Codiak BioSciences (CDAKQ) 424B5 Prospectus supplement for primary offering

Filed Pursuant to Rule 424(b)(5)
Registration No. 333-260781

Prospectus supplement

(To prospectus dated November 15, 2021)

13,333,333 Shares of Common Stock

Warrants to Purchase up to 13,333,333 Shares of Common Stock

We are offering 13,333,333 shares of our common stock in this offering. Each investor will also receive a warrant to purchase one share of our common stock with an exercise price of $1.875 per share (referred to as “warrants”) for each share of common stock purchased. The warrants are immediately exercisable and expire on the date five (5) years from the date of issuance. This offering also relates to the shares of common stock issuable upon exercise of the warrants sold in this offering. The shares of common stock and the accompanying warrants can only be purchased together in this offering but will be issued separately and will be immediately separable upon issuance.

Our common stock is listed on The Nasdaq Global Market under the symbol “CDAK.” On September 9, 2022, the last reported sale price of our common stock was $1.79 per share. There is no established public trading market for the warrants, and we do not expect a market to develop. We do not intend to list the warrants on The Nasdaq Global Market, any other national securities exchange or any other nationally recognized trading system. Without an active trading market, the liquidity of the warrants will be limited.

We are an “emerging growth company” and a “smaller reporting company” under the federal securities laws and, as such, have elected to comply with certain reduced reporting requirements for this prospectus and may elect to do so in future filings.

Investing in our common stock involves a high degree of risk. These risks are described under the caption “Risk Factors” beginning on page S-8 of this prospectus and in the documents incorporated by reference into this prospectus supplement.

Neither the Securities and Exchange Commission nor any state securities commission has approved or disapproved of these securities or passed upon the accuracy or adequacy of this prospectus. Any representation to the contrary is a criminal offense.

	PER SHARE AND ACCOMPANYING WARRANTS(1)		TOTAL
Public offering price	$	1.50	$	19,999,999.50
Underwriting discounts and commissions (2)	$	0.09	$	1,199,999.97
Proceeds, before expenses, to Codiak BioSciences, Inc.	$	1.41	$	18,799,999.53

⁽¹⁾  The public offering price is $1.50 per share of common stock and accompanying warrants.

⁽²⁾  See “Underwriting” for a description of compensation payable to the underwriter.

The above summary of offering proceeds to us does not give effect to any exercise of the warrants being issued in this offering.

We have granted the underwriter an option to purchase up to 1,999,999 additional shares of our common stock and warrants to purchase up to an aggregate of 1,999,999 additional shares of our common stock, in each case at their respective public offering prices, less underwriting discounts and commissions. The underwriter can exercise this option at any time within 30 days after the date of this prospectus supplement. If the underwriter exercises its option to purchase 1,999,999 additional shares of our common stock together with accompanying warrants to purchase up to 1,999,999 shares of our common stock in full, we estimate that our net proceeds from this offering will be approximately $21.4 million, excluding the proceeds, if any, for the exercise of the warrants issued pursuant to this offering, after deducting underwriting discounts and commissions and estimated offering expenses payable by us.

Delivery of the shares of common stock and accompanying warrants will be made through book-entry facilities of The Depository Trust Company. The underwriter expects to deliver the shares of common stock and warrants against payment in New York, New York on September 15, 2022.

Jefferies

Prospectus supplement dated September 12, 2022

TABLE OF CONTENTS

	PAGE
About This Prospectus Supplement		S-1
Prospectus Supplement Summary		S-3
The Offering		S-6
Risk Factors		S-8
Special Note Regarding Forward-Looking Statements		S-10
Use of Proceeds		S-13
Dividend Policy		S-14
Description of the Securities We Are Offering		S-15
Material US Federal Income Tax Considerations for Non-US Holders of Common Stock and Warrants		S-16
Underwriting		S-20
Legal Matters		S-28
Experts		S-29
Where You Can Find More Information		S-30
Incorporation of Documents by Reference		S-31
	PAGE
About This Prospectus		1
Prospectus Summary		2
Risk Factors		4
Special Note Regarding Forward-Looking Statements		5
Use of Proceeds		8
Plan of Distribution		9
Description of Common Stock		11
Description of Preferred Stock		12
Description of Debt Securities		14
Description of Warrants		20
Description of Rights		21
Description of Units		23
Certain Provisions of Delaware Law and of The Company’s Certificate of Incorporation and By-laws		25
Legal Matters		29
Experts		30
Where You Can Find More Information		31
Incorporation of Documents by Reference		32

ABOUT THIS PROSPECTUS SUPPLEMENT

This prospectus supplement and the accompanying prospectus are part of a “shelf” registration statement on Form S-3 (File No. 333-260781) that we filed with the Securities and Exchange Commission (the “SEC”) on November 4, 2021, and which was declared effective by the SEC on November 15, 2021. This document is in two parts. The first part is this prospectus supplement, which describes the specific terms of this common stock offering and also adds to and updates information contained in the accompanying prospectus and the documents incorporated by reference herein. The second part, the accompanying prospectus, including the documents incorporated by reference therein, provides more general information. Generally, when we refer to this prospectus supplement, we are referring to both parts of this document combined.

Before buying any of the common stock that we are offering, we urge you to carefully read this prospectus supplement, the accompanying prospectus, and all of the information incorporated by reference herein and therein, as well as the additional information described under the headings “Where You Can Find More Information” and “Incorporation of Documents by Reference.” These documents contain important information that you should consider when making your investment decision.

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 any document incorporated by reference therein, on the other hand, you should rely on the information in this prospectus supplement; provided that if any statement in one of these documents is inconsistent with a statement in another document having a later date—for example, a document incorporated by reference in the accompanying prospectus—the statement in the document having the later date modifies or supersedes the earlier statement.

You should rely only on the information contained in this prospectus supplement or the accompanying prospectus, or incorporated by reference herein, and in any free writing prospectuses we may provide to you in connection with this offering. Neither we nor the underwriter have authorized any other person to provide you with different information. If anyone provides you with different or inconsistent information, you should not rely on it. The information contained in this prospectus supplement or the accompanying prospectus, or incorporated by reference herein is accurate only as of the respective dates thereof, regardless of the time of delivery of this prospectus supplement and the accompanying prospectus or of any sale of our common stock. Our business, financial condition, results of operations and prospects may have changed materially 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 any document that is incorporated by reference in this prospectus supplement 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.

We are offering to sell, and seeking offers to buy, shares of our common stock and warrants only in jurisdictions where offers and sales are permitted. The distribution of this prospectus supplement and the accompanying prospectus and the offering of the common stock and warrants in certain jurisdictions may be restricted by law. Persons outside the United States who come into possession of this prospectus supplement and the accompanying prospectus must inform themselves about, and observe any restrictions relating to, the offering of the common stock and warrants and the distribution of this prospectus supplement and the accompanying prospectus outside the United States. This prospectus supplement and the accompanying prospectus do not constitute, and may not be used in connection with, an offer to sell, or a solicitation of an offer to buy, any securities offered by this prospectus supplement and the accompanying prospectus by any person in any jurisdiction in which it is unlawful for such person to make such an offer or solicitation.

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Unless the context otherwise requires, “Codiak,” “CDAK,” “the Company,” “we,” “us,” “our” and similar terms refer to Codiak BioSciences, Inc. and our subsidiary.

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PROSPECTUS SUPPLEMENT 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 supplement and the accompanying prospectus. We urge you to read this entire prospectus supplement and 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. Investing in our securities involves risks. Therefore, carefully consider the risk factors set forth in our most recent annual and quarterly filings with the SEC, as well as other information in this prospectus supplement, the accompanying prospectus, 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 Codiak BioSciences, Inc.

We are a clinical-stage biopharmaceutical company focused on pioneering the development of exosome-based therapeutics, a new class of medicines with the potential to transform the treatment of a wide spectrum of diseases with high unmet medical need. Exosomes have evolved as intercellular transfer mechanisms for complex, biologically active macromolecules and have emerged in recent years as a compelling potential drug delivery vehicle. By leveraging our deep understanding of exosome biology, we have developed our engineering and manufacturing platform (“engEx Platform”) to expand upon the innate properties of exosomes to design, engineer and manufacture novel exosome therapeutics. We have utilized our engEx Platform to generate a deep pipeline of engineered exosomes (“engEx exosomes”) aimed at treating a broad range of diseases, including oncology, and infectious disease and rare disease.

In September 2020, we initiated clinical trials of our lead engEx product candidates, exoSTING and exoIL-12, to address oncology indications. In June 2022, we initiated a Phase 1 clinical trial of exoASO-STAT6. This is our first systemically delivered exosome therapeutic candidate. To our knowledge, exoSTING, exoIL-12 and exoASO-STAT6 are the first engineered exosomes to enter clinical development.

In December 2020 and February 2021, we reported positive results from Part A of our Phase 1 clinical trial of exoIL-12 in healthy human volunteers. In this randomized, placebo controlled, double-blind study, exoIL-12 demonstrated a favorable safety and tolerability profile, with no local or systemic treatment-related adverse events and no detectable systemic exposure of IL-12. Results also confirmed retention of active IL-12 at the injection site and prolonged pharmacodynamic effects. We believe these results in healthy volunteers, which are consistent with our preclinical observations, provide validation of our engEx Platform and one of the founding principles of Codiak—that engineered exosomes can offer the opportunity to tailor therapeutic payloads to provide an active biological response while at the same time limiting unwanted side effects.

In November 2021, we reported initial data from the first three dose escalating cohorts (0.3 mcg, 1.0 mcg, and 3.0 mcg) enrolled in the Phase 1/2 study of exoSTING. Trial participants (n=11) were administered exoSTING intratumorally and all subjects had received at least two prior therapies prior to study entry, with most (73%) having progressed on checkpoint inhibitors. Plasma pharmacokinetic (“PK”) measurements of subjects that received exoSTING showed no systemic exposure to the agonist. Further, analyses of available plasma biomarkers indicated a lack of systemic inflammatory cytokines detectable in blood after exoSTING administration. exoSTING appeared to be generally well-tolerated. Blood biomarker assessments conducted post-dosing showed evidence of dose-dependent activation of the STING pathway and Type I INF induction along with CXCL10, indicating activation of the innate immune response. Paired tumor biopsies available from two subjects showed evidence of an adaptive immune response and CD8 effector T cell infiltration into the tumor, as well as an increase in PD-L1 expression. Finally, in subjects evaluable for early signs of antitumor activity (n=8), tumor shrinkage was observed in injected as well as distal, non-injected tumors, in a subset of subjects. We have paused our plans to initiate Phase 2 trials of exoSTING and exoIL-12. See “—Recent Developments” below for more information.

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In June 2022, we reported initial data from the clinical trials of exoSTING and exoIL-12. In the cutaneous T cell lymphoma (“CTCL”) portion of the exoIL-12 study, two patients with early stage CTCL whose disease progressed on prior therapy had been treated as of the June 10, 2022 data cut-off. Each patient had received more than 20 injections of exoIL-12 (6.0 µg) across multiple lesions. Duration of treatment had been greater than six months, and no treatment-related adverse events (“SAEs”) Grade 3 or higher or serious adverse events were observed, and no dose modifications were required. exoIL-12 demonstrated improvement in overall tumor burden, as measured by the Modified Severity Weighted Assessment Tool, and lesion severity, as measured by the Composite Assessment of Index Lesion Severity, in both patients treated. PK measurements of both healthy volunteers and patients that received exoIL-12 showed no systemic exposure, with levels of IL-12 below the limit of quantification. In contrast, previous rIL-12 clinical studies showed dose-dependent systemic exposure with dosages of 5 and 12 mcg resulting in Cmax plasma levels of approximately 15 to 45 pg/ml within six to 12 hours after dosing.

Data as of June 10, 2022 have been reported from all five escalation dose cohorts (0.3 mcg, 1.0 mcg, 3.0 mcg, 6.0 mcg and 12.0 mcg) enrolled in the Phase 1/2 study of exoSTING. Trial participants (n=23) were administered exoSTING intratumorally, and nearly all had received at least two prior therapies prior to study entry with most (65%) having progressed on checkpoint inhibitors. PK measurements of patients that received exoSTING showed no systemic exposure to the agonist. Further, analyses of available plasma biomarkers indicated a lack of systemic inflammatory cytokines detectable in blood after exoSTING administration. Within all dose cohorts, exoSTING was generally well tolerated and no dose limiting toxicities or treatment-emergent adverse events of Grade 3 or higher were observed. Treatment-related serious adverse events (“TRSAEs”) were observed in three patients (2 patients with Grade 2 cytokine release syndrome and 1 patient with Grade 1 pyrexia). All patients who experienced a TRSAE were retreated and remained on study without additional SAEs.

Blood biomarker assessments conducted post-dosing demonstrated dose-dependent activation of the STING pathway at doses 100-fold lower in comparison to other free STING agonists. Paired tumor biopsies available from Cohorts 1-4 show evidence of an adaptive immune response, including consistent increases in CD-8 effector T-cells and PD-L1 in the tumor micro-environment. Signs of antitumor activity were observed with tumor shrinkage in injected as well as distal, non-injected tumors.

Recent Developments

On August 30, 2022, we announced a reprioritization of our clinical and research initiatives, an acceleration of discussions related to potential strategic corporate and program-based partnerships, and a restructuring of operations to support a streamlined set of priorities. We aligned our organization to reflect our smaller, refocused pipeline and our workforce has been reduced by 37%, to 53 full-time employees, to support the priority programs mentioned below.

Program Updates

∎ exoASO-STAT6 is our first systemically administered exosome-based drug candidate, and our third candidate to enter clinical trials. exoASO-STAT6 is engineered to selectively deliver antisense oligonucleotides to disrupt STAT6 signaling in tumor associated macrophages (“TAMs”) and induce an anti-tumor immune response. Preclinical studies of exoASO-STAT6 showed single agent anti-tumor activity in models of aggressive hepatocellular carcinoma (“HCC”). Enrollment continues in the Phase 1 clinical trial of exoASO-STAT6 in patients with advanced HCC, liver metastases from primary gastric cancer and colorectal cancer where high STAT6 transcript levels correlate with poor prognosis for patients. Data is expected during the first half of 2023.

