Filed Pursuant to Rule 424(b)(3)
Registration No. 333-258185

PROSPECTUS

ATHENEX, INC.

$300,000,000

COMMON STOCK

PREFERRED STOCK

WARRANTS

UNITS

SELLING STOCKHOLDERS

15,601,667 Shares of Common Stock

We may offer and sell up to $300,000,000 in the aggregate of the securities identified above from time to time in one or more offerings. This prospectus provides you with a general description of the securities. We may also offer common stock or preferred stock on conversion of common stock on conversion of preferred stock, or common stock or preferred stock on exercise of warrants.

This prospectus may also be used by the Selling Stockholders (as defined below), from time to time in one or more offerings, of up to 15,601,667 shares of our common stock held by such Selling Stockholders at prices and on terms that will be determined at the time of any such offerings. “Selling stockholders” refers to the selling stockholders named in this prospectus or in any supplement to this prospectus, or certain transferees, assignees or other successors-in-interest that may receive our securities from the selling stockholders. We will not receive any proceeds from the sale of shares of our common stock by the Selling Stockholders. We have agreed to bear certain expenses of the registration of the common stock, under the federal securities laws, on behalf of the Selling Stockholders.

This prospectus describes some of the general terms that may apply to an offering of our securities by us or any Selling Stockholders. When we or any Selling Stockholders decide to sell securities under this prospectus, we will provide the specific terms of these offerings and securities herein or in one or more supplements to this prospectus. We may also authorize one or more free writing prospectuses to be provided to you in connection with these offerings. The prospectus supplement and any related free writing prospectus may also add, update or change information contained in this prospectus. You should carefully read this prospectus, the applicable prospectus supplement and any related free writing prospectus, as well as the documents incorporated by reference, before buying any of the securities being offered.

Securities may be offered and sold by us or any Selling Stockholders to or through underwriters or dealers, directly to purchasers or through agents designated from time to time. For additional information on the methods of sale, you should refer to the section entitled “Plan of Distribution” in this prospectus and in the applicable prospectus supplement. If any underwriters are involved in the sale of any securities by us with respect to which this prospectus is being delivered, the names of such underwriters and any applicable discounts or commissions and over-allotment options will be set forth in a prospectus supplement.

The price to the public of such securities and the net proceeds we expect to receive from such sale will also be set forth in a prospectus supplement. The proceeds that we receive from any sales by us of the securities offered under this prospectus and any accompanying prospectus supplement will be reduced by any registration and offering fees and expenses.

Our common stock is traded on The Nasdaq Global Select Market under the symbol “ATNX.” On August 3, 2021, the last reported sale price of our common stock on The Nasdaq Global Select Market was $3.80 per share. We will indicate in any prospectus supplement if the securities offered thereby will be listed on any securities exchange.

Investing in our common stock involves a high degree of risk. Please read “Risk Factors” beginning on page 4 of this prospectus before making a decision to invest in our common stock.

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.

The date of this prospectus is August 12, 2021

TABLE OF CONTENTS

ABOUT THIS PROSPECTUS	1
FORWARD-LOOKING STATEMENTS	2
PROSPECTUS SUMMARY	2
RISK FACTORS	4
WHERE YOU CAN FIND MORE INFORMATION	5
INCORPORATION BY REFERENCE	5
DESCRIPTIONS OF THE SECURITIES WE MAY OFFER	6
DESCRIPTION OF CAPITAL STOCK	6
DESCRIPTION OF WARRANTS	10
DESCRIPTION OF UNITS	11
USE OF PROCEEDS	12
SELLING STOCKHOLDERS	13
PLAN OF DISTRIBUTION	14
LEGAL MATTERS	17
EXPERTS	17
PART II	II-1

You should rely only on the information contained in, or incorporated by reference into, this prospectus and the applicable prospectus supplement, along with the information contained in any free writing prospectuses we have authorized for use in connection with a specific offering. We have not authorized anyone to provide you with different information. We are not making an offer to sell or seeking an offer to buy securities under this prospectus or the applicable prospectus supplement and any related free writing prospectus in any jurisdiction where the offer or sale is not permitted. The information contained in this prospectus, the applicable prospectus supplement or any related free writing prospectus, and the documents incorporated by reference herein and therein, are accurate only as of their respective dates, regardless of the time of delivery of this prospectus, the applicable prospectus supplement or any related free writing prospectus, or any sale of a security.

ABOUT THIS PROSPECTUS

This prospectus is part of a registration statement on Form S-3 that we filed with the Securities and Exchange Commission, or SEC, using a “shelf” registration process. Under this shelf registration statement, from time to time, we may sell, in one or more offerings, common stock, preferred stock, or warrants to purchase any of such securities, either individually or in combination with other securities described in this prospectus for an aggregate offering price of $300,000,000. Each time we sell any type or series of securities under this prospectus, we will provide a prospectus supplement that will include more specific information about the terms of that offering. We may also authorize one or more free writing prospectuses to be provided to you that may contain material information relating to these offerings. In a prospectus supplement or free writing prospectus, we may also add, update, or change any of the information contained in this prospectus or in the documents we have incorporated by reference into this prospectus. This prospectus, together with the applicable prospectus supplement, any related free writing prospectus, and the documents incorporated by reference into this prospectus and the applicable prospectus supplement, will include all material information relating to the applicable offering. Before buying any of the securities being offered, you should carefully read both this prospectus and the applicable prospectus supplement and any related free writing prospectus, together with the additional information described in the section entitled “Where You Can Find Additional Information” and “Incorporation by Reference.” You should not assume that the information in this prospectus, any documents we incorporate by reference herein, or any accompanying prospectus supplement, if any, is accurate as of any date other than the date on the front of each such document. Our business, financial condition, results of operation and prospects may have changed since this date.

In addition, under this process, the Selling Stockholders named herein may offer and sell, from time to time in one or more offerings, up to an aggregate of 15,601,667 shares of our common stock.

This prospectus contains summaries of certain provisions contained in some of the documents described herein, but reference is made to the actual documents for complete information. All of the summaries are qualified in their entirety by the actual documents. Copies of some of the documents referred to herein have been filed, will be filed or will be incorporated by reference as exhibits to the registration statement of which this prospectus is a part, and you may obtain copies of those documents as described below under the section entitled “Where You Can Find More Information.”

This prospectus and the documents that are incorporated by reference herein contain certain market data and industry statistics and forecasts that are based on studies and clinical trials sponsored by Athenex, Inc. or third parties, independent industry publications and other publicly available information. Although we believe these sources are reliable, we do not guarantee the accuracy or completeness of this information and we have not verified any of this data. Further, many of these statements involve risks and uncertainties and are subject to change based on various factors, including those discussed under the caption “Risk Factors” in this prospectus and under similar captions in the documents that are incorporated by reference herein. Accordingly, investors should not place undue reliance on this information.

Unless otherwise mentioned or unless the context requires otherwise, when used in this prospectus, the terms “Athenex”, “Company”, “we”, “us”, and “our” refer to Athenex, Inc. and its subsidiaries.

