cccc-20250807
0001662579false00016625792025-08-072025-08-07

UNITED STATES
SECURITIES AND EXCHANGE COMMISSION
WASHINGTON, D.C. 20549
_________________________________________________________________
FORM 8-K
_________________________________________________________________
CURRENT REPORT
Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934
Date of Report (Date of earliest event reported): August 7, 2025
_________________________________________________________________
C4 THERAPEUTICS, INC.
(Exact name of Registrant as Specified in Its Charter)
_________________________________________________________________
Delaware001-3956747-5617627
(State or Other Jurisdiction
of Incorporation)
(Commission File Number)
(IRS Employer
Identification No.)
490 Arsenal Way,   Suite 120
Watertown,  MA
02472
(Address of Principal Executive Offices)(Zip Code)
Registrant’s Telephone Number, Including Area Code: (617) 231-0700
Not Applicable
(Former Name or Former Address, if Changed Since Last Report)
_________________________________________________________________
Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions:
oWritten communications pursuant to Rule 425 under the Securities Act (17 CFR 230.425)
oSoliciting material pursuant to Rule 14a-12 under the Exchange Act (17 CFR 240.14a-12)
oPre-commencement communications pursuant to Rule 14d-2(b) under the Exchange Act (17 CFR 240.14d-2(b))
oPre-commencement communications pursuant to Rule 13e-4(c) under the Exchange Act (17 CFR 240.13e-4(c))
Securities registered pursuant to Section 12(b) of the Act:
Title of each class
Trading
Symbol(s)
Name of each exchange on which registered
Common Stock, $0.0001 par value per shareCCCCThe Nasdaq Global Select Market
Indicate by check mark whether the registrant is an emerging growth company as defined in Rule 405 of the Securities Act of 1933 (§ 230.405 of this chapter) or Rule 12b-2 of the Securities Exchange Act of 1934 (§ 240.12b-2 of this chapter).
Emerging growth company o
If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act. o
 


