Nature of the Business	12 Months Ended
Dec. 31, 2021
Organization Consolidation And Presentation Of Financial Statements [Abstract]
Nature of the Business	1. Nature of the business Codiak BioSciences, Inc. (collectively, with its consolidated subsidiaries, any of Codiak, we, us, or the Company) was incorporated in Delaware on June 12, 2015 and is headquartered in Cambridge, Massachusetts. Codiak is 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 Codiak’s deep understanding of exosome biology, the Company has developed its engineering and manufacturing platform (the engEx Platform), to expand upon the innate properties of exosomes to design, engineer and manufacture novel exosome therapeutics. Codiak has utilized its engEx Platform to generate a deep pipeline of engineered exosomes (engEx exosomes) aimed at treating a broad range of diseases, including oncology, neuro-oncology, and infectious disease and rare disease. In September 2020, Codiak initiated clinical trials for its two lead product candidates, exoSTING and exoIL-12, which are being developed to address solid tumors. In November 2021, Codiak announced that the U.S. Food and Drug Administration, or FDA, cleared its Investigational New Drug Application (IND) for exoASO-STAT6. This will be Codiak’s first systemically delivered exosome therapeutic candidate. To its knowledge, exoSTING,exoIL-12 and exoASO-STAT6 are the first engineered exosomes to enter clinical development. Since its inception, the Company has devoted substantially all of its resources to its research and development efforts, including activities to develop its engEx Platform, advance engEx product candidates into clinical trials, perform preclinical research to identify potential engEx product candidates, to perform process development to refine Codiak’s exosome engineering and manufacturing processes, and to provide general and administrative support for these operations. The Company has primarily funded its operations with proceeds from the sales of common stock, redeemable convertible preferred stock, collaborative and research arrangements with Jazz and Sarepta and its Loan and Security agreement with Hercules Capital, Inc. (Hercules). As of December 31, 2021, the Company has raised an aggregate of $168.2 million through the issuance of its redeemable convertible preferred stock and convertible debt, net of issuance costs, $24.6 million from its term loan facility with Hercules, net of issuance costs, and received $66.0 million in payments from its collaborations with Jazz and Sarepta. On October 16, 2020, the Company completed its initial public offering (IPO), pursuant to which it issued and sold 5,500,000 shares of its common stock at a public offering price of $15.00 per share, resulting in net proceeds of $74.4 million, after deducting underwriting discounts and commissions and other offering expenses. In addition, on February 17, 2021, the Company completed a follow-on public offering, pursuant to which it issued and sold 3,162,500 shares of its common stock (inclusive of the exercise of the underwriter’s option to purchase 412,500 additional shares of common stock) at a public offering price of $21.00 per share, resulting in aggregate net proceeds of $61.7 million, after deducting underwriting discounts and commissions and other offering expenses. The Company has incurred significant operating losses and negative cash flows from operations since inception. The Company expects to continue to incur significant expenses and operating losses for the foreseeable future. In addition, the Company anticipates that its expenses will increase significantly in connection with ongoing activities to support its engEx Platform development, drug discovery and preclinical and clinical development, in addition to creating a portfolio of intellectual property and providing administrative support. The Company does not expect to generate significant revenue from sales of its engEx product candidates unless and until clinical development has been successfully completed and regulatory approval is obtained. If the Company obtains regulatory approval for any of its investigational products, it expects to incur significant commercialization expenses. As a result, the Company will need substantial additional funding to support its continued operations and growth strategy. Until such a time as the Company can generate significant revenue from product sales, if ever, the Company expects to finance its operations through the sale of equity, debt financings or other capital sources, including collaborations with other companies or other strategic transactions. The Company may be unable to raise additional funds or enter into such other agreements on favorable terms, or at all. If the Company fails to raise capital or enter into such agreements as, and when, needed, the Company may have to significantly delay, scale back or discontinue the development and commercialization of one or more of its product candidates or delay its pursuit of potential in-licenses or acquisitions. The Company has evaluated whether there are conditions and events, considered in the aggregate, that raise substantial doubt about its ability to continue as a going concern within one year after the date that the consolidated financial statements are issued. The Company expects that its cash and cash equivalents as of December 31, 2021 of $76.9 million, will be insufficient to allow the Company to fund its current operating plan through at least the next twelve months from the issuance of these financial statements. These conditions raise substantial doubt about the Company’s ability to continue as a going concern for a period of at least one year from the date these financial statements are issued. Accordingly, the Company will be required to raise additional funds through a public equity financing, establish collaborations with, or license its technology to other companies, seek alternative means of financial support or both, in order to continue to fund its operations in the future. There can be no assurance, however, that additional fund raising will be successful and available on terms acceptable to the Company, or at all. If the Company is unable to raise capital when needed or on attractive terms, it may be forced to delay, reduce or eliminate certain costs related to its operations and research and development programs. The Company is subject to those risks associated with any biopharmaceutical company that has substantial expenditures for research and development. There can be no assurance that the Company’s research and development projects will be successful, that products developed will obtain necessary regulatory approval, or that any approved product will be commercially viable. In addition, the Company operates in an environment of rapid technological change and is largely dependent on the services of its employees and consultants. If the Company fails to become profitable or is unable to sustain profitability on a continuing basis, then it may be unable to continue its operations at planned levels and be forced to reduce its operations.