∎ We announced in July 2022 a new partnership with the Coalition for Epidemic Preparedness Innovations (“CEPI”) to advance our exoVACC pan betacoronavirus program. As part of the partnership, CEPI is providing seed funding of up to $2.5 million, which we anticipate will fund the completion of preclinical development and identification of a clinical candidate by early next year.

∎ Preclinical data presented at the annual meeting of the American Society of Gene & Cell Therapy held on May 16-20, 2022 on our engEx-AAV discovery program, demonstrated incorporation of AAV

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capsids inside exosomes where they were not subject to neutralization by antibodies against AAV. These engineered constructs transduce target cells and support the idea of engEx-AAV for repeat dosing of gene delivery constructs. Our team will continue to advance this program toward generation of in vivo proof-of-concept data later this year.

∎ We are pausing plans to initiate Phase 2 trials of exoSTING and exoIL-12. Platform-supporting data from Phase 1 trials for both programs were reported in June 2022, which we believe demonstrates potential for best-in-class profiles, and we identified a recommended Phase 2 dose for each candidate.

∎ We are prioritizing discussions related to establishing potential new strategic and collaborative initiatives for us, including program-based partnerships. Our existing research and business partnerships with Lonza Rockland, Inc. (“Lonza”) and Jazz Pharmaceuticals Ireland Limited are continuing, with resources committed to attain key goals.

Additional Information

For additional information related to our business and operations, please refer to the reports incorporated herein by reference, as described under the caption “Incorporation of Documents by Reference” of this prospectus supplement.

Our Corporate Information

We were incorporated under the laws of the State of Delaware in 2015. Our principal executive office is located at 35 CambridgePark Drive, Suite 500, Cambridge, Massachusetts 02140, and our telephone number is (617) 949-4100. Our website address is https://www.codiakbio.com. We do not incorporate the information on or accessible through our website into this prospectus supplement, and you should not consider any information on, or that can be accessed through, our website as part of this prospectus supplement.

We own various US federal trademark applications and unregistered trademarks and service marks, including “Codiak BioSciences”, our corporate logo, “engEx”, “exoSTING”, “exoIL-12”, “exoASO-STAT6”, “exoVACC”, “engEx-AAV” and others. This prospectus supplement contains references to our trademarks and to trademarks belonging to other entities. Solely for convenience, trademarks and trade names referred to in this prospectus supplement, including logos, artwork and other visual displays, may appear without the ^® or TM symbols, but such references are not intended to indicate, in any way, that we will not assert, to the fullest extent under applicable law, our rights or the rights of the applicable licensor to these trademarks and trade names. We do not intend our use or display of other companies’ trade names or trademarks to imply a relationship with, or endorsement or sponsorship of us by, any other companies.

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THE OFFERING

Common stock offered by us pursuant to this prospectus supplement 13,333,333 shares of our common stock, plus 13,333,333 shares of our common stock underlying the warrants offered in this offering.

Warrants offered by us pursuant to this prospectus supplement Warrants to purchase up to 13,333,333 shares of common stock. For each share of common stock purchased, each investor will receive a warrant to purchase one share of our common stock with an exercise price of $1.875 per share (referred to as “warrants”). The warrants are immediately exercisable and expire on the date five (5) years from the date of issuance. This prospectus supplement also relates to the offering of the shares of common stock issuable upon exercise of the warrants.

Option to purchase additional shares and warrants We have granted the underwriter a 30-day option to purchase up to 1,999,999 additional shares of our common stock and warrants to purchase up to an aggregate of 1,999,999 shares of our common stock.

Common stock estimated to be outstanding after this offering 35,878,864 shares (or 37,878,863 shares if the underwriter exercises its option to purchase additional shares in full), excluding shares issuable upon exercise of the warrants issued in this offering.

Use of proceeds We estimate that the net proceeds from this offering will be approximately $18.6 million (or approximately $21.4 million if the underwriter exercises in full its option to purchase additional shares of common stock and warrants), excluding the proceeds, if any, for the exercise of the warrants issued pursuant to this offering, after deducting underwriting discounts and commissions and estimated offering expenses payable by us.

We currently intend to use the net proceeds from this offering for general corporate purposes, including, but not limited to, initiating new clinical trials and advancing our ongoing clinical trials, preclinical studies and research and development activities, as well as for working capital, capital expenditures, investments, acquisitions and pursuing strategic partnerships at the corporate, platform or program level, should we choose to pursue any, collaborations, and commercialization efforts. See the section entitled “Use of Proceeds” of this prospectus supplement.

Risk factors See the “Risk Factors” section beginning on page S-8 of this prospectus supplement and the other information included in, or incorporated by reference into, this prospectus supplement and the accompanying prospectus for a discussion of certain factors you should carefully consider before deciding to invest in shares of our common stock and accompanying warrants.

Nasdaq Global Market symbol “CDAK.” We do not intend to list the warrants on The Nasdaq Global Market, any other national securities exchange or any other nationally recognized trading system.

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The number of shares of our common stock that will be outstanding immediately after this offering as shown above is based on 22,545,531 shares of our common stock issued and outstanding as of June 30, 2022 and excludes the shares of common stock issuable upon exercise of the warrants being offered by us in this offering and also excludes, unless otherwise indicated, each of the following as of June 30, 2022:

∎ 5,462,941 shares of our common stock issuable upon the exercise of stock options outstanding under our 2020 Stock Option and Incentive Plan (our “2020 Stock Plan”) at a weighted average exercise price of $11.03 per share;

∎ 1,084,105 shares of our common stock available for future issuance under our 2020 Stock Plan;

∎ 828,827 shares of restricted stock units outstanding; and

∎ 208,680 shares of our common stock available for future issuance under our 2020 Employee Stock Purchase Plan.

Unless otherwise indicated, all information in this prospectus supplement:

∎ assumes no exercise of the outstanding stock options described above;

∎ assumes no exercise by the underwriter of its option to purchase additional shares of our common stock and warrants in this offering; and

∎ does not reflect the potential issuance of shares of our common stock that remain available for sale as of the date of this prospectus supplement under our “at-the-market” offering program, pursuant to which we may sell common stock for remaining gross proceeds of up to approximately $99.0 million from time to time under our sales agreement with Jefferies LLC.

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RISK FACTORS

Investing in our common stock and warrants involves a high degree of risk. Before deciding whether to invest in our common stock and/or warrants, you should carefully consider the risks described below and discussed under the sections captioned “Risk Factors” contained in our most recent Annual Report on Form 10-K, as well as in any of our subsequent Quarterly Reports on Form 10-Q or our Current Reports on Form 8-K, which are incorporated by reference herein in their entirety, together with other information in this prospectus supplement, the accompanying prospectus, the information and documents incorporated by reference in this prospectus supplement, the accompanying prospectus, and any free writing prospectus that we have authorized for use in connection with this offering. The occurrence of any of the events or developments described below could harm our business, financial condition, results of operations and growth prospects. In such an event, the market price of our common stock could decline, and you may lose all or part of your investment. Additional risks and uncertainties not presently known to us or that we currently deem immaterial also may impair our business operations.

Our management will have broad discretion over the use of the net proceeds from this offering, and you may not agree with how we use the proceeds, and the proceeds may not be invested successfully. Our management will have broad discretion as to the use of the net proceeds from this offering and could use them for purposes other than those contemplated at the time of this offering. Accordingly, you are relying on the judgment of our management with regard to the use of these net proceeds, and you will not have the opportunity, as part of your investment decision, to assess whether the proceeds will be used appropriately. It is possible that the proceeds will be invested in a way that does not yield a favorable, or any, return for us.

You may experience future dilution as a result of future equity offerings. In order 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. We cannot assure you that we will be able to sell shares or other securities in any other offering at a price per share that is equal to or greater 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 other securities convertible into or exchangeable for our common stock in future transactions may be higher or lower than the price per share in this offering.

Our stock price is and may continue to be volatile and you may not be able to resell our securities at or above the price you paid. The market price for our common stock is volatile and may fluctuate significantly in response to a number of factors, most of which we cannot control, such as quarterly fluctuations in financial results, the timing and our ability to advance the development of our product candidates or changes in securities analysts’ recommendations could cause the price of our stock to fluctuate substantially. Each of these factors, among others, could harm your investment in our common stock and could result in your being unable to resell the common stock that you purchase at a price equal to or above the price you paid. During the period from the closing our initial public offering on October 16, 2020 to September 9, 2022, the closing price of our common stock ranged from a high of $32.30 per share to a low of $1.72 per share. The stock market in general and the market for smaller biopharmaceutical companies in particular have experienced extreme volatility that has often been unrelated to the operating performance of particular companies.

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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 depress the market price of our common stock and impair our ability to raise capital through the sale of additional equity securities. We cannot predict the effect that future sales of our common stock would have on the market price of our common stock. In addition, the sale of substantial amounts of our common stock could adversely impact its price. The sale or the availability for sale of a large number of shares of our common stock in the public market could cause the price of our common stock to decline.

If securities or industry analysts do not publish research or publish inaccurate or unfavorable research about our business, our stock price and trading volume could decline. The trading market for our common stock depends in part on the research and reports that securities or industry analysts publish about us or our business. If one or more of the analysts who covers us downgrades our stock or publishes inaccurate or unfavorable research about our business, our stock price may decline. If one or more of these analysts ceases coverage of our company or fails to publish reports on us regularly, demand for our stock could decrease, which might cause our stock price and trading volume to decline.

We do not anticipate paying any cash dividends on our common stock in the foreseeable future. Accordingly, stockholders must rely on capital appreciation, if any, for any return on their investment.

We have never declared or paid cash dividends on our common stock. We currently intend to retain all of our future earnings, if any, to finance the growth and development of our business. As a result, capital appreciation, if any, of our common stock will be our stockholders’ sole source of gain for the foreseeable future.

Holders of warrants purchased in this offering will have no rights as common stockholders until such holders exercise their warrants and acquire our common stock.

Until holders of the warrants acquire shares of our common stock upon exercise of such warrants, the holders will have no rights with respect to the shares of our common stock underlying such warrants. Upon exercise of the warrants, the holders will be entitled to exercise the rights of a common stockholder only as to matters for which the record date occurs after the exercise.

The warrants being offered may not have value.

The warrants being offered by us in this offering have an exercise price of $1.875 per share, subject to certain adjustments, and expire five (5) years from the date of issuance, after which date any unexercised warrants will expire and have no further value. In the event that the market price of our common stock does not exceed the exercise price of the warrants during the period when they are exercisable, the warrants may not have any value.

We expect that the liquidity of the warrants will be limited.

There is no established public trading market for the warrants being offered in this offering, and we do not expect a market to develop. In addition, we do not intend to apply to list the warrants on any national securities exchange or other nationally recognized trading system, including The Nasdaq Global Market. Without an active market, the liquidity of the warrants will be limited.

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SPECIAL NOTE REGARDING FORWARD-LOOKING STATEMENTS

This prospectus supplement, the accompanying prospectus, and the documents incorporated by reference herein include forward-looking statements within the meaning of Section 27A of the Securities Act of 1933, as amended (the “Securities Act”), and Section 21E of the Securities Exchange Act of 1934, as amended (the “Exchange Act”) that relate to future events or our future financial performance and involve known and unknown risks, uncertainties and other factors that may cause our actual results, levels of activity, performance or achievements to differ materially from any future results, levels of activity, performance or achievements expressed or implied by these forward-looking statements. Words such as, but not limited to, “believe,” “expect,” “anticipate,” “estimate,” “intend,” “may,” “plan,” “potential,” “predict,” “project,” “targets,” “likely,” “will,” “would,” “could,” “should,” “continue,” and similar expressions or phrases, or the negative of those expressions or phrases, are intended to identify forward-looking statements, although not all forward-looking statements contain these identifying words. Although we believe that we have a reasonable basis for each forward-looking statement contained in this prospectus supplement, the accompanying prospectus and the documents incorporated by reference herein and therein, we caution you that these statements are based on our projections of the future that are subject to known and unknown risks and uncertainties and other factors that may cause our actual results, level of activity, performance or achievements expressed or implied by these forward-looking statements, to differ. The sections in our periodic reports, including our most recent Annual Report on Form 10-K for the fiscal year ended December 31, 2021, as supplemented by our subsequent Quarterly Reports on Form 10-Q and our Current Reports on Form 8-K, entitled “Business,” “Risk Factors,” and “Management’s Discussion and Analysis of Financial Condition and Results of Operations,” as well as other sections in this prospectus supplement, the accompanying prospectus, and the other documents or reports incorporated by reference herein and therein, discuss some of the factors that could contribute to these differences. These forward-looking statements include, among other things, statements about:

∎ the offering and our intended use of the net proceeds from the offering of our securities under this prospectus supplement and accompanying prospectus;

∎ the success, cost and timing of our product development activities, preclinical studies and clinical trials, including statements regarding the timing of initiation and completion of studies or trials and related preparatory work, the period during which the results of the trials will become available and our research and development programs;

∎ the design and conduct of our clinical trials of exoSTING, exoIL-12 and exoASO-STAT6;

∎ our ability to successfully advance any of our engEx product candidates into and through clinical trials, or obtain marketing approval;

∎ the potential and capabilities of our engEx Platform, engEx product candidates and engEx discovery programs;

∎ the potential and capability of our engEx Platform to generate additional engEx product candidates;

∎ our ability to secure from Lonza, under our manufacturing arrangement with them, sufficient supply of our product candidates for clinical trials or commercial use, if approved;

∎ our ability to successfully procure from third parties sufficient supply of our product candidates for preclinical studies, clinical trials or commercial use, if approved;