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FORWARD-LOOKING STATEMENTS

This prospectus, including the documents that we incorporate by reference herein, contains, and any applicable prospectus supplement or free writing prospectus including the documents we incorporate by reference therein may contain, forward-looking statements, including statements regarding our future financial condition, business strategy and plans and objectives of management for future operations. Forward-looking statements include all statements that are not historical facts. In some cases, you can identify forward-looking statements by terminology such as “believe,” “will,” “may,” “estimate,” “continue,” “anticipate,” “intend,” “should,” “plan,” “might,” “approximately,” “expect,” “predict,” “could,” “potentially” or the negative of these terms or other similar expressions. Forward-looking statements appear in a number of places throughout this prospectus and the documents that we incorporate by reference herein, and include statements regarding our intentions, beliefs, projections, outlook, analyses or current expectations concerning, among other things, our ongoing and planned preclinical development and clinical trials, the timing of and our ability to make regulatory filings and obtain and maintain regulatory approvals and our future product candidates, our intellectual property position, the degree of clinical utility of our future product candidates, particularly in specific patient populations, our ability to develop commercial functions, expectations regarding clinical trial data, our results of operations, cash needs, spending of the proceeds from offerings of securities under this prospectus, financial condition, liquidity, prospects, growth and strategies, the industry in which we operate and the trends that may affect our industry or us.

Discussions containing these forward-looking statements may be found, among other places, in the sections entitled “Business,” “Risk Factors” and “Management’s Discussion and Analysis of Financial Condition and Results of Operations” incorporated by reference from our most recent Annual Report on Form 10-K, as well as any amendments thereto, filed with the SEC. These statements relate to future events or our future financial performance and involve known and unknown risks, uncertainties and other factors that could cause our actual results, levels of activity, performance or achievement to differ materially from those expressed or implied by these forward-looking statements. We discuss in greater detail, and incorporate by reference into this prospectus in their entirety, many of these risks and uncertainties under the heading “Risk Factors” contained in the applicable prospectus supplement, in any free writing prospectus we may authorize for use in connection with a specific offering, and in our most recent Annual Report on Form 10-K, as well as any amendments thereto reflected in subsequent filings with the SEC. These statements reflect our current views with respect to future events and are based on assumptions and subject to risks and uncertainties. Given these uncertainties, you should not place undue reliance on these forward-looking statements. These forward-looking statements represent our estimates and assumptions only as of the date of the document containing the applicable statement and, except as required by law, we undertake no obligation to update or revise publicly any forward-looking statements, whether as a result of new information, future events or otherwise.

PROSPECTUS SUMMARY

The following summary, because it is a summary, may not contain all the information that may be important to you. This prospectus incorporates important business and financial information about the Company that is not included in, or delivered with, this prospectus. Before making an investment, you should read the entire prospectus and any amendment carefully. You should also carefully read the risks of investing discussed under “Risk Factors” and the financial statements included in our other filings with the SEC, including in our most recent Quarterly Report on Form 10-Q for the quarter and three months ended March 31, 2021, which we filed with the SEC on May 6, 2021, our Annual Report on Form 10-K for the fiscal year ended December 31, 2020, which we filed with the SEC on March 1, 2021, and our Current Reports on Form 8-K filed May 5, 2021 and Form 8-K/A filed July 20, 2021. This information is incorporated by reference into this prospectus, and you can obtain it from the SEC as described below under the headings “Where You Can Find Additional Information About Us” and “Incorporation of Certain Documents by Reference.”

We will provide to each person, including any beneficial owner, to whom a prospectus is delivered, a copy of any or all of the information that has been incorporated by reference in the prospectus but not delivered with the prospectus. You may request a copy of these filings, excluding the exhibits to such filings which we have not specifically incorporated by reference in such filings, at no cost, by writing us at the following address: 1001 Main Street, Suite 600, Buffalo, NY, United States. You may also contact us at (716) 427-2950.

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OUR COMPANY

Overview

We are a global biopharmaceutical company dedicated to becoming a leader in the discovery, development and commercialization of next generation drugs for the treatment of cancer. Our mission is to improve the lives of cancer patients by creating more effective, safer and tolerable treatments. We are organized around three platforms, an Oncology Innovation Platform, a Commercial Platform and a Global Supply Chain Platform. Our current clinical pipeline in the Oncology Innovation Platform is derived from four different technologies: (1) Orascovery, based on a P-glycoprotein (“P-gp”) pump inhibitor, (2) Src Kinase inhibition, (3) Cell therapy, and (4) Arginine deprivation therapy. We have assembled a strong and experienced leadership team and have established operations across the pharmaceutical value chain to execute our goal of becoming a global leader in bringing innovative cancer treatments to the market and improving health outcomes.

Oncology Innovation Platform

Orascovery Platform

Our Orascovery technology is based on the novel P-gp pump inhibitor molecule, encequidar, formerly known as HM30181A. Oral administration of encequidar in combination with established chemotherapy agents such as paclitaxel, irinotecan, docetaxel and eribulin has been shown in our clinical studies to date to improve the absorption of these agents by blocking the P-gp pump in the intestinal wall. Oral paclitaxel and encequidar, formerly known as Oraxol (“Oral Paclitaxel”) is our lead asset in our Orascovery platform. We are also advancing the following clinical candidates for the treatment of solid tumors on this platform: oral irinotecan and encequidar, formerly known as Oratecan (“Oral Irinotecan”); oral docetaxel and encequidar, formerly known as Oradoxel (“Oral Docetaxel”); and oral eribulin and encequidar (“Oral Eribulin”).

Src Kinase Inhibition Platform

Our Src Kinase inhibition platform technology is based on novel small molecule compounds that have multiple mechanisms of action, including the inhibition of the activity of Src Kinase and the inhibition of tubulin polymerization, which may limit the growth or proliferation of cancerous cells. We believe the combination of these mechanisms of action provides a broader range of anti-cancer activity compared to either mechanism of action alone. Our lead product candidate on our Src Kinase inhibition platform is tirbanibulin (formerly known as KX2-391 and KX-01) ointment, which we are advancing for the treatment of actinic keratosis (“AK”).

Other Platforms

The other technologies in our Oncology Innovation Platform are our TCR-T immunotherapy technology under which we are advancing TCR affinity-enhancing specific T-cell (TAEST) therapy with our first T cell therapy product, TCRT-ESO-A2, and our Arginine deprivation therapy technology under which we are advancing PT01.

Kuur Acquisition

Kuur Therapeutics (formerly known as Cell Medica, “Kuur”) is a clinical-stage biopharmaceutical company focused on the development of allogeneic, or “off-the-shelf”, NKT cell immunotherapies for the treatment of solid and hematological malignancies. Kuur’s immunotherapy platform engineers CARs expressed by semi-invariant NKT cells, which combine features of T and NK cells, and is being developed in partnership with Baylor College of Medicine and Texas Children’s Hospital. Allogeneic cell therapy has the potential to be faster and less expensive than patient-specific autologous products, and NKT cells offer several advantages over other cell types for allogeneic immunotherapy applications. NKT cells have the cytotoxic and anti-tumor properties of conventional T cells, but with other biological attributes that are expected to improve their ability to attack hematological and solid tumors. These include amplification of the immune response, innate tissue and solid tumor homing properties, as well as endogenous anti-tumor activity based on the ability to eliminate immune suppressive cells and activate host immune cells within the tumor microenvironment.

