foreign estate or trust, the income of which is not subject to U.S. federal income tax on a net income basis.

This discussion does not address the tax treatment of partnerships or other entities that are pass-through entities for U.S. federal income tax purposes or persons that hold their common stock through partnerships or other pass-through entities. A partner in a partnership or other pass-through entity that will hold our common stock should consult his, her or its tax advisor regarding the tax consequences of holding and disposing of our common stock through a partnership or other pass-through entity, as applicable.

This discussion is based on current provisions of the Internal Revenue Code of 1986, as amended, or the Code, existing and proposed U.S. Treasury Regulations promulgated thereunder, current administrative rulings and judicial decisions, all as in effect as of the date of this prospectus and, all of which are subject to change or to differing interpretation, possibly with retroactive effect. Any such change or differing interpretation could alter the tax consequences to non-U.S. holders described in this prospectus. There can be no assurance that the Internal Revenue Service, which we refer to as the IRS, will not challenge one or more of the tax consequences described herein. We assume in this discussion that a non-U.S. holder holds shares of our common stock as a capital asset within the meaning of Section 1221 of the Code, which is generally property held for investment.

This discussion does not address all aspects of U.S. federal income taxation that may be relevant to a particular non-U.S. holder in light of that non-U.S. holder’s individual circumstances including the alternative minimum tax, or the Medicare tax on net investment income, the timing of income accruals required under Section 451(b) of the Code, the rules regarding qualified small business stock within the meaning of Section 1202 of the Code and any election to apply Section 1400Z-2 of the Code to gains recognized with respect to shares of our common stock. This discussion also does not address any U.S. state, local or non-U.S. taxes or any other aspect of any U.S. federal tax other than the income tax. This discussion also does not consider any specific facts or circumstances that may apply to a non-U.S. holder and does not address the special tax rules applicable to particular non-U.S. holders, such as:

• insurance companies;

• tax-exempt or governmental organizations;

• financial institutions;

• brokers or dealers in securities;

• regulated investment companies;

• pension plans;

• “controlled foreign corporations,” “passive foreign investment companies,” and corporations that accumulate earnings to avoid U.S. federal income tax;

• “qualified foreign pension funds,” or entities wholly-owned by a “qualified foreign pension fund”;

• partnerships or other entities or arrangements treated as partnerships for U.S. federal income tax purposes (and partners and investors therein);

• persons deemed to sell our common stock under the constructive sale provisions of the Code;

• persons that hold our common stock as part of a straddle, hedge, conversion transaction, synthetic security or other integrated investment;

• persons who have elected to mark securities to market;

• persons who have a functional currency other than the U.S. dollar;

• persons that own, or have owned, actually or constructively, more than 5% of our common stock;•persons who hold or receive our common stock pursuant to the exercise of any employee stock option or otherwise as compensation; and

• certain U.S. expatriates.

This discussion is for general information only and is not tax advice. Accordingly, all prospective non-U.S. holders of our common stock should consult their tax advisors with respect to the U.S. federal, state, local and non-U.S. tax consequences of the purchase, ownership and disposition of our common stock.

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Distributions on our common stock

Distributions, if any, on our common stock will constitute dividends for U.S. federal income tax purposes to the extent paid from our current or accumulated earnings and profits, as determined under U.S. federal income tax principles. If a distribution exceeds our current and accumulated earnings and profits, the excess will be treated as a tax-free return of the non-U.S. holder’s investment, up to such holder’s tax basis in the common stock. Any remaining excess will be treated as capital gain, subject to the tax treatment described below in “Gain on sale or other taxable disposition of our common stock.” Any such distributions will also be subject to the discussions below under the sections titled “Backup withholding and information reporting” and “Withholding and information reporting requirements—FATCA.”

Subject to the discussion in the following two paragraphs in this section, dividends paid to a non-U.S. holder generally will be subject to withholding of U.S. federal income tax at a 30% rate or such lower rate as may be specified by an applicable income tax treaty between the United States and such holder’s country of residence. If we or another withholding agent apply over-withholding or if a non-U.S. holder does not timely provide us with the required certification, the non-U.S. holder may be entitled to a refund or credit of any excess tax withheld by timely filing an appropriate claim with the IRS.

