Nature of the business and basis of presentation	3 Months Ended
Mar. 31, 2025
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Nature of the business and basis of presentation	Nature of the business and basis of presentation C4 Therapeutics, Inc., or, together with its subsidiary, the Company, is a clinical-stage biopharmaceutical company dedicated to the advancement of targeted protein degradation, or TPD, science to develop a new generation of small-molecule medicines to transform how disease is treated. The Company leverages its proprietary TORPEDO platform to efficiently design and optimize small-molecule medicines that harness the body’s natural protein recycling system to rapidly degrade disease-causing protein, offering the potential to overcome drug resistance, drug undruggable targets, and improve patient outcomes. The Company uses its TORPEDO platform to advance multiple targeted oncology programs to the clinic while expanding its research platform to deliver the next wave of medicines for difficult-to-treat diseases. The Company was incorporated in Delaware on October 7, 2015 and has its principal office in Watertown, Massachusetts. Liquidity and capital resources Since its inception, the Company’s primary activities have been focused on research and development activities, building the Company’s intellectual property, recruiting and retaining personnel, and raising capital to support these activities. To date, the Company has funded its operations primarily with proceeds received from the sales of redeemable convertible preferred stock, public offerings of the Company’s common stock, private placement of the Company's common stock, through its collaboration agreements, and debt financing. The Company has incurred recurring losses since its inception, including net losses of $26.3 million and $28.4 million for the three months ended March 31, 2025 and 2024, respectively. In addition, as of March 31, 2025, the Company had an accumulated deficit of $660.0 million. To date, the Company has not generated any revenue from product sales as none of its product candidates have been approved for commercialization. The Company expects to continue to generate operating losses for the foreseeable future. The Company expects that its cash, cash equivalents, and marketable securities of $234.7 million as of March 31, 2025 will be sufficient to fund its operations for at least the next twelve months from the date of issuance of these consolidated financial statements. Accordingly, the condensed consolidated financial statements have been prepared on a basis that assumes the Company will continue as a going concern and contemplates the realization of assets and satisfaction of liabilities and commitments in the ordinary course of business. Risks and uncertainties The Company is subject to risks common to other life science companies in the early development stage including, but not limited to, uncertainty of ability to raise additional financing, product development and commercialization, development by its competitors of new technological innovations, dependence on key personnel, market acceptance of products, lack of marketing and sales history, product liability, protection of proprietary technology and intellectual property, and compliance with regulations of the Food and Drug Administration, or the FDA, and other government agencies. If the Company does not successfully advance its programs into and through human clinical trials and commercialize any of its product candidates either directly or through collaborations with other companies, the Company may be unable to produce product revenue or achieve profitability. There can be no assurance that the Company’s research and development efforts will be successful, adequate protection for the Company’s intellectual property will be obtained, any products developed will obtain necessary government regulatory approval, or any approved products will be commercially viable. Even if the Company’s product development efforts are successful, it is uncertain when, if ever, the Company will generate significant revenue from product sales. The Company operates in an environment of rapid change in technology and substantial competition from pharmaceutical and biotechnology companies.

C4 Therapeutics, Inc., or, together with its subsidiary, the Company, is a clinical-stage biopharmaceutical company dedicated to the advancement of targeted protein degradation, or TPD, science to develop a new generation of small-molecule medicines to transform how disease is treated. The Company leverages its proprietary TORPEDO platform to efficiently design and optimize small-molecule medicines that harness the body’s natural protein recycling system to rapidly degrade disease-causing protein, offering the potential to overcome drug resistance, drug undruggable targets, and improve patient outcomes. The Company uses its TORPEDO platform to advance multiple targeted oncology programs to the clinic while expanding its research platform to deliver the next wave of medicines for difficult-to-treat diseases. The Company was incorporated in Delaware on October 7, 2015 and has its principal office in Watertown, Massachusetts.

Since its inception, the Company’s primary activities have been focused on research and development activities, building the Company’s intellectual property, recruiting and retaining personnel, and raising capital to support these activities. To date, the Company has funded its operations primarily with proceeds received from the sales of redeemable convertible preferred stock, public offerings of the Company’s common stock, private placement of the Company's common stock, through its collaboration agreements, and debt financing.

The Company has incurred recurring losses since its inception, including net losses of $26.3 million and $28.4 million for the three months ended March 31, 2025 and 2024, respectively. In addition, as of March 31, 2025, the Company had an accumulated deficit of $660.0 million. To date, the Company has not generated any revenue from product sales as none of its product candidates have been approved for commercialization. The Company expects to continue to generate operating losses for the foreseeable future.

The Company expects that its cash, cash equivalents, and marketable securities of $234.7 million as of March 31, 2025 will be sufficient to fund its operations for at least the next twelve months from the date of issuance of these consolidated financial statements. Accordingly, the condensed consolidated financial statements have been prepared on a basis that assumes the Company will continue as a going concern and contemplates the realization of assets and satisfaction of liabilities and commitments in the ordinary course of business.

The Company is subject to risks common to other life science companies in the early development stage including, but not limited to, uncertainty of ability to raise additional financing, product development and commercialization, development by its competitors of new technological innovations, dependence on key personnel, market acceptance of products, lack of marketing and sales history, product liability, protection of proprietary technology and intellectual property, and compliance with regulations of the Food and Drug Administration, or the FDA, and other government agencies. If the Company does not successfully advance its programs into and through human clinical trials and commercialize any of its product candidates either directly or through collaborations with other companies, the Company may be unable to produce product revenue or achieve profitability. There can be no assurance that the Company’s research and development efforts will be successful, adequate protection for the Company’s intellectual property will be obtained, any products developed will obtain necessary government regulatory approval, or any approved products will be commercially viable. Even if the Company’s product development efforts are successful, it is uncertain when, if ever, the Company will generate significant revenue from product sales. The Company operates in an environment of rapid change in technology and substantial competition from pharmaceutical and biotechnology companies.