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Kuur’s pipeline consists of three products: KUR-501, KUR-502, and KUR-503:

KUR-501 is an autologous product in which NKT cells are engineered with a CAR targeting GD2, which is expressed on almost all neuroblastoma tumors, as well as other malignancies. KUR-501 is being tested in the phase 1 GINAKIT2 clinical study in patients with R/R high risk neuroblastoma. The single-arm study will evaluate six dose levels of KUR-501 with patients receiving pre-dose lymphodepletion chemotherapy consisting of cyclophosphamide and fludarabine. Neuroblastoma is a pediatric cancer and patients with R/R high risk neuroblastoma have a poor prognosis and a significant unmet medical need. The KUR-501 development program is also designed to provide autologous proof-of-concept for CAR-NKT cells in solid tumors using a validated target. The GINAKIT2 study is supported by Kuur Therapeutics and conducted by Kuur’s collaborator, Baylor College of Medicine (“BCM”), and is currently recruiting patients.

KUR-502 is an allogeneic product in which NKT cells are engineered with a CAR targeting CD19. KUR-502 is built on Kuur’s next-generation CAR-NKT platform with novel engineering capabilities that harness and enhance the unique properties of NKT cells. The NKT cells used in Kuur’s CAR-NKT platform have a semi-invariant TCR that does not distinguish between self- and non-self-tissues, making the cells unlikely to induce graft versus host disease (GvHD). As a result, KUR-502 cells are harvested and manufactured from healthy donors. The ANCHOR clinical study is a phase 1, first-in-human, dose escalation evaluation of KUR-502 in adults with R/R CD19 positive malignancies including B cell lymphomas, acute lymphoblastic leukemia (ALL), and chronic lymphocytic leukemia (CLL). The single-arm study will evaluate three dose levels with patients receiving lymphodepletion chemotherapy consisting of cyclophosphamide and fludarabine followed by infusion with KUR-502. Patients with R/R CD19-positive malignancies have limited effective treatment options. While CD19-directed autologous CAR-T cells are now available for these patients, they are limited by a requirement for patient leukapheresis, delays to receive treatment due to the requirement for autologous manufacturing, limited access, and variable final product quality. Off-the-shelf KUR-502 is designed to overcome these limitations. The ANCHOR study is being sponsored and conducted by Kuur’s collaborator, BCM and is currently recruiting patients.

KUR-503 is a product in which NKT cells are engineered with a CAR targeting GPC3 (glypican-3). GPC3 is a molecule that is highly expressed on most hepatocellular carcinomas (HCC), but not normal liver or other non-neoplastic tissue, making it an ideal target. Because NKT cells home to the liver, they are excellent candidates to deliver immune effector therapy for patients with HCC. HCC is now the fourth most common cause of cancer related death worldwide, with an estimated 750,000 new cases each year. Although there have been some recent approvals of new agents to treat advanced HCC, these patients still have poor outcomes and there is a significant unmet need. KUR-503 is currently in preclinical development and the company is planning to submit an IND in 2022.

We believe that the acquisition of Kuur Therapeutics can potentially launch our cell therapy product portfolio to be one of the leaders in cell therapy. Kuur’s pipeline enables us to expand the cell therapy R&D pipeline by adding to Athenex’s current TCRT immunotherapy program. The first cell therapy product in the TCRT immunotherapy program, TCRT-ESO-A2, is based on an autologous approach of transducing a patient’s T cells with a T cell receptor (TCR) that recognizes a cancer antigen derived from the protein NYESO-1. The broad applicability of NKT cells allow for insertion of a CAR to target hematological malignancies and a TCR to target solid tumors.

RISK FACTORS

Investing in our securities involves risk. The prospectus supplement applicable to a particular offering of securities will contain a discussion of the risks applicable to an investment in Athenex, Inc. and to the particular types of securities that we are offering under that prospectus supplement. Before making an investment decision, you should carefully consider the risks described under “Risk Factors” in the applicable prospectus supplement and the risks described in our most recent Annual Report on Form 10-K, or any updates in our Quarterly Reports on Form 10-Q, together with all of the other information appearing in or incorporated by reference into this prospectus, including the additional information described in the section entitled “Where You Can Find Additional Information” and “Incorporation by Reference”, and any applicable prospectus supplement, in light of your particular investment objectives and financial circumstances. Our business, financial condition or results of operations could be materially adversely affected by any of these risks. The trading price of our securities could decline due to any of these risks, and you may lose all or part of your investment.

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WHERE YOU CAN FIND MORE INFORMATION

We file annual, quarterly and current reports, proxy statements and other information with the SEC. Our filings with the SEC are available to the public through the SEC’s internet site at www.sec.gov. Our annual, quarterly and current reports and amendments to those reports, if any, are also available via the internet at our website, www.athenex.com. All internet addresses provided in this prospectus are for informational purposes only and are not intended to be hyperlinks. In addition, the information on, or accessible through, our internet site, or any other internet site described herein, is not a part of, and is not incorporated or deemed to be incorporated by reference in, this prospectus, and you should not consider it to be a part of this prospectus. In addition, you may request copies of these filings, including the documents listed below under the heading “Incorporation by Reference,” at no cost, by calling us at (716) 427-2950 or by writing to us at: Athenex, Inc., Main Street, Suite 600, Buffalo, NY, United States.

We have filed with the SEC a registration statement under the Securities Act relating to the offering of these securities. The registration statement, including the attached exhibits, contains additional relevant information about us and the securities. This prospectus does not contain all of the information set forth in the registration statement. You may review a copy of the registration statement and the documents incorporated by reference herein through the SEC’s internet web site referred to above.

INCORPORATION BY REFERENCE

THIS PROSPECTUS INCORPORATES DOCUMENTS BY REFERENCE THAT ARE NOT PRESENTED IN OR DELIVERED WITH THIS PROSPECTUS. YOU SHOULD RELY ONLY ON THE INFORMATION CONTAINED IN THIS PROSPECTUS AND IN THE DOCUMENTS THAT WE HAVE INCORPORATED BY REFERENCE INTO THIS PROSPECTUS. WE HAVE NOT AUTHORIZED ANYONE TO PROVIDE YOU WITH INFORMATION THAT IS DIFFERENT FROM OR IN ADDITION TO THE INFORMATION CONTAINED IN THIS DOCUMENT AND INCORPORATED BY REFERENCE INTO THIS PROSPECTUS.