∎ our ability to utilize our engEx Platform to engineer exosomes to carry various biologically active drug molecules, target specific cell types or cellular pathways or enhance the value of existing drug modalities;

∎ the potential indications that we may be able to target with engineered exosomes generated from our engEx Platform;

∎ the size, composition and growth potential of the patient populations and markets we intend to target with our engEx product candidates and our ability to develop and commercialize engEx product candidates to address those patient populations and markets;

∎ the ability and willingness of our current and future collaborators to continue research and development activities relating to our engEx exosomes;

∎ our ability to maintain regulatory approval, if obtained, of any of our current or future engEx product candidates, and any related restrictions, limitations and/or warnings in the label of an approved product candidate;

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∎ our expectations regarding our ability to obtain and maintain intellectual property protection for our product candidates, including, for example, with respect to our European patent, EP 3,672,614 (app. no. 19731027.9), which is the subject of a notice of opposition that, if results in the revocation of the patent, could impair our ability to market some of our early stage products that may utilize luminal scaffolding intellectual property, including exoVACC;

∎ our ability to license intellectual property relating to our product candidates and to comply with our existing license and collaboration agreements;

∎ our ability to commercialize our products, if approved, in light of the intellectual property rights of others;

∎ developments relating to the use of exosomes to develop therapeutics;

∎ the success of competing therapies that are or become available;

∎ our ability to obtain funding for our operations, including funding necessary to complete further development and commercialization of our product candidates;

∎ our plans to research, develop and commercialize our engEx product candidates and enhance the capabilities of our engEx Platform;

∎ our ability to attract collaborators with development, regulatory and commercialization expertise;

∎ future agreements with third parties in connection with the commercialization of our product candidates and any other approved product;

∎ the rate and degree of market acceptance of our product candidates, if approved;

∎ regulatory developments in the United States and foreign countries;

∎ our ability to contract with third-party suppliers and manufacturers and their ability to perform adequately;

∎ our ability to attract and retain key scientific or management personnel;

∎ our expectations regarding the time during which we will be an emerging growth company under the Jumpstart Our Business Startups Act;

∎ the accuracy of our estimates regarding expenses, future revenue, capital requirements and needs for additional financing;

∎ the impact of laws and regulations;

∎ the program reprioritization, plans to expand discussions related to potential strategic corporate and program-based partnerships, and the restructuring of operations; and

∎ the direct or indirect impact of the COVID-19 pandemic on our business, operations, development timelines, and the markets and communities in which we and our partners, collaborators, vendors and customers operate.

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 cautionary statements in this prospectus supplement, the accompanying prospectus, and the documents incorporated by reference herein and therein, particularly in the “Risk Factors” section, that we believe could cause actual results or events to differ materially from the forward-looking statements that we make. These risks, uncertainties and other factors are described in greater detail under the caption “Risk Factors” in this prospectus supplement and the accompanying prospectus, as updated and supplemented by the discussion of risks and uncertainties under “Risk Factors” contained 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, as well as any amendments thereto, as filed with the SEC and which are incorporated herein by reference. The information contained in this document is believed to be current as of the date of this document. We do not intend to update any of the forward-looking statements after the date of this document to conform these statements to actual results or to changes in our expectations, except as required by law.

In light of these assumptions, risks and uncertainties, the results and events discussed in the forward-looking statements contained in this prospectus supplement, the accompanying prospectus, or in any document incorporated herein or therein by reference might not occur. Investors are cautioned not to place undue reliance on the forward-looking statements, which speak only as of the date of this prospectus supplement or the date of the document

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incorporated by reference in this prospectus supplement. We are not under any obligation, and we expressly disclaim any obligation, to update or alter any forward-looking statements, whether as a result of new information, future events or otherwise. All subsequent forward-looking statements attributable to us or to any person acting on our behalf are expressly qualified in their entirety by the cautionary statements contained or referred to in this section.

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USE OF PROCEEDS

We estimate that the net proceeds from this offering will be approximately $18.6 million, or approximately $21.4 million if the underwriter exercises its option to purchase additional shares and warrants in full, after deducting the underwriting discounts and commissions and estimated offering expenses payable by us and excluding the proceeds, if any, from the exercise of the warrants issued pursuant to this offering.

We currently intend to use the net proceeds from this offering for general corporate purposes, including, but not limited to, initiating new clinical trials and advancing our ongoing clinical trials, preclinical studies and research and development activities, as well as for working capital, capital expenditures, investments, acquisitions and pursuing strategic partnerships at the corporate, platform or program level, should we choose to pursue any, collaborations, and commercialization efforts.

This expected use of the net proceeds from this offering, together with our existing cash and cash equivalents, represents our intentions based upon our current plans and business conditions, which could change in the future as our plans and business conditions evolve. As of the date of this prospectus supplement, we cannot specify with certainty all of the particular uses for the net proceeds to be received upon the closing of this offering or the amounts that we will actually spend on the uses set forth above. Due to uncertainties inherent in the exosome therapeutic development process, it is difficult to estimate the exact amounts of the net proceeds that will be used for any particular purpose. We may use our existing cash and cash equivalents and the future payments, if any, generated from any future collaboration agreements to fund our operations, either of which may alter the amount of net proceeds used for a particular purpose. In addition, the amount, allocation and timing of our actual expenditures will depend upon numerous factors, including the results of our research and development efforts, feedback from the FDA and other regulatory authorities, the timing and success of preclinical studies and clinical trials and the timing of regulatory submissions. We may also use a portion of the net proceeds to in-license, acquire or invest in additional businesses, technologies, products or assets, although currently we have no specific agreements, commitments or understandings in this regard. Accordingly, we will have broad discretion in using these proceeds. Pending their uses, we plan to invest the net proceeds of this offering in short- and immediate-term, interest-bearing obligations, investment-grade instruments, certificates of deposit or direct or guaranteed obligations of the US government.

The expected net proceeds from this offering, together with our existing cash and cash equivalents, will not be sufficient for us to fund any of our engEx product candidates through regulatory approval, and we will need to raise additional capital to complete the development and commercialization of our engEx product candidates. We expect to finance our cash needs through a combination of equity offerings, debt financings and potential collaborations, license and development agreements.

Based on our current operating plan, we expect our cash and cash equivalents as of June 30, 2022, together with the net proceeds from this offering, will enable us to fund our operating expenses and capital expenditure requirements into the second half of 2023. We have based this estimate on assumptions that may prove to be incorrect, and we could expend our available capital resources at a rate greater than we currently expect.

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DIVIDEND POLICY

We have never declared or paid any cash dividends on our common stock or any other securities. We anticipate that we will retain all available funds and any future earnings, if any, for use in the operation of our business and do not anticipate paying cash dividends in the foreseeable future. In addition, pursuant to our loan agreement with Hercules Capital, Inc. (“Hercules”), as amended, we are prohibited from paying cash dividends without the prior written consent of Hercules. Moreover, any future indebtedness we may incur could also materially restrict our ability to pay dividends on our common stock. Payment of future cash dividends, if any, will be at the discretion of our board of directors after taking into account various factors, including our financial condition, operating results, current and anticipated cash needs, the requirements of then-existing debt instruments and other factors our board of directors deems relevant.

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DESCRIPTION OF THE SECURITIES WE ARE OFFERING

We are offering shares of our common stock and warrants to purchase shares of our common stock (and the shares of our common stock issuable from time to time upon exercise of the offered warrants). The common stock and warrants will be issued separately. The common stock offered by this prospectus supplement and the accompanying prospectus is described in the accompanying prospectus under the heading “Description of Common Stock.” The warrants offered by this prospectus supplement and the accompanying prospectus are described immediately below.

Warrants

Form. The warrants will be issued pursuant to individual warrant agreements to the investors.

Duration and Exercise Price. Each warrant represents the right to purchase one share of common stock at an exercise price equal to $1.875 per share, subject to adjustment as described below. The exercise price is subject to appropriate adjustment in the event of certain stock dividends and distributions, stock splits, stock combinations, reclassifications or similar events affecting our common stock and also upon any distributions of assets, including cash, stock or other property to our stockholders. The warrants are exercisable beginning on the date of issuance and at any time up to the date five (5) years from the date of issuance.

Exercisability. The warrants will be exercisable, at the option of each holder, in whole or in part, by delivering to us a duly executed exercise notice accompanied by payment in full for the number of shares of our common stock purchased upon such exercise (except in the case of a cashless exercise as discussed below). No fractional shares of common stock will be issued in connection with the exercise of a warrant. In lieu of fractional shares, we will pay the holder an amount in cash computed by multiplying the fractional interest by (i) the fair market value of a full share, less (ii) the then-effective warrant price.

Cashless Exercise. If, at the time a holder exercises its warrants a registration statement registering the issuance of the shares of common stock underlying such warrants under the Securities Act is not then effective or available for the issuance of such shares, or the prospectus contained therein is not available for the issuance of such shares, then in lieu of making the cash payment to us upon such exercise in payment of the aggregate exercise price, the holder may elect instead to receive upon such exercise (either in whole or in part) the net number of shares of common stock determined according to a formula set forth in the warrant.

Fundamental Transaction. In the event of an Acquisition (as defined in the warrant), we or any surviving entity shall, at the holder’s option, exercisable at any time concurrently with, or within 30 days after, the consummation of the Acquisition (or, if later, the date of the public announcement of the applicable Acquisition), purchase such warrants from the holder by paying to the holder an amount of cash equal to the Black Scholes Value (as defined in the warrant) of the remaining unexercised portion of such warrants on the date of the consummation of such Acquisition; provided, however, that if the Acquisition is not within our control, including not approved by our board of directors, the holder shall only be entitled to receive the same type or form of consideration (and in the same proportion), at the Black Scholes Value of the unexercised portion of such warrants, that is being offered and paid to the holders of our common stock in connection with the Acquisition, whether that consideration be in the form of cash, stock or any combination thereof, or whether the holders of our common stock are given the choice to receive from among alternative forms of consideration in connection with the Acquisition. However, if holders of our common stock are not offered or paid any consideration in such Acquisition, such holders of our common stock will be deemed to have received common stock of the surviving entity in such Acquisition.

Exchange Listing. There is no public trading market for the warrants, and we do not expect a market to develop. In addition, we do not intend to apply for listing of the warrants on any securities exchange or other trading system.

Rights as a Stockholder. Except as otherwise provided in the warrants or by virtue of such holder’s ownership of shares of our common stock, the holder of a warrant does not have the rights or privileges of a holder of our common stock, including any voting rights, until the holder exercises the warrant.

Amendment and Waiver. No term of the warrants may be amended or waived without our written consent and the written consent of the holder of such warrants.

Governing Law. The warrant is governed by New York law.

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MATERIAL US FEDERAL INCOME TAX CONSIDERATIONS FOR NON-US HOLDERS

OF COMMON STOCK AND WARRANTS

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

∎ a non-resident alien individual;

∎ a corporation or other organization taxable as a corporation for US federal income tax purposes that is created or organized in or under laws other than the laws of the United States, or the US, any state thereof, or the District of Columbia;

∎ an estate the income of which is not subject to US federal income tax on a net income basis; or

∎ a trust the income of which is not subject to US federal income tax on a net income basis and that (1) is not subject to the primary supervision of a court within the US or over which no US persons have authority to control all substantial decisions and (2) has not made an election to be treated as a US person.

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

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

This discussion does not address all aspects of US federal income taxation that may be relevant to a particular non-US holder in light of that non-US holder’s individual circumstances nor does it address any US state, local or non-US taxes, the alternative minimum tax, the Medicare tax on net investment income, the rules regarding qualified small business stock within the meaning of Section 1202 of the Code or any other aspect of any US federal tax other than the income tax. This discussion also does not consider any specific facts or circumstances that may apply to a non-US holder and does not address the special tax rules applicable to particular non-US holders, such as:

∎ insurance companies;

∎ tax-exempt or governmental organizations;

∎ financial institutions;

∎ brokers or dealers in securities;

∎ regulated investment companies;

∎ pension plans;

∎ “controlled foreign corporations,” “passive foreign investment companies,” and corporations that accumulate earnings to avoid US federal income tax;

∎ “qualified foreign pension funds,” or entities wholly owned by “qualified foreign pension funds”;

∎ persons who hold or receive our common stock or warrants pursuant to the exercise of any employee stock option or otherwise as compensation;

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∎ persons deemed to sell our common stock or warrants under the constructive sale provisions of the Code;

∎ persons that own, or have owned, actually or constructively, more than 5% of our common stock and/or warrants;

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

∎ certain US expatriates.

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

Exercise and Expiration of Warrants

In general, a non-US holder will not recognize gain or loss for US federal income tax purposes upon the exercise of warrants into shares of common stock. The US federal income tax treatment of a cashless exercise of warrants into our common stock is unclear. A non-US holder should consult his, her, or its own tax advisor regarding the US federal income tax consequences of a cashless exercise of warrants.

The expiration of a warrant will be treated as if the non-US holder sold or exchanged the warrant and recognized a capital loss equal to the non-US holder’s tax basis in the warrant. However, a non-US holder will not be able to utilize a loss recognized upon expiration of a warrant against the non-US holder’s US federal income tax liability unless the loss is effectively connected with the non-US holder’s conduct of a trade or business within the United States (and, if an income tax treaty applies, is attributable to a permanent establishment or fixed base in the United States) or is treated as a US-source loss and the non-US holder is present 183 days or more in the taxable year of disposition and certain other conditions are met.

Certain Adjustments to Warrants

Under Section 305 of the Code, an adjustment to the number of shares of common stock issued on the exercise of the warrants or an adjustment to the exercise price of the warrants may be treated as a constructive distribution to a non-US holder of the warrants if, and to the extent that, such adjustment has the effect of increasing such non-US holder’s proportionate interest in our “earnings and profits” or assets, depending on the circumstances of such adjustment (for example, if such adjustment is to compensate for a distribution of cash or other property to our shareholders). An adjustment made pursuant to a bona fide reasonable adjustment formula that has the effect of preventing dilution should generally not be considered to result in a constructive distribution. If an adjustment is made that does not qualify as being made pursuant to a bona fide reasonable adjustment formula, a non-US holder of warrants may be deemed to have received a constructive distribution from us, even though such non-US holder has not received any cash or property as a result of such adjustment, which would be treated as described under the section titled “—Distributions on Our Common Stock” below. Any resulting withholding tax attributable to deemed dividends would be collected from other amounts payable or distributable to the non-US holder. Non-US holders should consult their tax advisors regarding the proper treatment of any adjustments to and distributions on the warrants.