Dividends that are treated as effectively connected with a trade or business conducted by a non-U.S. holder within the United States and, if an applicable income tax treaty so provides, that are attributable to a permanent establishment or a fixed base maintained by the non-U.S. holder within the United States, are generally exempt from the 30% withholding tax if the non-U.S. holder satisfies applicable certification and disclosure requirements. However, such U.S. effectively connected income, net of specified deductions and credits, is taxed at the same graduated U.S. federal income tax rates applicable to United States persons (as defined in the Code). Any U.S. effectively connected income received by a non-U.S. holder that is a corporation may also, under certain circumstances, be subject to an additional “branch profits tax” at a 30% rate or such lower rate as may be specified by an applicable income tax treaty between the United States and such holder’s country of residence.

A non-U.S. holder of our common stock who claims the benefit of an applicable income tax treaty between the United States, and such holder’s country of residence generally will be required to provide a properly executed IRS Form W-8BEN or W-8BEN-E (or successor form) to the applicable withholding agent and satisfy applicable certification and other requirements. Non-U.S. holders are urged to consult their tax advisors regarding their entitlement to benefits under a relevant income tax treaty. A non-U.S. holder that is eligible for a reduced rate of U.S. withholding tax under an income tax treaty may obtain a refund or credit of any excess amounts withheld by timely filing a U.S. tax return with the IRS.

 Gain on sale or other taxable disposition of our common stock

Subject to the discussions below under “Backup withholding and information reporting” and “Withholding and information reporting requirements—FATCA,” a non-U.S. holder generally will not be subject to any U.S. federal income tax on any gain realized upon such holder’s sale or other taxable disposition of shares of our common stock unless:

• the gain is effectively connected with the non-U.S. holder’s conduct of a U.S. trade or business and, if an applicable income tax treaty so provides, is attributable to a permanent establishment or a fixed-base maintained by such non-U.S. holder in the United States, in which case the non-U.S. holder generally will be taxed on a net income basis at the graduated U.S. federal income tax rates applicable to United States persons (as defined in the Code) and, if the non-U.S. holder is a foreign corporation, the branch profits tax described above in “Distributions on our common stock” also may apply;

• the non-U.S. holder is a nonresident alien individual who is present in the United States for a period or periods aggregating 183 days or more in the taxable year of the disposition and certain other conditions are met, in which case the non-U.S. holder will be subject to a 30% tax (or such lower rate as may be specified by an applicable income tax treaty between the United States and such holder’s country of residence) on the net gain derived from the disposition, which may be offset by certain U.S. source capital losses of the non-U.S. holder, if any (even though the individual is not considered a resident of the United States), provided that the non-U.S. holder has timely filed U.S. federal income tax returns with respect to such losses; or

• we are, or have been, at any time during the five-year period preceding such sale or other taxable disposition (or the non-U.S. holder’s holding period, if shorter) a “U.S. real property holding corporation,” unless our common stock is regularly traded on an established securities market and the non-U.S. holder holds no more than 5% of our outstanding common stock, directly or indirectly, actually or constructively, during the shorter of the 5-year period ending on the date of the disposition or the period that the non-U.S. holder held our common stock. Generally, a corporation is a U.S. real property holding corporation only if the fair market value of its U.S. real property interests equals or exceeds 50% of the sum of the fair market value of its worldwide real property interests plus its other assets used or held for use in a trade or business. Although there can be no assurance, we do not believe that we are, or have been, a U.S. real property holding corporation, or that we are likely to become one in the future. No assurance can be provided that our common stock will be regularly traded on an established securities market for purposes of the rules described above

Backup withholding and information reporting

We must report annually to the IRS and to each non-U.S. holder the gross amount of the distributions on our common stock paid to such holder and the tax withheld, if any, with respect to such distributions. Non-U.S. holders may have to comply with specific certification procedures to establish that the holder is not a United States person (as defined in the Code) in order to avoid backup withholding at the applicable rate with respect to dividends on our common stock. Dividends paid to non-U.S. holders subject to withholding of U.S. federal income tax, as described above in “Distributions on our common stock,” generally will be exempt from U.S. backup withholding.