The SEC allows us to incorporate by reference information into this prospectus and any accompanying prospectus supplement from other documents that we file with it, which means that we can disclose important information to you by referring you to those documents. The information incorporated by reference is considered to be part of this prospectus. Information in this prospectus supersedes information incorporated by reference that we filed with the SEC prior to the date of this prospectus, while information that we file later with the SEC will automatically update and supersede the information in this prospectus. We incorporate by reference into this prospectus and the registration statement of which this prospectus is a part the information or documents listed below that we have filed with the SEC, except for information “furnished” under Items 2.02 or 7.01 and any related Items 9.01 on Form 8-K or other information “furnished” to the SEC which is not deemed filed and not incorporated in this prospectus, until the termination of the offering of securities described in this prospectus:

• Annual Report on Form 10-K for the fiscal year ended December 31, 2020, filed with the SEC on March 1, 2021;

• Definitive Proxy Statement on Schedule 14A, filed with the SEC on April 29, 2021, to the extent incorporated into our Annual Report on Form 10-K for the fiscal year ended December 31, 2020, filed with the SEC on March 1, 2021;

• Quarterly Reports on Form 10-Q for the quarterly period ended March 31, 2021 filed with the SEC on May 6, 2021;

• Current reports on Form 8-K filed with the SEC on February 18, 2021, May  5, 2021 (as amended on July 20, 2021), May  6, 2021, June 23, 2021, July 20, 2021, and August 5, 2021; and

• The description of our common stock contained in our registration statement on Form 8-A, filed with the SEC on June 12, 2017, and any amendment or report filed for the purpose of updating such description.

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We also incorporate by reference any future filings (other than current reports furnished under Item 2.02 or Item 7.01 of Form 8-K and exhibits filed on such form that are related to such items unless such Form 8-K expressly provides to the contrary) made with the SEC pursuant to Sections 13(a), 13(c), 14 or 15(d) of the Exchange Act, including those made after the date of the initial filing of the registration statement of which this prospectus is a part and prior to effectiveness of such registration statement, until we file a post-effective amendment that indicates the termination of the offering of the securities made by this prospectus, which will become a part of this prospectus from the date that such documents are filed with the SEC. Information in such future filings updates and supplements the information provided in this prospectus. Any statements in any such future filings will automatically be deemed to modify and supersede any information in any document we previously filed with the SEC that is incorporated or deemed to be incorporated herein by reference to the extent that statements in the later-filed document modify or replace such earlier statements. We will furnish without charge to each person, including any beneficial owner, to whom a prospectus is delivered, upon written or oral request, a copy of any or all of the documents incorporated by reference into this prospectus but not delivered with the prospectus, including exhibits that are specifically incorporated by reference into such documents. You should direct any requests for documents to:

Athenex, Inc.

1001 Main Street, Suite 600

Buffalo, NY 14203

(716) 427-2950

DESCRIPTIONS OF THE SECURITIES WE MAY OFFER

The descriptions of the securities contained in this prospectus, together with any applicable prospectus supplement, summarize all the material terms and provisions of the various types of securities that we may offer and any Selling Stockholders may offer hereunder for resale. We will describe in the applicable prospectus supplement relating to a particular offering the specific terms of the securities offered by that prospectus supplement. We will indicate in the applicable prospectus supplement if the terms of the securities differ from the terms we have summarized below. We will also include in the prospectus supplement information, where applicable, material United States federal income tax considerations relating to the securities.

We may offer and sell from time to time, in one or more offerings:

• shares of our common stock;

• shares of preferred stock;

• warrants to purchase any of the securities listed above.

Other than with respect to the resale of common stock by the Selling Stockholders named herein, this prospectus may not be used to consummate a sale of securities unless it is accompanied by a prospectus supplement.

DESCRIPTION OF CAPITAL STOCK

The following is a description of certain provisions of our amended and restated certificate of incorporation and bylaws, both of which were adopted in connection with our initial public offering in June 2017, and certain provisions of our outstanding options and the Delaware General Corporation Law, or DGCL. The following description does not purport to be complete and is subject to, and qualified in its entirety by reference to, the forms of our amended and restated certificate of incorporation and amended and restated bylaws, the forms of stock option agreements filed as exhibits to the registration statement, of which this prospectus forms a part, and the terms and provisions of the DGCL. For more complete information, you should carefully review the forms of our amended and restated certificate of incorporation and amended and restated bylaws and stock option agreements, which have been filed with the SEC as exhibits to our registration statement of which this prospectus forms a part and which may be obtained as described below under “Where You Can Find More Information.”

Our authorized capital stock consists of 250,000,000 shares of common stock, par value $0.001 per share, our “common stock,” and 25,000,000 shares of preferred stock, par value $0.001 per share, our “preferred stock”.

As of July 26, 2021, there were 109,307,740 shares of our common stock outstanding, which included 22,500 issued but unvested restricted shares, and no shares of our preferred stock outstanding. As of July 26, 2021, there were 102 holders of record of our common stock. The actual number of stockholders is greater than this number of record holders and includes stockholders who are beneficial owners but whose shares are held in street by brokers and other nominees.

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Common Stock

Under our amended and restated certificate of incorporation and amended and restated bylaws, holders of our common stock are entitled to one vote per share on all matters submitted to a vote of our common stockholders and do not have cumulative voting rights in the election of directors. This means that, subject to any rights of holders of outstanding shares of our preferred stock, if any, to elect or vote in the election of directors, the holders of a majority of the outstanding shares of our common stock can elect all of the directors standing for election by holders of our common stock and the holders of the remaining outstanding shares of our common stock are not able to elect any such directors. Under the terms of our amended and restated certificate of incorporation and our amended and restated bylaws, holders of our common stock do not have any conversion rights with respect to our common stock, nor is our common stock subject to any redemption or sinking provisions.

Holders of common stock are entitled to share ratably in any common stock dividends that may be declared by the board of directors out of legally available funds, subject to any preferential rights of our preferred stockholders, if any, to receive dividends and the terms of any existing or future agreements between us and our lenders. We presently intend to retain all available cash, if any, for use in the operation and expansion of our business and we therefore do not anticipate paying cash dividends on our common stock in the foreseeable future. In the event of our liquidation, dissolution or winding up, common stockholders are entitled to share ratably in all assets legally available for distribution to our common stockholder after payment of or provision for all of our debts and other liabilities, and subject to any preferential rights of our preferred stock to receive distributions in the event of our liquidation, distribution or winding up.

Preferred Stock

Our board of directors is authorized, without vote or action by the stockholders, to issue from time to time up to an aggregate of 25,000,000 shares of preferred stock in one or more series and to fix or alter the designations, preferences, rights and any qualifications, limitations or restrictions of the shares of each of these series, including, if applicable, the dividend rights and preferences, conversion rights, voting rights, terms and rights of redemption, including without limitation sinking fund provisions, redemption price or prices, liquidation rights and preferences, and the number of shares constituting any series. The issuance of preferred stock may have the effect of delaying, deferring or preventing a change in control of us without further action by our stockholders and may adversely affect the dividend, liquidation and voting and other rights of the holders of common stock. The issuance of preferred stock with voting and conversion rights may adversely affect the voting power of the holders of common stock, including the loss of voting control to others. We currently have no plans to issue any shares of preferred stock.

We believe that the ability to issue preferred stock without the expense and delay of a special stockholders’ meeting provides us with increased flexibility in structuring possible future financings and acquisitions, and in meeting other corporate needs that might arise. This also permits the board of directors to issue preferred stock containing terms which could impede the completion of a takeover attempt. This could discourage an acquisition attempt or other transaction which stockholders might believe to be in their best interests or in which they might receive a premium for their stock over the then market price of the stock.

