sbph-424b5.htm

We have entered into a Controlled Equity Offering^SM Sales Agreement, or the Sales Agreement, with Cantor Fitzgerald & Co., or Cantor Fitzgerald, relating to shares of our common stock offered by this prospectus supplement and the accompanying prospectus. In accordance with the terms of the Sales Agreement, we may offer and sell shares of our common stock from time to time through Cantor Fitzgerald, acting as sales agent, having an aggregate offering price of up to $50,000,000, pursuant to this prospectus supplement and the accompanying prospectus.

Our common stock is listed on The NASDAQ Capital Market under the symbol “SBPH.” On August 17, 2017, the last reported sale price of our common stock was $13.15 per share.

Sales of our common stock, if any, under this prospectus supplement and the accompanying prospectus may be made by any method deemed to be an “at the market offering” as defined in Rule 415(a)(4) promulgated under the Securities Act of 1933, as amended, or the Securities Act. Subject to the terms of the Sales Agreement, Cantor Fitzgerald will act as sales agent and use commercially reasonable efforts to sell on our behalf all of the shares of common stock requested to be sold by us, consistent with its normal trading and sales practices, on mutually agreed terms between Cantor Fitzgerald and us. There is no arrangement for funds to be received in any escrow, trust or similar arrangement.

Cantor Fitzgerald is entitled to compensation at a commission rate of 3.0% of the gross sales price per share sold under the Sales Agreement. See “Plan of Distribution” beginning on page S-12 for additional information regarding the compensation to be paid to Cantor Fitzgerald. In connection with the sale of shares of our common stock on our behalf, Cantor Fitzgerald will be deemed to be an “underwriter” within the meaning of the Securities Act and the compensation of Cantor Fitzgerald will be deemed to be underwriting commissions or discounts.

We are an “emerging growth company” under the Jumpstart Our Business Startups Act of 2012 and applicable Securities and Exchange Commission rules, and, as such, have elected to comply with certain reduced public company reporting requirements for this prospectus supplement and future filings.

Investing in our securities involves a high degree of risk. Before deciding whether to invest in our securities, you should consider carefully the risks that we have described on page S-7 of this prospectus supplement under the caption “Risk Factors”, in the documents incorporated by reference into this prospectus supplement and on page 6 of the accompanying base prospectus.

Neither the Securities and Exchange Commission nor any state securities commission has approved or disapproved of these securities or determined if this prospectus supplement is truthful or complete. Any representation to the contrary is a criminal offense.

This prospectus supplement and the accompanying prospectus relate to the offering of our common stock. This prospectus supplement, the accompanying prospectus and any free writing prospectus we provide you, include or incorporate by reference important information about us, our common stock, and other matters you should know before investing. You should read this prospectus supplement, the accompanying prospectus and any free writing prospectus we provide you, as well as additional information described under “Where You Can Find More Information” and “Incorporation of Documents by Reference” in this prospectus supplement before making an investment decision.

This document is in two parts and is part of the registration statement (No. 333-218399) that we filed with the Securities and Exchange Commission, or the SEC, using a "shelf" registration process. The first part is this prospectus supplement, which describes the terms of this offering and also adds to and updates information contained in the accompanying prospectus and the documents incorporated by reference in this prospectus supplement and the accompanying prospectus. The second part, the accompanying prospectus dated June 12, 2017, including the documents incorporated by reference therein, provides more general information, some of which may not apply to this offering. Generally, when we refer to this prospectus, we are referring to both parts of this document combined. To the extent there is a conflict between the information contained in this prospectus supplement, on the one hand, and the information contained in the accompanying prospectus or in any document incorporated by reference herein or therein that was filed with the SEC before the date of this prospectus supplement, on the other hand, you should rely on the information in this prospectus supplement. 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 the accompanying prospectus—the statement in the document having the later date modifies or supersedes the earlier statement.

You should rely only on this prospectus supplement, the accompanying prospectus and the information incorporated or deemed to be incorporated by reference in herein or therein or in any free writing prospectuses we provide you. We have not, and Cantor Fitzgerald has not, authorized anyone to provide you with information that is in addition to, or different from, that contained or incorporated by reference in this prospectus supplement or the accompanying prospectus or contained in any free writing prospectus we provide you. If anyone provides you with different or inconsistent information, you should not rely on it. We are not, and Cantor Fitzgerald is not, offering to sell securities in any jurisdiction where the offer or sale of such securities is not permitted as of the time of such sale. You should not assume that the information contained or incorporated by reference in this prospectus supplement or the accompanying prospectus or contained in any free writing prospectus we provide you is accurate as of any date other than as of the date of these respective documents or in the case of the documents incorporated by reference, the date of such documents regardless of the time of delivery of this prospectus supplement, the accompanying prospectus or any free writing prospectus we provide you or any sale of our common shares. Our business, financial condition, liquidity, results of operations, and prospects may have changed since those dates.

We further note that the representations, warranties and covenants made by us in any agreement that is filed as an exhibit to the registration statement to which the accompanying prospectus forms a part or to any document that is incorporated by reference in this prospectus supplement or the accompanying prospectus were made solely for the benefit of the parties to such agreement, including, in some cases, for the purpose of allocating risk among the parties to such agreements, and should not be deemed to be a representation, warranty or covenant to you. Moreover, such representations, warranties or covenants were accurate only as of the date when made. Accordingly, such representations, warranties and covenants should not be relied on as accurately representing the current state of our affairs.

Unless the context otherwise requires, “Spring Bank Pharmaceuticals,” “the Company,” “we,” “us,” “our” and similar terms refer to Spring Bank Pharmaceuticals, Inc. and our subsidiaries. When we refer to “you” or “yours” we mean the investors and potential investors in the shares of common stock offered hereby.

Our trademarks include, without limitation, our name and corporate logo. Other service marks, trademarks and trade names contained in this prospectus supplement, the accompanying prospectus or the documents incorporated by reference herein and therein are the property of their respective owners.

The following is a summary of what we believe to be the most important aspects of our business and the offering of our securities under this prospectus supplement and the accompanying prospectus. We urge you to read this entire prospectus supplement and the accompanying prospectus, including the more detailed consolidated financial statements, notes to the consolidated financial statements and other information incorporated by reference from our other filings with the SEC, and the information included in any free writing prospectus we provide you. Investing in our securities involves risks. Therefore, carefully consider the risk factors set forth in this prospectus supplement, the accompanying prospectus and in any free writing prospectus we provide you, or incorporated by reference herein and therein, as well as other information in this prospectus supplement, the accompanying prospectus and in any free writing prospectus we provide you, as well as in the documents incorporated by reference herein and therein, before purchasing our securities. Each of the risk factors could adversely affect our business, operating results and financial condition, as well as adversely affect the value of an investment in our securities.

We are a clinical-stage biopharmaceutical company engaged in the discovery and development of a novel class of therapeutics using our proprietary small molecule nucleic acid hybrid, or SMNH, chemistry platform. Our SMNH compounds are small segments of nucleic acids that we design to selectively target and modulate the activity of specific proteins implicated in various disease states. We are developing our most advanced SMNH product candidate, SB 9200, for the treatment of certain viral diseases. We have designed SB 9200 to selectively activate– within infected cells the cellular proteins, retinoic acid-inducible gene 1 (RIG-I) and nucleotide-binding oligomerization domain-containing protein 2 (NOD2), to inhibit viral replication and to cause the induction of intracellular interferon signaling pathways for antiviral defense. We believe that SB 9200 may play an important role in antiviral therapy by modulating the body’s immune response through its mechanisms of action to fight viral infections. We are also developing other SMNH product candidates, including SB 11285, an immunotherapeutic agent for the treatment of selected cancers through the activation of the STimulator of INterferon Genes, or STING, pathway.

We are currently developing SB 9200 for the treatment of chronic hepatitis B virus, or HBV. We are conducting a Phase 2a multi-center clinical trial of SB 9200 in Canada, Hong Kong, Korea and Taiwan, which is the first segment of our Phase 2 ACHIEVE trial. The Phase 2a trial is a randomized, placebo-controlled, multiple ascending dose trial in up to 80 non-cirrhotic patients infected with chronic HBV using doses of 25 mg, 50 mg, 100 mg and 200 mg of SB 9200 as a monotherapy administered daily for 12 weeks. Following this treatment, all patients will receive treatment with the oral antiviral agent tenofovir disoproxil fumarate (marketed by Gilead Sciences, Inc., or Gilead, as Viread®, which we refer to as Viread) as a monotherapy for 12 weeks. Patients will be sequentially enrolled into one of the four dose cohorts and randomized between a SB 9200 dose group or placebo on a 4:1 basis. Patients are stratified based on HBeAg positive (+) or negative (–) status. HBeAg is a non-structural protein which is secreted by the virus and whose presence in blood, or HBeAg–positive, is indicative of wild type or non-mutated virus with high levels of viral replication. The loss of HBeAg occurs secondary to mutations in the virus and results in a patient becoming HBeAg–negative with a resulting lower level of actively replicating virus. The primary endpoints of the Phase 2a clinical trial are safety and antiviral activity, as measured by the change in HBV DNA at week 12 from baseline. Multiple exploratory secondary endpoints include reduction or loss of HBV surface antigen, or HBsAg, and HBeAg, quantitative HBV RNA as a marker for control of virus production and studies of immune activity.

In May 2017, we reported top-line results from the first SB 9200 monotherapy dosing cohort of the Phase 2a clinical trial indicating that a low dose (25mg) of SB 9200 alone showed a favorable safety profile and antiviral activity against HBV DNA and HBsAg. The first SB 9200 monotherapy dosing cohort consisted of 11 HBeAg-positive and 9 HBeAg–negative patients, of which 80% were genotype B/C, the most common Asian genotypes. Administration of SB 9200 resulted in a statistically significant reduction in HBV DNA at week 12 (unpaired t-test 2.85, p=0.01) compared to placebo, with a mean reduction of 0.6 log₁₀ (range 0 to 1.87 log₁₀) in the SB 9200 treatment group. For the secondary endpoint of reduction or loss of HBsAg, 5 of 16 patients (31%) in the SB 9200 treatment group had a greater than 0.5 log₁₀ reduction at any time point (range 0.52 to 1.01 log₁₀), compared to none in the placebo group. The 7 HBeAg–negative patients in the SB 9200 treatment group had the greatest mean reduction in HBV DNA at 0.9 log₁₀, and 3 of these 7 patients also had a greater than 0.5 log₁₀ reduction in HBsAg. The overall safety profile of SB 9200 was favorable with no serious adverse events observed during the 12-week study. Treatment-emergent adverse events ranged from mild to moderate in severity with no interferon-like side effects and were comparable to patients on placebo.

We expect to report top-line results from the second SB 9200 monotherapy dosing cohort (50mg) of the Phase 2a clinical trial in the fourth quarter of 2017, and to report top-line monotherapy results for all patients treated with SB 9200 alone in the first half of 2018. Subject to the complete results of the Phase 2a clinical trial, we expect to initiate a Phase 2b clinical trial in the second half of 2018 in patients with chronic HBV to explore the use of SB 9200 as a monotherapy and in combination with Viread. The Phase 2a

clinical trial is being conducted under our clinical trial supply and collaboration agreement with Gilead, and the Phase 2b clinical trial will be conducted under the same collaboration.

We are also pursuing the development of the co-formulation of SB 9200 with Viread and with entecavir (marketed as Baraclude®, which we refer to as Baraclude) as potential fixed-dose combination products for the treatment of patients with chronic HBV who may benefit from the combined use of SB 9200 as a potential immunomodulatory agent, and Baraclude or Viread, as the antiviral agent. We anticipate that the fixed-dose combination product could result in enhanced patient compliance and potentially allow for a more favorable safety profile. We have conducted early development work on co-formulations with Viread and believe that SB 9200 with Viread is compatible in the same formulation. We believe that the immunomodulatory activity provided by SB 9200 could become a key component of a future combinatorial treatment of patients infected with chronic HBV, which could increase the percentage of chronic HBV patients who achieve a functional cure.