Information reporting and backup withholding will generally apply to the proceeds of a disposition of our common stock by a non-U.S. holder effected by or through the U.S. office of any broker, U.S. or foreign, unless the holder certifies its status as a non-U.S. holder and satisfies certain

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other requirements, or otherwise establishes an exemption. Generally, information reporting and backup withholding will not apply to a payment of disposition proceeds to a non-U.S. holder where the transaction is effected outside the United States through a non-U.S. office of a broker. However, for information reporting purposes, dispositions effected through a non-U.S. office of a broker with substantial U.S. ownership or operations generally will be treated in a manner similar to dispositions effected through a U.S. office of a broker. Non-U.S. holders should consult their tax advisors regarding the application of the information reporting and backup withholding rules to them. Copies of information returns may be made available to the tax authorities of the country in which the non-U.S. holder resides or is incorporated under the provisions of a specific treaty or agreement. Backup withholding is not an additional tax. Any amounts withheld under the backup withholding rules from a payment to a non-U.S. holder can be refunded or credited against the non-U.S. holder’s U.S. federal income tax liability, if any, provided that an appropriate claim is filed with the IRS in a timely manner.

Withholding and information reporting requirements — FATCA

Provisions of the Code commonly referred to as the Foreign Account Tax Compliance Act, or FATCA, generally imposes a U.S. federal withholding tax at a rate of 30% on payments of dividends on our common stock paid to a foreign entity unless (i) if the foreign entity is a “foreign financial institution,” such foreign entity undertakes certain due diligence, reporting, withholding, and certification obligations, (ii) if the foreign entity is not a “foreign financial institution,” such foreign entity identifies certain of its U.S. investors, if any, or (iii) the foreign entity is otherwise exempt under FATCA. Under applicable U.S. Treasury regulations, withholding under FATCA currently applies to payments of dividends on our common stock. Currently proposed U.S. Treasury Regulations provide that FATCA withholding does not apply to gross proceeds from the disposition of property of a type that can produce U.S. source dividends or interest; however, prior versions of the rules would have made such gross proceeds subject to FATCA withholding. Taxpayers (including withholding agents) can generally rely on the proposed Treasury Regulations until final Treasury Regulations are issued. Under certain circumstances, a non-U.S. holder may be eligible for refunds or credits of this withholding tax. An intergovernmental agreement between the United States and an applicable foreign country may modify the requirements described in this paragraph. Non-U.S. holders should consult their tax advisors regarding the possible implications of this legislation on their investment in our common stock and the entities through which they hold our common stock, including, without limitation, the process and deadlines for meeting the applicable requirements to prevent the imposition of the 30% withholding tax under FATCA.

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PLANOFDISTRIBUTION

We have entered into a sales agreement with Jefferies, under which we may offer and sell up to $50 million of our shares of common stock from time to time through Jefferies acting as agent. Sales of our shares of common stock, if any, under this prospectus supplement and the accompanying prospectus will be made by any method that is deemed to be an “at the market offering” as defined in Rule 415(a)(4) under the Securities Act.

Each time we wish to issue and sell our shares of common stock under the sales agreement, we will notify Jefferies of the number of shares to be issued, the dates on which such sales are anticipated to be made, any limitation on the number of shares to be sold in any one day and any minimum price below which sales may not be made. Once we have so instructed Jefferies, unless Jefferies declines to accept the terms of such notice, Jefferies has agreed to use its commercially reasonable efforts consistent with its normal trading and sales practices to sell such shares up to the amount specified on such terms. The obligations of Jefferies under the sales agreement to sell our shares of common stock are subject to a number of conditions that we must meet. 

The settlement of sales of shares between us and Jefferies is generally anticipated to occur on the second trading day following the date on which the sale was made. Sales of our shares of common stock as contemplated in this prospectus supplement will be settled through the facilities of The Depository Trust Company or by such other means as we and Jefferies may agree upon. There is no arrangement for funds to be received in an escrow, trust or similar arrangement.

We will pay Jefferies a commission equal to 3.0% of the aggregate gross proceeds we receive from each sale of our shares of common stock. Because there is no minimum offering amount required as a condition to close this offering, the actual total public offering amount, commissions and proceeds to us, if any, are not determinable at this time. In addition, we have agreed to reimburse Jefferies for the fees and disbursements of its counsel, payable upon execution of the sales agreement, in an amount not to exceed $75,000, in addition to certain ongoing disbursements of its legal counsel. We estimate that the total expenses for the offering, excluding any commissions or expense reimbursement payable to Jefferies under the terms of the sales agreement, will be approximately $0.3 million. The remaining sale proceeds, after deducting any other transaction fees, will equal our net proceeds from the sale of such shares.

Jefferies will provide written confirmation to us before the open on The Nasdaq Global Select Market on the day following each day on which our shares of common stock are sold under the sales agreement. Each confirmation will include the number of shares sold on that day, the aggregate gross proceeds of such sales and the proceeds to us.