Distributions on Our Common Stock

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

Subject to the discussion in the following two paragraphs in this section, dividends paid to a non-US holder generally will be subject to withholding of US federal income tax at a 30% rate or such lower rate as may be specified by an applicable income tax treaty between the US and such holder’s country of residence.

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Dividends that are treated as effectively connected with a trade or business conducted by a non-US holder within the US and, if an applicable income tax treaty so provides, that are attributable to a permanent establishment or a fixed base maintained by the non-US holder within the US, are generally exempt from the 30% withholding tax if the non-US holder satisfies applicable certification and disclosure requirements. To claim the exemption, the non-US holder must generally furnish to the applicable withholding agent a properly executed IRS Form W-8ECI (or applicable successor form). However, such US effectively connected income, net of specified deductions and credits, is taxed at the same US federal income tax rates applicable to US persons (as defined in the Code). Any US effectively connected income received by a non-US holder that is a corporation may also, under certain circumstances, be subject to an additional “branch profits tax” at a 30% rate or such lower rate as may be specified by an applicable income tax treaty between the US and such holder’s country of residence.

A non-US holder who claims the benefit of an applicable income tax treaty between the US and such holder’s country of residence generally will be required to provide a properly executed IRS Form W-8BEN or W-8BEN-E (or successor form) to the applicable withholding agent and satisfy applicable certification and other requirements. Non-US holders are urged to consult their tax advisors regarding their entitlement to benefits under a relevant income tax treaty. Non-US holders that do not timely provide the required certification, but that qualify for a reduced treaty rate, may obtain a refund of any excess amounts withheld by timely filing an appropriate claim for refund with the IRS.

Gain on Sale or Other Taxable Disposition of Our Common Stock or Warrants

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

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

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

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

Backup Withholding and Information Reporting

We must report annually to the IRS and to each non-US holder the gross amount of the distributions on our common stock or warrants paid to such holder and the tax withheld, if any, with respect to such distributions. Non-US holders

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may have to comply with specific certification procedures to establish that the holder is not a US person (as defined in the Code) in order to avoid backup withholding at the applicable rate with respect to dividends on our common stock or warrants. Dividends paid to non-US holders subject to withholding of US federal income tax, as described above in “Distributions on Our Common Stock,” generally will be exempt from US backup withholding.

Information reporting and backup withholding will generally apply to the proceeds of a disposition of our common stock or warrants by a non-US holder effected by or through the US office of any broker, US or foreign, unless the holder certifies its status as a non-US holder and satisfies certain other requirements, or otherwise establishes an exemption. Generally, information reporting and backup withholding will not apply to a payment of disposition proceeds to a non-US holder where the transaction is effected outside the US through a non-US office of a broker. However, for information reporting purposes, dispositions effected through a non-US office of a broker with substantial US ownership or operations generally will be treated in a manner similar to dispositions effected through a US office of a broker.

Non-US holders should consult their tax advisors regarding the application of the information reporting and backup withholding rules to them. Copies of information returns may be made available to the tax authorities of the country in which the non-US holder resides or is incorporated under the provisions of a specific treaty or agreement. Backup withholding is not an additional tax. Any amounts withheld under the backup withholding rules from a payment to a non-US holder can be refunded or credited against the non-US holder’s US federal income tax liability, if any, provided that an appropriate claim is filed with the IRS in a timely manner.

Withholding and Information Reporting Requirements—FATCA

Provisions of the Code commonly referred to as the Foreign Account Tax Compliance Act (“FATCA”) generally impose a US federal withholding tax at a rate of 30% on payments of dividends on, and, subject to the discussion of certain proposed Treasury Regulations below, gross proceeds from the sale or other disposition of, our common stock or warrants paid to a foreign entity unless (i) if the foreign entity is a “foreign financial institution,” such foreign entity undertakes certain due diligence, reporting, withholding, and certification obligations, (ii) if the foreign entity is not a “foreign financial institution,” such foreign entity identifies certain of its US investors, if any, or (iii) the foreign entity is otherwise exempt under FATCA. The US Treasury released proposed Treasury Regulations which, if finalized in their present form, would eliminate the federal withholding tax of 30% applicable to the gross proceeds of a sale or other disposition of our common stock or warrants. In its preamble to such proposed Treasury Regulations, the US Treasury stated that taxpayers may generally rely on the proposed regulations until final regulations are issued. Under certain circumstances, a non-US holder may be eligible for refunds or credits of this withholding tax. An intergovernmental agreement between the US and an applicable foreign country may modify the requirements described in this paragraph. Non-US holders should consult their tax advisors regarding the possible implications of this legislation on their investment in our common stock or warrants and the entities through which they hold our common stock or warrants, including, without limitation, the process and deadlines for meeting the applicable requirements to prevent the imposition of the 30% withholding tax under FATCA.

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UNDERWRITING

Subject to the terms and conditions set forth in the underwriting agreement, dated September 12, 2022, between us and Jefferies LLC, as the underwriter named below and the book-running manager of this offering, we have agreed to sell to the underwriter and the underwriter has agreed to purchase from us, the respective number of shares of common stock and accompanying warrants shown opposite its name below:

UNDERWRITER	NUMBER OF SHARES		NUMBER OF WARRANTS
Jefferies LLC		13,333,333		13,333,333
Total		13,333,333		13,333,333

The underwriting agreement provides that the obligations of the underwriter are subject to certain conditions precedent such as the receipt by the underwriter of officers’ certificates and legal opinions and approval of certain legal matters by its counsel. The underwriting agreement provides that the underwriter will purchase all of the shares of common stock and accompanying warrants if any of them are purchased. If the underwriter defaults, the underwriting agreement provides that the underwriting agreement may be terminated. We have agreed to indemnify the underwriter and certain of its controlling persons against certain liabilities, including liabilities under the Securities Act, and to contribute to payments that the underwriter may be required to make in respect of those liabilities.

The underwriter has advised us that, following the completion of this offering, it currently intends to make a market in the common stock as permitted by applicable laws and regulations. However, the underwriter is not obligated to do so, and the underwriter may discontinue any market-making activities at any time without notice in its sole discretion. Accordingly, no assurance can be given as to the liquidity of the trading market for the common stock, that you will be able to sell any of the common stock held by you at a particular time or that the prices that you receive when you sell will be favorable.

The underwriter is offering the shares of common stock and warrants subject to its acceptance of the shares of common stock and warrants from us and subject to prior sale. The underwriter reserves the right to withdraw, cancel or modify offers to the public and to reject orders in whole or in part.

Commission and Expenses

The underwriter has advised us that it proposes to offer the shares of common stock and warrants to the public at the public offering price set forth on the cover page of this prospectus supplement and to certain dealers, which may include the underwriter, at that price less a concession not in excess of $0.054 per share of common stock and related warrants. No such reduction will change the amount of proceeds to be received by us as set forth on the cover page of this prospectus supplement.

The following table shows the public offering price, the underwriting discounts and commissions that we are to pay the underwriter and the proceeds, before expenses, to us in connection with this offering. Such amounts are shown assuming both no exercise and full exercise of the underwriter’s option to purchase additional shares and warrants.

	PER SHARE AND RELATED WARRANTS		TOTAL WITHOUT OPTION TO PURCHASE ADDITIONAL SHARES AND WARRANTS		TOTAL WITH OPTION TO PURCHASE ADDITIONAL SHARES AND WARRANTS
Public offering price	$	1.50	$	19,999,999.50	$	22,999,998.00
Underwriting discounts and commissions paid by us	$	0.09	$	1,199,999.97	$	1,379,999.88
Proceeds to us, before expenses	$	1.41	$	18,799,999.53	$	21,619,998.12

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We estimate expenses payable by us in connection with this offering, other than the underwriting discounts and commissions referred to above, will be approximately $236,000. We have agreed to reimburse the underwriter for expenses relating to the clearance of this offering with the Financial Industry Regulatory Authority, Inc. (“FINRA”) in an amount up to $30,000.

Listing

Our common stock is listed on The Nasdaq Global Market under the trading symbol “CDAK.” There is no public trading market for the warrants, and we do not expect a market to develop. In addition, we do not intend to apply for listing of the warrants on any securities exchange or other trading system. Without a trading market, the liquidity of the warrants will be extremely limited.

Option to Purchase Additional Shares

We have granted to the underwriter an option, exercisable for 30 days from the date of this prospectus supplement, to purchase, from time to time, in whole or in part, up to an aggregate of 1,999,999 shares from us at the public offering price set forth on the cover page of this prospectus supplement and warrants to purchase up to an aggregate of 1,999,999 shares of our common stock at the public offering price set forth on the cover page of this prospectus supplement, less underwriting discounts and commissions.

No Sales of Similar Securities

We, our officers, directors and certain of our stockholders have agreed, subject to certain exceptions, not to directly or indirectly dispose of or hedge any shares of our common stock, warrants or securities convertible or exchangeable for shares of our common stock during the period from the date of this prospectus supplement continuing through the date that is 90 days after the date of this prospectus supplement, except with the prior written consent of the underwriter. This agreement does not apply to any existing employee benefit plans.

The restrictions described in the immediately preceding paragraph do not apply to our directors, officers, equity holders or option holders with respect to:

∎ transactions relating to shares of our common stock, warrants or other securities acquired in open market transactions after the consummation of this offering;

∎ transfers of shares of our common stock, warrants or any security convertible into our common stock as a bona fide gift or gifts or to a charitable organization or educational institution in a transaction not involving a disposition for value, provided that the recipient agrees to be bound in writing by the same restrictions and no filing under the Securities Exchange Act of 1934, as amended (the “Exchange Act”), or other public filing or disclosure reporting a reduction in beneficial ownership is required or voluntarily made during the restricted period;

∎ transfers, distributions or dispositions of shares of our common stock or warrants to members or stockholders of the holder, any member of the immediate family of the holder or any trust for the direct or indirect benefit of the holder or the immediate family of the holder in a transaction not involving a disposition for value, provided that the recipient agrees to be bound in writing by the same restrictions and no filing under the Exchange Act or other public filing or disclosure reporting a reduction in beneficial ownership is required or voluntarily made during the restricted period;

∎ transfers or dispositions of shares of our common stock, warrants or other securities to any corporation, partnership, limited liability company or other entity, in each case, all of the beneficial ownership interests of which are held by the holder or the immediate family of the holder in a transaction not involving a disposition for value, provided that the recipient agrees to be bound in writing by the same restrictions and no filing under the Exchange Act or other public filing or disclosure reporting a reduction in beneficial ownership is required or voluntarily made during the restricted period;

∎ transfers or dispositions of shares of our common stock, warrants or other securities by will, other testamentary document or intestate succession to the legal representative, heir, beneficiary or a member of the immediate family of the holder upon the death of the holder, or by operation of law pursuant to a domestic order or negotiated divorce settlement, provided that the recipient agrees to be bound in writing by the same restrictions and no filing under the Exchange Act or other public filing or disclosure reporting a reduction in beneficial ownership is required or voluntarily made during the restricted period;

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∎ transfers of shares of our common stock, warrants or any security convertible into our common stock to the Company pursuant to any contractual arrangement that provides for the repurchase of the holder’s securities by the Company or in connection with the termination of the holder’s employment with or service to the Company, provided that no filing by any party under the Exchange Act or other public announcement, reporting a reduction in beneficial ownership of shares of our common stock, shall be required or voluntarily made during the restricted period in connection with any such transfers (other than any Form 4 or Form 5 required to be filed under the Exchange Act if the holder is subject to Section 16 reporting with respect to the Company under the Exchange Act and indicating by footnote disclosure or otherwise the nature of the transfer or disposition);

∎ the establishment of a trading plan pursuant to Rule 10b5-1 under the Exchange Act for the transfer of shares of our common stock, provided that such plan does not provide for the transfer of our common stock during the restricted period and no filing by any party under the Exchange Act or other public announcement shall be required or voluntarily made by or on behalf of the holder or the Company in connection with the establishment of such plan; and

∎ transfers or dispositions of shares of our common stock, warrants or such other securities pursuant to a bona fide third party tender offer for shares of the our capital stock, merger, consolidation or other similar transaction made to all holders of our capital stock and involving a change of control of the Company after this offering and approved by our board of directors, provided that in the event that such transaction is not completed, the shares of our common stock, warrants or other securities held by the holder shall remain subject to the restrictions described above for the remainder of the restricted period.

In addition, the restrictions above relating to us do not apply to:

∎ the shares to be sold in the offering;

∎ any shares of common stock or other securities or other awards convertible into, exercisable for, or that represent the right to receive, shares of common stock pursuant to any stock option plan, incentive plan or stock purchase plan or otherwise in equity compensation arrangements described in this prospectus supplement, provided that recipients thereof have provided the underwriter a signed lock-up agreement;

∎ the filing by us of any registration statement on Form S-8 or a successor form thereto relating to any stock option plan, incentive plan or stock purchase plan described in this prospectus supplement;

∎ any shares of common stock issued from time to time pursuant to that certain Sales Agreement, dated as of November 4, 2021, by and between us and Jefferies LLC, as sales agent, following the earlier to occur of (x) the underwriter’s exercise in full of its option to purchase optional shares in this offering and (y) the date that is 30 days following the date of this prospectus supplement; and

∎ any shares of common stock or any securities convertible into or exchangeable for, or that represent the right to receive, shares of common stock issued in connection with any joint venture, commercial relationship or other strategic transactions or the acquisition by us of the securities, businesses, property or other assets of another person or entity or pursuant to any employee benefit plan assumed by us in connection with any such acquisition, provided that (x) the aggregate number of shares of common stock that we may sell or issue or agree to sell or issue shall not exceed 10% of the total number of shares of common stock issued and outstanding immediately following the completion of this offering and (y) the recipients thereof provide the underwriter a signed lock-up agreement.