Item 2.02 Results of Operations and Financial Condition.
On August 7, 2025, C4 Therapeutics, Inc. (the “Company”) issued a press release announcing its financial results and business highlights for the quarter ended June 30, 2025. A copy of the press release is being furnished as Exhibit 99.1 to this Current Report on Form 8-K.
The information contained in Item 2.02 of this Current Report on Form 8-K and Exhibit 99.1 attached hereto is intended to be furnished and shall not be deemed “filed” for purposes of Section 18 of the Securities Exchange Act of 1934, as amended (the “Exchange Act”), or otherwise subject to the liabilities of that section, nor shall it be deemed incorporated by reference in any filing under the Securities Act of 1933, as amended (the “Securities Act”), or the Exchange Act, except as expressly set forth by specific reference in such a filing.
Item 7.01 Regulation FD Disclosure.
On August 7, 2025, the Company posted a corporate presentation on its website at https://ir.c4therapeutics.com/events-presentations. A copy of the presentation is furnished herewith as Exhibit 99.2 to this Current Report on Form 8-K.
The information contained in Item 7.01 of this Current Report on Form 8-K and Exhibit 99.2 attached hereto is intended to be furnished and shall not be deemed “filed” for purposes of Section 18 of the Exchange Act, or otherwise subject to the liabilities of that section, nor shall it be deemed incorporated by reference in any filing under the Securities Act or the Exchange Act, except as expressly set forth by specific reference in such a filing. The furnishing of this information hereby shall not be deemed an admission as to the materiality of any such information.
Item 8.01 Other Events.
On August 7, 2025, the Company provided the following updates from its Phase 1 clinical trial of cemsidomide:
•Completed enrollment and dose escalation for the Phase 1 trial of cemsidomide in multiple myeloma (“MM”) and non-Hodgkin’s Lymphoma (“NHL”). As of the data cutoff date of July 23, 2025, cemsidomide continued to demonstrate a well-tolerated profile and compelling response rates in MM and NHL, with an overall response rate in the MM cemsidomide plus dexamethasone arm of 40% at the 75 μg and 50% at the 100 μg dose levels. The highest dose level studied in both indications was 100 μg once daily.
•By year-end 2025, Company expects to align with the FDA on a recommended Phase 2 dose based on the existing Phase 1 MM data, and remains on track to initiate registrational development of cemsidomide in early 2026. The next phase of development will evaluate cemsidomide in combination with dexamethasone in the late-line MM setting and in combination with a B-cell maturation antigen bispecific T-cell engager (BCMA BiTE) for earlier lines of MM treatment.
Forward-Looking Statements
This information under Item 8.01 of this Current Report on Form 8-K contains “forward-looking statements” of C4 Therapeutics, Inc. within the meaning of the Private Securities Litigation Reform Act of 1995. These forward-looking statements may include, but may not be limited to, express or implied statements regarding the Company’s ability to develop potential therapies for patients; the design and potential efficacy of the Company’s therapeutic approaches; the predictive capability of the Company’s TORPEDO® platform in the development of novel, selective, orally bioavailable BiDAC™ and MonoDAC® degraders; the potential timing, design and advancement of the Company’s preclinical studies and clinical trials, including the potential timing for and receipt of regulatory advice or authorization related to clinical trials and other clinical development activities including clinical trial commencement or cohort initiation; the Company’s ability and the potential to successfully manufacture and supply its product candidates for clinical trials; the Company’s ability to replicate results achieved in preclinical studies or clinical trials in any future studies or trials; the Company’s ability to replicate interim or early-stage results from its clinical trials in the results obtained when those clinical trials are completed or when those therapies complete later-stage clinical trials; regulatory developments in the United States and foreign countries; the anticipated timing and content of presentations of data from the Company’s clinical trials; and the Company’s ability to fund its future operations. Any forward-looking statements included under Item 8.01 of this Current Report on Form 8-K are based on management’s current expectations and beliefs of future events and are subject to a number of risks and uncertainties that could cause actual results to differ materially and adversely from those set forth in or implied by such forward-looking statements. These risks and uncertainties include, but are not limited to: uncertainties related to the initiation, timing, advancement and conduct of preclinical and clinical studies and other development requirements for the Company’s product candidates; the risk that any one or more of the Company’s product candidates will cost more to develop or may not be successfully developed and commercialized; and the risk that sufficient capital to fund the Company’s future operations will be available on acceptable terms or at the times required. For a discussion of these and other risks and uncertainties, and other important factors, any of which could cause our actual results to differ from those contained in the forward-looking statements, see the section entitled “Risk Factors” in the Company’s most recent Annual Report on Form 10-K and/or Quarterly Report on Form 10-Q, as filed with the Securities and Exchange Commission. All information in Item 8.01 of this Current Report on Form 8-K is as of the date of the filing, and the Company undertakes no duty to update this information unless required by law.


Item 9.01 Financial Statements and Exhibits.
(d) Exhibits. The exhibits shall be deemed to be filed or furnished, depending on the relevant item requiring such exhibit, in accordance with the provisions of Item 601 of Regulation S-K (17 CFR 229.601) and Instruction B.2 to this form.
Exhibit
Number
Description
99.1
99.2
104Cover Page Interactive Data File (embedded within the Inline XBRL document)


SIGNATURES
Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned thereunto duly authorized.
C4 Therapeutics, Inc.
Date: August 7, 2025
By:/s/ Jolie M. Siegel
Jolie M. Siegel
Chief Legal Officer and Secretary