In connection with the sale of our shares of common stock on our behalf, Jefferies may be deemed to be an “underwriter” within the meaning of the Securities Act, and the compensation of Jefferies will be deemed to be underwriting commissions or discounts. We have agreed to indemnify Jefferies against certain civil liabilities, including liabilities under the Securities Act. We have also agreed to contribute to payments Jefferies may be required to make in respect of such liabilities.

The offering of our shares of common stock pursuant to the sales agreement will terminate upon the earlier of (i) the sale of all shares of common stock subject to the sales agreement and (ii) the termination of the sales agreement as permitted therein. We and Jefferies may each terminate the sales agreement at any time upon ten days’ prior notice.

This summary of the material provisions of the sales agreement does not purport to be a complete statement of its terms and conditions. A copy of the sales agreement is filed as an exhibit to the registration statement of which this prospectus supplement forms a part.

Jefferies and its affiliates may in the future provide various investment banking, commercial banking, financial advisory and other financial services for us and our affiliates, for which services they may in the future receive customary fees. In the course of its business, Jefferies may actively trade our securities for its own account or for the accounts of customers, and, accordingly, Jefferies may at any time hold long or short positions in such securities.

A prospectus supplement and the accompanying prospectus in electronic format may be made available on a website maintained by Jefferies, and Jefferies may distribute the prospectus supplement and the accompanying prospectus electronically.

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LEGALMATTERS

CertainlegalmattersinconnectionwiththisofferingwillbepasseduponforusbyGoodwinProcterLLP,Boston,Massachusetts. Jefferies LLC is being represented in connection with thisofferingby Mintz, Levin, Cohn, Ferris, Glovsky and Popeo, P.C., Boston, Massachusetts.

EXPERTS

The consolidated financial statements of Galecto Inc. appearing in Galecto, Inc.'s Annual Report on Form 10-K for the year ended December 31,2020, have been audited by EY Godkendt Revisionspartnerselskab, independent registered public accounting firm, as set forth in their report thereon, included therein, and incorporated herein by reference. Such consolidated financial statements are incorporated herein by reference in reliance upon such report given on the authority of such firm as experts in accounting and auditing.

WHEREYOUCANFINDMOREINFORMATION

We have filed with the SEC a registration statement on Form S-3 under the Securities Act with respect to the common stock offered hereby. Thisprospectus, which constitutes a part of the registration statement, does not contain all of the information set forth in the registration statement or theexhibits filed therewith. For further information about us and the common stock offered hereby, reference is made to the accompanying base prospectus and registration statement of which it is a part and the exhibits filed therewith. Statements contained in this prospectus regarding the contents of anycontract or any other document that is filed as an exhibit to the accompanying base prospectus and the registration statement of which it is a part are notnecessarily complete, and in each instance we refer you to the copy of such contract or other document filed as an exhibit to the registration statement or theexhibitstothe reportsorotherdocumentsincorporatedbyreference inthisprospectusforacopyofsuch contractorotherdocument.

We are subject to the informational requirements of the Exchange Act and are required to file annual, quarterly and other reports, proxystatements and other information with the SEC. The SEC maintains a website (http://www.sec.gov) that contains reports, proxy and information statements,and various other informationaboutus.

Information about us is also available at our website at http://www.galecto.com. However, the information contained on, or that can be accessedthrough,ourwebsiteisnotapartofthisprospectus and isnotincorporatedby referenceinto this prospectus.

INCORPORATIONOFCERTAININFORMATIONBYREFERENCE

The SEC allows us to “incorporate by reference” information that we file with the SEC, which means that we can disclose important informationto you by referring you to those other documents. The information incorporated by reference is an important part of this prospectus, and information we file later with the SEC will automatically update and supersede this information. We incorporate by reference the documents listed below, other thanthosedocuments orportionsofthosedocumentsdeemed to befurnished andnotfiledin accordancewithSECrules:

• OurAnnualReporton Form 10-KfortheyearendedDecember31,2020filedwiththeSEConMarch29,2021;

• Our Quarterly Reports on Form 10-Q for the quarters ended March 31, 2021, June 30, 2021 and September 30, 2021 and filed with the SEC on May 4, 2021, August 5, 2021 and November 4, 2021;

• Our Current Reports on Form 8-K filed on January 8, 2021, May 28, 2021 and July 6, 2021;

• Our Definitive Proxy Statement on Schedule 14A, filed with the SEC on April 14, 2021 (but only with respect to information required by Part III of our Annual Report on Form 10-K for the year ended December 31, 2020, which information shall update and supersede information included in Part III of our Annual Report on Form 10-K for the year ended December 31, 2020); and

• The description of our common stock in our Registration Statement on Form 8-A (No. 001-39655) filed with the SEC on October 23, 2020, and including any other amendments or reports filed for the purpose of updating such description.