Anti-takeover Provisions of Delaware Law, Our Amended and Restated Certificate of Incorporation and Amended and Restated Bylaws

The provisions of the DGCL, our amended and restated certificate of incorporation and our amended and restated bylaws may have the effect of delaying, deferring or discouraging another person from acquiring control of us by means of a tender offer, a proxy contest or otherwise, or removing incumbent officers and directors. These provisions, some of which are described below, may discourage certain types of coercive takeover practices and takeover bids that our board of directors may consider inadequate and to encourage any person seeking to acquire control of us to first negotiate with our board of directors. We believe the benefits of increased protection of our ability to negotiate with the proponent of an unfriendly or unsolicited proposal to acquire or restructure us outweighs the disadvantages of discouraging takeover or acquisition proposals because, among other things, negotiation of these proposals could result in an improvement of their terms.

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Classified Board

Our amended and restated certificate of incorporation provides that subject to the rights of holders of any one or more series of preferred stock to elect one or more directors, the board shall be divided into three (3) classes, with the intention that each class consist of approximately one-third of the total number of our directors. At each annual meeting of stockholders, each of the successors elected to replace the directors of a class whose term expires at such annual meeting shall be elected to hold office until the third annual meeting next succeeding his or her election and until his or her respective successor shall have been duly elected and qualified. Our stockholders elect only one class of directors each year. We believe that classification of our board of directors helps to assure the continuity of our business strategies and policies. The classified board provision could have the effect of making the replacement of incumbent directors more time consuming and difficult. At least two annual meetings of our stockholders generally are required to effect a change in a majority of our board of directors.

Removal of Directors; Filling Vacancies and Newly Created Directorships

Our amended and restated certificate of incorporation and amended and restated bylaws provide that subject to any limitations imposed by law and the rights of the holders of any series of our preferred stock, the board of directors or any individual director may be removed from office by our stockholders only for cause. Subject to the rights of holders of any series of outstanding preferred stock, vacancies in the board and newly created directorships shall, unless otherwise provided by law, be filled solely by the affirmative vote of a majority of directors then in office, or by a sole remaining director, and shall not be filled by stockholders. Our board of directors currently includes a total of seven directors. Our board of directors has the power to fix the number of directors within a range specified in our amended and restated bylaws.

No Written Consent of Stockholders

Our amended and restated certificate of incorporation provides that all stockholder actions are required to be taken by a vote of the stockholders at an annual or special meeting, and that stockholders may not take any action by written consent in lieu of a meeting.

Special Meetings of Stockholders

Our amended and restated certificate of incorporation provides that special meetings of stockholders may only be called by the chairman of our board of directors, our chief executive officer, or our board of directors. In addition, our amended and restated bylaws prohibit the conduct of any business at a special meeting other than as specified in the notice of such meeting.

Advance Notice Requirements and Procedures

Our amended and restated bylaws establish advance notice procedures with regard to stockholder proposals relating to the nomination of candidates for election as directors or new business to be brought before meetings of our stockholders. These procedures provide that notice of stockholder nominations and proposals must be timely given in writing to our secretary prior to the meeting at which the action is to be taken. Generally, to be timely, notice must be received at our principal executive offices not later than the ninetieth (90th) day nor earlier than the one hundred twentieth (120th) day prior to the first anniversary of the annual meeting for the preceding year. The notice must contain certain information specified in the bylaws. These provisions may have the effect of precluding the nomination of candidates for election as directors and the conduct of certain business at a meeting if the proper procedures are not followed. These provisions may also discourage or deter a potential acquirer from conducting a solicitation of proxies to elect the acquirer’s own slate of directors or otherwise attempting to obtain control of our company.

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Amendment to Certificate of Incorporation and Bylaws

Our amended and restated certificate of incorporation provides that the affirmative votes of the holders of at least seventy-five percent (75%) of the voting power of all of the then outstanding shares of our capital stock entitled to vote generally in the election of directors, voting together as a single class, are required to amend certain provisions of our certificate of incorporation, including provisions relating to the size of our board of directors, term and classification of directors, removal of directors, filling board vacancies and newly-created directorships, special meetings of stockholders, shareholder action by written consent, limitation of liability and indemnification, and amendment of the certificate of incorporation and bylaws.

The affirmative votes of the holders of at least seventy-five percent (75%) of the voting power of all of the then-outstanding shares of our voting stock are required to amend or repeal our bylaws. In addition, our amended and restated bylaws may be amended by our board of directors.

Blank Check Preferred Stock

Our amended and restated certificate of incorporation permits our board of directors, without vote or action by the stockholders, to issue from time to time up to an aggregate of 25,000,000 shares of preferred stock in one or more series and to fix or alter the number of shares and other terms and provisions of each such series, which may include voting rights, dividend rights and preferences, rights to convert to common stock or other securities, and liquidation rights and preferences. The existence of authorized but unissued shares of preferred stock may enable our board of directors to render more difficult or to discourage an attempt to obtain control of us by means of a merger, tender offer, proxy contest or otherwise. For example, if in the due exercise of its fiduciary obligations, our board of directors were to determine that a takeover proposal is not in the best interests of us or our stockholders, our board of directors could cause shares of preferred stock to be issued without stockholder approval in one or more private offerings or other transactions that might dilute the voting, economic or other rights of the proposed acquirer or insurgent stockholder or stockholder group. In this regard, our certificate of incorporation grants our board of directors broad power to establish the rights and preferences of authorized and unissued shares of preferred stock. The issuance of shares of preferred stock could decrease the amounts and assets available for distribution to holders of shares of common stock. The issuance may also adversely affect the rights and powers, including voting rights, of these holders and may have the effect of delaying, deterring or preventing a change in control of us.

Section 203 of the DGCL

We are subject to the provisions of Section 203 of the DGCL, as amended. In general, Section 203 prohibits a publicly-held Delaware corporation from engaging in a “business combination” with an “interested stockholder” for a three-year period following the time that this stockholder becomes an interested stockholder, unless the business combination is approved in a prescribed manner. A “business combination” includes, among other things, a merger, asset or stock sale or other transaction resulting in a financial benefit to the interested stockholder. An “interested stockholder” is, in general, a person who, together with affiliates and associates, owns, or did own within three years prior to the determination of interested stockholder status, 15 percent or more of the corporation’s voting stock.

Under Section 203, a business combination between a corporation and an interested stockholder is prohibited unless it satisfies one of the following conditions:

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

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

• at or after the time the stockholder became interested, the business combination was approved by the board of directors of the corporation and authorized at an annual or special meeting of the stockholders by the affirmative vote of at least 66 2/3 percent of the outstanding voting stock which is not owned by the interested stockholder.

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A Delaware corporation may “opt out” of these provisions with an express provision in its original certificate of incorporation or an express provision in its certificate of incorporation or bylaws resulting from a stockholders’ amendment approved by at least a majority of the outstanding voting shares. We have not opted out of these provisions. As a result, mergers or other takeover or change in control attempts of us may be discouraged or prevented.