Jefferies LLC may, in its sole discretion and at any time or from time to time before the termination of the lock-up period release all or any portion of the securities subject to lock-up agreements. There are no existing agreements between the underwriter and any of our shareholders who will execute a lock-up agreement, providing consent to the sale of shares prior to the expiration of the lock-up period.

Stabilization

The underwriter has advised us that, pursuant to Regulation M under the Exchange Act, certain persons participating in the offering may engage in short sale transactions, stabilizing transactions, syndicate covering transactions or the imposition of penalty bids in connection with this offering. These activities may have the effect of stabilizing or maintaining the market price of the common stock at a level above that which might otherwise prevail in the open market. Establishing short sales positions may involve either “covered” short sales or “naked” short sales.

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“Covered” short sales are sales made in an amount not greater than the underwriter’s option to purchase additional shares of our common stock in this offering. The underwriter may close out any covered short position by either exercising its option to purchase additional shares of our common stock or purchasing shares of our common stock in the open market. In determining the source of shares to close out the covered short position, the underwriter will consider, among other things, the price of shares available for purchase in the open market as compared to the price at which it may purchase shares through the option to purchase additional shares.

“Naked” short sales are sales in excess of the option to purchase additional shares of our common stock. The underwriter must close out any naked short position by purchasing shares in the open market. A naked short position is more likely to be created if the underwriter is concerned that there may be downward pressure on the price of the shares of our common stock in the open market after pricing that could adversely affect investors who purchase in this offering.

A stabilizing bid is a bid for the purchase of shares of common stock on behalf of the underwriter for the purpose of fixing or maintaining the price of the common stock. A syndicate covering transaction is the bid for or the purchase of shares of common stock on behalf of the underwriter to reduce a short position incurred by the underwriter in connection with the offering. Similar to other purchase transactions, the underwriter’s purchases to cover the syndicate short sales may have the effect of raising or maintaining the market price of our common stock or preventing or retarding a decline in the market price of our common stock. As a result, the price of our common stock may be higher than the price that might otherwise exist in the open market. A penalty bid is an arrangement permitting the underwriter to reclaim the selling concession otherwise accruing to a syndicate member in connection with the offering if the common stock originally sold by such syndicate member are purchased in a syndicate covering transaction and therefore have not been effectively placed by such syndicate member.

Neither we nor the underwriter make any representation or prediction as to the direction or magnitude of any effect that the transactions described above may have on the price of our common stock. The underwriter is not obligated to engage in these activities and, if commenced, any of the activities may be discontinued at any time.

Electronic Distribution

A prospectus in electronic format may be made available by e-mail or through online services maintained by the underwriter or its affiliates. In those cases, prospective investors may view offering terms online and may be allowed to place orders online. The underwriter may agree with us to allocate a specific number of shares of common stock and warrants for sale to online brokerage account holders. Any such allocation for online distributions will be made by the underwriter on the same basis as other allocations. Other than the prospectus in electronic format, the information on the underwriter’s web site and any information contained in any other web site maintained by the underwriter is not part of this prospectus, has not been approved and/or endorsed by us or the underwriter and should not be relied upon by investors.

Other Activities and Relationships

The underwriter and certain of its affiliates are full service financial institutions engaged in various activities, which may include securities trading, commercial and investment banking, financial advisory, investment management, investment research, principal investment, hedging, financing and brokerage activities. The underwriter and certain of its affiliates have, from time to time, performed, and may in the future perform, various commercial and investment banking and financial advisory services for us and our affiliates, for which they received or will receive customary fees and expenses. Jefferies LLC is the sales agent under an Open Market Sale Agreement dated as of November 4, 2021, with us. Under the Open Market Sale Agreement^SM, we may offer and sell, from time to time, shares of our common stock through Jefferies LLC through an “at the market offering” as defined in Rule 415(a)(4) promulgated under the Securities Act.

In the ordinary course of their various business activities, the underwriter and certain of its affiliates may make or hold a broad array of investments and actively trade debt and equity securities (or related derivative securities) and financial instruments (including bank loans) for their own account and for the accounts of their customers, and such investment and securities activities may involve securities and/or instruments issued by us and our affiliates. If the underwriter or its respective affiliates have a lending relationship with us, they routinely hedge their credit

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exposure to us consistent with their customary risk management policies. The underwriter and its respective affiliates may hedge such exposure by entering into transactions which consist of either the purchase of credit default swaps or the creation of short positions in our securities or the securities of our affiliates, including potentially the common stock and warrants offered hereby. Any such short positions could adversely affect future trading prices of the common stock and warrants offered hereby. The underwriter and certain of its respective affiliates may also communicate independent investment recommendations, market color or trading ideas and/or publish or express independent research views in respect of such securities or instruments and may at any time hold, or recommend to clients that they acquire, long and/or short positions in such securities and instruments.

Disclaimers about Non-US Jurisdictions

Notice to Prospective Investors in the European Economic Area

In relation to each Member State of the European Economic Area (each, a “Relevant State”), no shares have been offered or will be offered pursuant to the offering to the public in that Relevant State prior to the publication of a prospectus in relation to the shares which have been approved by the competent authority in that Relevant State or, where appropriate, approved in another Relevant State and notified to the competent authority in that Relevant State, all in accordance with the Prospectus Regulation, except that the shares may be offered to the public in that Relevant State at any time:

(a) to any legal entity which is a “qualified investor” as defined under Article 2 of the Prospectus Regulation;

(b) to fewer than 150 natural or legal persons (other than qualified investors as defined under Article 2 of the Prospectus Regulation), subject to obtaining the prior consent of representatives for any such offer; or

(c) in any other circumstances falling within Article 1(4) of the Prospectus Regulation,

provided that no such offer of the shares shall require us or any of the representatives to publish a prospectus pursuant to Article 3 of the Prospectus Regulation or supplement a prospectus pursuant to Article 23 of the Prospectus Regulation.

For the purposes of this provision, the expression “offer to the public” in relation to the shares in any Relevant State means the communication in any form and by any means of sufficient information on the terms of the offer and any shares to be offered so as to enable an investor to decide to purchase or subscribe for any shares, and the expression “Prospectus Regulation” means Regulation (EU) 2017/1129.

Notice to Prospective Investors in the United Kingdom

No shares have been offered or will be offered pursuant to the offering to the public in the United Kingdom prior to the publication of a prospectus in relation to the Shares which has been approved by the Financial Conduct Authority, except that the shares may be offered to the public in the United Kingdom at any time:

(a) to any legal entity which is a qualified investor as defined under Article 2 of the UK Prospectus Regulation;

(b) to fewer than 150 natural or legal persons (other than qualified investors as defined under Article 2 of the UK Prospectus Regulation), subject to obtaining the prior consent of the representatives for any such offer; or

(c) in any other circumstances falling within Section 86 of the FSMA,

provided that no such offer of the shares shall require the Issuer or any Manager to publish a prospectus pursuant to Section 85 of the FSMA or supplement a prospectus pursuant to Article 23 of the UK Prospectus Regulation. For the purposes of this provision, the expression an “offer to the public” in relation to the shares in the United Kingdom means the communication in any form and by any means of sufficient information on the terms of the offer and any shares to be offered so as to enable an investor to decide to purchase or subscribe for any shares and the expression “UK Prospectus Regulation” means Regulation (EU) 2017/1129 as it forms part of domestic law by virtue of the European Union (Withdrawal) Act 2018.

Notice to Prospective Investors in Hong Kong

No securities have been offered or sold, and no securities may be offered or sold, in Hong Kong, by means of any document, other than: (i) to persons whose ordinary business is to buy or sell shares or debentures, whether as principal or agent; or (ii) to “professional investors” as defined in the Securities and Futures Ordinance (Cap. 571)

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of Hong Kong (the “SFO”) and any rules made under that Ordinance; or in other circumstances which do not result in the document being a “prospectus” as defined in the Companies Ordinance (Cap. 32) of Hong Kong (the “CO”) or which do not constitute an offer or invitation to the public for the purpose of the CO or the SFO. No document, invitation or advertisement relating to the securities has been issued or may be issued or may be in the possession of any person for the purpose of issue (in each case whether in Hong Kong or elsewhere), that is directed at, or the contents of which are likely to be accessed or read by, the public of Hong Kong (except if permitted under the securities laws of Hong Kong) other than with respect to securities that are or are intended to be disposed of only to persons outside Hong Kong or only to “professional investors” as defined in the SFO and any rules made under that Ordinance.

This prospectus supplement and the accompanying prospectus have not been registered with the Registrar of Companies in Hong Kong. Accordingly, this prospectus supplement and the accompanying prospectus may not be issued, circulated or distributed in Hong Kong, and the securities may not be offered for subscription to members of the public in Hong Kong. Each person acquiring the securities will be required, and is deemed by the acquisition of the securities, to confirm that he is aware of the restriction on offers of the securities described in this prospectus supplement and accompanying prospectus and that he is not acquiring, and has not been offered, any securities in circumstances that contravene any such restrictions.

Notice to Prospective Investors in Japan

The offering has not been and will not be registered under the Financial Instruments and Exchange Law of Japan (Law No. 25 of 1948 of Japan, as amended, the “FIEL”) and the underwriter will not offer or sell any securities, directly or indirectly, in Japan or to, or for the benefit of, any resident of Japan (the term as used herein means any person resident in Japan, including any corporation or other entity organized under the laws of Japan), or to others for re-offering or resale, directly or indirectly, in Japan or to, or for the benefit of, any resident of Japan, except pursuant to an exemption from the registration requirements of, and otherwise in compliance with the FIEL and any other applicable laws, regulations and ministerial guidelines of Japan.

Notice to Prospective Investors in Singapore

This prospectus supplement and the accompanying prospectus have not been and will not be lodged or registered as a prospectus with the Monetary Authority of Singapore. Accordingly, this prospectus supplement and the accompanying prospectus and any other document or material in connection with the offer or sale, or invitation for subscription or purchase, of the shares of common stock and warrants offered hereby may not be circulated or distributed, nor may the shares of common stock or warrants be offered or sold, or be made the subject of an invitation for subscription or purchase, whether directly or indirectly, to persons in Singapore other than: (i) to an institutional investor under Section 274 of the Securities and Futures Act, Chapter 289 of Singapore (the “SFA”); (ii) to a relevant person pursuant to Section 275(1), or any person pursuant to Section 275(1A), and in accordance with the conditions specified in Section 275, of the SFA; or (iii) otherwise pursuant to, and in accordance with the conditions of, any other applicable provision of the SFA.

Where the shares of common stock or warrants are subscribed or purchased under Section 275 of the SFA by a relevant person that is:

∎ a corporation (which is not an accredited investor (as defined in Section 4A of the SFA)), the sole business of which is to hold investments and the entire share capital of which is owned by one or more individuals, each of whom is an accredited investor; or

∎ a trust (where the trustee is not an accredited investor) whose sole purpose is to hold investments and each beneficiary of the trust is an individual who is an accredited investor, securities (as defined in Section 239(1) of the SFA) of that corporation or the beneficiaries’ rights and interest (howsoever described) in that trust shall not be transferred within six months after that corporation or that trust has acquired the shares of common stock and warrants pursuant to an offer made under Section 275 of the SFA except:

∎ to an institutional investor or to a relevant person defined in Section 275(2) of the SFA, or to any person arising from an offer referred to in Section 275(1A) or Section 276(4)(i)(B) of the SFA;

∎ where no consideration is or will be given for the transfer;

∎ where the transfer is by operation of law;

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∎ as specified in Section 276(7) of the SFA; or

∎ as specified in Regulation 32 of the Securities and Futures (Offers of Investments) (Shares and Debentures) Regulations 2005 of Singapore.

Notice to Prospective Investors in Canada

(A) Resale Restrictions

The distribution of shares of common stock and warrants in Canada is being made only in the provinces of Ontario, Quebec, Alberta, British Columbia, Manitoba, New Brunswick and Nova Scotia on a private placement basis exempt from the requirement that we prepare and file a prospectus with the securities regulatory authorities in each province where trades of these securities are made. Any resale of the shares of common stock or warrants in Canada must be made under applicable securities laws which may vary depending on the relevant jurisdiction, and which may require resales to be made under available statutory exemptions or under a discretionary exemption granted by the applicable Canadian securities regulatory authority. Purchasers are advised to seek legal advice prior to any resale of the securities.

(B) Representations of Canadian Purchasers

By purchasing shares of common stock and warrants in Canada and accepting delivery of a purchase confirmation, a purchaser is representing to us and the dealer from whom the purchase confirmation is received that:

∎ purchaser is entitled under applicable provincial securities laws to purchase the shares of common stock and warrants without the benefit of a prospectus qualified under those securities laws as it is an “accredited investor” as defined under National Instrument 45-106 – Prospectus Exemptions or Section 73.3(1) of the Securities Act (Ontario), as applicable,

∎ the purchaser is a “permitted client” as defined in National Instrument 31-103—Registration Requirements, Exemptions and Ongoing Registrant Obligations,

∎ where required by law, the purchaser is purchasing as principal and not as agent, and

∎ the purchaser has reviewed the text above under Resale Restrictions.

(C) Conflicts of Interest

Canadian purchasers are hereby notified that certain of the underwriters are relying on the exemption set out in section 3A.3 or 3A.4, if applicable, of National Instrument 33-105 – Underwriting Conflicts from having to provide certain conflict of interest disclosure in this document.