We also incorporate by reference any future filings we make with the SEC under Section 13(a), 13(c), 14, or 15(d) of the Exchange Act (in eachcase, other than current reports furnished under Item 2.02 or Item 7.01 of Form 8-K and exhibits filed on such form or that are related to such items)between the date of the initial registration statement and the effectiveness of the registration statement and following the effectiveness of the registration statement until the offering of the securities under the registration statement is terminated or completed. These documents include, without limitation,AnnualReportsonForm10-K,QuarterlyReportsonForm10-Q, CurrentReportsonForm8-K, aswellasproxy statements, and any amendments thereto.

Upon written or oral request, we will provide without charge to each person, including any beneficial owner, to whom this prospectus is delivered, a copy of any or all of such information that has been incorporated herein by reference (other than exhibits to such documents unless such exhibits are specifically incorporated by reference into the documents that this prospectus incorporates). Written or oral requests for copies should be directed to General Counsel, Galecto, Inc., 75 State Street, Suite 100, Boston, MA 02109, Attention: General Counsel. See the section of this prospectus titled “Where You Can Find More Information” for information concerning how to read and obtain copies of materials that we file with the SEC.

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Any statement contained in this prospectus, or in a document all or a portion of which is incorporated by reference, shall be modified or superseded for purposes of this prospectus to the extent that a statement contained in this prospectus, any prospectus supplement or any document incorporated by reference modifies or supersedes such statement. Any such statement so modified or superseded shall not, except as so modified or superseded, constitute a part of this prospectus.

Any statement contained in a document incorporated or deemed to be incorporated by reference in this prospectus will be deemed modified, superseded or replaced for purposes of this prospectus to the extent that a statement contained in this prospectus modifies, supersedes or replaces such statement.

S-15

Upto$50,000,000

Common Stock

PROSPECTUS

Jefferies

,2021

PARTII

INFORMATIONNOTREQUIREDINPROSPECTUS

Item14.OtherExpensesofIssuanceandDistribution

The following table sets forth estimated expenses in connection with the issuance and distribution of the securities being registered. All theamountsshownareestimates,exceptfor theSEC registrationfeeandFINRA filingfee.

SECregistrationfee	$18,540
FINRAfilingfee	$ 30,500
Printingandengraving	*
Legalfeesandexpenses	*
Accountingfeesandexpenses	*
Transferagentand registrarfees andexpenses	*
Miscellaneousexpenses	*
Total	$*

* These fees are calculated based on the type of securities offered and the number of issuances and accordingly, cannot be estimated at this time. An estimate of the aggregate expenses in connection with the sale and distribution of securities being offered will be included in the applicableprospectussupplement.

Item15.IndemnificationofDirectorsandOfficers

Section 145 of the Delaware General Corporation Law, or DGCL, authorizes a corporation to indemnify its directors and officers against liabilities arising out of actions, suits and proceedings to which they are made or threatened to be made a party by reason of the fact that they have served or are currently serving as a director or officer to a corporation. The indemnity may cover expenses (including attorneys’ fees) judgments, fines and amounts paid in settlement actually and reasonably incurred by the director or officer in connection with any such action, suit or proceeding. Section 145 permits corporations to pay expenses (including attorneys’ fees) incurred by directors and officers in advance of the final disposition of such action, suit or proceeding. In addition, Section 145 provides that a corporation has the power to purchase and maintain insurance on behalf of its directors and officers against any liability asserted against them and incurred by them in their capacity as a director or officer, or arising out of their status as such, whether or not the corporation would have the power to indemnify the director or officer against such liability under Section 145.

We have adopted provisions in our amended and restated certificate of incorporation and amended and restated bylaws that limit or eliminate the personal liability of our directors to the fullest extent permitted by the DGCL, as it now exists or may in the future be amended. Consequently, a director will not be personally liable to us or our stockholders for monetary damages or breach of fiduciary duty as a director, except for liability for any breach of the director’s duty of loyalty to us or our stockholders; any act or omission not in good faith or that involves intentional misconduct or a knowing violation of law; any unlawful payments related to dividends or unlawful stock purchases, redemptions or other distributions; or any transaction from which the director derived an improper personal benefit.

