Nature of the Business	6 Months Ended
Jun. 30, 2022
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 its 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 and infectious disease and rare disease. In September 2020, Codiak initiated clinical trials for two of its lead product candidates, exoSTING and exoIL-12, which are being developed to address oncology indications. In June 2022, the Company initiated a Phase 1 clinical trial of exoASO-STAT6, Codiak’s first systemically delivered exosome therapeutic candidate. To the Company's 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, to 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 Pharmaceuticals Ireland Limited ("Jazz") and Sarepta Therapeutics, Inc. ("Sarepta") and its Loan and Security agreement with Hercules Capital, Inc. ("Hercules"). As of June 30, 2022, 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. On February 17, 2021, the Company completed a follow-on public offering, pursuant to which it issued 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. During the six-month period ended June 30, 2022, the Company raised $0.6 million utilizing an "at-the-market" offering facility, pursuant to which it sold 110,037 shares of its common stock. The Company has incurred significant operating losses and negative cash flows from operations since inception and expects to continue to incur 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. 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 of $41.8 million as of June 30, 2022 will be insufficient to allow the Company to fund its current operating plan through at least the next 12 months from the issuance of these financial statements. Maintaining the Company's ongoing operations is dependent upon its ability to obtain additional financing, as to which it can make no assurance. 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, or seek alternative means of financial support, 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

6 Months Ended

Jun. 30, 2022

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 its 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 and infectious disease and rare disease. In September 2020, Codiak initiated clinical trials for two of its lead product candidates, exoSTING and exoIL-12, which are being developed to address oncology indications. In June 2022, the Company initiated a Phase 1 clinical trial of exoASO-STAT6, Codiak’s first systemically delivered exosome therapeutic candidate. To the Company's 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, to 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 Pharmaceuticals Ireland Limited ("Jazz") and Sarepta Therapeutics, Inc. ("Sarepta") and its Loan and Security agreement with Hercules Capital, Inc. ("Hercules"). As of June 30, 2022, 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. On February 17, 2021, the Company completed a follow-on public offering, pursuant to which it issued 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. During the six-month period ended June 30, 2022, the Company raised $0.6 million utilizing an "at-the-market" offering facility, pursuant to which it sold 110,037 shares of its common stock.

The Company has incurred significant operating losses and negative cash flows from operations since inception and expects to continue to incur 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.

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 of $41.8 million as of June 30, 2022 will be insufficient to allow the Company to fund its current operating plan through at least the next 12 months from the issuance of these financial statements. Maintaining the Company's ongoing operations is dependent upon its ability to obtain additional financing, as to which it can make no assurance. 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, or seek alternative means of financial support, 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.