Exhibit 99.1
c4tlogo1.jpg

C4 Therapeutics Reports Second Quarter 2025 Financial Results and Recent Business Highlights
Cemsidomide Phase 1 Data in Multiple Myeloma Accepted as an Oral Presentation
at the International Myeloma Society (IMS) Annual Meeting; As of the July 23, 2025, Data Cutoff, Phase 1 ORR Remains at 40% at the 75 µg Dose Level and at 50% at the 100 µg Dose Level
Productive Type C Meeting Held With FDA; Registrational Development of Cemsidomide in Multiple Myeloma on Track to Initiate in Early 2026
Preclinical Milestone Achieved Under the Collaboration With Merck KGaA, Darmstadt, Germany, Which Is Focused on Two Projects Within the KRAS Family  
Disciplined Capital Allocation Extends Runway to Mid-2027
WATERTOWN, Mass., Aug. 7, 2025 (GLOBE NEWSWIRE) -- C4 Therapeutics, Inc. (C4T) (Nasdaq: CCCC), a clinical-stage biopharmaceutical company dedicated to advancing targeted protein degradation science, today reported financial results for the second quarter ended June 30, 2025, as well as business updates.
“The first half of 2025 was driven by focused execution across our business with the achievement of several research milestones with our collaborators and within our internal preclinical pipeline, the advancement of cemsidomide toward label-enabling trials and continued financial discipline that resulted in extending cash runway. We recently completed enrollment in the ongoing cemsidomide Phase 1 trials in multiple myeloma and non-Hodgkin’s lymphoma and look forward to sharing the full Phase 1 multiple myeloma data in September, which we believe further demonstrate cemsidomide’s best-in-class potential. Our recent Type C meeting with the FDA enabled refinement of our cemsidomide registrational development plans and we remain on track to initiate registrational development in early 2026,” said Andrew Hirsch, president and chief executive officer of C4 Therapeutics. “Additionally, as part of C4T’s commitment to strategic capital allocation and despite cemsidomide’s compelling response rates observed in non-Hodgkin’s lymphoma, we are prioritizing cemsidomide multiple myeloma registrational development as we believe this has the highest potential for patient impact and value creation.”
SECOND QUARTER 2025 HIGHLIGHTS AND RECENT ACHIEVEMENTS
Cemsidomide:
•Completed enrollment and dose escalation for the Phase 1 trial of cemsidomide in multiple myeloma (MM) and non-Hodgkin’s Lymphoma (NHL). Cemsidomide continued to demonstrate a well-tolerated profile and compelling response rates in MM and NHL. The highest dose level studied in both indications was 100 µg once daily (QD).
•Data from the cemsidomide Phase 1 trial in MM was accepted as an oral presentation at the International Myeloma Society (IMS) Annual Meeting taking place from September 17 – September 20, 2025 in Toronto, Canada. The presentation will include data from all safety and efficacy evaluable MM patients from all dose levels studied.
•C4T had a productive Type C meeting with the U.S. Food and Drug Administration (FDA) that enabled further refinement of the cemsidomide registrational development plan. By year-end