These limitations of liability do not alter director liability under the federal securities laws and do not affect the availability of equitable remedies such as an injunction or rescission.

In addition, our amended and restated bylaws provide that:

• we will indemnify our directors, officers and, in the discretion of our board of directors, certain employees to the fullest extent permitted by the DGCL, as it now exists or may in the future be amended; and

• officers and certain employees, in connection with legal proceedings relating to their service for or on behalf of us, subject to limited exceptions.

We have entered into indemnification agreements with each of our directors, executive officers, and other officers as determined from time to time by our board of directors or our compensation committee. These agreements provide that we will indemnify each of our directors, officers with whom we have entered into indemnification agreements, and, at times, their affiliates to the fullest extent permitted by Delaware law. We will advance expenses, including attorneys’ fees (but excluding judgments, fines and settlement amounts), to each indemnified director, executive officer or affiliate in connection with any proceeding in which indemnification is available and we will indemnify our directors and officers for certain actions or proceedings arising out of that person’s services as a director or officer brought on behalf of us or in furtherance of our rights. Additionally, certain of our directors or officers may have certain rights to indemnification, advancement of expenses or insurance provided by their affiliates or other third parties, which indemnification relates to and might apply to the same proceedings arising out of such director’s or officer’s services as a director referenced herein. Nonetheless, our obligations to those same directors or officers are primary and any obligation of such affiliates or other third parties to advance expenses or to provide indemnification for the expenses or liabilities incurred by those directors are secondary.

II-1

We also maintaingeneralliabilityinsurancewhichcoverscertainliabilitiesofourdirectorsandofficersarisingoutofclaimsbasedonactsoromissionsintheircapacitiesasdirectorsorofficers,includingliabilitiesundertheSecuritiesActof1933,asamended,ortheSecuritiesAct.

Item16.Exhibits

Incorporated by Reference

ExhibitNumber	ExhibitDescription	Form	FileNo.	Exhibit	Filing Date	Filed Herewith
1.1*	Formof UnderwritingAgreement
1.2	Sales Agreement, dated November 4, 2021, by and between the Registrant and Jefferies LLC					X
3.1	Amended and Restated Certificate of Incorporation of Registrant	8-K	001-39655	3.1	Nov. 4, 2020
3.2	Amended and Restated Bylaws of the Registrant	8-K	001-39655	3.2	Nov. 4, 2020
4.1	Specimen Common Stock Certificate	S-1/A	333-249369	4.1	Oct. 22,2020
4.2	Amended and Restated Investors’ Rights Agreement the Registrant and certain of its stockholders, dated September 25, 2020	S-1/A	333-249369	4.2	Oct. 22,2020
4.3	Form of Senior Indenture					X
4.4	Form of Subordinated Indenture					X
4.5*	Form of Warrant
4.6*	Form of Warrant Agreement
4.7*	Form of Specimen Preferred Share Certificate
5.1	Opinion of Goodwin Procter LLP					X
5.2	Opinion of Goodwin Procter LLP relating to sales agreement prospectus					X
23.1	Consent of EY Godkendt Revisionspartnerselskab, independent registered public accounting firm					X
23.2	Consent of Goodwin Procter LLP (included in Exhibit 5.1)					X
23.3	Consent of Goodwin Procter LLP (included in Exhibit 5.2)					X
24.1	Power of Attorney (included on the signature page hereto)					X
25.1**	Form T-1 Statement of Eligibility of Trustee for Senior IndentureundertheTrustIndenture Act of1939.
25.2**	Form T-1 Statement of Eligibility of Trustee for SubordinatedIndentureundertheTrustIndentureActof1939.

*To be filed by amendment or as an exhibit to a report pursuant to Section 13(a) or 15(d) of the Securities Exchange Act of 1934, as amended andincorporatedherein byreference.