Delaware as Sole and Exclusive Forum

Our amended and restated certificate of incorporation provides that, unless a majority of our board of directors consents in writing to an alternative forum, the Court of Chancery of the State of Delaware (or, if the Court of Chancery does not have jurisdiction, another state court located within the State of Delaware, or, if no court located within the State of Delaware has jurisdiction, the federal district court for the District of Delaware) shall, to the fullest extent permitted by law, be the sole and exclusive forum for (i) any derivative action or proceeding brought on behalf of us, (ii) any action asserting a claim of breach of a fiduciary duty owed by any of our directors, officers or other employees to us or our stockholders, (iii) any action asserting a claim against us arising pursuant to any provision of the DGCL, as amended, or our certificate of incorporation or bylaws, or (iv) any action asserting a claim against us or any of our directors, officers or employees governed by the internal affairs doctrine of the State of Delaware.

NASDAQ Global Select Market Listing

Our common stock is listed on The NASDAQ Global Select Market under the symbol “ATNX”.

Registration Rights

In connection with our acquisition of Kuur, we are registering for resale the shares of our common stock received by the stockholders and certain former employees and directors of Kuur in connection with the transaction under the Securities Act.

The transfer agent and registrar for our common stock is Computershare Trust Company, Inc.

DESCRIPTION OF WARRANTS

We may issue warrants for the purchase of common stock or preferred stock. We may issue warrants independently or together with any offered securities. The warrants may be attached to or separate from those offered securities. We will issue the warrants under one or more warrant agreements to be entered into between us and a warrant agent to be named in the applicable prospectus supplement. The warrant agent will act solely as our agent in connection with the warrants and will not assume any obligation or relationship of agency or trust for or with any holders or beneficial owners of warrants.

The prospectus supplement relating to any warrants that we may offer will contain the specific terms of the warrants. These terms may include the following:

• the title of the warrants;

• the price or prices at which the warrants will be issued;

• the designation, amount and terms of the securities for which the warrants are exercisable;

• the designation and terms of the other securities, if any, with which the warrants are to be issued and the number of warrants issued with each other security;

• the aggregate number of warrants;

• any provisions for adjustment of the number or amount of securities receivable upon exercise of the warrants or the exercise price of the warrants;

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• the price or prices at which the securities purchasable upon exercise of the warrants may be purchased;

• if applicable, the date on and after which the warrants and the securities purchasable upon exercise of the warrants will be separately transferable;

• a discussion of any material U.S. federal income tax considerations applicable to the exercise of the warrants;

• the date on which the right to exercise the warrants will commence, and the date on which the right will expire;

• the maximum or minimum number of warrants that may be exercised at any time;

• information with respect to book-entry procedures, if any; and

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

• any Selling Stockholder will act independently of us in making decisions with respect to the timing, manager and size of each sale of shares of common stock covered by this prospectus.

Exercise of Warrants

Each warrant will entitle the holder of the warrant to purchase for cash the amount of common stock or preferred stock at the exercise price stated or determinable in the applicable prospectus supplement for the warrants. Warrants may be exercised at any time up to the close of business on the expiration date shown in the applicable prospectus supplement, unless otherwise specified in such prospectus supplement. After the close of business on the expiration date, unexercised warrants will become void. Warrants may be exercised as described in the applicable prospectus supplement. When the warrant holder makes the payment and properly completes and signs the warrant certificate at the corporate trust office of the warrant agent or any other office indicated in the prospectus supplement, we will, as soon as possible, forward the common stock or preferred stock that the warrant holder has purchased. If the warrant holder exercises the warrant for less than all of the warrants represented by the warrant certificate, we will issue a new warrant certificate for the remaining warrants.

The description in the applicable prospectus supplement of any warrants we offer will not necessarily be complete and will be qualified in its entirety by reference to the applicable warrant agreement and warrant certificate, which will be filed with the SEC if we offer warrants. For more information on how you can obtain copies of any warrant certificate or warrant agreement if we offer warrants, see “Where You Can Find More Information” beginning on page 30 of this prospectus. We urge you to read the applicable warrant certificate, the applicable warrant agreement and any applicable prospectus supplement in their entirety.

DESCRIPTION OF UNITS

The following description, together with the additional information we may include in any applicable prospectus supplement, 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 offered 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 file as exhibits to the registration statement of which this prospectus is a part, or will incorporate by reference from a Current Report on Form 8-K that we file with the SEC, the form of unit agreement that describes the terms of the series of units being offered, 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 sell under this prospectus, as well as the complete unit agreement and any supplemental agreements that contain the terms of the units.

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General

We may issue units comprised of one or more shares of common stock and warrants in any combination. Each unit would 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 would have the rights and obligations of a holder of each included security. 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, including:

• the designation and terms of the units and of the securities comprising the units, including whether and under what circumstances those securities may be held or transferred separately;

• any provisions of the governing unit agreement that differ from those described below; and

• any provisions for the issuance, payment, settlement, transfer or exchange of the units or of the securities comprising the units.

The provisions described in this section, as well as those described under “Description of Capital Stock” and “Description of Warrants” will apply to each unit and to any common shares or warrants included in each unit, respectively.

Unit Agent

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

Issuance in Series

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

Enforceability of Rights by Holders of Units

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.

Title

We, the unit agents and any of their agents may treat the registered holder of any unit certificate as an absolute owner of the units evidenced by that certificate for any purpose and as the person entitled to exercise the rights attaching to the units so requested, despite any notice to the contrary.

USE OF PROCEEDS

Except as otherwise provided in the applicable prospectus supplement, we intend to use the net proceeds from the sale of the securities covered by this prospectus for general corporate purposes. Additional information on the use of net proceeds from an offering of securities covered by this prospectus may be set forth in the prospectus supplement relating to the specific offering.

We will not receive any proceeds from securities offered for resale by the Selling Stockholders named herein.

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SELLING STOCKHOLDERS

This prospectus covers the resale from time to time by the Selling Stockholders of an aggregate of up to 15,601,667 shares of our Common Stock. Each of the Selling Stockholders have each represented to us that it purchased all of the securities registered by the registration statement of which this prospectus is a part in connection with our acquisition of Kuur and, at the time of purchase, had no agreements or understandings, directly or indirectly, with any person to distribute such shares of Common Stock. Other than as described in the table below, the Selling Stockholders and their affiliates have not held a position or office, or had any material relationship, with us within the last three years.

The table below: (1) lists the Selling Stockholders and other information regarding the beneficial ownership (as determined under Section 13(d) of the Exchange Act and the rules and regulations thereunder) of our Common Stock by the Selling Stockholders; (2) has been prepared based upon information furnished to us by the Selling Stockholders; and (3) to our knowledge, is accurate as of the date of this prospectus. The Selling Stockholders may sell all, some or none of their securities in this offering. The Selling Stockholders identified in the table below may have sold, transferred or otherwise disposed of some or all of their securities since the date of this prospectus in transactions exempt from or not subject to the registration requirements of the Securities Act. Information concerning the Selling Stockholders may change from time to time and, if necessary, we will amend or supplement this prospectus accordingly and as required.