2025, C4T expects to align with the FDA on a recommended Phase 2 dose based on the existing Phase 1 MM data.
•Additionally, C4T is on track to initiate registrational development in early 2026. The next phase of development will evaluate cemsidomide in combination with dexamethasone in the late-line MM setting and in combination with a B-cell maturation antigen bispecific T-cell engager (BCMA BiTE) for earlier lines of MM treatment.
CFT8919:
•Partner Betta Pharmaceuticals continues to advance the CFT8919 Phase 1 dose escalation trial in Greater China.
Research and Discovery Collaborations:
•C4T advanced its collaboration with Merck KGaA, Darmstadt, Germany (MKDG), which is focused on two projects within the KRAS family, to a milestone on one of these projects. C4T earned $1 million upon achieving this milestone. 
•C4T has identified multiple degraders against two novel targets outside of oncology, which are now advancing into the next phase of discovery.
KEY UPCOMING MILESTONES AND DATA PRESENTATIONS
•Present data from full cemsidomide Phase 1 dose escalation in MM at IMS taking place from September 17 – September 20, 2025.
◦Binod Dhakal, M.D., M.S., associate professor of medicine, Medical College of Wisconsin, Division of Hematology, will present an oral presentation titled “Updated Results of a Phase 1 First-in-Human Study of Cemsidomide (CFT7455), a Novel MonoDAC® Degrader, with Dexamethasone in Patients with Relapsed/Refractory Multiple Myeloma.”
◦Management will host an investor call to discuss cemsidomide data in MM in conjunction with the IMS presentation.
•Present data from cemsidomide Phase 1 dose escalation in NHL in Q4 2025.
•Enable initiation of the next phase of cemsidomide clinical development in MM with new studies expected to initiate in early 2026.
•Present poster analyzing cemsidomide clinical data of population pharmacokinetic and exposure-response relationships in MM and NHL at the 2025 American Conference on Pharmacometrics (ACoP 2025) on October 20, 2025.
SECOND QUARTER 2025 FINANCIAL RESULTS
Revenue: Total revenue for the second quarter of 2025 was $6.5 million, compared to $12.0 million for the second quarter of 2024. The decrease in revenue was primarily due to an $8.0 million milestone that was earned from Biogen in the second quarter of 2024 partially offset by achievement of a preclinical milestone under our MKDG collaboration and continued progress on our other collaboration programs.
Research and Development (R&D) Expense: R&D expense for the second quarter of 2025 was $26.2 million compared to $23.8 million for the second quarter of 2024. The increase in R&D expense was primarily related to clinical trial expenses for cemsidomide, in addition to increased preclinical spend as the company’s research collaborations continue to advance.


General and Administrative (G&A) Expense: G&A expense for the second quarter of 2025 was $8.8 million compared to $9.7 million for the second quarter of 2024. The decrease was primarily related to lower stock-based compensation expense.
Net Loss and Net Loss per Share: Net loss for the second quarter of 2025 was $26.0 million, compared to $17.7 million for the second quarter of 2024. Net loss per share for the second quarter of 2025 was $0.37 compared to $0.26 for the second quarter of 2024.
Cash Position and Financial Guidance: Cash, cash equivalents and marketable securities as of June 30, 2025 were $223.0 million, compared to $234.7 million as of March 31, 2025 and $267.3 million as of December 31, 2024. The decrease during the second quarter was primarily the result of cash used to fund operations and advance our programs, partially offset by cash received for milestones under our Roche and MKDG collaborations. The company expects that its cash, cash equivalents and marketable securities as of June 30, 2025 will enable the company to fund its operating plan to mid-2027.
About C4 Therapeutics
C4 Therapeutics (C4T) (Nasdaq: CCCC) is a clinical-stage biopharmaceutical company dedicated to delivering on the promise of targeted protein degradation science to create a new generation of medicines that transforms patients’ lives. C4T is progressing targeted oncology programs through clinical studies and leveraging its TORPEDO® platform to efficiently design and optimize small-molecule medicines to address difficult-to-treat diseases. C4T’s degrader medicines are designed to harness the body’s natural protein recycling system to rapidly degrade disease-causing proteins, offering the potential to overcome drug resistance, drug undruggable targets and improve patient outcomes. For more information, please visit www.c4therapeutics.com.
About Cemsidomide
Cemsidomide is an investigational, orally bioavailable small-molecule degrader designed to be a more potent and selective degrader of IKZF1/3, transcription factors that drive multiple myeloma (MM) and non-Hodgkin’s lymphomas (NHL), with unique pharmacokinetic properties. Clinical data has shown that cemsidomide is well-tolerated. In MM, cemsidomide displays compelling evidence of anti-myeloma activity and immunomodulatory effects. In NHL, cemsidomide displays compelling evidence of anti-lymphoma activity. More information may be accessed at www.clinicaltrials.gov (identifier: NCT04756726).
About CFT8919
CFT8919 is an orally bioavailable allosteric degrader that is designed to be potent and selective against EGFR bearing an oncogenic L858R mutation. In preclinical studies, CFT8919 is active in in vitro and in vivo models of L858R driven non-small cell lung cancer. Importantly, CFT8919 retains full activity against additional EGFR mutations that confer resistance against approved EGFR inhibitors including L858R-C797S, L858R-T790M and L858R-T790M-C797S. C4T and Betta Pharmaceuticals have established a strategic partnership to develop CFT8919 in Greater China, where the Phase 1 clinical trial is underway. C4T retains development and commercialization rights for CFT8919 in the United States, European Union and rest of the world.
Forward-Looking Statements
This press release contains “forward-looking statements” of C4 Therapeutics, Inc. within the meaning of the Private Securities Litigation Reform Act of 1995. These forward-looking statements may include, but may not be limited to, express or implied statements regarding our ability to develop potential therapies for patients; the design and potential efficacy of our therapeutic approaches; the predictive capability of our TORPEDO® platform in the development of novel, selective, orally bioavailable BiDAC™ and