**TobefiledinaccordancewiththerequirementsofSection305(b)(2)oftheTrustIndentureActof1939andRule5b-3thereunder.

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Item17.Undertakings

(a) TheundersignedRegistranthereby undertakes:

(1)To file, during any period in which offers or sales are being made, a post-effective amendment to this registration statement:

(i) include any prospectus required by Section 10(a)(3) of the Securities Act;

(ii) to reflect in the prospectus any facts or events arising after the effective date of the registration statement (or the most recent post-effective amendment thereof) which, individually or in the aggregate, represent a fundamental change in the information set forth in the registration statement. Notwithstanding the foregoing, any increase or decrease in volume of securities offered (if the total dollar value of securities offered would not exceed that which was registered) and any deviation from the low or high end of the estimated maximum offering range may be reflected in the form of prospectus filed with the SEC pursuant to Rule 424(b) if, in the aggregate, the changes in volume and price represent no more than 20 percent change in the maximum aggregate offering price set forth in the “Calculation of Registration Fee” table in the effective registration statement; and

(iii) to include any material information with respect to the plan of distribution not previously disclosed in the registration statement or any material change to such information in the registration statement; provided, however, that subparagraphs (1)(i), (1)(ii), and (1)(iii) do not apply if the information required to be included in a post- effective amendment by those paragraphs is contained in reports filed with or furnished to the SEC by the Registrant pursuant to Section 13 or Section 15(d) of the Exchange Act that are incorporated by reference in this registration statement, or is contained in a form of prospectus filed pursuant to Rule 424(b) that is part of this registration statement.

(2)That, for the purpose of determining any liability under the Securities Act, each such post-effective amendment shall be deemed to be a new registration statement relating to the securities offered therein, and the offering of such securities at that time shall be deemed to be the initial bona fide offering thereof.

(3)To remove from registration by means of a post-effective amendment any of the securities being registered which remain unsold at the termination of the offering.

(4)That, for the purpose of determining liability under the Securities Act to any purchaser:

(i) Each prospectus filed by the Registrant pursuant to Rule 424(b)(3) shall be deemed to be part of the registration statement as of the date the filed prospectus was deemed part of and included in the registration statement; and

(ii) Each prospectus required to be filed pursuant to Rule 424(b)(2), (b)(5), or (b)(7) as part of a registration statement in reliance on Rule 430B relating to an offering made pursuant to Rule 415(a)(1)(i), (vii), or (x) for the purpose of providing the information required by Section 10(a) of the Securities Act shall be deemed to be part of and included in the registration statement as of the earlier of the date such form of prospectus is first used after effectiveness or the date of the first contract of sale of securities in the offering described in the prospectus. As provided in Rule 430B, for liability purposes of the issuer and any person that is at that date an underwriter, such date shall be deemed to be a new effective date of the registration statement relating to the securities in the registration statement to which that prospectus relates, and the offering of such securities at that time shall be deemed to be the initial bona fide offering thereof; provided, however, that no statement made in a registration statement or prospectus that is part of the registration statement or made in a document incorporated or deemed incorporated by reference into the registration statement or prospectus that is part of the registration statement will, as to a purchaser with a time of contract of sale prior to such effective date, supersede or modify any statement that was made in the registration statement or prospectus that was part of the registration statement or made in any such document immediately prior to such effective date.

(5)That, for the purpose of determining liability of the Registrant under the Securities Act to any purchaser in the initial distribution of the securities, the undersigned Registrant undertakes that in a primary offering of securities of the undersigned Registrant pursuant to this registration statement, regardless of the underwriting method used to sell the securities to the purchaser, if the securities are offered or sold to such purchaser by means of any of the following communications, the undersigned Registrant will be a seller to the purchaser and will be considered to offer or sell such securities to such purchaser:

(i) any preliminary prospectus or prospectus of the undersigned Registrant relating to the offering required to be filed pursuant to Rule 424;

(ii) any free writing prospectus relating to the offering prepared by or on behalf of the undersigned Registrant or used or referred to by the undersigned Registrant;

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(iii) theportionofanyotherfreewritingprospectusrelatingtotheofferingcontainingmaterialinformationabouttheundersignedRegistrantoritssecuritiesprovidedbyoronbehalfoftheundersignedRegistrant;and

(iv) any other communication that is an offer in the offering made by the undersigned Registrant to the purchaser.

(b)The undersigned Registrant hereby undertakes that, for purposes of determining any liability under the Securities Act, each filing of theRegistrant’s annual report pursuant to Section 13(a) or Section 15(d) of the Exchange Act (and, where applicable, each filing of an employee benefitplan’s annual report pursuant to Section 15(d) of the Exchange Act) that is incorporated by reference in the registration statement shall be deemed to bea new registration statement relating to the securities offered therein, and the offering of such securities at that time shall be deemed to be the initialbonafideoffering thereof.