We have entered into multiple collaborations and seek to enter into additional collaborations with third parties that are investigating and/or developing compounds for the treatment of chronic HBV with different pharmacological mechanisms of action than SB 9200. Pursuant to this strategy, in July 2017, we entered into a clinical trial supply and collaboration with Gilead under which Gilead will fund and conduct a Phase 2 trial examining the co-administration of SB 9200 and tenofovir alafenamide (marketed by Gilead as Vemlidy®) in patients infected with chronic HBV. We have also entered into agreements with other parties, including Arrowhead Pharmaceuticals, Inc. and Arbutus Biopharma Corporation.

We are developing SB 11285, a novel proprietary STING agonist, as a potential immunotherapeutic agent for the treatment of selected cancers. Recent published scientific literature indicates that the activation of the STING pathway can result in the induction of cellular interferons and cytokines and promote an aggressive and strong anti-tumor response through the induction of innate and adaptive immune response. In our preclinical studies performed in in vitro systems, SB 11285 has been observed to cause the induction of interferon and other cytokines, as well as cell death, or apoptosis, of multiple tumor-derived cell lines. We continue to conduct preclinical studies of SB 11285 in multiple in vivo cancer models. We presented data from in vivo studies in the A20 lymphoma and 4T1 breast cancer syngeneic mouse models at the March 2017 Cancer Immunology and Immunotherapy Keystone Symposia. In June 2017, an abstract was published at the American Society of Clinical Oncology (ASCO) Annual Meeting indicating that SB 11285 showed potent and highly-durable anti-tumor activity in the A20 and CT26 syngeneic mouse tumor models. The induction of immune-memory and abscopal anti-tumor activity upon intra-tumoral administration of SB 11285 was also observed in the A20 lymphoma model. In addition, SB 11285 exhibited dose-dependent, potent tumor growth inhibition and durable anti-tumor response upon intra-tumoral, intraperitoneal and intravenous routes of administration in the CT26 colon cancer syngeneic mouse model. In the orthotopic 4T1 breast cancer model, intraperitoneal administration of SB 11285 resulted in significant inhibition of primary tumor growth, as well as inhibition of tumor metastasis. We believe these preclinical studies demonstrate the potential for both intra-tumoral and systemic administration of SB 11285 to target a variety of tumors, which could potentially be used in combination with other therapeutic modalities.

We intend to continue the development of SB 11285 as a potentially important addition to the current standard of care in the treatment of various cancers that we believe could increase the treatment responses in patients. We intend to continue to advance the SB 11285 program with preclinical, toxicology, and process development efforts and hope to achieve further preclinical proof-of-principle for SB 11285 in relevant oncology models. Subject to the results of these preclinical studies, we hope to submit an investigational new drug application, or IND, and/or a clinical trial application, or CTA, for SB 11285 in mid-2018.

The following table summarizes the status of the development of our product candidates. We retain exclusive global commercial rights to all of our product candidates.


Product Candidate	Indication/ Therapeutic Area	Stage of Development	Anticipated Milestones

SB 9200	Chronic HBV	Phase 2	Top-line data on second monotherapy dosing cohort of Phase 2a clinical trial expected Q4 2017

	HBV/fixed dose combinations	Research	Establish preclinical proof-of-principle

	HBV/ collaborations for combination therapy	Research	Establish clinical & preclinical proof-of-principle

SB 11285	Immuno-oncology	Research	Advance to IND/CTA submission in mid-2018


SB 11177/11179	PDE4 inhibitors	Research	Establish preclinical proof-of-principle

We were incorporated under the laws of the Commonwealth of Massachusetts as Spring Bank Technologies, Inc. on October 7, 2002. On May 12, 2008, we filed a certificate of incorporation in the State of Delaware and changed our state of incorporation to Delaware and our name to Spring Bank Pharmaceuticals, Inc. Our principal executive offices are located at 86 South Street, Hopkinton, MA 01748, and our telephone number is (508) 473-5993. Our website address is www.springbankpharm.com. The information contained in, or accessible through, our website does not constitute a part of this prospectus supplement or the accompanying prospectus.

The Jumpstart Our Business Startups Act of 2012, or the JOBS Act, was enacted in April 2012 with the intention of encouraging capital formation in the United States and reducing the regulatory burden on newly public companies that qualify as “emerging growth companies.” We are an emerging growth company within the meaning of the JOBS Act. As an emerging growth company, we may take advantage of certain exemptions from various public reporting requirements, including the requirement that our internal control over financial reporting be audited by our independent registered public accounting firm pursuant to Section 404 of the Sarbanes-Oxley Act of 2002, certain requirements related to the disclosure of executive compensation in this prospectus supplement and in our periodic reports and proxy statements, and the requirement that we hold a nonbinding advisory vote on executive compensation and any golden parachute payments. We may choose to take advantage of some, all or none of these reduced burdens until we are no longer an emerging growth company. As a result, the information that we provide to our stockholders may be different than you might receive from other public reporting companies in which you hold equity interests.

Section 102(b)(1) of the JOBS Act exempts emerging growth companies from being required to comply with new or revised financial accounting standards until private companies (that is, those that have not had a registration statement under the Securities Act declared effective or do not have a class of securities registered under the Securities Exchange Act of 1934, as amended, or the Exchange Act) are required to comply with the new or revised financial accounting standard. We have chosen to “opt out” of the extended transition periods available under the JOBS Act for complying with new or revised accounting standards. Section 107 of the JOBS Act provides that our decision to opt out of the extended transition periods for complying with new or revised accounting standards is irrevocable.

THE OFFERING

The following summary contains basic information about our common stock and the offering and is not intended to be complete. It does not contain all the information that may be important to you. For a more complete understanding of our common stock, you should read this prospectus supplement and the accompanying prospectus and the documents referred to herein and therein.


Issuer	Spring Bank Pharmaceuticals, Inc.
Common stock offered by us	Shares of our common stock having an aggregate offering price of up to $50,000,000.
Common stock to be outstanding after this offering	Up to 16,497,738 shares (as more fully described in the notes following this table), assuming sales of 3,802,281 shares of our common stock in this offering at an assumed offering price of $13.15 per share, which was the last reported sale price of our common stock on the NASDAQ Capital Market on August 17, 2017. The actual number of shares issued in connection with this offering will vary depending on how many shares of our common stock we choose to sell and the prices at which such sales occur.
Plan of Distribution	Sales of shares of our common stock under this prospectus supplement and the accompanying prospectus may be made by any method deemed to be an “at the market offering” as defined in Rule 415(a)(4) under the Securities Act. Subject to the terms of the Sales Agreement, Cantor Fitzgerald will make all sales using commercially reasonable efforts consistent with its normal trading and sales practices and applicable state and federal laws, rules and regulations and the rules of The NASDAQ Capital Market, on mutually agreeable terms between Cantor Fitzgerald and us. See “Plan of Distribution” beginning on page S-12 of this prospectus supplement.
Sales agent	Cantor Fitzgerald
Use of Proceeds	We currently intend to use the net proceeds from this offering, if any, for working capital and general corporate purposes. See “Use of Proceeds” beginning on page S-10 of this prospectus supplement.
Risk Factors	Your investment in shares of our common stock involves substantial risks. You should consider the matters referred to under the heading “Risk Factors” in this prospectus supplement and the accompanying prospectus, including the risk factors incorporated by reference herein and therein from our filings with the SEC.
NASDAQ Capital Market symbol	“SBPH”

The number of shares of our common stock to be outstanding after this offering is based on 12,695,457 shares of our common stock issued and outstanding as of June 30, 2017 and excludes:

•

977,565 shares of our common stock issuable upon the exercise of stock options outstanding as of June 30, 2017, at a weighted-average exercise price of $10.78 per share;

•

1,798,084 shares of our common stock issuable upon the exercise of warrants outstanding as of June 30, 2017, at a weighted-average exercise price of $11.22 per share; and

•

473,668 shares of common stock available for future issuance under our 2015 Stock Incentive Plan as of June 30, 2017.

An investment in our common stock involves risks. You should carefully consider the risks described below, as well as the other information included or incorporated by reference in this prospectus supplement and the accompanying prospectus, including “Risk Factors” included in our Annual Report on Form 10-K for the year ended December 31, 2016, filed with the SEC on February 14, 2017 and our Quarterly Report on Form 10-Q for the quarter ended June 30, 2017, filed with the SEC on July 31, 2017, and in any subsequent Annual Reports on Form 10-K, Quarterly Reports on Form 10-Q and Current Reports on Form 8-K, before making an investment decision. In addition, please read “About this Prospectus Supplement” in this prospectus supplement and “Special Note Regarding Forward-Looking Statements” in this prospectus supplement, where we describe additional uncertainties associated with our business and the forward-looking statements included or incorporated by reference in this prospectus supplement and the accompanying prospectus. If any of these risks occur, our business, financial condition, results of operations and future growth prospects could be materially and adversely affected. In these circumstances, the market price of our common stock could decline, and you may lose all or part of your investment. Please note that additional risks not currently known to us or that we currently deem immaterial may also impair our business and operations.

The assumed offering price per share of our common stock in this offering is substantially higher than the current net tangible book value per share of our common stock. Therefore, if you purchase shares of our common stock in this offering, you will pay a price per share that substantially exceeds our net tangible book value per share after this offering. Assuming the sale of $50,000,000 of our common stock in this offering, based on the assumed offering price of $13.15 per share, which was the last reported sale price of our common stock on the NASDAQ Capital Market on August 17, 2017, and net tangible book value per share of our common stock of $3.33 as of June 30, 2017, if you purchase shares in this offering, you will suffer immediate and substantial dilution of $7.66 per share in the as adjusted net tangible book value of common stock purchased. See “Dilution” beginning on page S-11 of this prospectus supplement for a more detailed description of the dilution to new investors in this offering.

We have broad discretion in the use of net proceeds from this offering and may not use them effectively.

We currently intend to use the net proceeds, if any, from this offering for working capital and general corporate purposes. See “Use of Proceeds” beginning on page S-10 of this prospectus supplement for further detail. Although we currently intend to use the net proceeds, if any, from this offering in such a manner, we will have broad discretion in the application of such net proceeds. Our failure to apply these funds effectively could result in unfavorable returns and uncertainty about our prospects, each of which could cause the price of our common stock to decline. Pending their use, we may invest the net proceeds from this offering in a manner that does not produce income or loses value.

To raise additional capital, we may in the future offer additional shares of our common stock or other securities convertible into or exchangeable for our common stock at prices that may not be the same as the price per share in this offering. We may sell shares or other securities in any other offering at a price per share that is less than the price per share paid by investors in this offering, and investors purchasing shares or other securities in the future could have rights superior to existing stockholders. The price per share at which we sell additional shares of our common stock, or securities convertible or exchangeable into common stock, in future transactions may be higher or lower than the price per share paid by investors in this offering.

Sales of a significant number of shares of our common stock in the public markets, or the perception that such sales could occur, could depress the market price of our common stock.

Sales of a substantial number of shares of our common stock in the public markets could occur at any time and could depress the market price of our common stock and impair our ability to raise capital through the sale of additional equity or equity-based securities. We cannot predict the effect that future sales of our common stock would have on the market price of our common stock.

Because we have no current plans to pay cash dividends on our common stock for the foreseeable future, you may not receive any return on investment unless you sell your common stock for a price greater than that which you paid for it.