MonoDAC® degraders; the potential timing, design and advancement of our preclinical studies and clinical trials, including the potential timing for and receipt of regulatory advice or authorization related to clinical trials and other clinical development activities including clinical trial commencement or cohort initiation; our ability and the potential to successfully manufacture and supply our product candidates for clinical trials; our ability to replicate results achieved in our preclinical studies or clinical trials in any future studies or trials; our ability to replicate interim or early-stage results from our clinical trials in the results obtained when those clinical trials are completed or when those therapies complete later-stage clinical trials; regulatory developments in the United States and foreign countries; the anticipated timing and content of presentations of data from our clinical trials; and our ability to fund our future operations. Any forward-looking statements in this press release are based on management’s current expectations and beliefs of future events and are subject to a number of risks and uncertainties that could cause actual results to differ materially and adversely from those set forth in or implied by such forward-looking statements. These risks and uncertainties include, but are not limited to: uncertainties related to the initiation, timing, advancement and conduct of preclinical and clinical studies and other development requirements for our product candidates; the risk that any one or more of our product candidates will cost more to develop or may not be successfully developed and commercialized; and the risk that sufficient capital to fund our future operations will be available to us on acceptable terms or at the times required. For a discussion of these and other risks and uncertainties, and other important factors, any of which could cause our actual results to differ from those contained in the forward-looking statements, see the section entitled “Risk Factors” in C4 Therapeutics’ most recent Annual Report on Form 10-K and/or Quarterly Report on Form 10-Q, as filed with the Securities and Exchange Commission. All information in this press release is as of the date of the release, and C4 Therapeutics undertakes no duty to update this information unless required by law.

Contacts:
Investors:
Courtney Solberg
Associate Director, Investor Relations
[email protected]
Media:
Loraine Spreen
Senior Director, Corporate Communications & Patient Advocacy
[email protected]


Condensed Consolidated Balance Sheet Data 
(in thousands) 
(Unaudited)

June 30, 2025December 31, 2024
Cash, cash equivalents and marketable securities$222,973 $267,263 
Total assets296,527 349,602 
Deferred revenue43,770 47,169 
Total stockholders' equity174,064 215,986 
 Condensed Consolidated Statements of Operations 
(in thousands, except share and per share amounts)
(Unaudited)
Three Months Ended June 30,Six Months Ended June 30,
2025202420252024
Revenue from collaboration agreements$6,463 $12,006 $13,701 $15,045 
Operating expenses:
Research and development26,197 23,753 53,269 46,286 
General and administrative8,767 9,695 18,097 19,983 
Restructuring
— — — 2,437 
Total operating expenses34,964 33,448 71,366 68,706 
Loss from operations(28,501)(21,442)(57,665)(53,661)
Other income, net:
Interest and other income, net2,481 3,726 5,323 7,584 
Total other income, net
2,481 3,726 5,323 7,584 
Net loss$(26,020)$(17,716)$(52,342)$(46,077)
Net loss per share − basic and diluted
$(0.37)$(0.26)$(0.74)$(0.67)
Weighted-average shares outstanding − basic and diluted
71,005,743 68,810,259 70,919,871 68,621,214 