(D) Statutory Rights of Action

Securities legislation in certain provinces or territories of Canada may provide a purchaser with remedies for rescission or damages if the prospectus supplement and the accompanying prospectus contains a misrepresentation, provided that the remedies for rescission or damages are exercised by the purchaser within the time limit prescribed by the securities legislation of the purchaser’s province or territory. The purchaser of these securities in Canada should refer to any applicable provisions of the securities legislation of the purchaser’s province or territory for particulars of these rights or consult with a legal advisor.

(E) Enforcement of Legal Rights

All of our directors and officers as well as the experts named herein may be located outside of Canada and, as a result, it may not be possible for Canadian purchasers to effect service of process within Canada upon us or those persons. All or a substantial portion of our assets and the assets of those persons may be located outside of Canada and, as a result, it may not be possible to satisfy a judgment against us or those persons in Canada or to enforce a judgment obtained in Canadian courts against us or those persons outside of Canada.

(F) Taxation and Eligibility for Investment

Canadian purchasers of shares of common stock and warrants should consult their own legal and tax advisors with respect to the tax consequences of an investment in the shares of common stock and warrants in their particular circumstances and about the eligibility of the shares of common stock and warrants for investment by the purchaser under relevant Canadian legislation.

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Notice to Prospective Investors in Australia

This prospectus supplement and the accompanying prospectus is not a disclosure document for the purposes of Australia’s Corporations Act 2001 (Cth) of Australia (the “Corporations Act”), has not been lodged with the Australian Securities and Investments Commission and is only directed to the categories of exempt persons set out below. Accordingly, if you receive this prospectus supplement and the accompanying prospectus in Australia, you confirm and warrant that you are either:

∎ a “sophisticated investor” under Section 708(8)(a) or (b) of the Corporations Act;

∎ a “sophisticated investor” under Section 708(8)(c) or (d) of the Corporations Act and that you have provided an accountant’s certificate to the Company that complies with the requirements of Section 708(8)(c)(i) or (ii) of the Corporations Act and related regulations before the offer has been made;

∎ a person associated with the Company under Section 708(12) of the Corporations Act; or

∎ a “professional investor” under Section 708(11)(a) or (b) of the Corporations Act.

To the extent that you are unable to confirm or warrant that you are an exempt sophisticated investor, associated person or professional investor under the Corporations Act, any offer made to you under this prospectus supplement and the accompanying prospectus is void and incapable of acceptance.

Further, you warrant and agree that you will not offer any of the securities issued to you pursuant to this prospectus supplement and the accompanying prospectus for resale in Australia within 12 months of those securities being issued unless any such resale offer is exempt from the requirement to issue a disclosure document under Section 708 of the Corporations Act.

Notice to Prospective Investors in Israel

This document does not constitute a prospectus under the Israeli Securities Law, 5728-1968 (the “Israeli Securities Law”), and has not been filed with or approved by the Israel Securities Authority. In Israel, this prospectus supplement and the accompanying prospectus is being distributed only to, and is directed only at, and any offer of the shares of common stock and warrants offered hereby is directed only at: (i) a limited number of persons in accordance with the Israeli Securities Law; and (ii) investors listed in the first addendum to the Israeli Securities Law, as it may be amended from time to time (the “Addendum”), consisting primarily of joint investment in trust funds, provident funds, insurance companies, banks, portfolio managers, investment advisors, members of the Tel Aviv Stock Exchange, underwriters, venture capital funds, entities with equity in excess of NIS 50 million and “qualified individuals,” each as defined in the Addendum, collectively referred to as qualified investors (in each case, purchasing for their own account or, where permitted under the Addendum, for the accounts of their clients who are investors listed in the Addendum). Qualified investors are required to submit written confirmation that they fall within the scope of the Addendum, are aware of the meaning of the Addendum and agree to it.

Notice to Prospective Investors in Switzerland

The shares of common stock and warrants may not be publicly offered in Switzerland and will not be listed on the SIX Swiss Exchange (“SIX”) or on any other stock exchange or regulated trading facility in Switzerland. This prospectus supplement and the accompanying prospectus has been prepared without regard to the disclosure standards for issuance prospectuses under art. 652a or art. 1156 of the Swiss Code of Obligations or the disclosure standards for listing prospectuses under art. 27 ff. of the SIX Listing Rules or the listing rules of any other stock exchange or regulated trading facility in Switzerland. Neither this prospectus supplement and the accompanying prospectus, nor any other offering or marketing material relating to the shares of common stock, warrants or the offering, may be publicly distributed or otherwise made publicly available in Switzerland.

Neither this prospectus supplement and the accompanying prospectus, nor any other offering or marketing material relating to the offering, the Company or the shares of common stock and warrants offered hereby, have been or will be filed with or approved by any Swiss regulatory authority. In particular, this prospectus supplement and the accompanying prospectus will not be filed with, and the offer of securities will not be supervised by, the Swiss Financial Market Supervisory Authority FINMA, and the offer of securities has not been and will not be authorized under the Swiss Federal Act on Collective Investment Schemes (the “CISA”). The investor protection afforded to acquirers of interests in collective investment schemes under the CISA does not extend to acquirers of shares of common stock and warrants offered hereby.

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LEGAL MATTERS

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 supplement. Certain legal matters related to this offering will be passed upon for the underwriter by Ropes & Gray LLP, Boston, Massachusetts.

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EXPERTS

Ernst & Young LLP, independent registered public accounting firm, has audited our consolidated financial statements included in our Annual Report on Form 10-K for the year ended December 31, 2021, as set forth in their report (which contains an explanatory paragraph describing conditions that raise substantial doubt about the Company’s ability to continue as a going concern as described in Note 1 to the consolidated financial statements), which is incorporated by reference in this prospectus supplement and elsewhere in the registration statement. Our financial statements are incorporated by reference in reliance on Ernst & Young LLP’s report, given on their authority as experts in accounting and auditing.

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WHERE YOU CAN FIND MORE INFORMATION

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. SEC filings are available at the SEC’s web site at http://www.sec.gov.

This prospectus supplement is only part of a registration statement on Form S-3 (File No. 333-260781) that we have filed with the SEC under the Securities Act 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 supplement and the accompanying 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.

We also maintain a website at https://www.codiakbio.com/ through which you can access our SEC filings. The information set forth on our website is not part of this prospectus supplement or the accompanying prospectus.

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INCORPORATION OF DOCUMENTS BY REFERENCE

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 supplement, 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 with the SEC with respect to the securities we may offer pursuant to this prospectus supplement. This prospectus supplement 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 supplement. Statements in this prospectus supplement 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 accessed on the SEC website as noted above in “Where You Can Find More Information.” The documents we are incorporating by reference are:

∎ our Annual Report on Form 10-K for the fiscal year ended December 31, 2021, as filed on March 10, 2022;

∎ the portions of our definitive proxy statement on Schedule 14A that we filed with the SEC on April 29, 2022 that are incorporated by reference into our Annual Report on Form 10-K for the fiscal year ended December 31, 2021 and deemed “filed” with the SEC under the Exchange Act;

∎ our Quarterly Reports on Form 10-Q for the quarter ended March 31, 2022, which we filed with the SEC on May 5, 2022, and for the quarter ended June  30, 2022, which we filed with the SEC on August 4, 2022;

∎ our Current Reports on Form 8-K, which we filed with the SEC on June 21, 2022, June 29, 2022, and August 30, 2022;

∎ the description of the common stock contained in our registration statement on Form 8-A, as filed with the SEC on October  13, 2020, under the Exchange Act, as supplemented by the description of our common stock contained in Exhibit 4.3 in our Annual Report on Form 10-K for the year ended December 31, 2020, as filed with the SEC on March 17, 2021, including any amendment or report filed for the purpose of updating such description; and

∎ all reports and other documents subsequently filed by us pursuant to Sections 13(a), 13(c), 14 and 15(d) of the Exchange Act after the date of this prospectus supplement and prior to the termination or completion of the offering of securities under this prospectus supplement shall be deemed to be incorporated by reference in this prospectus supplement and to be a part hereof from the date of filing such reports and other documents.

The file number for all of the documents listed above is 001-39615. 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 supplement.

Any statement contained in this prospectus supplement, the accompanying prospectus, or in a document incorporated or deemed to be incorporated by reference herein or therein will be deemed to be modified or superseded for purposes of this prospectus supplement or the accompanying prospectus to the extent that a statement contained in this prospectus supplement, the accompanying prospectus, or any other subsequently filed document that is deemed to be incorporated by reference herein or therein 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:

Codiak BioSciences, Inc.

35 CambridgePark Drive, Suite 500

Cambridge, MA 02140

(617) 949-4100

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You may also access these documents on our website, https://www.codiakbio.com. The information contained on, or that can be accessed through, our website is not a part of this prospectus supplement. We have included our website address in this prospectus supplement solely as an inactive textual reference.

You should rely only on information contained in, or incorporated by reference into, this prospectus supplement and the accompanying prospectus. We have not authorized anyone to provide you with information different from that contained in this prospectus supplement, the accompanying prospectus, or incorporated by reference herein or therein. 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.

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PROSPECTUS

Codiak BioSciences, Inc.

$300,000,000

COMMON STOCK

PREFERRED STOCK

DEBT SECURITIES

WARRANTS

RIGHTS

UNITS

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 $300,000,000 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 preferred stock; or common stock, preferred stock or debt securities upon the exercise of warrants or rights.

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 Global Market under the symbol “CDAK.” On November 1, 2021, the last reported sale price of our common stock was $15.15 per share. The applicable prospectus supplement will contain information, where applicable, as to any other listing, if any, on the Nasdaq Global 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. See “Risk Factors” included in any accompanying prospectus supplement and in the documents incorporated by reference in this prospectus for a discussion of the factors you should carefully consider before deciding to purchase these securities.

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 November 15, 2021.

TABLE OF CONTENTS

	Page
ABOUT THIS PROSPECTUS		1
PROSPECTUS SUMMARY		2
RISK FACTORS		4
SPECIAL NOTE REGARDING FORWARD-LOOKING STATEMENTS		5
USE OF PROCEEDS		8
PLAN OF DISTRIBUTION		9
DESCRIPTION OF COMMON STOCK		11
DESCRIPTION OF PREFERRED STOCK		12
DESCRIPTION OF DEBT SECURITIES		14
DESCRIPTION OF WARRANTS		20
DESCRIPTION OF RIGHTS		21
DESCRIPTION OF UNITS		23
CERTAIN PROVISIONS OF DELAWARE LAW AND OF THE COMPANY’S CERTIFICATE OF INCORPORATION AND BY-LAWS		25
LEGAL MATTERS		29
EXPERTS		30
WHERE YOU CAN FIND MORE INFORMATION		31
INCORPORATION OF DOCUMENTS BY REFERENCE		32

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ABOUT THIS PROSPECTUS

This prospectus is part of a registration statement that we filed with the Securities and Exchange Commission (the “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 or rights to purchase any such securities, either individually or in units, in one or more offerings, with a total value of up to $300,000,000. 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 this 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, “Codiak,” “CDAK,” “the Company,” “we,” “us,” “our” and similar terms refer to Codiak BioSciences, Inc. and our subsidiary.

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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 Codiak BioSciences, Inc.

We are a clinical-stage biopharmaceutical company focused on pioneering the development of exosome-based therapeutics, a new class of medicines with the potential to transform the treatment of a wide spectrum of diseases with high unmet medical need. Exosomes have evolved as intercellular transfer mechanisms for complex, biologically active macromolecules and have emerged in recent years as a compelling potential drug delivery vehicle. By leveraging our deep understanding of exosome biology, we have developed our engineering and manufacturing platform (“engEx Platform”) to expand upon the innate properties of exosomes to design, engineer and manufacture novel exosome therapeutics. We have utilized our engEx Platform to generate a deep pipeline of engineered exosomes (“engEx exosomes”) aimed at treating a broad range of diseases, including oncology, neuro-oncology, infectious disease and rare disease.

Additional Information

For additional information related to our business and operations, please refer to the reports incorporated herein by reference, as described under the caption “Incorporation of Documents by Reference” on page 32 of this prospectus.

Our Corporate Information

We were incorporated under the laws of the State of Delaware in 2015. Our principal executive office is located at 35 CambridgePark Drive, Suite 500, Cambridge, Massachusetts 02140, and our telephone number is (617) 949-4100. Our website address is https://www.codiakbio.com. We do not incorporate the information on or accessible through our website into this prospectus, and you should not consider any information on, or that can be accessed through, our website as part of this prospectus.

We own various US federal trademark applications and unregistered trademarks and service marks, including “Codiak BioSciences”, our corporate logo, “engEx”, “exoSTING”, “exoIL-12”, “exoASO-STAT6”, “exoVACC”, “engEx-AAV” and others. This prospectus contains references to our trademarks and to trademarks belonging to other entities. Solely for convenience, trademarks and trade names referred to in this prospectus, including logos, artwork and other visual displays, may appear without the ^® or TM symbols, but such references are not intended to indicate, in any way, that we will not assert, to the fullest extent under applicable law, our rights or the rights of the applicable licensor to these trademarks and trade names. We do not intend our use or display of other companies’ trade names or trademarks to imply a relationship with, or endorsement or sponsorship of us by, any other companies.

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 or rights to purchase any of such securities, either individually or in units, with a total

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value of up to $300,000,000, 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:

• designation or classification;

• aggregate principal amount or aggregate offering price;

• maturity, if applicable;

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

• redemption, conversion or sinking fund terms, if any;

• voting or other rights, if any; and

• 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:

• the names of those agents or underwriters;

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

• details regarding over-allotment options, if any; and

• 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.

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RISK FACTORS

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 Codiak. 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.