We intend to retain future earnings, if any, for future operations and expansion of our business and have no current plans to pay any cash dividends for the foreseeable future. The declaration, amount and payment of any future dividends on shares of common stock will be at the sole discretion of our Board of Directors. Our Board of Directors may take into account general and economic conditions, our financial condition, and results of operations, our available cash and current and anticipated cash needs, capital

requirements, contractual, legal, tax and regulatory restrictions, implications on the payment of dividends by us to our stockholders or by our subsidiaries to us and such other factors as our Board of Directors may deem relevant. In addition, our ability to pay dividends is limited by covenants of our existing and outstanding indebtedness and may be limited by covenants of any future indebtedness we or our subsidiaries incur. As a result, you may not receive any return on an investment in our common stock unless you sell our common stock for a price greater than that which you paid for it.

This prospectus supplement, the accompanying prospectus and the information incorporated by reference herein and therein include “forward-looking statements” within the meaning of Section 27A of the Securities Act of 1933, as amended, or the Securities Act, and Section 21E of the Exchange Act. All statements, other than statements of historical facts, included in this prospectus supplement, the accompanying prospectus and the information incorporated by reference herein and therein regarding our strategy, future operations, future financial position, future revenue, projected costs, prospects, plans, objectives of management and expected market growth are forward-looking statements. The words “anticipate,” “believe,” “contemplate,” “estimate,” “expect,” “forecast,” “intend,” “may,” “plan,” “predict,” “project,” “target,” “potential,” “will,” “would,” “could,” “should,” “continue” and similar expressions are intended to identify forward-looking statements, although not all forward-looking statements contain these identifying words. These forward-looking statements include, among other things, statements about:

We may not actually achieve the plans, intentions or expectations disclosed in our forward-looking statements, and you should not place undue reliance on our forward-looking statements. Actual results or events could differ materially from the plans, intentions and expectations disclosed in the forward-looking statements we make. We have included important factors in the cautionary statements included in this prospectus supplement, the accompanying prospectus, and the information incorporated by reference herein and therein, particularly in the “Risk Factors” sections of this prospectus supplement, the accompanying prospectus and of our Annual Report on Form10-K for the year ended December 31, 2016 and Quarterly Report on Form 10-Q for the quarter ended June 30, 2017, which are incorporated by reference herein, that could cause actual results or events to differ materially from the forward-looking statements that we make. Our forward-looking statements do not reflect the potential impact of any future acquisitions, mergers, dispositions, joint ventures or investments that we may make.

We may issue and sell shares of our common stock having aggregate gross sales proceeds of up to $50,000,000 from time to time under this prospectus supplement and the accompanying prospectus. Because there is no minimum offering amount required pursuant to the Sales Agreement with Cantor Fitzgerald, the actual total public offering amount, commissions and proceeds to us, if any, are not determinable at this time. Actual net proceeds will depend on the number of shares we sell and the prices at which such sales occur. There can be no assurance that we will sell any shares under or fully utilize the Sales Agreement with Cantor Fitzgerald as a source of financing.

We currently intend to use the net proceeds, if any, from sales of shares of our common stock covered by this prospectus supplement and the accompanying prospectus for working capital and general corporate purposes, which may include, among other things, the funding of capital and other expenditures, including to expand our manufacturing capabilities, and the acquisition or in-license of additional drugs, product candidates or technology.

Our expected use of net proceeds, if any, from the sale of shares of common stock pursuant to the Sales Agreement with Cantor Fitzgerald represents our intentions based upon our present plans and business conditions as of the date of this prospectus supplement, which could change in the future as our plans and business conditions evolve. The amounts and timing of our actual expenditures will depend upon numerous factors, including, but not limited to:

As a result, our management will have broad discretion over the use of the net proceeds from this offering, if any. We may temporarily invest the net proceeds in investment-grade, interest-bearing securities pending their use for the purposes described above. We have not determined the amount of net proceeds to be used specifically for such purposes and, as a result, management will retain broad discretion over the allocation of net proceeds from this offering, if any.

If you invest in this offering, your ownership interest will be diluted to the extent of the difference between the public offering price per share and the as adjusted net tangible book value per share after giving effect to this offering. We calculate net tangible book value per share by dividing the net tangible book value, which is tangible assets less total liabilities, by the number of outstanding shares of our common stock. Dilution represents the difference between the amount per share paid by purchasers of shares in this offering and the as adjusted net tangible book value per share of our common stock immediately after giving effect to this offering. Our net tangible book value as of June 30, 2017 was approximately $42.2 million, or $3.33 per share.

After giving effect to the sale of our common stock pursuant to this prospectus supplement and accompanying prospectus in the aggregate amount of $50,000,000 at an assumed offering price of $13.15 per share, which was the last reported sale price of our common stock on the NASDAQ Capital Market on August 17, 2017, and after deducting offering commissions and estimated expenses payable by us in the aggregate, our net tangible book value as of June 30, 2017 would have been $90.6 million, or $5.49 per share of common stock. This represents an immediate increase in the net tangible book value of $2.16 per share to our existing stockholders and an immediate dilution in net tangible book value of $7.66 per share to new investors. The following table illustrates this per share dilution:

Assumed offering price per share			$	13.15
Net tangible book value per share as of June 30, 2017	$	3.33
Increase per share attributable to this offering		2.16

As adjusted net tangible book value per share as of June 30, 2017 after giving effect to this offering				5.49

Dilution per share to new investors in this offering			$	7.66

The table above assumes for illustrative purposes that an aggregate of 3,802,281 shares of our common stock are sold at a price of $13.15 per share, which was the last reported sale price of our common stock on the NASDAQ Capital Market on August 17, 2017, for aggregate gross proceeds of $50,000,000. The shares sold in this offering, if any, will be sold from time to time at various prices. An increase of $1.00 per share in the price at which the shares are sold from the assumed offering price of $13.15 per share shown in the table above, assuming all of our common stock in the aggregate amount of $50,000,000 during the term of the Sales Agreement with Cantor Fitzgerald is sold at that price, would increase our as adjusted net tangible book value per share after the offering to $5.58 per share and would increase the dilution in net tangible book value per share to new investors in this offering to $8.57 per share, after deducting offering commissions and estimated expenses payable by us. A decrease of $1.00 per share in the price at which the shares are sold from the assumed offering price of $13.15 per share shown in the table above, assuming all of our common stock in the amount of $50,000,000 during the term of the Sales Agreement with Cantor Fitzgerald is sold at that price, would decrease our as adjusted net tangible book value per share after the offering to $5.39 per share and would decrease the dilution in net tangible book value per share to new investors in this offering to $6.76 per share, after deducting offering commissions and estimated offering expenses payable by us. This information is supplied for illustrative purposes only and may differ based on the actual offering price and the actual number of shares offered.

The above discussion and table are based on 12,695,457 shares of our common stock issued and outstanding as of June 30, 2017 and exclude:

To the extent that any options are exercised, new equity awards are granted under our equity incentive plans or we otherwise issue additional shares of common stock in the future, investors purchasing shares in this offering could experience further dilution. In addition, we may choose to raise additional capital due to market conditions or strategic considerations, even if we believe we have sufficient funds for our current or future operating plans. To the extent that additional capital is raised through the sale of equity or equity-based securities, the issuance of these securities could result in further dilution to our stockholders.

We have entered into a Controlled Equity Offering^SM Sales Agreement, or the Sales Agreement, with Cantor Fitzgerald & Co., or Cantor Fitzgerald, under which we may offer and sell shares of our common stock having an aggregate gross sales price of up to $50,000,000 from time to time through Cantor Fitzgerald acting as agent. The Sales Agreement has been filed as an exhibit to a Current Report on Form 8-K and incorporated by reference into this prospectus supplement and the accompanying prospectus.

Upon delivery of a placement notice and subject to the terms and conditions of the Sales Agreement, Cantor Fitzgerald may offer and sell shares of our common stock by any method permitted by law deemed to be an “at the market offering” as defined in Rule 415(a)(4) promulgated under the Securities Act. We may instruct Cantor Fitzgerald not to sell common stock if the sales cannot be effected at or above the price designated by us from time to time. We or Cantor Fitzgerald may suspend the offering of common stock upon notice and subject to other conditions.

We will pay Cantor Fitzgerald commissions, in cash, for its services in acting as agent in the sale of our common stock. Cantor Fitzgerald is entitled to compensation at a commission rate of 3.0% of the gross sales price per share sold under the Sales Agreement. 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. We have also agreed to reimburse Cantor Fitzgerald for certain specified expenses, including the reasonable and documented fees and disbursements of its legal counsel in an amount not to exceed $50,000. We estimate that the total expenses for the offering under this prospectus supplement, excluding compensation and reimbursements payable to Cantor Fitzgerald under the terms of the Sales Agreement, will be approximately $125,000.

Settlement for sales of shares of common stock will occur on the third business day following the date on which any sales are made (or the second business day following the date on which any such sales are made, if such sales are made on or after September 5, 2017), or on some other date that is agreed upon by us and Cantor Fitzgerald in connection with a particular transaction, in return for payment of the net proceeds to us. Sales of our 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 Cantor Fitzgerald may agree upon. There is no arrangement for funds to be received in an escrow, trust or similar arrangement.

Cantor Fitzgerald will use its commercially reasonable efforts, consistent with its sales and trading practices, to solicit offers to purchase the shares of common stock under the terms and subject to the conditions set forth in the Sales Agreement. In connection with the sale of the shares of common stock on our behalf, Cantor Fitzgerald will be deemed to be an “underwriter” within the meaning of the Securities Act and the compensation of Cantor Fitzgerald will be deemed to be underwriting commissions or discounts. We have agreed to provide indemnification and contribution to Cantor Fitzgerald against certain civil liabilities, including liabilities under the Securities Act.

The offering of shares of our common stock pursuant to the Sales Agreement will terminate upon the termination of the Sales Agreement as permitted therein. We and Cantor Fitzgerald may each terminate the Sales Agreement at any time upon ten days’ prior notice.

Cantor Fitzgerald and its affiliates may in the future provide various investment banking, commercial banking and other financial services for us and our affiliates, for which services they may in the future receive customary fees. To the extent required by Regulation M, Cantor Fitzgerald will not engage in any market making activities involving our common stock while the offering is ongoing under this prospectus supplement.

This prospectus supplement and the accompanying prospectus in electronic format may be made available on a website maintained by Cantor Fitzgerald and Cantor Fitzgerald may distribute this prospectus supplement and the accompanying prospectus electronically.

The validity of the shares of common stock offered hereby will be passed upon for us by Mintz, Levin, Cohn, Ferris, Glovsky and Popeo, P.C., Boston, Massachusetts. Cantor Fitzgerald is being represented in connection with this offering by Latham & Watkins LLP, San Diego, California.

The consolidated financial statements of Spring Bank Pharmaceuticals, Inc. and its subsidiaries as of December 31, 2016 and 2015 and for each of the years in the two-year period ended December 31, 2016 incorporated in this prospectus supplement by reference from the Spring Bank Pharmaceuticals, Inc. Annual Report on Form 10-K for the year ended December 31, 2016 have been audited by RSM US LLP, an independent registered public accounting firm, as stated in their report thereon incorporated herein by reference, and have been incorporated in this prospectus supplement and registration statement in reliance upon such report and upon the authority of such firm as experts in accounting and auditing.

We have filed with the SEC a registration statement on Form S-3 under the Securities Act with respect to the securities offered by this prospectus supplement. This prospectus supplement and the accompanying prospectus, which are part of the registration statement, omits certain information, exhibits, schedules and undertakings set forth in the registration statement, as permitted by the SEC. For further information pertaining to us and the securities offered in this prospectus supplement, reference is made to that registration statement and the exhibits and schedules to the registration statement. Statements contained in this prospectus supplement and the accompanying prospectus as to the contents or provisions of any documents referred to in this prospectus are not necessarily complete, and in each instance where a copy of the document has been filed as an exhibit to the registration statement, reference is made to the exhibit for a more complete description of the matters involved.