Protein degraded. Disease targeted. Lives transformed. August 2025

 
Forward-looking Statements and Intellectual Property FORWARD-LOOKING STATEMENTS The following presentation contains forward-looking statements. All statements other than statements of historical fact are forward-looking statements, which are often indicated by terms such as “anticipate,” “believe,” “could,” “estimate,” “expect,” “goal,” “intend,” “look forward to,” “may,” “plan,” “potential,” “predict,” “project,” “should,” “will,” “would” and similar expressions. These forward-looking statements include, but are not limited to, statements regarding the therapeutic potential of C4 Therapeutics, Inc.’s technology and products. These forward-looking statements are not promises or guarantees and involve substantial risks and uncertainties. Among the factors that could cause actual results to differ materially from those described or projected herein include uncertainties associated generally with research and development, clinical trials and related regulatory reviews and approvals, as well as the fact that the product candidates that we are developing or may develop may not demonstrate success in clinical trials. Prospective investors are cautioned not to place undue reliance on these forward-looking statements, which speak only as of the date hereof. The forward-looking statements included in this presentation are subject to a variety of risks and uncertainties, including those set forth in our most recent and future filings with the Securities and Exchange Commission. Our actual results could vary significantly from those anticipated in this presentation, and our financial condition and results of operations could be materially adversely affected. C4 Therapeutics, Inc. undertakes no obligation to update or revise the information contained in this presentation, whether as a result of new information, future events or circumstances or otherwise. This presentation also contains estimates, projections and other information concerning the markets for C4 Therapeutics, Inc.’s product candidates, including data regarding the estimated size of those markets, and the incidence and prevalence of certain medical conditions and patient use of medicines. Information that is based on estimates, forecasts, projections, market research, or similar methodologies is inherently subject to uncertainties and actual events, and circumstances may differ materially from events and circumstances reflected in this information. Unless otherwise expressly stated, the Company obtained this industry, business, market and other data from reports, research surveys, clinical trials studies and similar data prepared by market research firms and other third parties, from industry, medical and general publications, from other publicly available information, and from government data and similar sources. INTELLECTUAL PROPERTY C4 Therapeutics, Inc. owns various registered and unregistered trademarks and service marks in the U.S. and internationally, including, without limitation, C4 THERAPEUTICS, our housemark logo, the name of our TORPEDO platform, and the names of our BIDAC and MONODAC degrader products. All trademarks, service marks, or trade names referred to in this presentation that we do not own are the property of their respective owners. Solely for convenience, the trademarks, service marks, and trade names in this presentation are referred to without the symbols ®, SM and , but those references should not be construed as any indicator that their respective owners will not assert, to the fullest extent under applicable law, their rights to. © 2025 C4 Therapeutics, Inc. 2

 
Our Mission To deliver on the promise of targeted protein degradation science to create a new generation of medicines that transform patients’ lives. Our portfolio of degrader medicines pursues targets that may benefit from a degrader approach: Cemsidomide1 targeting IKZF1/3 for multiple myeloma and non-Hodgkin’s lymphoma CFT8919 targeting EGFR L858R for non-small cell lung cancer CFT19462 targeting BRAF V600 mutant for solid tumors including melanoma & colorectal cancer Internal Discovery Pipeline targets in therapeutic areas in and beyond oncology with a strong degrader rationale and genetic link to disease 3 1C4T has prioritized multiple myeloma development 2CFT1946 Phase 1 trial is ongoing. C4T will not advance CFT1946 beyond the Phase 1 trial