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SPECIAL NOTE REGARDING FORWARD-LOOKING STATEMENTS

This prospectus and the documents incorporated by reference in this prospectus include forward-looking statements within the meaning of Section 27A of the Securities Act of 1933, as amended (the “Securities Act”), and Section 21E of the Securities Exchange Act of 1934, as amended (the “Exchange Act”), that relate to future events or our future financial performance and involve known and unknown risks, uncertainties and other factors that may cause our actual results, levels of activity, performance or achievements to differ materially from any future results, levels of activity, performance or achievements expressed or implied by these forward-looking statements. Words such as, but not limited to, “believe,” “expect,” “anticipate,” “estimate,” “intend,” “may,” “plan,” “potential,” “predict,” “project,” “targets,” “likely,” “will,” “would,” “could,” “should,” “continue,” and similar expressions or phrases, or the negative of those expressions or phrases, are intended to identify forward-looking statements, although not all forward-looking statements contain these identifying words. Although we believe that we have a reasonable basis for each forward-looking statement contained in this prospectus and incorporated by reference in this prospectus, we caution you that these statements are based on our projections of the future that are subject to known and unknown risks and uncertainties and other factors that may cause our actual results, level of activity, performance or achievements expressed or implied by these forward-looking statements, to differ. The sections in our periodic reports, including our most recent Annual Report on Form 10-K for the fiscal year ended December 31, 2020, as supplemented by our subsequent Quarterly Reports on Form 10-Q and our Current Reports on Form 8-K, entitled “Business,” “Risk Factors,” and “Management’s Discussion and Analysis of Financial Condition and Results of Operations,” as well as other sections in this prospectus and the other documents or reports incorporated by reference in this prospectus, discuss some of the factors that could contribute to these differences. These forward-looking statements include, among other things, statements about:

• our intended use of the net proceeds from offerings of our securities under this prospectus and any accompanying prospectus supplement;

• the success, cost and timing of our product development activities, preclinical studies and clinical trials, including statements regarding the timing of initiation and completion of studies or trials and related preparatory work, the period during which the results of the trials will become available and our research and development programs;

• the design and conduct of our clinical trials of exoSTING and exoIL-12 and planned clinical trial of exoASO-STAT6;

• our ability to successfully advance any our engEx product candidates into and through clinical trials, or obtain marketing approval;

• the potential and capabilities of our engEx Platform, engEx product candidates and engEx discovery programs;

• the potential and capability of our engEx Platform to generate additional engEx product candidates;

• our ability to secure from Lonza Rockland, Inc., under our manufacturing arrangement with them, sufficient supply of our product candidates for clinical trials or commercial use, if approved;

• our ability to successfully procure from third parties sufficient supply of our product candidates for preclinical studies, clinical trials or commercial use, if approved;

• our ability to utilize our engEx Platform to engineer exosomes to carry various biologically active drug molecules, target specific cell types or cellular pathways or enhance the value of existing drug modalities;

• the potential indications that we may be able to target with our engEx Platform;

• the size, composition and growth potential of the patient populations and markets we intend to target with our engEx product candidates and our ability to develop and commercialize engEx product candidates to address those patient populations and markets;

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• the ability and willingness of our current and future collaborators to continue research and development activities relating to our engEx exosomes;

• our ability to maintain regulatory approval, if obtained, of any of our current or future engEx product candidates, and any related restrictions, limitations and/or warnings in the label of an approved product candidate;

• our expectations regarding our ability to obtain and maintain intellectual property protection for our product candidates;

• our ability to license intellectual property relating to our product candidates and to comply with our existing license and collaboration agreements;

• our ability to commercialize our products, if approved, in light of the intellectual property rights of others;

• developments relating to the use of exosomes to develop therapeutics;

• the success of competing therapies that are or become available;

• our ability to obtain funding for our operations, including funding necessary to complete further development and commercialization of our product candidates;

• our plans to research, develop and commercialize our engEx product candidates and enhance the capabilities of our engEx Platform;

• our ability to attract collaborators with development, regulatory and commercialization expertise;

• future agreements with third parties in connection with the commercialization of our product candidates and any other approved products;

• the rate and degree of market acceptance of our product candidates, if approved;

• regulatory developments in the United States and foreign countries;

• our ability to contract with third-party suppliers and manufacturers and their ability to perform adequately;

• our ability to attract and retain key scientific or management personnel;

• our expectations regarding the time during which we will be an emerging growth company under the Jumpstart Our Business Startups Act;

• the accuracy of our estimates regarding expenses, future revenue, capital requirements and needs for additional financing;

• the impact of laws and regulations; and

• the direct or indirect ongoing impact of the COVID-19 pandemic on our business, operations, development timelines, and the markets and communities in which we and our partners, collaborators, vendors and customers operate.

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 cautionary statements in this prospectus and in the documents incorporated by reference in this prospectus, particularly in the “Risk Factors” section, that we believe could cause actual results or events to differ materially from the forward-looking statements that we make. For a summary of such factors, please refer to the section entitled “Risk Factors” in this prospectus, as updated and supplemented by the discussion of risks and uncertainties under “Risk Factors” contained in any supplements to this prospectus and in our most recent Annual Report on Form 10-K, as revised or supplemented by our

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subsequent Quarterly Reports on Form 10-Q or our Current Reports on Form 8-K, as well as any amendments thereto, as filed with the SEC and which are incorporated herein by reference. The information contained in this document is believed to be current as of the date of this document. We do not intend to update any of the forward-looking statements after the date of this document to conform these statements to actual results or to changes in our expectations, except as required by law.

In light of these assumptions, risks and uncertainties, the results and events discussed in the forward-looking statements contained in this prospectus or in any document incorporated herein by reference might not occur. Investors are cautioned not to place undue reliance on the forward-looking statements, which speak only as of the date of this prospectus or the date of the document incorporated by reference in this prospectus. We are not under any obligation, and we expressly disclaim any obligation, to update or alter any forward-looking statements, whether as a result of new information, future events or otherwise. All subsequent forward-looking statements attributable to us or to any person acting on our behalf are expressly qualified in their entirety by the cautionary statements contained or referred to in this section.

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USE OF PROCEEDS

Unless otherwise indicated in the applicable prospectus supplement, we intend to use any net proceeds from the sale of securities under this prospectus for general corporate purposes, including, but not limited to, initiating new clinical trials and advancing our ongoing clinical trials, preclinical studies and research and development activities, as well as for working capital, capital expenditures, investments, acquisitions, should we choose to pursue any, collaborations, and commercialization efforts. 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, or interest-bearing securities.

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PLAN OF DISTRIBUTION

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:

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

• market prices prevailing at the time of sale;

• prices related to the prevailing market prices; or

• negotiated prices.

We may directly solicit offers to purchase the securities being offered by this prospectus. We may also designate agents to solicit offers to purchase the securities from time to time 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:

• 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

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• 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.

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.

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 Global Market. The applicable prospectus supplement will contain information, where applicable, as to any other listing, if any, on the Nasdaq Global 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.

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DESCRIPTION OF COMMON STOCK

We are authorized to issue 150,000,000 shares of common stock, par value $0.0001 per share, and 10,000,000 shares of preferred stock, par value $0.0001 per share. As of September 30, 2021, we had 22,361,305 shares of common stock outstanding with approximately 20 common stockholders of record and no shares of preferred stock outstanding.

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 By-laws” and our amended and restated certificate of incorporation and our amended and restated by-laws, 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.

General

We are authorized to issue one class of common stock. Holders of our common stock are entitled to one vote for each share of common stock held of record for the election of directors and on all matters submitted to a vote of stockholders, except matters that relate only to one or more of the series of our preferred stock, and no holder has cumulative voting rights. Accordingly, the holders of a majority of the shares of common stock entitled to vote in any election of directors can elect all of the directors standing for election, if they so choose. Subject to preferences that may be applicable to any then outstanding preferred stock, holders of our common stock are entitled to receive dividends ratably, if any, as may be declared by our board of directors out of legally available funds, subject to any preferential dividend rights of any preferred stock then outstanding. Upon our dissolution, liquidation or winding up, holders of our common stock are entitled to share ratably in our net assets legally available after the payment of all our debts and other liabilities, subject to the preferential rights of any preferred stock then outstanding. Holders of our common stock have no preemptive, subscription, redemption or conversion rights. The rights, preferences and privileges of holders of common stock are subject to, and may be adversely affected by, the rights of the holders of shares of any series of preferred stock that are currently designated and issued or that we may designate and issue in the future. Except as described under “Certain Provisions of Delaware Law and of the Company’s Certificate of Incorporation and By-laws—Anti-Takeover Provisions” below, a majority vote of the holders of common stock is generally required to take action under our amended and restated certificate of incorporation and amended and restated by-laws.

Stock Options

As of September 30, 2021, we had outstanding options to purchase 4,953,272 shares of our common stock at a weighted average price of $12.68 per share. All of our stock options expire 10 years after their grant date.

Transfer Agent and Registrar

The transfer agent and registrar for our common stock is American Stock Transfer & Trust Company, LLC. The transfer agent for any series of preferred stock that we may offer under this prospectus will be named and described in the applicable prospectus supplement for that series.

Stock Exchange Listing

Our common stock is listed for quotation on the Nasdaq Global Market under the symbol “CDAK.”

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DESCRIPTION OF PREFERRED STOCK

The following description of our preferred stock and the description of the terms of any particular series of preferred stock that we choose to issue hereunder are not complete. These descriptions are qualified in their entirety by reference to our amended and restated certificate of incorporation and the certificate of designation relating to any series of preferred stock issued by us. The rights, preferences, privileges and restrictions of the preferred stock of each series will be fixed by the certificate of designation relating to that series.

We are authorized, without action by the stockholders, to designate and issue up to an aggregate of 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 amended and restated certificate of incorporation and our amended and restated by-laws, 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.

General

Our board of directors can designate the rights, preferences and privileges of the shares of each series and any of its qualifications, limitations or restrictions. Our board of directors may authorize the issuance of preferred stock with voting or conversion rights that could adversely affect the voting power or other rights of the holders of common stock. The issuance of preferred stock, while providing flexibility in connection with possible future financings and acquisitions and other corporate purposes could, under certain circumstances, have the effect of restricting dividends on our common stock, diluting the voting power of our common stock, impairing the liquidation rights of our common stock, or delaying, deferring or preventing a change in control of our Company, which might harm the market price of our common stock. See also “Certain Provisions of Delaware Law and of the Company’s Certificate of Incorporation and By-laws—Anti-Takeover Provisions.” Our board of directors will make any determination to issue such shares based on its judgment as to our Company’s best interests and the best interests of our stockholders.

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 amended and restated certificate establishing the terms of the preferred stock with the SEC. To the extent required, this description will include:

• the maximum number of shares;

• the designation of the shares;

• the annual dividend rate, if any, whether the dividend rate is fixed or variable, the date or dates on which dividends will accrue, the dividend payment dates, and whether dividends will be cumulative;

• the price and the terms and conditions for redemption, if any, including redemption at the option of Codiak or at the option of the holders, including the time period for redemption, and any accumulated dividends or premiums;

• the liquidation preference, if any, and any accumulated dividends upon the liquidation, dissolution or winding up of our affairs;

• any sinking fund or similar provision, and, if so, the terms and provisions relating to the purpose and operation of the fund;

• the terms and conditions, if any, for conversion or exchange of shares of any other class or classes of our capital stock or any series of any other class or classes, or of any other series of the same class, or any other securities or assets, including the price or the rate of conversion or exchange and the method, if any, of adjustment;

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• the voting rights;

• any or all other preferences and relative, participating, optional or other special rights, privileges or qualifications, limitations or restrictions; and

• any preferred stock issued will be fully paid and nonassessable upon issuance.

Transfer Agent and Registrar

The transfer agent and registrar for any series of preferred stock that is designated by our board of directors will be set forth in the applicable prospectus supplement.

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DESCRIPTION OF DEBT SECURITIES

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.

General

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:

• the title or designation;

• the aggregate principal amount and any limit on the amount that may be issued;

• the currency or units based on or relating to currencies in which debt securities of such series are denominated and the currency or units in which principal or interest or both will or may be payable;

• whether we will issue the series of debt securities in global form, the terms of any global securities and who the depositary will be;

• the maturity date and the date or dates on which principal will be payable;

• the interest rate, which may be fixed or variable, or the method for determining the rate and the date interest will begin to accrue, the date or dates interest will be payable and the record dates for interest payment dates or the method for determining such dates;

• whether or not the debt securities will be secured or unsecured, and the terms of any secured debt;

• the terms of the subordination of any series of subordinated debt;

• the place or places where payments will be payable;

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• our right, if any, to defer payment of interest and the maximum length of any such deferral period;

• the date, if any, after which, and the price at which, we may, at our option, redeem the series of debt securities pursuant to any optional redemption provisions;

• the date, if any, on which, and the price at which we are obligated, pursuant to any mandatory sinking fund provisions or otherwise, to redeem, or at the holder’s option to purchase, the series of debt securities;

• whether the indenture will restrict our ability to pay dividends, or will require us to maintain any asset ratios or reserves;

• whether we will be restricted from incurring any additional indebtedness;

• a discussion of any material or special U.S. federal income tax considerations applicable to a series of debt securities;

• the denominations in which we will issue the series of debt securities, if other than denominations of $1,000 and any integral multiple thereof; and

• any other specific terms, preferences, rights or limitations of, or restrictions on, the 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.

Conversion or Exchange Rights

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.

Events of Default Under the Indenture

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

• if we fail to pay interest when due and our failure continues for 90 days and the time for payment has not been extended or deferred;

• if we fail to pay the principal, or premium, if any, when due and the time for payment has not been extended or delayed;

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• if we fail to observe or perform any other covenant set forth in the debt securities of such series or the applicable indentures, other than a covenant specifically relating to and for the benefit of holders of another series of debt securities, and our failure continues for 90 days after we receive written notice from the debenture trustee or holders of not less than a majority in aggregate principal amount of the outstanding debt securities of the applicable series; and

• if specified events of bankruptcy, insolvency or reorganization occur as to us.

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:

• the direction so given by the holder is not in conflict with any law or the applicable indenture; and

• subject to its duties under the Trust Indenture Act, the debenture trustee need not take any action that might involve it in personal liability or might be unduly prejudicial to the holders not involved in the proceeding.