We are subject to the reporting requirements of the Exchange Act and file annual, quarterly and current reports, proxy statements and other information with the SEC. You may read and copy these reports, proxy statements and other information at the SEC’s public reference facilities at 100 F Street, N.E., Room 1580, Washington, D.C. 20549. You can request copies of these documents by writing to the SEC and paying a fee for the copying cost. Please call the SEC at 1-800-SEC-0330 for more information about the operation of the public reference facilities. SEC filings are also available at the SEC’s web site at http://www.sec.gov. Our common stock is listed on The NASDAQ Capital Market, and you can read and inspect our filings at the offices of the Financial Industry Regulatory Authority at 1735 K Street, Washington, D.C. 20006.

Our common stock is listed on the NASDAQ Capital Market under the symbol “SBPH.” General information about our company, including our Annual Report on Form 10-K, Quarterly Reports on Form 10-Q and Current Reports on Form 8-K, as well as any amendments and exhibits to those reports, are available free of charge through our website at www.springbankpharm.com as soon as reasonably practicable after we file them with, or furnish them to, the SEC. Information on, or than can be accessed through, our website is not incorporated into this prospectus supplement or other securities filings and is not a part of these filings.

The SEC allows us to incorporate by reference in this prospectus supplement and the accompanying prospectus much of the information we file with the SEC, which means that we can disclose important information to you by referring you to those publicly available documents. The information that we incorporate by reference in this prospectus supplement and the accompanying prospectus is considered to be part of this prospectus supplement and the accompanying prospectus. Because we are incorporating by reference future filings with the SEC, this prospectus supplement and the accompanying prospectus is continually updated and those future filings may modify or supersede some of the information included or incorporated in this prospectus supplement and the accompanying prospectus. This means that you must look at all of the SEC filings that we incorporate by reference to determine if any of the statements in this prospectus supplement, the accompanying prospectus or in any document previously incorporated by reference have been modified or superseded. This prospectus supplement and the accompanying prospectus incorporate by reference the documents listed below (File No. 001-37718) and any future filings we make with the SEC under Sections 13(a), 13(c), 14 or 15(d) of the Exchange Act (in each case, other than those documents or the portions of those documents not deemed to be filed) until the offering of the securities under the registration statement is terminated or completed:

Any statement contained in this prospectus supplement or in a document incorporated or deemed to be incorporated by reference into this prospectus supplement will be deemed to be modified or superseded for purposes of this prospectus supplement to the extent that a statement contained in this prospectus supplement or any other subsequently filed document that is deemed to be incorporated by reference into this prospectus supplement modifies or supersedes the statement. Any statement so modified or superseded will not be deemed, except as so modified or superseded, to constitute a part of this prospectus supplement.

You may request, orally or in writing, a copy of any or all of the documents incorporated herein by reference. These documents will be provided to you at no cost, by contacting:

Spring Bank Pharmaceuticals, Inc.
86 South Street
Hopkinton, Massachusetts 01748
Attention: Corporate Secretary
Telephone: (508) 473-5993

You should rely only on information contained in, or incorporated by reference into, this prospectus supplement. We have not authorized anyone to provide you with information different from that contained in this prospectus supplement or incorporated by reference in this prospectus supplement. We are not making offers to sell the securities in any jurisdiction in which such an offer or solicitation is not authorized or in which the person making such offer or solicitation is not qualified to do so or to anyone to whom it is unlawful to make such offer or solicitation.

This prospectus will allow us to issue, from time to time at prices and on terms to be determined at or prior to the time of the offering, up to $150,000,000 of any combination of the securities described in this prospectus, either individually or in units. We may also offer common stock or preferred stock upon conversion of or exchange for the debt securities; common stock upon conversion of or exchange for the preferred stock; common stock, preferred stock or debt securities upon the exercise of warrants, rights or performance of purchase contracts; or any combination of these securities upon the performance of purchase contracts.

This prospectus describes the general terms of these securities and the general manner in which these securities will be offered. We will provide you with the specific terms of any offering in one or more supplements to this prospectus. The prospectus supplements will also describe the specific manner in which these securities will be offered and may also supplement, update or amend information contained in this document. You should read this prospectus and any prospectus supplement, as well as any documents incorporated by reference into this prospectus or any prospectus supplement, carefully before you invest.

Our securities may be sold directly by us to you, through agents designated from time to time or to or through underwriters or dealers. For additional information on the methods of sale, you should refer to the section entitled “Plan of Distribution” in this prospectus and in the applicable prospectus supplement. If any underwriters or agents are involved in the sale of our securities with respect to which this prospectus is being delivered, the names of such underwriters or agents and any applicable fees, commissions or discounts and over- allotment options will be set forth in a prospectus supplement. The price to the public of such securities and the net proceeds that we expect to receive from such sale will also be set forth in a prospectus supplement.

Our common stock is listed on The NASDAQ Capital Market under the symbol “SBPH.” On May 31, 2017, the last reported sale price of our common stock was $12.41 per share. The applicable prospectus supplement will contain information, where applicable, as to any other listing, if any, on The NASDAQ Capital Market or any securities market or other securities exchange of the securities covered by the prospectus supplement. Prospective purchasers of our securities are urged to obtain current information as to the market prices of our securities, where applicable.

Investing in our securities involves a high degree of risk. Before deciding whether to invest in our securities, you should consider carefully the risks that we have described on page 6 of this prospectus under the caption “Risk Factors.” We may include specific risk factors in supplements to this prospectus under the caption “Risk Factors.” This prospectus may not be used to sell our securities unless accompanied by a prospectus supplement.

Neither the Securities and Exchange Commission nor any state securities commission has approved or disapproved of these securities or determined if this prospectus is truthful or complete. Any representation to the contrary is a criminal offense.

This prospectus is part of a registration statement that we filed with the Securities and Exchange Commission, or SEC, utilizing a “shelf” registration process. Under this shelf registration process, we may offer shares of our common stock and preferred stock, various series of debt securities and/or warrants, rights or purchase contracts to purchase any of such securities, either individually or in units, in one or more offerings, with a total value of up to $150,000,000. This prospectus provides you with a general description of the securities we may offer. Each time we offer a type or series of securities under this prospectus, we will provide a prospectus supplement that will contain specific information about the terms of that offering.

This prospectus does not contain all of the information included in the registration statement. For a more complete understanding of the offering of the securities, you should refer to the registration statement, including its exhibits. The prospectus supplement may also add, update or change information contained or incorporated by reference in this prospectus. However, no prospectus supplement will offer a security that is not registered and described in this prospectus at the time of its effectiveness. This prospectus, together with the applicable prospectus supplements and the documents incorporated by reference into this prospectus, includes all material information relating to the offering of securities under this prospectus. You should carefully read this prospectus, the applicable prospectus supplement, the information and documents incorporated herein by reference and the additional information under the heading “Where You Can Find More Information” before making an investment decision.

You should rely only on the information we have provided or incorporated by reference in this prospectus or any prospectus supplement. We have not authorized anyone to provide you with information different from that contained or incorporated by reference in this prospectus. No dealer, salesperson or other person is authorized to give any information or to represent anything not contained or incorporated by reference in this prospectus. You must not rely on any unauthorized information or representation. This prospectus is an offer to sell only the securities offered hereby, but only under circumstances and in jurisdictions where it is lawful to do so. You should assume that the information in this prospectus or any prospectus supplement is accurate only as of the date on the front of the document and that any information we have incorporated herein by reference is accurate only as of the date of the document incorporated by reference, regardless of the time of delivery of this prospectus or any sale of a security.

We further note that the representations, warranties and covenants made by us in any agreement that is filed as an exhibit to any document that is incorporated by reference in the accompanying prospectus were made solely for the benefit of the parties to such agreement, including, in some cases, for the purpose of allocating risk among the parties to such agreements, and should not be deemed to be a representation, warranty or covenant to you. Moreover, such representations, warranties or covenants were accurate only as of the date when made. Accordingly, such representations, warranties and covenants should not be relied on as accurately representing the current state of our affairs.

This prospectus may not be used to consummate sales of our securities, unless it is accompanied by a prospectus supplement. To the extent there are inconsistencies between any prospectus supplement, this prospectus and any documents incorporated by reference, the document with the most recent date will control.

Unless the context otherwise requires, “Spring Bank,” “SBPH,” “the Company,” “we,” “us,” “our” and similar terms refer to Spring Bank Pharmaceuticals, Inc. and our subsidiaries.

PROSPECTUS SUMMARY

The following is a summary of what we believe to be the most important aspects of our business and the offering of our securities under this prospectus. We urge you to read this entire prospectus, including the more detailed consolidated financial statements, notes to the consolidated financial statements and other information incorporated by reference from our other filings with the SEC or included in any applicable prospectus supplement. Investing in our securities involves risks. Therefore, carefully consider the risk factors set forth in any prospectus supplements and in our most recent annual and quarterly filings with the SEC, as well as other information in this prospectus and any prospectus supplements and the documents incorporated by reference herein or therein, before purchasing our securities. Each of the risk factors could adversely affect our business, operating results and financial condition, as well as adversely affect the value of an investment in our securities.

About Spring Bank Pharmaceuticals

We are a clinical-stage biopharmaceutical company engaged in the discovery and development of a novel class of therapeutics using our proprietary small molecule nucleic acid hybrid, or SMNH, chemistry platform. Our SMNH compounds are small segments of nucleic acids that we design to selectively target and modulate the activity of specific proteins implicated in various disease states. We are developing our most advanced SMNH product candidate, SB 9200, for the treatment of certain viral diseases. We have designed SB 9200 to selectively activate within infected cells the cellular proteins, retinoic acid-inducible gene 1 (RIG-I) and nucleotide-binding oligomerization domain-containing protein 2 (NOD2), to inhibit viral replication and to cause the induction of intracellular interferon signaling pathways for antiviral defense. We believe that SB 9200 may play an important role in antiviral therapy by modulating the body’s immune response through its mechanisms of action to fight viral infections. We are also developing other SMNH product candidates, including SB 11285, an immunotherapeutic agent for the treatment of selected cancers through the activation of the STimulator of INterferon Genes, or STING, pathway.

SB 9200

We are currently developing SB 9200 for the treatment of chronic hepatitis B virus, or HBV. We are conducting a Phase 2a multi-center clinical trial of SB 9200 in Canada, Hong Kong, Korea and Taiwan. The trial is a randomized, placebo-controlled, multiple ascending dose trial in up to 80 non-cirrhotic patients infected with chronic HBV using doses of 25 mg, 50 mg, 100 mg and 200 mg of SB 9200 as a monotherapy administered daily for 12 weeks. Following this treatment, all patients will receive treatment with the oral antiviral agent tenofovir disoproxil fumarate (marketed as Viread®, which we refer to as Viread) as a monotherapy for 12 weeks. Patients will be sequentially enrolled into one of the four dose cohorts and randomized between a SB 9200 dose group or placebo on a 4:1 basis. Patients will be stratified based on HBeAg+/- status. HBeAg is a non-structural protein whose presence in blood, or HBeAg+, is indicative of actively replicating virus. The primary endpoints of the Phase 2a clinical trial are safety and reduction in HBV DNA from pre-treatment levels with multiple exploratory secondary endpoints, including reduction or loss of hepatitis B surface antigen, or HBsAg, and HBeAg, both of which are important markers of viral replication and early surrogate markers for functional cure. In June 2016, we initiated our Phase 2a ACHIEVE clinical trial in non-cirrhotic patients infected with chronic HBV, and in May 2017, we reported top-line results from the first SB 9200 monotherapy dosing cohort of the Phase 2a clinical trial, which indicated that a low dose (25mg) of SB 9200 alone showed a favorable safety profile and antiviral activity against HBV DNA and HBsAg.