	Shares Beneficially Owned Prior to the Offering(1)					Maximum Number of Shares to be sold in this Offering(2)		Shares Beneficially Owned After the Offering(1)(2)(3)
Selling Stockholder	Number		Percentage					Number		Percentage
IP2IPO Portfolio L.P (4)		9,205,672		8.42	%		9,205,672		—		—
Schroder UK Public Private Trust PLC (5)		2,081,106		1.90	%		2,081,106		—		—
HPSO SPV Limited		1,432,893		1.31	%		1,432,893		—		—
Touchstone Innovations Businesses LLP (6)		1,049,082		0.96	%		1,049,082		—		—
Kevin S. Boyle, Sr.		492,036		0.45	%		492,036		—		—
Baylor College of Medicine		416,668		0.38	%		416,668		—		—
Kurt Christian Gunter		266,520		0.24	%		266,520		—		—
Annalisa Mary Jenkins		246,018		0.23	%		246,018		—		—
Thomas Hecht		164,012		0.15	%		164,012		—		—
Julia P. Gregory		164,012		0.15	%		164,012		—		—
State Street Nominees Limited 34ZG (7)		42,645		0.04	%		42,645		—		—
Melinda Kay Lackey		41,003		0.04	%		41,003		—		—
TOTAL		15,601,667		14.27	%		15,601,667		—		—

(1) Percentage ownership for the Selling Stockholders is determined in accordance with Section 13(d) of the Exchange Act and the rules and regulations thereunder and is based on 109,307,740 outstanding shares of our Common Stock as of July 26, 2021.

(2) Since the Selling Stockholders may sell all, some or none of their shares, we cannot estimate the aggregate number of shares that the Selling Stockholders will offer pursuant to this prospectus or that the Selling Stockholders will own upon completion of the offering to which this prospectus relates. For purposes of the above table we assumed the Selling Stockholders will sell all of their shares, however, certain Selling Stockholders are subject to contractual restrictions pursuant to lock-up agreements.

(3) The totals reported in this column assume that (a) all of the securities registered by the registration statement of which this prospectus is a part are sold in this offering; (b) the Selling Stockholders do not (i) sell any of the shares of Common Stock, if any, that have been issued to them other than those covered by this prospectus; and (ii) acquire additional shares of our Common Stock after the date of this prospectus and prior to the completion of this offering.

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(4) Based solely on the Schedule 13G filed with the SEC on May 27, 2021 by IP Group PLC on behalf of the following persons: (i) IP Group PLC, a public limited company incorporated in England and Wales (“IP Group”); (ii) IP2IPO Portfolio L.P., a limited partnership registered in England and Wales (“IP2IPO”); and Touchstone Innovations Businesses LLP, a limited liability partnership incorporated in England and Wales (“Touchstone”):

These securities are directly held by IP2IPO, which is an indirect subsidiary wholly owned by IP Group, and, therefore, IP Group may be deemed to beneficially own all of the securities directly held by IP2IPO.

The principal address of each of IP Group and IP2IPO is The Walbrook, 25 Walbrook, London, United Kingdom EC4N 8AF.

(5) Schroder Adveq Management AG is the beneficial owner of these shares.

(6) Based solely on the Schedule 13G filed with the SEC on May 27, 2021 by IP Group on behalf of the following persons: (i) IP Group; (ii) IP2IP; and Touchstone:

These securities are directly held by Touchstone, which is an indirect subsidiary wholly owned by IP Group, and, therefore, IP Group may be deemed to beneficially own all of the securities directly held by Touchstone.

The principal address of each of IP Group and Touchstone is The Walbrook, 25 Walbrook, London, United Kingdom EC4N 8AF.

(7) Omnis Income & Growth Fund is the beneficial owner of these shares.

Set forth below is a description of the relationship between certain selling stockholders and the Company (and its predecessors and affiliates) within the last three years. Kuur Therapeutics Ltd. (formerly known as Cell Medica Ltd.) (“Kuur Ltd.”) is a subsidiary of Kuur.

• Kevin S. Boyle, Sr. is currently a consultant to Athenex, Inc. and was previously the Chief Executive Officer of Kuur, Kuur Therapeutics Ltd. (formerly known as Cell Medica Ltd.) (“Kuur Ltd.”), and was also the Chief Financial Officer of Kuur Ltd.

• Kurt Christian Gunter is currently the Chief Medical Officer for Cell Therapy and Head of Regulatory Affairs for Athenex, Inc. and was previously the Chief Medical Officer of Kuur and Kuur Ltd.

• Annalisa Mary Jenkins was previously a board member of Kuur and Kuur Ltd. within the last three years.

• Thomas Hecht was previously a board member of Kuur and Kuur Ltd. within the last three years.

• Julia P. Gregory was previously a board member of Kuur and Kuur Ltd. within the last three years.

• Melinda Kay Lackey is currently Legal Counsel, Cell Therapy of Athenex, Inc. and was previously Legal Counsel of Kuur and Kuur Ltd. and the Senior Legal counsel of Kuur Ltd.

• Sam Williams was previously a member of the board of Kuur. Each of Touchstone and IP2IPO are indirect subsidiaries wholly owned by IP Group to which Sam Williams is the managing partner of the life sciences department.

• Baylor College of Medicine is a party to a license agreement and co-development agreement with Cell Medica, Inc., an indirect subsidiary of the Company, pursuant to which Baylor College of Medicine licenses certain technology to the Company and performs research services related to that licensed technology. Baylor College of Medicine held a seat on Kuur Therapeutic, Inc.’s board of directors based on their equity ownership in the entity, which was greater than 5%. This seat was occupied by Shawn Davis.

PLAN OF DISTRIBUTION

We may sell the securities being offered hereby in one or more of the following ways from time to time:

• through underwriters for resale to purchasers;

• through dealers to purchasers;

• through agents to purchasers;

• directly to one or more purchasers; or

• through a combination of any of these methods of sale.

We may also sell the securities covered by this registration statement in an “at the market offering” as defined in Rule 415 under the Securities Act. Such offering may be made into an existing trading market for such securities in transactions at other than a fixed price, either:

• on or through the facilities of the NASDAQ Global Select Market or any other securities exchange or quotation or trading service on which such securities may be listed, quoted or traded at the time of sale; and/or

• to or through a market maker other than on the NASDAQ Global Select Market or such other securities exchanges or quotation or trading services.

We may also issue the securities as a dividend or distribution or in a subscription rights offering to our stockholders, in each case subject to applicable restrictive covenants contained in agreements and instruments governing our debt at the time of such dividend, distribution or offering. Any such dividend, distribution or subscription rights may or may not be transferable by stockholders. Other than with respect to the resale of common stock by the Selling Stockholders, the applicable prospectus supplement will describe the specific terms of the dividend, distribution or subscription rights, including the terms of the dividend, distribution or subscription rights offering, the terms, procedures and limitations relating to the exchange and exercise of the dividend, distribution or subscription rights and, if applicable, the material terms of any standby underwriting or purchase arrangement entered into by us in connection with the offering of common stock, other class of securities or units through the issuance of a dividend, distribution or subscription rights.

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We may directly solicit offers to purchase securities, or agents may be designated to solicit such offers. We will, in the prospectus supplement relating to such offering, name any agent that could be viewed as an underwriter under the Securities Act, and describe any commissions that we must pay. Any such agent will be acting on a best efforts basis for the period of its appointment or, if indicated in the applicable prospectus supplement, on a firm commitment basis.

The distribution of the securities may be effected from time to time in one or more transactions:

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

• at market prices prevailing at the time of sale; or

• at prices related to such prevailing market prices;

Each prospectus supplement will describe the method of distribution of the securities and any applicable restrictions.

