The Company	9 Months Ended
Sep. 30, 2020
Organization Consolidation And Presentation Of Financial Statements [Abstract]
The Company	(1) The Company C4 Therapeutics, Inc. (together with its subsidiary, the “Company”) is a biopharmaceutical company focused on harnessing the body’s natural regulation of protein levels to develop novel therapeutic candidates to target and eliminate disease-causing proteins for the treatment of cancer, neurodegenerative conditions and other diseases. The Company was incorporated in Delaware on October 7, 2015 and has its principal office in Watertown, Massachusetts. The Company is subject to risks common to other life science companies in the early development stage including, but not limited to, uncertainty of product development and commercialization, lack of marketing and sales history, development by its competitors of new technological innovations, dependence on key personnel, market acceptance of products, product liability, protection of proprietary technology, ability to raise additional financing and compliance with the Food and Drug Administration (“FDA”) and other government regulations. If the Company does not successfully advance its programs into and through human clinical trials and/or enter into collaborations for its programs and commercialize any of its product candidates, the Company may be unable to produce product revenue or achieve profitability. Initial Public Offering As further described in Note 13, in October 2020, the Company completed an initial public offering (IPO) of its common stock. Liquidity The Company has evaluated whether there are certain conditions and events, considered in the aggregate, that raise substantial doubt about the Company’s ability to continue as a going concern within one year after the date that the financial statements are issued. The Company has incurred recurring losses since its inception, including net losses of $44.5 million and $24.1 million for the nine months ended September 30, 2020 and 2019, respectively. In addition, as September 30, 2020, the Company had an accumulated deficit of $162.0 million. To date, the Company has not generated any revenue from product sales as none of its product candidates has been approved for commercialization. The Company expects to continue to generate operating losses for the foreseeable future. The Company’s primary activities since inception have been focused around research and development activities, building the Company’s intellectual property, recruiting personnel and raising capital to support these activities. Through September 30, 2020, the Company has funded its operations primarily with proceeds received from the sale of redeemable convertible preferred stock (collectively, the “Preferred Stock”) and through its collaboration agreements. In addition, the Company has cash and cash equivalents and short-term investments of $199.4 million as of September 30, 2020. Management considers that there are no conditions or events, in the aggregate, that raise substantial doubt about the entity’s ability to continue as a going concern for a period of at least one year from the date the condensed consolidated financial statements are issued. 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. Reverse Stock Split On September 25, 2020, the Company’s effected a one-for-8.4335 reverse stock split of its issued and outstanding common stock and stock options, and a proportional adjustment to the existing conversion ratios for the Company’s convertible preferred stock. Accordingly, all issued and outstanding common stock, options to purchase common stock and per share amounts contained in the condensed consolidated financial statements have been retroactively adjusted to give effect to the reverse stock split for all periods presented except as otherwise stated. COVID-19 Pandemic The impact of the COVID-19 coronavirus outbreak on the Company’s financial performance will depend on future developments, including the duration and spread of the outbreak and related governmental advisories and restrictions. These developments and the impact of COVID-19 on the financial markets and the overall economy are highly uncertain and cannot be predicted. If the financial markets and/or the overall economy are impacted for an extended period, the Company’s results may be materially adversely affected. The Company is currently unable to determine the extent of the impact of the pandemic to its operations and financial condition, as the Company has not yet started any clinical trials. Once the Company begins its clinical trials, it will assess any potential delays as a result of the pandemic, as well as their financial impact.

The Company

9 Months Ended

Sep. 30, 2020

Organization Consolidation And Presentation Of Financial Statements [Abstract]

(1) The Company

C4 Therapeutics, Inc. (together with its subsidiary, the “Company”) is a biopharmaceutical company focused on harnessing the body’s natural regulation of protein levels to develop novel therapeutic candidates to target and eliminate disease-causing proteins for the treatment of cancer, neurodegenerative conditions and other diseases. The Company was incorporated in Delaware on October 7, 2015 and has its principal office in Watertown, Massachusetts. The Company is subject to risks common to other life science companies in the early development stage including, but not limited to, uncertainty of product development and commercialization, lack of marketing and sales history, development by its competitors of new technological innovations, dependence on key personnel, market acceptance of products, product liability, protection of proprietary technology, ability to raise additional financing and compliance with the Food and Drug Administration (“FDA”) and other government regulations. If the Company does not successfully advance its programs into and through human clinical trials and/or enter into collaborations for its programs and commercialize any of its product candidates, the Company may be unable to produce product revenue or achieve profitability.

Initial Public Offering

As further described in Note 13, in October 2020, the Company completed an initial public offering (IPO) of its common stock.

Liquidity

The Company has evaluated whether there are certain conditions and events, considered in the aggregate, that raise substantial doubt about the Company’s ability to continue as a going concern within one year after the date that the financial statements are issued.

The Company has incurred recurring losses since its inception, including net losses of $44.5 million and $24.1 million for the nine months ended September 30, 2020 and 2019, respectively. In addition, as September 30, 2020, the Company had an accumulated deficit of $162.0 million. To date, the Company has not generated any revenue from product sales as none of its product candidates has been approved for commercialization. The Company expects to continue to generate operating losses for the foreseeable future.

The Company’s primary activities since inception have been focused around research and development activities, building the Company’s intellectual property, recruiting personnel and raising capital to support these activities. Through September 30, 2020, the Company has funded its operations primarily with proceeds received from the sale of redeemable convertible preferred stock (collectively, the “Preferred Stock”) and through its collaboration agreements. In addition, the Company has cash and cash equivalents and short-term investments of $199.4 million as of September 30, 2020. Management considers that there are no conditions or events, in the aggregate, that raise substantial doubt about the entity’s ability to continue as a going concern for a period of at least one year from the date the condensed consolidated financial statements are issued. 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.

Reverse Stock Split

On September 25, 2020, the Company’s effected a one-for-8.4335 reverse stock split of its issued and outstanding common stock and stock options, and a proportional adjustment to the existing conversion ratios for the Company’s convertible preferred stock. Accordingly, all issued and outstanding common stock, options to purchase common stock and per share amounts contained in the condensed consolidated financial statements have been retroactively adjusted to give effect to the reverse stock split for all periods presented except as otherwise stated.

COVID-19 Pandemic

The impact of the COVID-19 coronavirus outbreak on the Company’s financial performance will depend on future developments, including the duration and spread of the outbreak and related governmental advisories and restrictions. These developments and the impact of COVID-19 on the financial markets and the overall economy are highly uncertain and cannot be predicted. If the financial markets and/or the overall economy are impacted for an extended period, the Company’s results may be materially adversely affected. The Company is currently unable to determine the extent of the impact of the pandemic to its operations and financial condition, as the Company has not yet started any clinical trials. Once the Company begins its clinical trials, it will assess any potential delays as a result of the pandemic, as well as their financial impact.