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:

• the holder previously has given written notice to the debenture trustee of a continuing event of default with respect to that series;

• the holders of at least a majority in aggregate principal amount of the outstanding debt securities of that series have made written request, and such holders have offered reasonable indemnity to the debenture trustee to institute the proceeding as trustee; and

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• the debenture trustee does not institute the proceeding and does not receive from the holders of a majority in aggregate 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) other conflicting directions within 60 days after the notice, request and offer.

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.

Modification of Indenture; Waiver

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

• to fix any ambiguity, defect or inconsistency in the indenture; and

• to change anything that does not materially adversely affect the interests of any holder of debt securities of any series issued pursuant to such indenture.

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:

• extending the fixed maturity of the series of debt securities;

• reducing the principal amount, reducing the rate of or extending the time of payment of interest, or any premium payable upon the redemption of any debt securities;

• reducing the principal amount of discount securities payable upon acceleration of maturity;

• making the principal of or premium or interest on any debt security payable in currency other than that stated in the debt security; or

• reducing the percentage of debt securities, the holders of which are required to consent to any amendment or waiver.

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.

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Discharge

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:

• register the transfer or exchange of debt securities of the series;

• replace stolen, lost or mutilated debt securities of the series;

• maintain paying agencies;

• hold monies for payment in trust;

• compensate and indemnify the trustee; and

• appoint any successor trustee.

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.

Form, Exchange, and Transfer

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:

• issue, register the transfer of, or exchange any debt securities of that series during a period beginning at the opening of business 15 days before the day of mailing of a notice of redemption of any debt securities that may be selected for redemption and ending at the close of business on the day of the mailing; or

• register the transfer of or exchange any debt securities so selected for redemption, in whole or in part, except the unredeemed portion of any debt securities we are redeeming in part.

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Information Concerning the Debenture Trustee

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.

Payment and Paying Agents

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.

Governing Law

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

Subordination of Subordinated Debt Securities

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.

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DESCRIPTION OF WARRANTS

General

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 specific designation and aggregate number of, and the price at which we will issue, the warrants;

• the currency or currency units in which the offering price, if any, and the exercise price are payable;

• the designation, amount and terms of the securities purchasable upon exercise of the warrants;

• if applicable, the exercise price for shares of our common stock and the number of shares of common stock to be received upon exercise of the warrants;

• if applicable, the exercise price for shares of our preferred stock, the number of shares of preferred stock to be received upon exercise, and a description of that series of our preferred stock;

• if applicable, the exercise price for our debt securities, the amount of debt securities to be received upon exercise, and a description of that series of debt securities;

• the date on which the right to exercise the warrants will begin and the date on which that right will expire or, if you may not continuously exercise the warrants throughout that period, the specific date or dates on which you may exercise the warrants;

• whether the warrants will be issued in fully registered form or bearer form, in definitive or global form or in any combination of these forms, although, in any case, the form of a warrant included in a unit will correspond to the form of the unit and of any security included in that unit;

• any applicable material U.S. federal income tax consequences;

• the identity of the warrant agent for the warrants and of any other depositaries, execution or paying agents, transfer agents, registrars or other agents;

• the proposed listing, if any, of the warrants or any securities purchasable upon exercise of the warrants on any securities exchange;

• if applicable, the date from and after which the warrants and the common stock, preferred stock and/or debt securities will be separately transferable;

• if applicable, the minimum or maximum amount of the warrants that may be exercised at any one time;

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

• the anti-dilution provisions of the warrants, if any;

• any redemption or call provisions;

• whether the warrants may be sold separately or with other securities as parts of units; and

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

Transfer Agent and Registrar

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

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DESCRIPTION OF RIGHTS

General

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 or warrants, 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:

• the date of determining the stockholders entitled to the rights distribution;

• the aggregate number of shares of common stock, preferred stock or other securities purchasable upon exercise of the rights;

• the exercise price;

• the aggregate number of rights issued;

• whether the rights are transferrable and the date, if any, on and after which the rights may be separately transferred;

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

• the method by which holders of rights will be entitled to exercise;

• the conditions to the completion of the offering, if any;

• the withdrawal, termination and cancellation rights, if any;

• whether there are any backstop or standby purchaser or purchasers and the terms of their commitment, if any;

• whether stockholders are entitled to oversubscription rights, if any;

• any applicable material U.S. federal income tax considerations; and

• any other terms of the rights, including terms, procedures and limitations relating to the distribution, exchange and exercise of the rights, as applicable.

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

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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.

Rights Agent

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

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DESCRIPTION OF UNITS

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.

General

We may issue units consisting of common stock, preferred stock, one or more debt securities, warrants or rights 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 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 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,” and “Description of Rights” will apply to each unit, as applicable, and to any common stock, preferred stock, debt security, warrant or right included in each unit, as applicable.

Unit Agent

The name and address of the unit agent, if any, 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

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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.

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CERTAIN PROVISIONS OF DELAWARE LAW AND OF THE COMPANY’S CERTIFICATE OF INCORPORATION AND BY-LAWS

Anti-Takeover Provisions

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

Board composition and filling vacancies

Our certificate of incorporation provides for the division of our board of directors into three classes serving staggered three-year terms, with one class being elected each year. Our certificate of incorporation also provides that directors may be removed only for cause and then only by the affirmative vote of the holders of two-thirds or more of the shares then entitled to vote at an election of directors. Furthermore, any vacancy on our board of directors, however occurring, including a vacancy resulting from an increase in the size of our board, may only be filled by the affirmative vote of a majority of our directors then in office even if less than a quorum. The classification of directors, together with the limitations on removal of directors and treatment of vacancies, has the effect of making it more difficult for stockholders to change the composition of our board of directors.

No written consent of stockholders

Our certificate of incorporation provides that all stockholder actions are required to be taken by a vote of the stockholders at an annual or special meeting, and that stockholders may not take any action by written consent in lieu of a meeting. This limit may lengthen the amount of time required to take stockholder actions and would prevent the amendment of our by-laws or removal of directors by our stockholders without holding a meeting of stockholders.

Meetings of stockholders

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

Advance notice requirements

Our by-laws establish advance notice procedures with regard to stockholder proposals relating to the nomination of candidates for election as directors or new business to be brought before meetings of our stockholders. These procedures provide that notice of stockholder proposals must be timely given in writing to our corporate secretary prior to the meeting at which the action is to be taken. Generally, to be timely, notice must be received at our principal executive offices not less than 90 days nor more than 120 days prior to the first anniversary date of the annual meeting for the preceding year. Our by-laws specify the requirements as to form and content of all stockholders’ notices. These requirements may preclude stockholders from bringing matters before the stockholders at an annual or special meeting.

Amendment to certificate of incorporation and by-laws

Any amendment of our certificate of incorporation must first be approved by a majority of our board of directors, and if required by law or our certificate of incorporation, must thereafter be approved by a majority of the outstanding shares entitled to vote on the amendment and a majority of the outstanding shares of each class

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entitled to vote thereon as a class, except that the amendment of the provisions relating to stockholder action, board composition and limitation of liability must be approved by not less than two thirds of the outstanding shares of each class entitled to vote thereon as a class, and the amendment of our by-laws must be approved by not less than two-thirds of the outstanding shares entitled to vote on the amendment. Our by-laws may be amended by the affirmative vote of a majority of the directors then in office, subject to any limitations set forth in the by-laws; and may also be amended by the affirmative vote of a majority of the outstanding shares entitled to vote on the amendment, or, if our board of directors recommends that the stockholders approve the amendment, by the affirmative vote of the majority of the outstanding shares entitled to vote on the amendment, in each case voting together as a single class.

Undesignated preferred stock

Our certificate of incorporation provides for 10,000,000 authorized shares of preferred stock. The existence of authorized but unissued shares of preferred stock may enable our board of directors to 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 our stockholders, our board of directors could cause shares of preferred stock to be issued without stockholder approval in one or more private offerings or other transactions that might dilute the voting or other rights of the proposed acquirer or insurgent stockholder or stockholder group. In this regard, our certificate of incorporation grants our board of directors broad power to establish the rights and preferences of authorized and unissued shares of preferred stock. The issuance of shares of preferred stock could decrease the amount of earnings and assets available for distribution to holders of shares of common stock. The issuance may also adversely affect the rights and powers, including voting rights, of these holders and may have the effect of delaying, deterring or preventing a change in control of us.

Choice of forum

Our by-laws provide that, unless we consent in writing to the selection of an alternative form, the Court of Chancery of the State of Delaware will be the sole and exclusive forum for state law claims for: (1) any derivative action or proceeding brought on our behalf; (2) any action asserting a claim of breach of a fiduciary duty by any of our directors, officers or other employees to us or our stockholders; (3) any action asserting a claim against us arising pursuant to any provision of the General Corporation Law of the State of Delaware or our certificate of incorporation or by-laws; or (4) any action asserting a claim governed by the internal affairs doctrine. In addition, our by-laws provide that, unless we consent in writing to the selection of an alternative forum, the United States District Court for the District of Massachusetts shall be the sole and exclusive forum for resolving any complaint asserting a cause of action arising under the Securities Act. A person or entity purchasing or otherwise acquiring any interest in shares of our capital stock will be deemed to have notice of and to have consented to this choice of forum provision.

Section 203 of the Delaware General Corporation Law

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

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

• upon consummation of the transaction which resulted in the stockholder becoming an interested stockholder, the interested stockholder owned at least 85% of the voting stock of the corporation

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outstanding at the time the transaction commenced, excluding for purposes of determining the voting stock outstanding, shares owned by persons who are directors and also officers, and employee stock plans, in some instances, but not the outstanding voting stock owned by the interested stockholder; or

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

Section 203 defines a business combination to include:

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

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

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

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

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

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

Limitation of Liability and Indemnification

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 amended and 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:

• any breach of the director’s duty of loyalty to us or our stockholders;

• any act or omission not in good faith or that involves intentional misconduct or a knowing violation of law;

• any unlawful payments related to dividends or unlawful stock repurchases, redemptions or other distributions; or

• any transaction from which the director derived an improper personal benefit.

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 by-laws provide that:

• we will indemnify our directors and officers to the fullest extent permitted by law;

• we may indemnify our other employees and other agents to the same extent that we indemnify our officers and directors, unless otherwise determined by our board of directors; and

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• we will advance expenses to our directors and officers in connection with legal proceedings in connection with a legal proceeding to the fullest extent permitted by law.

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 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 amended and restated certificate of incorporation, amended and restated by-laws, indemnification agreements and Delaware law is not intended to be exhaustive and is qualified in its entirety by such amended and restated certificate of incorporation, amended and restated by-laws, 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.

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LEGAL MATTERS

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.

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EXPERTS

Ernst & Young LLP, independent registered public accounting firm, has audited our consolidated financial statements included in our Annual Report on Form 10-K for the year ended December 31, 2020, as set forth in their report, which is incorporated by reference in this prospectus and elsewhere in the registration statement. Our financial statements are incorporated by reference in reliance on Ernst & Young LLP’s report, given on their authority as experts in accounting and auditing.

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WHERE YOU CAN FIND MORE INFORMATION

We are subject to the informational requirements of the Exchange Act and file annual, quarterly and current reports, proxy statements and other information with the SEC. You can read our SEC filings, including the registration statement, at the SEC’s website at www.sec.gov. We also maintain a website at https://www.codiakbio.com. You may access, free of charge, our annual reports on Form 10-K, quarterly reports on Form 10-Q, current reports on Form 8-K and amendment to those reports filed or furnished pursuant to Section 13(a) or 15(d) of the Exchange Act as soon as reasonably practicable after such material is electronically filed with, or furnished to, the SEC. The information set forth on our website is not part of this prospectus.

This prospectus is only part of a registration statement on Form S-3 that we have filed with the SEC under the Securities Act 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.

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INCORPORATION OF DOCUMENTS BY REFERENCE

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 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 accessed on the SEC website as noted above in “Where You Can Find More Information.” The documents we are incorporating by reference are:

• our Annual Report on Form 10-K for the fiscal year ended December 31, 2020, as filed on March 17, 2021;

• the portions of our definitive proxy statement on Schedule 14A that we filed with the SEC on April 30, 2021 that are incorporated by reference into our Annual Report on Form 10-K for the fiscal year ended December 31, 2020 and deemed “filed” with the SEC under the Exchange Act;

• our Quarterly Reports on Form 10-Q for the quarter ended March 31, 2021, which we filed with the SEC on May 6, 2021, for the quarter ended June  30, 2021, which we filed with the SEC on August 5, 2021, and for the quarter ended September 30, 2021, which we filed with the SEC on November 4, 2021;

• our Current Reports on Form 8-K, which we filed with the SEC on January 26, 2021, February 4, 2021, March  8, 2021, March 26, 2021, May  10, 2021, May 20, 2021, June  23, 2021, July  6, 2021, August  18, 2021, September  21, 2021, October  7, 2021 and November 2, 2021;

• the description of the Common Stock contained in our registration statement on Form 8-A as filed with the SEC on October  13, 2020, under the Exchange Act, as supplemented by the description of our common stock contained in Exhibit 4.3 in our Annual Report on Form 10-K for the year ended December 31, 2020, as filed with the SEC on March 17, 2021, including any amendment or report filed for the purpose of updating such description; and

• all reports and other documents subsequently filed by us pursuant to Sections 13(a), 13(c), 14 and 15(d) of the Exchange Act after the date of this prospectus and prior to the termination or completion of the offering of securities under this prospectus shall be deemed to be incorporated by reference in this prospectus and to be a part hereof from the date of filing such reports and other documents.

The file number for all of the documents listed above is 001-39615. 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.

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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:

Codiak BioSciences, Inc.

35 CambridgePark Drive, Suite 500

Cambridge, MA 02140

(617) 949-4100

You may also access these documents on our website, https://www.codiakbio.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.

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13,333,333 Shares of Common Stock

Warrants to Purchase up to 13,333,333 Shares of Common Stock

Codiak BioSciences, Inc.

Jefferies