The prospectus supplement with respect to the securities of a particular series will describe the terms of the offering of the securities, including the following:

• the name of the agent or any underwriters;

• the public offering or purchase price and the proceeds we will receive from the sale of the securities;

• any discounts and commissions to be allowed or re-allowed or paid to the agent or underwriters;

• all other items constituting underwriting compensation;

• any discounts and commissions to be allowed or re-allowed or paid to dealers; and

• any exchanges on which the securities will be listed.

If any underwriters or agents are utilized in the sale of the securities in respect of which this prospectus is delivered, we will enter into an underwriting agreement or other agreement with them at the time of sale to them, and we will set forth in the prospectus supplement relating to such offering the names of the underwriters or agents and the terms of the related agreement with them.

If a dealer is utilized in the sale of the securities in respect of which this prospectus is delivered, we will sell such securities to the dealer, as principal. The dealer may then resell such securities to the public at varying prices to be determined by such dealer at the time of resale.

We may sell securities directly or through agents we designate from time to time. We will name any agent involved in the offering and sale of securities, and we will describe any commissions we will pay the agent in the prospectus supplement. Unless the prospectus supplement states otherwise, our agent will act on a best-efforts basis for the period of its appointment.

We may authorize agents or underwriters to solicit offers by certain types of institutional investors to purchase securities from us at the public offering price set forth in the prospectus supplement pursuant to delayed delivery contracts providing for payment and delivery on a specified date in the future. We will describe the conditions to these contracts and the commissions we must pay for solicitation of these contracts in the prospectus supplement.

We or any Selling Stockholder may directly solicit offers to purchase securities, or agents may be designated to solicit such offers. We will, in the prospectus supplement relating to such offering, name any agent that could be viewed as an underwriter under the Securities Act and describe any commissions that we must pay. Any such agent will be acting on a best efforts basis for the period of its appointment or, if indicated in the applicable prospectus supplement, on a firm commitment basis. Agents, dealers and underwriters may be customers of, engage in transactions with, or perform services for us in the ordinary course of business.

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The Selling Stockholders may use any one or more of the following methods when disposing of shares or interests therein:

• ordinary brokerage transactions and transactions in which the broker-dealer solicits purchasers;

• block trades in which the broker-dealer will attempt to sell the shares as agent, but may position and resell a portion of the block as principal to facilitate the transaction;

• purchases by a broker-dealer as principal and resale by the broker-dealer for its account;

• an exchange distribution in accordance with the rules of the applicable exchange;

• privately negotiated transactions;

• short sales effected after the date the registration statement of which this prospectus is a part is declared effective by the SEC;

• through the writing or settlement of options or other hedging transactions, whether through an options exchange or otherwise;

• broker-dealers may agree with the Selling Stockholders to sell a specified number of such shares at a stipulated price per share;

• the in-kind distribution of the shares by an investment fund to its limited partners, members or other equity holders;

• a combination of any such methods of sale; and

• any other method permitted by applicable law.

Remarketing firms, agents, underwriters, dealers and other persons may be entitled under agreements which they may enter 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.

If so indicated in the applicable prospectus supplement, we will authorize underwriters 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 the 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 the 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:

• the purchase by an institution of the securities covered under that contract shall not, at the time of delivery, be prohibited under the laws of the jurisdiction to which that institution is subject; and

• if the securities are also being sold to underwriters acting as principals for their own account, the underwriters shall have purchased such securities not sold for delayed delivery. The underwriters and other persons acting as our agents will not have any responsibility in respect of the validity or performance of delayed delivery contracts.

Certain agents, underwriters and dealers, and their associates and affiliates may be customers of, have borrowing relationships with, engage in other transactions with, or perform services (including investment banking services) for us or one or more of our respective affiliates in the ordinary course of business.

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In order to facilitate the offering of the securities, any underwriters may engage in transactions that stabilize, maintain or otherwise affect the price of the securities or any other securities the prices of which may be used to determine payments on such securities. Specifically, any underwriters may over-allot in connection with the offering, creating a short position for their own accounts. In addition, to cover overallotments or to stabilize the price of the securities or of any such other securities, the underwriters may bid for, and purchase, the securities or any such other securities in the open market. Finally, in any offering of the securities through a syndicate of underwriters, the underwriting syndicate may reclaim selling concessions allowed to an underwriter or a dealer for distributing the securities in the offering if the syndicate repurchases previously distributed securities in transactions to cover syndicate short positions, in stabilization transactions or otherwise. Any of these activities may stabilize or maintain the market price of the securities above independent market levels. Any such underwriters are not required to engage in these activities and may end any of these activities at any time.

Under Rule 15c6-1 of the Exchange Act, trades in the secondary market generally are required to settle in three business days, unless the parties to any such trade expressly agree otherwise. The applicable prospectus supplement may provide that the original issue date for your securities may be more than three scheduled business days after the trade date for your securities. Accordingly, in such a case, if you wish to trade securities on any date prior to the third business day before the original issue date for your securities, you will be required, by virtue of the fact that your securities initially are expected to settle more than three scheduled business days after the trade date for your securities, to make alternative settlement arrangements to prevent a failed settlement.

In compliance with the guidelines of the Financial Industry Regulatory Authority, or FINRA, the aggregate maximum discount, commission or agency fees or other items constituting underwriting compensation to be received by any FINRA member or independent broker-dealer will not exceed 8% of the proceeds from any offering pursuant to this prospectus and any applicable prospectus supplement.

LEGAL MATTERS

Harter Secrest & Emery LLP will be passing upon matters of United States law for us with respect to securities offered by this prospectus and any accompanying prospectus supplement.

EXPERTS

The consolidated financial statements, and the related consolidated financial statement schedule, incorporated in this Prospectus by reference from the Company’s Annual Report on Form 10-K, and the effectiveness of the Company’s internal control over financial reporting, have been audited by Deloitte & Touche LLP, an independent registered public accounting firm, as stated in their reports, which are herein incorporated by reference. Such consolidated financial statements and consolidated financial statement schedule have been so incorporated in reliance upon the reports of such firm given upon their authority as experts in accounting and auditing.

The consolidated financial statements of Kuur Therapeutics Inc. as of and for the year ending December 31, 2020, appearing in the Company’s Current Report on Form 8-K/A dated May 4, 2021, have been audited by Moss Adams LLP, independent auditors, as set forth in their report included therein, which is incorporated herein by reference. Such consolidated financial statements have been so incorporated in reliance upon the report of such firm given upon their authority as experts in accounting and auditing.

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ATHENEX, INC.

Common Stock

Preferred Stock

Warrants

Units

Selling Stockholders

15,601,667 Shares of our

Common Stock

PROSPECTUS

August 12, 2021

We have not authorized any dealer, salesperson or other person to give any information or represent anything not contained in or incorporated by reference into this prospectus. You must not rely on any unauthorized information. If anyone provides you with different or inconsistent information, you should not rely on it. This prospectus does not offer to sell any shares in any jurisdiction where it is unlawful. Neither the delivery of this prospectus, nor any sale made hereunder, shall create any implication that the information in this prospectus is correct after the date hereof.