We are also pursuing the development of the co-formulation of SB 9200 with entecavir (marketed as Baraclude®, which we refer to as Baraclude) and Viread as potential fixed-dose combination products for the treatment of patients with chronic HBV who may benefit from the combined use of SB 9200 as an immunomodulatory agent, and Baraclude or Viread, as the antiviral agent. We anticipate that the fixed-dose combination product could result in enhanced patient compliance and potentially allow for the delivery of lower doses of the individual compounds for equivalent efficacy and a more favorable safety profile. We have conducted early development work on co-formulations with Baraclude and Viread and believe that SB 9200 and these antiviral agents are compatible in the same formulation. We believe that the immunomodulatory activity provided by SB 9200 could be a key component of a future combinatorial treatment of patients infected with chronic HBV, which could increase the percentage of chronic HBV patients who achieve a functional cure. We have entered into collaborations and seek to enter into additional collaborations with third parties that are investigating and/or developing compounds for the treatment of chronic HBV with different pharmacological mechanisms of action than

SB 9200. Pursuant to this strategy, we entered into agreements with Arrowhead Pharmaceuticals, Inc. and Arbutus Biopharma Corporation.

SB 11285

Additional Information

For additional information related to our business and operations, please refer to the reports incorporated herein by reference, including our Annual Report on Form 10-K for the year ended December 31, 2016, as described under the caption “Incorporation of Documents by Reference” on page 28 of this prospectus.

Risks Associated with Our Business

Our business is subject to numerous risks and uncertainties, including those highlighted in the section entitled “Risk Factors” immediately following this prospectus summary. Some of these risks are:

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we have a history of limited operations, have incurred significant losses since our inception, expect to incur losses for the foreseeable future and may never achieve or maintain profitability;

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we will need additional funding to complete the development of our product candidates and, if our products are approved by the FDA or other applicable regulatory authorities, before we can expect to become profitable from the commercial sale of our products. If we are unable to raise capital when needed, we could be forced to delay, reduce or eliminate our product development programs or commercialization efforts;

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our business currently depends substantially on the success of clinical trials for SB 9200, which is still under development. If we are unable to obtain regulatory approval for, or successfully commercialize SB 9200, our business will be materially harmed;

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we are very early in our development efforts and our product candidates may not be successful in later stage clinical trials. As a result, they may never be approved as marketable therapeutics;

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we rely, and expect to continue to rely, on third parties to conduct our clinical trials and to manufacture our product candidates for preclinical and clinical testing. These third parties may not perform satisfactorily, which could delay our product development activities;

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if we are unable to adequately protect our proprietary technology, or obtain and maintain issued patents which are sufficient to protect our product candidates, others could compete against us more directly, which would have a material adverse impact on our business, results of operations, financial condition and prospects; and

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we may not be able to retain key executives or to attract, retain and motivate key personnel.

It is difficult to predict the time and cost of product candidate development and subsequently obtaining regulatory approval.

Our Corporate Information

(508) 473-5993. Our website address is www.springbankpharm.com. The information contained in, or accessible through, our website does not constitute a part of this prospectus.

All brand names or trademarks appearing in this prospectus are the property of their respective holders. Use or display by us of other parties’ trademarks, trade dress, or products in this prospectus is not intended to, and does not, imply a relationship with, or endorsements or sponsorship of, us by the trademark or trade dress owners.

Implications of Being an Emerging Growth Company

The Jumpstart Our Business Startups Act of 2012, or the JOBS Act, was enacted in April 2012 with the intention of encouraging capital formation in the United States and reducing the regulatory burden on newly public companies that qualify as “emerging growth companies.” We are an emerging growth company within the meaning of the JOBS Act. As an emerging growth company, we may take advantage of certain exemptions from various public reporting requirements, including the requirement that our internal control over financial reporting be audited by our independent registered public accounting firm pursuant to Section 404 of the Sarbanes-Oxley Act of 2002, certain requirements related to the disclosure of executive compensation in this prospectus and in our periodic reports and proxy statements, and the requirement that we hold a nonbinding advisory vote on executive compensation and any golden parachute payments. We may choose to take advantage of some, all or none of these reduced burdens until we are no longer an emerging growth company. As a result, the information that we provide to our stockholders may be different than you might receive from other public reporting companies in which you hold equity interests. .

We will remain an emerging growth company until the earliest to occur of:

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the last day of the fiscal year in which we have approximately $1.0 billion or more in annual gross revenue;

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the date we qualify as a “large accelerated filer,” with at least $700 million of equity securities held by non-affiliates;

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the date on which we have issued, in any three-year period, more than $1.0 billion in non-convertible debt securities; or

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the last day of the fiscal year ending after the fifth anniversary of the closing of our initial public offering.

Section 102(b)(1) of the JOBS Act exempts emerging growth companies from being required to comply with new or revised financial accounting standards until private companies (that is, those that have not had a registration statement under the Securities Act of 1933, as amended, or the Securities Act, declared effective or do not have a class of securities registered under the Securities Exchange Act of 1934, as amended, or the Exchange Act) are required to comply with the new or revised financial accounting standard. We have chosen to “opt out” of the extended transition periods available under the JOBS Act for complying with new or revised accounting standards. Section 107 of the JOBS Act provides that our decision to opt out of the extended transition periods for complying with new or revised accounting standards is irrevocable.

Offerings Under This Prospectus

Under this prospectus, we may offer shares of our common stock and preferred stock, various series of debt securities and/or warrants, rights or purchase contracts to purchase any of such securities, either individually or in units, with a total value of up to $150,000,000, from time to time at prices and on terms to be determined by market conditions at the time of the offering. This prospectus provides you with a general description of the securities we may offer. Each time we offer a type or series of securities under this prospectus, we will provide a prospectus supplement that will describe the specific amounts, prices and other important terms of the securities, including, to the extent applicable:

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designation or classification;

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aggregate principal amount or aggregate offering price;

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maturity, if applicable;

•

rates and times of payment of interest or dividends, if any;

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redemption, conversion or sinking fund terms, if any;

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voting or other rights, if any; and

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conversion or exercise prices, if any.

The prospectus supplement also may add, update or change information contained in this prospectus or in documents we have incorporated by reference into this prospectus. However, no prospectus supplement will fundamentally change the terms that are set forth in this prospectus or offer a security that is not registered and described in this prospectus at the time of its effectiveness.

We may sell the securities directly to investors or to or through agents, underwriters or dealers. We, and our agents or underwriters, reserve the right to accept or reject all or part of any proposed purchase of securities. If we offer securities through agents or underwriters, we will include in the applicable prospectus supplement:

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the names of those agents or underwriters;

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applicable fees, discounts and commissions to be paid to them;

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details regarding over-allotment options, if any; and

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the net proceeds to us.

This prospectus may not be used to consummate a sale of any securities unless it is accompanied by a prospectus supplement.

Investing in our securities involves significant risk. The prospectus supplement applicable to each offering of our securities will contain a discussion of the risks applicable to an investment in Spring Bank. Prior to making a decision about investing in our securities, you should carefully consider the specific factors discussed under the heading “Risk Factors” in the applicable prospectus supplement, together with all of the other information contained or incorporated by reference in the prospectus supplement or appearing or incorporated by reference in this prospectus. You should also consider the risks, uncertainties and assumptions discussed under the heading “Risk Factors” included in our most recent annual report on Form 10-K, as revised or supplemented by our subsequent quarterly reports on Form 10-Q or our current reports on Form 8-K that we have filed with the SEC, all of which are incorporated herein by reference, and which 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 also affect our operations. The occurrence of any of these risks might cause you to lose all or part of your investment in the offered securities.

Any time debt securities or preferred securities are offered pursuant to this prospectus, we will provide a table setting forth our ratio of earnings to fixed charges, or combined fixed charges and preference dividends to earnings, if applicable, on a historical basis in the applicable prospectus supplement, if required.

This prospectus contains forward-looking statements. All statements other than statements of historical facts contained in this prospectus, including statements regarding our future results of operations and financial position, business strategy, product candidates, product approvals, research and development costs, timing and likelihood of success, plans and objectives of management for future operations and future results of anticipated products, are forward-looking statements. These statements involve known and unknown risks, uncertainties and other important factors that may cause our actual results, performance or achievements to be materially different from any future results, performance or achievements expressed or implied by the forward-looking statements.

In some cases, you can identify forward-looking statements by terms such as “may,” “will,” “should,” “expect,” “plan,” “anticipate,” “could,” “intend,” “target,” “project,” “contemplate,” “believe,” “estimate,” “predict,” “potential” or “continue” or the negative of these terms or other similar expressions. The forward-looking statements in this prospectus are only predictions. We have based these forward-looking statements largely on our current expectations and projections about future events and financial trends that we believe may affect our business, financial condition and results of operations. These forward-looking statements speak only as of the date of this prospectus and are subject to a number of risks, uncertainties and assumptions described under the sections in our periodic report reports, including our Annual Report on Form 10-K for the fiscal year ended December 31, 2016, entitled “Risk Factors” and “Management’s Discussion and Analysis of Financial Condition and Results of Operations,” as well as other sections elsewhere in this prospectus, any accompanying prospectus supplement and the documents or reports incorporated by reference in this prospectus.

Because forward-looking statements are inherently subject to risks and uncertainties, some of which cannot be predicted or quantified and some of which are beyond our control, you should not rely on these forward-looking statements as predictions of future events. The events and circumstances reflected in our forward-looking statements may not be achieved or occur and actual results could differ materially from those projected in the forward-looking statements. Moreover, we operate in an evolving environment. New risk factors and uncertainties may emerge from time to time, and it is not possible for management to predict all risk factors and uncertainties. Except as required by applicable law, we do not plan to publicly update or revise any forward-looking statements contained herein, whether as a result of any new information, future events, changed circumstances or otherwise.

You should read this prospectus, any accompanying prospectus supplement, the documents that we reference in this prospectus and the documents we have filed as exhibits to the registration statement with the understanding that our actual future results may be materially different from what we expect. We qualify all of our forward-looking statements by these cautionary statements.

Unless otherwise indicated in the applicable prospectus supplement, we intend to use any net proceeds from the sale of securities under this prospectus to fund activities relating to the development and commercialization of our product candidates, and for other general corporate purposes, including, but not limited to, working capital, capital expenditures, investments, acquisitions, should we choose to pursue any, and collaborations. We have not determined the amounts we plan to spend on any of the areas listed above or the timing of these expenditures. As a result, our management will have broad discretion to allocate the net proceeds, if any, we receive in connection with securities offered pursuant to this prospectus for any purpose. Pending application of the net proceeds as described above, we may initially invest the net proceeds in short-term, investment-grade, interest-bearing securities or apply them to the reduction of short-term indebtedness. Additional information on the use of proceeds from the sale of securities offered by this prospectus may be set forth in the prospectus supplement relating to that offering.

We may offer securities under this prospectus from time to time pursuant to underwritten public offerings, negotiated transactions, block trades or a combination of these methods. We may sell the securities (1) through underwriters or dealers, (2) through agents or (3) directly to one or more purchasers, or through a combination of such methods. We may distribute the securities from time to time in one or more transactions at:

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, and may enter into arrangements for “at-the-market,” equity line or similar transactions. We will name in a prospectus supplement any underwriter or agent involved in the offer or sale of the securities.

If we utilize a dealer in the sale of the securities being offered by this prospectus, we will sell the securities to the dealer, as principal. The dealer may then resell the securities to the public at varying prices to be determined by the dealer at the time of resale.

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 which 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 the 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 the underwriter may compensate those dealers in the form of discounts, concessions or commissions.

With respect to underwritten public offerings, negotiated transactions and block trades, we will provide in the applicable prospectus supplement information regarding 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, or to contribute to payments they may be required to make in respect thereof.