(c)The undersigned Registrant hereby undertakes to deliver or cause to be delivered with the prospectus, to each person to whom the prospectusis sent or given, the latest annual report, to security holders that is incorporated by reference in the prospectus and furnished pursuant to and meeting the requirements of Rule 14a-3 or Rule 14c-3 under the Exchange Act; and, where interim financial information required to be presented by Article 3 ofRegulation S-X is not set forth in the prospectus, to deliver, or cause to be delivered to each person to whom the prospectus is sent or given, the latestquarterlyreportthat is specificallyincorporatedbyreferenceintheprospectustoprovidesuch interimfinancial information.

(d)Insofar as indemnification for liabilities arising under the Securities Act may be permitted to directors, officers, and controlling persons of the Registrant pursuant to the foregoing provisions, or otherwise, the Registrant has been advised that in the opinion of the Securities and ExchangeCommission such indemnification is against public policy as expressed in the Securities Act and is, therefore, unenforceable. In the event that a claimfor indemnification against such liabilities (other than the payment by the Registrant of expenses incurred or paid by a director, officer, or controllingperson of the Registrant in the successful defense of any action, suit, or proceeding) is asserted by such director, officer, or controlling person inconnection with the securities being registered, the Registrant will, unless in the opinion of its counsel the matter has been settled by controllingprecedent, submit to a court of appropriate jurisdiction the question whether such indemnification by it is against public policy as expressed in theSecuritiesActand willbegovernedbythefinal adjudication ofsuch issue.

(e)If and when applicable, the Registrant hereby further undertakes to file an application for the purpose of determining the eligibility of thetrustee to act under subsection (a) of Section 310 of the Trust Indenture Act in accordance with the rules and regulations prescribed by the SEC underSection305(b)(2)of the Trust Indenture Act.

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SIGNATURES

Pursuant to the requirements of the Securities Act of 1933, the Registrant certifies that it has reasonable grounds to believe that it meets all of the requirements for filing on Form S-3 and has duly caused this Registration Statement to be signed on its behalf by the undersigned, thereunto dulyauthorized,in the city of Copenhagen, Denmark, on the 4th of November, 2021.

	Galecto, Inc.
Date: November 4, 2021	By:	/s/ Hans T. Schambye
		Hans T. Schambye, M.D., Ph.D.
		President, Chief Executive Officer and Director (Principal Executive Officer)

POWEROFATTORNEY

KNOW ALL PERSONS BY THESE PRESENTS, that each person whose signature appears below hereby constitutes and appoints Hans T. Schambye and Jonathan Freve, or each one of them individually, as the undersigned’s true and lawful attorney-in-fact and agents, with fullpower of substitution and resubstitution for each such person and in such person’s name, place and stead, in any and all capacities, to sign any and allamendments (including post-effective amendments, exhibits thereto, and other documents in connection therewith to this Registration Statement and any later registration statement filedby theregistrantunder Rule462(b) ofthe Securities Actof 1933,which relatesto this RegistrationStatement) and tofile the same with exhibits thereto and other documents in connection therewith with the Securities and Exchange Commission, granting unto saidattorney-in-fact and agent full power and authority to do and perform each and every act and thing requisite and necessary to be done, as fully to allintents and purposes as such person might or could do in person, hereby ratifying and confirming all that each of said attorney-in-fact and agent, or theirsubstituteorsubstitutesmay lawfullydo orcause tobedoneby virtuehereof.

Pursuant to the requirements of the Securities Act, this Registration Statement has been signed by the following persons in the capacities and onthedates indicated.

Signature	Title	Date
/s/ Hans T. Schambye	Chief Executive Officer and Director (PrincipalExecutiveOfficer)	November 4, 2021
Hans T. Schambye, M.D., Ph.D.
/s/ Jonathan Freve	ChiefFinancialOfficer (PrincipalFinancialandAccountingOfficer)	November 4, 2021
Jonathan Freve
/s/ Carl Goldfischer, M.D.	Chairman	November 4, 2021
Carl Goldfischer, M.D.
/s/ Jayson Dallas,M.D.	Director	November 4, 2021
Jayson Dallas,M.D.
/s/ Chau Q. Khuong	Director	November 4, 2021
Chau Q. Khuong
/s/ Søren Møller	Director	November 4, 2021
Søren Møller
/s/ Amit D. Munshi	Director	November 4, 2021
Amit D. Munshi

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Signature	Title	Date
/s/ Anne Prener	Director	November 4, 2021
Anne Prener
/s/ David Shapiro, M.D.	Director	November 4, 2021
David Shapiro, M.D.

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