Nature of the Business

12 Months Ended

Dec. 31, 2021

Organization Consolidation And Presentation Of Financial Statements [Abstract]

1. Nature of the business

Codiak BioSciences, Inc. (collectively, with its consolidated subsidiaries, any of Codiak, we, us, or the Company) was incorporated in Delaware on June 12, 2015 and is headquartered in Cambridge, Massachusetts. Codiak is 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 Codiak’s deep understanding of exosome biology, the Company has developed its engineering and manufacturing platform (the engEx Platform), to expand upon the innate properties of exosomes to design, engineer and manufacture novel exosome therapeutics. Codiak has utilized its engEx Platform to generate a deep pipeline of engineered exosomes (engEx exosomes) aimed at treating a broad range of diseases, including oncology, neuro-oncology, and infectious disease and rare disease. In September 2020, Codiak initiated clinical trials for its two lead product candidates, exoSTING and exoIL-12, which are being developed to address solid tumors. In November 2021, Codiak announced that the U.S. Food and Drug Administration, or FDA, cleared its Investigational New Drug Application (IND) for exoASO-STAT6. This will be Codiak’s first systemically delivered exosome therapeutic candidate. To its knowledge, exoSTING,exoIL-12 and exoASO-STAT6 are the first engineered exosomes to enter clinical development.

Since its inception, the Company has devoted substantially all of its resources to its research and development efforts, including activities to develop its engEx Platform, advance engEx product candidates into clinical trials, perform preclinical research to identify potential engEx product candidates, to perform process development to refine Codiak’s exosome engineering and manufacturing processes, and to provide general and administrative support for these operations.

The Company has primarily funded its operations with proceeds from the sales of common stock, redeemable convertible preferred stock, collaborative and research arrangements with Jazz and Sarepta and its Loan and Security agreement with Hercules Capital, Inc. (Hercules). As of December 31, 2021, the Company has raised an aggregate of $168.2 million through the issuance of its redeemable convertible preferred stock and convertible debt, net of issuance costs, $24.6 million from its term loan facility with Hercules, net of issuance costs, and received $66.0 million in payments from its collaborations with Jazz and Sarepta. On October 16, 2020, the Company completed its initial public offering (IPO), pursuant to which it issued and sold 5,500,000 shares of its common stock at a public offering price of $15.00 per share, resulting in net proceeds of $74.4 million, after deducting underwriting discounts and commissions and other offering expenses. In addition, on February 17, 2021, the Company completed a follow-on public offering, pursuant to which it issued and sold 3,162,500 shares of its common stock (inclusive of the exercise of the underwriter’s option to purchase 412,500 additional shares of common stock) at a public offering price of $21.00 per share, resulting in aggregate net proceeds of $61.7 million, after deducting underwriting discounts and commissions and other offering expenses.

The Company has incurred significant operating losses and negative cash flows from operations since inception. The Company expects to continue to incur significant expenses and operating losses for the foreseeable future. In addition, the Company anticipates that its expenses will increase significantly in connection with ongoing activities to support its engEx Platform development, drug discovery and preclinical and clinical development, in addition to creating a portfolio of intellectual property and providing administrative support.

The Company does not expect to generate significant revenue from sales of its engEx product candidates unless and until clinical development has been successfully completed and regulatory approval is obtained. If the Company obtains regulatory approval for any of its investigational products, it expects to incur significant commercialization expenses.

As a result, the Company will need substantial additional funding to support its continued operations and growth strategy. Until such a time as the Company can generate significant revenue from product sales, if ever, the Company expects to finance its operations through the sale of equity, debt financings or other capital sources, including collaborations with other companies or other strategic transactions. The Company may be unable to raise additional funds or enter into such other agreements on favorable terms, or at all. If the Company fails to raise capital or enter into such agreements as, and when, needed, the Company may have to significantly delay, scale back or discontinue the development and commercialization of one or more of its product candidates or delay its pursuit of potential in-licenses or acquisitions.

The Company has evaluated whether there are conditions and events, considered in the aggregate, that raise substantial doubt about its ability to continue as a going concern within one year after the date that the consolidated financial statements are issued. The Company expects that its cash and cash equivalents as of December 31, 2021 of $76.9 million, will be insufficient to allow the Company to fund its current operating plan through at least the next twelve months from the issuance of these financial statements. These conditions raise substantial doubt about the Company’s ability to continue as a going concern for a period of at least one year from the date these financial statements are issued. Accordingly, the Company will be required to raise additional funds through a public equity financing, establish collaborations with, or license its technology to other companies, seek alternative means of financial support or both, in order to continue to fund its operations in the future. There can be no assurance, however, that additional fund raising will be successful and available on terms acceptable to the Company, or at all. If the Company is unable to raise capital when needed or on attractive terms, it may be forced to delay, reduce or eliminate certain costs related to its operations and research and development programs.

The Company is subject to those risks associated with any biopharmaceutical company that has substantial expenditures for research and development. There can be no assurance that the Company’s research and development projects will be successful, that products developed will obtain necessary regulatory approval, or that any approved product will be commercially viable. In addition, the Company operates in an environment of rapid technological change and is largely dependent on the services of its employees and consultants. If the Company fails to become profitable or is unable to sustain profitability on a continuing basis, then it may be unable to continue its operations at planned levels and be forced to reduce its operations.