C4 Therapeutics, Inc. SEC Filings

C4 Therapeutics (CCCC) filed its Q3 2025 10‑Q, reporting collaboration revenue of $11.23 million and a net loss of $32.17 million. Revenue declined year over year as milestone and services mix shifted, while expenses rose on a $10.73 million non‑cash impairment tied to a new sublease, bringing total operating expenses to $45.64 million. Interest and other income contributed $2.25 million.

Cash, cash equivalents and marketable securities were $199.8 million as of September 30, 2025. The company sold 2,950,225 shares via its at‑the‑market program for $7.5 million in net proceeds and later terminated the ATM sales agreement. Shares outstanding were 74,174,515 as of September 30, 2025.

Collaboration updates include a Clinical Trial Collaboration and Supply Agreement with Pfizer under which Pfizer will supply elranatamab at no cost for a planned Phase 1b multiple myeloma study; C4T will sponsor and fund the trial, and the parties will jointly own clinical data. Merck provided notice to terminate the DAC collaboration effective late November 2025; the $10.0 million upfront tied to that program has been fully recognized. C4T also recorded a $2.0 million Biogen milestone in September and previously added $4.0 million in Roche milestones in March.

C4 Therapeutics (CCCC) reported an insider equity change by its Chief Scientific Officer. On 10/28/2025, 19,200 shares of Common Stock were acquired at $0.00 upon vesting of previously disclosed RSUs. To cover taxes, the issuer withheld 5,644 shares at $2.58, which the filing states does not represent a sale by the reporting person. Following these transactions, the officer directly beneficially owned 99,356 shares.

C4 Therapeutics, Inc. (CCCC) announced two updates. The company posted a presentation with data from its Phase 1 trial of cemsidomide plus dexamethasone in relapsed/refractory multiple myeloma, available on its investor relations site and filed as Exhibit 99.1.

The company also ended its current ATM prospectus. Effective October 16, 2025, the sales agreement prospectus dated November 13, 2024 was terminated. The underlying Sales Agreement with TD Securities (USA) LLC (TD Cowen) remains in effect, and no further common stock sales will be made under that prospectus unless a new prospectus supplement or a new registration statement with sales agreement prospectus is filed. As of June 30, 2025, the company had sold 3,769,483 shares under the Sales Agreement for gross proceeds of approximately $9.6 million before commissions.

C4 Therapeutics (CCCC) launched a primary offering of 21,895,000 shares of common stock and pre-funded warrants to purchase up to 28,713,500 shares, each sold with accompanying Class A and Class B warrants to purchase an aggregate 50,608,500 shares under each class. The combined public offering prices were $2.47 per share unit and $2.4699 per pre-funded warrant unit, for gross proceeds of $125,000,123.65 and underwriting discounts of $7,500,179.70, resulting in proceeds to the company of $117,499,943.95 before expenses.

The Class A and Class B warrants have $2.22 exercise prices (or $2.2199 per pre-funded warrant). Class A warrants are exercisable after issuance and expire on the earlier of 30 days following the public release of nine‑month median follow-up data from any expansion cohort in the planned Phase 1b cemsidomide/elranatamab study or five years; Class B warrants expire five years after issuance and may be mandatorily exercised on or after six months if the stock closes above $6.66 for ten consecutive trading days. Common shares are listed on Nasdaq as CCCC; the warrants and pre-funded warrants will not be listed. Shares outstanding were 71,007,083 as of June 30, 2025.

The company expects to use net proceeds, together with $223.0 million of cash, cash equivalents and marketable securities as of June 30, 2025, to fund ongoing and planned cemsidomide clinical trials, other R&D, and for working capital and general corporate purposes.

C4 Therapeutics announced an underwritten equity offering consisting of 21,895,000 shares of common stock and, in lieu of common stock to certain investors, pre-funded warrants to purchase 28,713,500 shares. Each share or pre-funded warrant was sold together with accompanying Class A and Class B warrants, at a combined price of $2.47 per share package and $2.4699 per pre-funded package. The company expects approximately $117.0 million in net proceeds, extending its cash runway to the end of 2028. If all warrants are cash exercised in full, aggregate net proceeds are expected to be $341.7 million. Closing is expected on October 17, 2025, subject to customary conditions.

The pre-funded warrants have a $0.0001 exercise price and do not expire. Class A and Class B warrants each have an initial exercise price of $2.22 per share and are exercisable immediately. Class A warrants expire on the earlier of 30 days after public release of nine-month median follow-up data from any expansion cohort in the planned Phase 1b study of cemsidomide with elranatamab or the fifth anniversary; Class B warrants expire on the fifth anniversary and may be mandatorily exercised after six months if the stock closes above $6.66 for ten consecutive trading days. Warrant exercises are subject to a Beneficial Ownership Limitation of 4.99% or 9.99%, adjustable up to 19.99% with 61 days’ notice.

C4 Therapeutics form 4 disclosure: A company director, Kenneth Carl Anderson, acquired 5,349 shares of C4 Therapeutics common stock as compensation in lieu of cash, at a price equal to the stock's closing market price of $2.15 on the transaction date. After the issuance, the reporting person directly beneficially owns 140,574 shares and reports additional indirect holdings through trusts and a spouse totaling multiple separate share blocks: 47,316 (spouse), 61,265 (2016 GRAT), 61,265 (spouse's 2016 GRAT), 16,939 (2015 irrevocable trust), and 16,939 (spouse's 2015 irrevocable trust). The filing states these trust-held shares are disclaimed except to the extent of pecuniary interest. The acquisition was made under the issuer's Non-Employee Director Compensation Policy, reflecting an election to take equity instead of cash for board service.

Donna Grogan, a non-employee director of C4 Therapeutics, Inc. (CCCC), received 6,740 shares of common stock on 10/01/2025 by electing to take equity in lieu of cash under the company’s Non-Employee Director Compensation Policy. The shares were recorded at a per-share price of $2.15, equal to the closing market price on the transaction date. After the grant, the reporting person beneficially owned 58,629 shares, held directly. The Form 4 discloses the transaction code and confirms the shares were issued as director compensation.

C4 Therapeutics, Inc. announced on October 1, 2025 that it entered a clinical trial collaboration and supply agreement with Pfizer. Under the agreement, Pfizer will supply elranatamab (ELREXFIO®), a BCMAxCD3 bispecific antibody, at no cost for C4's upcoming Phase 1b trial testing the safety and tolerability of cemsidomide plus dexamethasone in combination with elranatamab for patients receiving second-line or later therapy for multiple myeloma. C4 will sponsor and run the trial while Pfizer will receive access to trial data. The company furnished a press release as Exhibit 99.1 to the current report.