If so indicated in the applicable prospectus supplement, we will authorize underwriters, dealers or other persons acting as our agents to solicit offers by certain institutions to purchase securities from us pursuant to delayed delivery contracts providing for payment and delivery on the date stated in each applicable prospectus supplement. Each contract will be for an amount not less than, and the aggregate amount of securities sold pursuant to such contracts shall not be less nor more than, the respective amounts stated in each applicable prospectus supplement. Institutions with whom the contracts, when authorized, may be made include commercial and savings banks, insurance companies, pension funds, investment companies, educational and charitable institutions and other institutions, but shall in all cases be subject to our approval. Delayed delivery contracts will not be subject to any conditions except that:

One or more firms, referred to as “remarketing firms,” may also offer or sell the securities, if a prospectus supplement so indicates, in connection with a remarketing arrangement upon their purchase. Remarketing firms will

act as principals for their own accounts or as our agents. These remarketing firms will offer or sell the securities in accordance with the terms of the securities. Each prospectus supplement will identify and describe any remarketing firm and the terms of its agreement, if any, with us and will describe the remarketing firm’s compensation. Remarketing firms may be deemed to be underwriters in connection with the securities they remarket. Remarketing firms may be entitled under agreements that may be entered into with us to indemnification by us against certain civil liabilities, including liabilities under the Securities Act, and may be customers of, engage in transactions with or perform services for us in the ordinary course of business.

Certain underwriters may use this prospectus and any accompanying prospectus supplement for offers and sales related to market-making transactions in the securities. These underwriters may act as principal or agent in these transactions, and the sales will be made at prices related to prevailing market prices at the time of sale. Any underwriters involved in the sale of the securities may qualify as “underwriters” within the meaning of Section 2(a)(11) of the Securities Act. In addition, the underwriters’ commissions, discounts or concessions may qualify as underwriters’ compensation under the Securities Act and the rules of the Financial Industry Regulatory Authority, Inc., or FINRA.

Shares of our common stock sold pursuant to the registration statement of which this prospectus is a part will be authorized for listing and trading on The NASDAQ Capital Market. The applicable prospectus supplement will contain information, where applicable, as to any other listing, if any, on The NASDAQ Capital Market or any securities market or other securities exchange of the securities covered by the prospectus supplement. Underwriters may make a market in our common stock, but will not be obligated to do so and may discontinue any market making at any time without notice. We can make no assurance as to the liquidity of or the existence, development or maintenance of trading markets for any of the securities.

In order to facilitate the offering of the 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 over- allotments or short sales of the securities, which involve the sale by persons participating in the offering of more securities than we sold to them. In these circumstances, these persons would cover such over-allotments or short positions by making purchases in the open market or by exercising their over-allotment option. In addition, these persons may stabilize or maintain the price of the securities by bidding for or purchasing the applicable security in the open market or by imposing penalty bids, whereby selling concessions allowed to dealers participating in the offering may be reclaimed if the 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.

The underwriters, dealers and agents may engage in other transactions with us, or perform other services for us, in the ordinary course of their business.

We are authorized to issue 200,000,000 shares of common stock, par value $0.0001 per share. As of May 15, 2017, we had 9,426,238 shares of common stock outstanding and approximately 142 stockholders of record.

The following summary of certain provisions of our common stock does not purport to be complete. You should refer to the section of this prospectus entitled “Certain Provisions of Delaware Law and of the Company’s Certificate of Incorporation and Bylaws” and our restated certificate of incorporation and our restated bylaws, both of which are included as exhibits to the registration statement of which this prospectus is a part. The summary below is also qualified by provisions of applicable law.

The holders of common stock are entitled to one vote per share on all matters submitted to a vote of our stockholders and do not have cumulative voting rights. An election of directors by our stockholders shall be determined by a plurality of the votes cast by the stockholders entitled to vote on the election. Other matters shall be decided by the affirmative vote of our stockholders having a majority in voting power of the votes cast by the stockholders present or represented and voting on such matter, except as otherwise disclosed below.

Our bylaws provide that the holders of a majority of the outstanding shares of our common stock, if present in person or by proxy, represent a quorum for the transaction of business at stockholders meetings, except where a separate vote by a class of capital stock is required, the holders of a majority in voting power of such class, if present by remote communication or by proxy, represent a quorum for such matter. Subject to preferences that may be applicable to any preferred stock outstanding at the time, the holders of outstanding shares of common stock are entitled to receive ratably any dividends declared by our board of directors. In the event of our liquidation, dissolution or winding up, holders of our common stock are entitled to share ratably in all assets remaining after payment of liabilities and the liquidation preference of any then-outstanding shares of preferred stock. Holders of our common stock do not have preemptive or conversion rights, or other subscription rights. There are no redemption provisions applicable to the common stock.

As of May 15, 2017, we had outstanding options to purchase 955,565 shares of our common stock at a weighted average price $10.70 per share. All of our stock options expire 10 years after their grant date.

As of May 15, 2017, we had outstanding warrants to purchase 1,798,084 shares of our common stock at exercise prices ranging from $10.79 to $16.00 per share. Warrants to purchase 125,000 shares of our common stock will expire on August 1, 2018, warrants to purchase 28,347 shares of our common stock will expire on May 5, 2021 and warrants to purchase 1,644,737 shares of our common stock will expire on November 23, 2021.

The transfer agent and registrar for our common stock is Computershare Trust Company, N.A., with offices at 250 Royall Street, Canton, Massachusetts 02021.

Our common stock is listed for quotation on The NASDAQ Capital Market under the symbol “SBPH.”

We are authorized to issue 10,000,000 shares of preferred stock, par value $0.0001 per share. As of the date of this prospectus, no shares of our preferred stock were outstanding or designated. The following summary of certain provisions of our preferred stock does not purport to be complete. You should refer to our restated certificate of incorporation and our restated bylaws, both of which are included as exhibits to the registration statement of which this prospectus is a part. The summary below is also qualified by provisions of applicable law.

Our board of directors may, without further action by our stockholders, from time to time, direct the issuance of shares of preferred stock in series and may, at the time of issuance, determine the rights, preferences and limitations of each series, including voting rights, dividend rights and redemption and liquidation preferences. Satisfaction of any dividend preferences of outstanding shares of preferred stock would reduce the amount of funds available for the payment of dividends on shares of our common stock. Holders of shares of preferred stock may be entitled to receive a preference payment in the event of any liquidation, dissolution or winding-up of our company before any payment is made to the holders of shares of our common stock. In some circumstances, the issuance of shares of preferred stock may render more difficult or tend to discourage a merger, tender offer or proxy contest, the assumption of control by a holder of a large block of our securities or the removal of incumbent management. Upon the affirmative vote of our board of directors, without stockholder approval, we may issue shares of preferred stock with voting and conversion rights which could adversely affect the holders of shares of our common stock.

If we offer a specific series of preferred stock under this prospectus, we will describe the terms of the preferred stock in the prospectus supplement for such offering and will file a copy of the restated certificate establishing the terms of the preferred stock with the SEC. To the extent required, this description will include:

The transfer agent and registrar for our preferred stock will be set forth in the applicable prospectus supplement.

The following description, together with the additional information we include in any applicable prospectus supplements, summarizes the material terms and provisions of the debt securities that we may offer under this prospectus. While the terms we have summarized below will apply generally to any future debt securities we may offer pursuant to this prospectus, we will describe the particular terms of any debt securities that we may offer in more detail in the applicable prospectus supplement. If we so indicate in a prospectus supplement, the terms of any debt securities offered under such prospectus supplement may differ from the terms we describe below, and to the extent the terms set forth in a prospectus supplement differ from the terms described below, the terms set forth in the prospectus supplement shall control.

We may sell from time to time, in one or more offerings under this prospectus, debt securities, which may be senior or subordinated. We will issue any such senior debt securities under a senior indenture that we will enter into with a trustee to be named in the senior indenture. We will issue any such subordinated debt securities under a subordinated indenture, which we will enter into with a trustee to be 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. We use the term “indentures” to refer to either the senior indenture or the subordinated indenture, as applicable. The indentures will be qualified under the Trust Indenture Act of 1939, as in effect on the date of the indenture. We use the term “debenture 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 the provisions of the indenture applicable to a particular series of debt securities.

Each indenture provides that debt securities may be issued from time to time in one or more series and may be denominated and payable in foreign currencies or units based on or relating to foreign currencies. Neither indenture limits the amount of debt securities that may be issued thereunder and each indenture provides that the specific terms of any series of debt securities shall be set forth in, or determined pursuant to, an authorizing resolution and/or a supplemental indenture, if any, relating to such series.

We will describe in each prospectus supplement the following terms relating to a series of debt securities:

We may issue debt securities that provide for an amount less than their stated principal amount to be due and payable upon declaration of acceleration of their maturity pursuant to the terms of the indenture. We will provide you with information on the federal income tax considerations and other special considerations applicable to any of these debt securities in the applicable prospectus supplement.

We will set forth in the prospectus supplement the terms, if any, on which a series of debt securities may be convertible into or exchangeable for our common stock or our other securities. We will include provisions as to whether conversion or exchange is mandatory, at the option of the holder or at our option. We may include provisions pursuant to which the number of shares of our common stock or our other securities that the holders of the series of debt securities receive would be subject to adjustment.

Consolidation, Merger or Sale; No Protection in Event of a Change of Control or Highly Leveraged Transaction

The indentures do not contain any covenant that restricts our ability to merge or consolidate, or sell, convey, transfer or otherwise dispose of all or substantially all of our assets. However, any successor to or acquirer of such assets must assume all of our obligations under the indentures or the debt securities, as appropriate.

Unless we state otherwise in the applicable prospectus supplement, the debt securities will not contain any provisions that may afford holders of the debt securities protection in the event we have a change of control or in the event of a highly leveraged transaction (whether or not such transaction results in a change of control), which could adversely affect holders of debt securities.

The following are events of default under the indentures with respect to any series of debt securities that we may issue:

No event of default with respect to a particular series of debt securities (except as to certain events of bankruptcy, insolvency or reorganization) necessarily constitutes an event of default with respect to any other series of debt securities. The occurrence of an event of default may constitute an event of default under any bank credit agreements we may have in existence from time to time. In addition, the occurrence of certain events of default or

an acceleration under the indenture may constitute an event of default under certain of our other indebtedness outstanding from time to time.

If an event of default with respect to debt securities of any series at the time outstanding occurs and is continuing, then the trustee or the holders of not less than a majority in principal amount of the outstanding debt securities of that series may, by a notice in writing to us (and to the debenture trustee if given by the holders), declare to be due and payable immediately the principal (or, if the debt securities of that series are discount securities, that portion of the principal amount as may be specified in the terms of that series) of and premium and accrued and unpaid interest, if any, on all debt securities of that series. Before a judgment or decree for payment of the money due has been obtained with respect to debt securities of any series, the holders of a majority in principal amount of the outstanding debt securities of that series (or, at a meeting of holders of such series at which a quorum is present, the holders of a majority in principal amount of the debt securities of such series represented at such meeting) may rescind and annul the acceleration if all events of default, other than the non-payment of accelerated principal, premium, if any, and interest, if any, with respect to debt securities of that series, have been cured or waived as provided in the applicable indenture (including payments or deposits in respect of principal, premium or interest that had become due other than as a result of such acceleration). We refer you to the prospectus supplement relating to any series of debt securities that are discount securities for the particular provisions relating to acceleration of a portion of the principal amount of such discount securities upon the occurrence of an event of default.

Subject to the terms of the indentures, if an event of default under an indenture shall occur and be continuing, the debenture trustee will be under no obligation to exercise any of its rights or powers under such indenture at the request or direction of any of the holders of the applicable series of debt securities, unless such holders have offered the debenture trustee reasonable indemnity. The holders of a majority in principal amount of the outstanding debt securities of any series will have the right to direct the time, method and place of conducting any proceeding for any remedy available to the debenture trustee, or exercising any trust or power conferred on the debenture trustee, with respect to the debt securities of that series, provided that:

A holder of the debt securities of any series will only have the right to institute a proceeding under the indentures or to appoint a receiver or trustee, or to seek other remedies if:

These limitations do not apply to a suit instituted by a holder of debt securities if we default in the payment of the principal, premium, if any, or interest on, the debt securities.

We will periodically file statements with the applicable debenture trustee regarding our compliance with specified covenants in the applicable indenture.

The debenture trustee and we may change the applicable indenture without the consent of any holders with respect to specific matters, including:

In addition, under the indentures, the rights of holders of a series of debt securities may be changed by us and the debenture trustee with the written consent of the holders of at least a majority in aggregate principal amount of the outstanding debt securities of each series (or, at a meeting of holders of such series at which a quorum is present, the holders of a majority in principal amount of the debt securities of such series represented at such meeting) that is affected. However, the debenture trustee and we may make the following changes only with the consent of each holder of any outstanding debt securities affected:

Except for certain specified provisions, the holders of at least a majority in principal amount of the outstanding debt securities of any series (or, at a meeting of holders of such series at which a quorum is present, the holders of a majority in principal amount of the debt securities of such series represented at such meeting) may on behalf of the holders of all debt securities of that series waive our compliance with provisions of the indenture. The holders of a majority in principal amount of the outstanding debt securities of any series may on behalf of the holders of all the debt securities of such series waive any past default under the indenture with respect to that series and its consequences, except a default in the payment of the principal of, premium or any interest on any debt security of that series or in respect of a covenant or provision, which cannot be modified or amended without the consent of the holder of each outstanding debt security of the series affected; provided, however, that the holders of a majority in principal amount of the outstanding debt securities of any series may rescind an acceleration and its consequences, including any related payment default that resulted from the acceleration.

Each indenture provides that we can elect to be discharged from our obligations with respect to one or more series of debt securities, except for obligations to:

In order to exercise our rights to be discharged with respect to a series, we must deposit with the trustee money or government obligations sufficient to pay all the principal of, the premium, if any, and interest on, the debt securities of the series on the dates payments are due.

We will issue the debt securities of each series only in fully registered form without coupons and, unless we otherwise specify in the applicable prospectus supplement, in denominations of $1,000 and any integral multiple thereof. The indentures provide that we may issue debt securities of a series in temporary or permanent global form and as book-entry securities that will be deposited with, or on behalf of, The Depository Trust Company or another depositary named by us and identified in a prospectus supplement with respect to that series.

At the option of the holder, subject to the terms of the indentures and the limitations applicable to global securities described in the applicable prospectus supplement, the holder of the debt securities of any series can exchange the debt securities for other debt securities of the same series, in any authorized denomination and of like tenor and aggregate principal amount.

Subject to the terms of the indentures and the limitations applicable to global securities set forth in the applicable prospectus supplement, holders of the debt securities may present the debt securities for exchange or for registration of transfer, duly endorsed or with the form of transfer endorsed thereon duly executed if so required by us or the security registrar, at the office of the security registrar or at the office of any transfer agent designated by us for this purpose. Unless otherwise provided in the debt securities that the holder presents for transfer or exchange or in the applicable indenture, we will make no service charge for any registration of transfer or exchange, but we may require payment of any taxes or other governmental charges. We will name in the applicable prospectus supplement the security registrar, and any transfer agent in addition to the security registrar, that we initially designate for any debt securities. We may at any time designate additional transfer agents or rescind the designation of any transfer agent or approve a change in the office through which any transfer agent acts, except that we will be required to maintain a transfer agent in each place of payment for the debt securities of each series.

If we elect to redeem the debt securities of any series, we will not be required to:

The debenture trustee, other than during the occurrence and continuance of an event of default under the applicable indenture, undertakes to perform only those duties as are specifically set forth in the applicable indenture. Upon an event of default under an indenture, the debenture trustee under such indenture must use the same degree of care as a prudent person would exercise or use in the conduct of his or her own affairs. Subject to this provision, the debenture trustee is under no obligation to exercise any of the powers given it by the indentures at the request of any holder of debt securities unless it is offered reasonable security and indemnity against the costs, expenses and liabilities that it might incur.

Unless we otherwise indicate in the applicable prospectus supplement, we will make payment of the interest on any debt securities on any interest payment date to the person in whose name the debt securities, or one or more predecessor securities, are registered at the close of business on the regular record date for the interest.

We will pay principal of and any premium and interest on the debt securities of a particular series at the office of the paying agents designated by us, except that unless we otherwise indicate in the applicable prospectus supplement, will we make interest payments by check which we will mail to the holder. Unless we otherwise indicate in a prospectus supplement, we will designate the corporate trust office of the debenture trustee in the City of New York as our sole paying agent for payments with respect to debt securities of each series. We will name in the applicable prospectus supplement any other paying agents that we initially designate for the debt securities of a particular series. We will maintain a paying agent in each place of payment for the debt securities of a particular series.

All money we pay to a paying agent or the debenture trustee for the payment of the principal of or any premium or interest on any debt securities which remains unclaimed at the end of two years after such principal, premium or interest has become due and payable will be repaid to us, and the holder of the security thereafter may look only to us for payment thereof.

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.

Our obligations pursuant to any subordinated debt securities will be unsecured and will be subordinate and junior in priority of payment to certain of our other indebtedness to the extent described in a prospectus supplement. The subordinated indenture does not limit the amount of senior indebtedness we may incur. It also does not limit us from issuing any other secured or unsecured debt.

We may issue warrants to purchase shares of our common stock, preferred stock and/or debt securities in one or more series together with other securities or separately, as described in the applicable prospectus supplement. Below is a description of certain general terms and provisions of the warrants that we may offer. Particular terms of the warrants will be described in the warrant agreements and the prospectus supplement relating to the warrants.

The applicable prospectus supplement will contain, where applicable, the following terms of and other information relating to the warrants:

The transfer agent and registrar for any warrants will be set forth in the applicable prospectus supplement.

We may issue rights to our stockholders to purchase shares of our common stock, preferred stock or the other securities described in this prospectus. We may offer rights separately or together with one or more additional rights, debt securities, preferred stock, common stock, warrants or purchase contracts, or any combination of those securities in the form of units, as described in the applicable prospectus supplement. Each series of rights will be issued under a separate rights agreement to be entered into between us and a bank or trust company, as rights agent. The rights agent will act solely as our agent in connection with the certificates relating to the rights of the series of certificates and will not assume any obligation or relationship of agency or trust for or with any holders of rights certificates or beneficial owners of rights. The following description sets forth certain general terms and provisions of the rights to which any prospectus supplement may relate. The particular terms of the rights to which any prospectus supplement may relate and the extent, if any, to which the general provisions may apply to the rights so offered will be described in the applicable prospectus supplement. To the extent that any particular terms of the rights, rights agreement or rights certificates described in a prospectus supplement differ from any of the terms described below, then the terms described below will be deemed to have been superseded by that prospectus supplement. We encourage you to read the applicable rights agreement and rights certificate for additional information before you decide whether to purchase any of our rights. We will provide in a prospectus supplement the following terms of the rights being issued:

Each right will entitle the holder of rights to purchase for cash the principal amount of shares of common stock, preferred stock or other securities at the exercise price provided in the applicable prospectus supplement. Rights may be exercised at any time up to the close of business on the expiration date for the rights provided in the applicable prospectus supplement.

Holders may exercise rights as described in the applicable prospectus supplement. Upon receipt of payment and the rights certificate properly completed and duly executed at the corporate trust office of the rights agent or any other office indicated in the prospectus supplement, we will, as soon as practicable, forward the shares of common stock, preferred stock or other securities, as applicable, purchasable upon exercise of the rights. If less than all of the rights issued in any rights offering are exercised, we may offer any unsubscribed securities directly to persons other than stockholders, to or through agents, underwriters or dealers or through a combination of such methods, including pursuant to standby arrangements, as described in the applicable prospectus supplement.

The rights agent for any rights we offer will be set forth in the applicable prospectus supplement.

We may issue purchase contracts, including contracts obligating holders to purchase from us, and for us to sell to holders, a specific or variable number of our debt securities, shares of common stock, preferred stock, warrants or rights, or securities of an entity unaffiliated with us, or any combination of the above, at a future date or dates. Alternatively, the purchase contracts may obligate us to purchase from holders, and obligate holders to sell to us, a specific or variable number of our debt securities, shares of common stock, preferred stock, warrants, rights or other property, or any combination of the above. The price of the securities or other property subject to the purchase contracts may be fixed at the time the purchase contracts are issued or may be determined by reference to a specific formula described in the purchase contracts. We may issue purchase contracts separately or as a part of units each consisting of a purchase contract and one or more of our other securities described in this prospectus or securities of third parties, including U.S. Treasury securities, securing the holder’s obligations under the purchase contract. The purchase contracts may require us to make periodic payments to holders or vice versa and the payments may be unsecured or pre-funded on some basis. The purchase contracts may require holders to secure the holder’s obligations in a manner specified in the applicable prospectus supplement.

The applicable prospectus supplement will describe the terms of any purchase contracts in respect of which this prospectus is being delivered, including, to the extent applicable, the following:

The preceding description sets forth certain general terms and provisions of the purchase contracts to which any prospectus supplement may relate. The particular terms of the purchase contracts to which any prospectus supplement may relate and the extent, if any, to which the general provisions may apply to the purchase contracts so offered will be described in the applicable prospectus supplement. To the extent that any particular terms of the purchase contracts described in a prospectus supplement differ from any of the terms described above, then the terms described above will be deemed to have been superseded by that prospectus supplement. We encourage you to read the applicable purchase contract for additional information before you decide whether to purchase any of our purchase contracts.

The following description, together with the additional information that we include in any applicable prospectus supplements, summarizes the material terms and provisions of the units that we may offer under this prospectus. While the terms we have summarized below will apply generally to any units that we may offer under this prospectus, we will describe the particular terms of any series of units in more detail in the applicable prospectus supplement. The terms of any units offered under a prospectus supplement may differ from the terms described below.

We will incorporate by reference from reports that we file with the SEC, the form of unit agreement that describes the terms of the series of units we are offering, and any supplemental agreements, before the issuance of the related series of units. The following summaries of material terms and provisions of the units are subject to, and qualified in their entirety by reference to, all the provisions of the unit agreement and any supplemental agreements applicable to a particular series of units. We urge you to read the applicable prospectus supplements related to the particular series of units that we may offer under this prospectus, as well as any related free writing prospectuses and the complete unit agreement and any supplemental agreements that contain the terms of the units.

We may issue units consisting of common stock, preferred stock, one or more debt securities, warrants, rights or purchase contacts for the purchase of common stock, preferred stock and/or debt securities in one or more series, in any combination. Each unit 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 security included in the unit. The unit agreement under which a unit is issued may provide that the securities included in the unit may not be held or transferred separately, at any time or at any time before a specified date.

We will describe in the applicable prospectus supplement the terms of the series of units being offered, including:

The provisions described in this section, as well as those set forth in any prospectus supplement or as described under “Description of Common Stock,” “Description of Preferred Stock,” “Description of Debt Securities,” “Description of Warrants,” “Description of Rights” and “Description of Purchase Contracts” will apply to each unit, as applicable, and to any common stock, preferred stock, debt security, warrant, right or purchase contract included in each unit, as applicable.

The name and address of the unit agent for any units we offer will be set forth in the applicable prospectus supplement.

We may issue units in such amounts and in such numerous distinct series as we determine.

Each unit agent will act solely as our agent under the applicable unit agreement and will not assume any obligation or relationship of agency or trust with any holder of any unit. A single bank or trust company may act as unit agent for more than one series of units. A unit agent will have no duty or responsibility in case of any default by us under the applicable unit agreement or unit, including any duty or responsibility to initiate any proceedings at law or otherwise, or to make any demand upon us. Any holder of a unit may, without the consent of the related unit agent or the holder of any other unit, enforce by appropriate legal action its rights as holder under any security included in the unit.

CERTAIN PROVISIONS OF DELAWARE LAW AND OF THE COMPANY’S CERTIFICATE OF INCORPORATION AND BYLAWS

The provisions of Delaware law, our restated certificate of incorporation and our restated bylaws may have the effect of delaying, deferring or discouraging another person from acquiring control of our company.

Section 203 of the Delaware General Corporation Law prevents some Delaware corporations from engaging, under some circumstances, in a business combination, which includes a merger or sale of at least 10% of the corporation’s assets with any interested stockholder, meaning a stockholder who, together with affiliates and associates, owns or, within three years prior to the determination of interested stockholder status, did own 15% or more of the corporation’s outstanding voting stock, unless:

If Section 203 applied to us, the restrictions could prohibit or delay mergers or other takeover or change in control attempts and, accordingly, could discourage attempts to acquire us.

Our restated certificate of incorporation and our restated bylaws include a number of provisions that may have the effect of deterring hostile takeovers or delaying or preventing changes in control of our management team, including the following:

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Exclusive Forum. Our restated certificate of incorporation specifies that, unless we consent in writing to the selection of an alternative forum, the Court of Chancery of the State of Delaware will be the sole and exclusive forum for: (i) any derivative action or proceeding brought on behalf of the corporation; (ii) any action asserting a claim of breach of a fiduciary duty owed by any director, officer or other employee of the corporation to the corporation or the corporation’s stockholders; (iii) any action asserting a claim arising pursuant to any provision of the DGCL; and (iv) any action asserting a claim governed by the internal affairs doctrine. We believe this provision benefits us by providing increased consistency in the application of Delaware law by chancellors particularly experienced in resolving corporate disputes, efficient administration of cases on a more expedited schedule relative to other forums and protection against the burdens of multi-forum litigation. However, the provision may have the effect of discouraging lawsuits against our directors and officers. The enforceability of similar choice of forum provisions in other companies’ certificates of incorporation has been challenged in legal proceedings, and it is possible that, in connection with any applicable action brought against us, a court could find the choice of forum provisions contained in our restated certificate of incorporation to be inapplicable or unenforceable in such action.

As permitted by Delaware law, we have adopted provisions in our certificate of incorporation that limit or eliminate the personal liability of our directors. Our restated certificate of incorporation limits the liability of directors to the maximum extent permitted by Delaware law. Delaware law provides that directors of a corporation will not be personally liable for monetary damages for breaches of their fiduciary duties as directors, except liability for:

These limitations do not apply to liabilities arising under federal securities laws and do not affect the availability of equitable remedies, including injunctive relief or rescission. If Delaware law is amended to authorize the further elimination or limiting of a director, then the liability of our directors will be eliminated or limited to the fullest extent permitted by Delaware law as so amended.

As permitted by Delaware law, our certificate of incorporation also provides that:

The indemnification provisions contained in our certificate of incorporation are not exclusive. In addition, we have entered into indemnification agreements with each of our directors and executive officers. Each of these indemnification agreements provides, among other things, that we will indemnify such director or executive officer to the fullest extent permitted by law for claims arising in his or her capacity as a director or officer, as applicable, provided that he or she acted in good faith and in a manner that he or she reasonably believed to be in, or not opposed to, our best interests and, with respect to any criminal proceeding, had no reasonable cause to believe that his or her conduct was unlawful. Each of these indemnification agreements provide that in the event that we do not assume the defense of a claim against a director or officer, as applicable, we will be required to advance his or her expenses in connection with his or her defense, provided that he or she undertakes to repay all amounts advanced if it is ultimately determined that he or she is not entitled to be indemnified by us.

We believe that these provisions and agreements are necessary to attract and retain qualified persons as directors and officers. Insofar as indemnification for liabilities arising under the Securities Act of 1933, which we refer to as the Securities Act, may be permitted to directors, officers or persons controlling our company pursuant to the foregoing provisions, we understand that in the opinion of the SEC such indemnification is against public policy as expressed in the Securities Act and is therefore unenforceable.

In addition, we maintain standard policies of insurance under which coverage is provided to our directors and officers against losses arising from claims made by reason of breach of duty or other wrongful act, and to us with respect to payments which may be made by us to such directors and officers pursuant to the above indemnification provisions or otherwise as a matter of law.

The foregoing discussion of our restated certificate of incorporation, restated bylaws, indemnification agreements and Delaware law is not intended to be exhaustive and is qualified in its entirety by such restated certificate of incorporation, restated bylaws, indemnification agreements or law.

Insofar as indemnification for liabilities arising under the Securities Act may be permitted to our directors, officers and controlling persons pursuant to the foregoing provisions, or otherwise, we have been advised that in the opinion of the SEC such indemnification is against public policy as expressed in the Securities Act and is, therefore, unenforceable.

Mintz, Levin, Cohn, Ferris, Glovsky and Popeo, P.C., Boston, Massachusetts, will pass upon the validity of the issuance of the securities to be offered by this prospectus.

The consolidated financial statements of Spring Bank Pharmaceuticals, Inc. and its subsidiaries as of December 31, 2016 and 2015 and for each of the years in the two-year period ended December 31, 2016, incorporated by reference in this prospectus and registration statement from the Spring Bank Pharmaceuticals, Inc.’s Annual Report on Form 10-K for the year ended December 31, 2016, have been audited by RSM US LLP, an independent registered public accounting firm, as stated in their report thereon incorporated herein by reference, and have been incorporated in this prospectus and registration statement in reliance upon such report and upon the authority of such firm as experts in accounting and auditing.

We are subject to the reporting requirements of the Securities Exchange Act of 1934, as amended, and file annual, quarterly and current reports, proxy statements and other information with the SEC. You may read and copy these reports, proxy statements and other information at the SEC’s public reference facilities at 100 F Street, N.E., Room 1580, Washington, D.C. 20549. You can request copies of these documents by writing to the SEC and paying a fee for the copying cost. Please call the SEC at 1-800-SEC-0330 for more information about the operation of the public reference facilities. SEC filings are also available at the SEC’s web site at http://www.sec.gov. This prospectus is only part of a registration statement on Form S-3 that we have filed with the SEC under the Securities Act of 1933, as amended, and therefore omits certain information contained in the registration statement. We have also filed exhibits and schedules with the registration statement that are excluded from this prospectus, and you should refer to the applicable exhibit or schedule for a complete description of any statement referring to any contract or other document. You may inspect a copy of the registration statement, including the exhibits and schedules, without charge, at the public reference room or obtain a copy from the SEC upon payment of the fees prescribed by the SEC.

We also maintain a website at www.springbankpharm.com, through which you can access our SEC filings. The information set forth on our website is not part of this prospectus.

The SEC allows us to “incorporate by reference” information that we file with them. Incorporation by reference allows us to disclose important information to you by referring you to those other documents. The information incorporated by reference is an important part of this prospectus, and information that we file later with the SEC will automatically update and supersede this information. We filed a registration statement on Form S-3 under the Securities Act of 1933, as amended, with the SEC with respect to the securities we may offer pursuant to this prospectus. This prospectus omits certain information contained in the registration statement, as permitted by the SEC. You should refer to the registration statement, including the exhibits, for further information about us and the securities we may offer pursuant to this prospectus. Statements in this prospectus regarding the provisions of certain documents filed with, or incorporated by reference in, the registration statement are not necessarily complete and each statement is qualified in all respects by that reference. Copies of all or any part of the registration statement, including the documents incorporated by reference or the exhibits, may be obtained upon payment of the prescribed rates at the offices of the SEC listed above in “Where You Can Find More Information.” The documents we are incorporating by reference are:

Unless otherwise noted, the SEC file number for each of the documents listed above is 001-37718.

In addition, all reports and other documents filed by us pursuant to the Exchange Act after the date of the initial registration statement and prior to effectiveness of the registration statement shall be deemed to be incorporated by reference into this prospectus.

Any statement contained in this prospectus or in a document incorporated or deemed to be incorporated by reference into this prospectus will be deemed to be modified or superseded for purposes of this prospectus to the extent that a statement contained in this prospectus or any other subsequently filed document that is deemed to be incorporated by reference into this prospectus modifies or supersedes the statement. Any statement so modified or superseded will not be deemed, except as so modified or superseded, to constitute a part of this prospectus.

You may request, orally or in writing, a copy of any or all of the documents incorporated herein by reference. These documents will be provided to you at no cost, by contacting:

You may also access these documents on our website, http://www.springbankpharm.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.

You should rely only on information contained in, or incorporated by reference into, this prospectus and any prospectus supplement. We have not authorized anyone to provide you with information different from that contained in this prospectus or incorporated by reference in this prospectus. We are not making offers to sell the securities in any jurisdiction in which such an offer or solicitation is not authorized or in which the person making such offer or solicitation is not qualified to do so or to anyone to whom it is unlawful to make such offer or solicitation.

	Page
ABOUT THIS PROSPECTUS SUPPLEMENT	S-1
PROSPECTUS SUPPLEMENT SUMMARY	S-2
THE OFFERING	S-6
RISK FACTORS	S-7
SPECIAL NOTE REGARDING FORWARD-LOOKING STATEMENTS	S-9
USE OF PROCEEDS	S-10
DILUTION	S-11
PLAN OF DISTRIBUTION	S-12
LEGAL MATTERS	S-13
EXPERTS	S-13
WHERE YOU CAN FIND MORE INFORMATION	S-13
INCORPORATION OF DOCUMENTS BY REFERENCE	S-13

	Page
ABOUT THIS PROSPECTUS	1
PROSPECTUS SUMMARY	2
RISK FACTORS	6
RATIO OF EARNINGS TO FIXED CHARGES	6
SPECIAL NOTE REGARDING FORWARD-LOOKING STATEMENTS	7
USE OF PROCEEDS	8
PLAN OF DISTRIBUTION	9
DESCRIPTION OF COMMON STOCK	11
DESCRIPTION OF PREFERRED STOCK	12
DESCRIPTION OF DEBT SECURITIES	13
DESCRIPTION OF WARRANTS	19
DESCRIPTION OF RIGHTS	20
DESCRIPTION OF PURCHASE CONTRACTS	22
DESCRIPTION OF UNITS	23
CERTAIN PROVISIONS OF DELAWARE LAW AND OF THE COMPANY’S CERTIFICATE OF INCORPORATION AND BYLAWS	24
LEGAL MATTERS	27
EXPERTS	27
WHERE YOU CAN FIND MORE INFORMATION	27
INCORPORATION OF DOCUMENTS BY REFERENCE	28

	Page
ABOUT THIS PROSPECTUS	1
PROSPECTUS SUMMARY	2
RISK FACTORS	6
RATIO OF EARNINGS TO FIXED CHARGES	6
SPECIAL NOTE REGARDING FORWARD-LOOKING STATEMENTS	7
USE OF PROCEEDS	8
PLAN OF DISTRIBUTION	9
DESCRIPTION OF COMMON STOCK	11
DESCRIPTION OF PREFERRED STOCK	12
DESCRIPTION OF DEBT SECURITIES	13
DESCRIPTION OF WARRANTS	19
DESCRIPTION OF RIGHTS	20
DESCRIPTION OF PURCHASE CONTRACTS	22
DESCRIPTION OF UNITS	23
CERTAIN PROVISIONS OF DELAWARE LAW AND OF THE COMPANY’S CERTIFICATE OF INCORPORATION AND BYLAWS	24
LEGAL MATTERS	27
EXPERTS	27
WHERE YOU CAN FIND MORE INFORMATION	27
INCORPORATION OF DOCUMENTS BY REFERENCE	28