 
C4T Has Been at the Forefront of TPD Science and Is On the Path to Becoming a Fully Integrated Biotechnology Company © 2025 C4 Therapeutics, Inc. Built TORPEDO platform to design highly catalytic, orally bioavailable degraders Established collaborations with leading global pharmaceutical companies, building expertise across a range of diseases and target classes Assembled strong catalog of intellectual property Progressed four development candidates into the clinic with three clinical trials ongoing Delivered two development candidates to a collaborator for non-oncology targets Achieved blood-brain barrier penetration in several development candidates Advancing clinical programs to approval for patients with high unmet needs Leveraging TORPEDO platform to develop a sustainable pipeline against targets with a strong degrader rationale and genetic link to disease in therapeutic areas in and beyond oncology Expanding application of targeted protein degradation through high-value collaborations Leading the Way in Designing Orally Bioavailable Degraders 2015 – 2020 Delivering on the Promise of Targeted Protein Degradation 2025 and beyond Demonstrating Proof of Concept 2020 – 2025 4 MM cemsidomide data shared in May 2025

 
PROGRAM TARGET INDICATIONS RESEARCH PRECLINICAL EARLY DEVELOPMENT LATE DEVELOPMENT RIGHTS Cemsidomide1 IKZF1/3 Multiple Myeloma & Non-Hodgkin’s Lymphoma CFT89192 EGFR L858R Non-Small Cell Lung Cancer CFT19463 BRAF V600 Mutant V600 Mutant Cancers Discovery Programs Oncology & Non-oncology Indications 1In August 2025, C4T announced prioritization of multiple myeloma development 2 License and collaboration agreement with Betta Pharmaceuticals for development and commercialization in Greater China 3 In May 2025, C4T announced CFT1946 will not advance beyond Phase 1 and that the company will seek partnership for the BRAF program © 2025 C4 Therapeutics, Inc. MM Focused Pipeline to Advance a Portfolio of Degrader Medicines Targeting Areas of High Unmet Need 5 CRC, Melanoma, Other BRAF V600 Mutant Cancers NHL

 
Prioritized Portfolio with Multiple 2025 Milestones © 2025 C4 Therapeutics, Inc. Cemsidomide IKZF1/3 2Q 2025: Completed Phase 1 dose escalation in MM September 2025: Present data from full Phase 1 dose escalation in MM at IMS Annual Meeting 4Q 2025: Present data from Phase 1 dose escalation data in NHL 2025: Enable initiation of the next phase of cemsidomide clinical development in MM with new studies expected to initiate in early 2026 CFT8919 EGFR L858R Year-end 2025: Utilize data from Phase 1 dose escalation trial in Greater China to inform ex-China clinical development 2Q 2025: Advanced two programs to preclinical milestones through the Roche collaboration 3Q 2025: Advanced one project to preclinical milestones through the MKDG collaboration 2025: Advanced internal and collaboration programs to key discovery milestones 2025: Present and publish preclinical work from internal pipeline and TORPEDO platform Discovery Multiple myeloma (MM); peripheral T-cell lymphoma (PTCL), a subtype of NHL; International Myeloma Society (IMS); non-Hodgkin’s Lymphoma (NHL) 6 2Q 2025: Complete monotherapy Phase 1 dose escalation trial in BRAF V600 mutant solid tumors 2Q 2025: Generate sufficient data from Phase 1 cohorts to inform next stepsCFT1946 BRAF V600 Mutant

 
Advancing Oncology and Non-oncology Discovery Programs With Collaboration Partners © 2025 C4 Therapeutics, Inc. Evaluating targets in autoimmune diseases & oncology Advanced two programs to preclinical milestones Discovering targeted protein degraders against critical oncogenic proteins Focused on two projects within the KRAS family; achieved preclinical milestone on one of these projects Discovering and developing degrader antibody conjugates in oncology Delivered two development candidates for non-oncology targets1 1Delivered development candidates to Biogen in Q1 2024 and Q3 2024 7

 
Cemsidomide IKZF1/3 Degrader Multiple Myeloma & Non-Hodgkin’s Lymphoma

 
IKZF1/3 Are Key Promoters of Myeloma and Lymphoma Cell Survival and Will Remain Important Therapeutic Targets for These Indications Multiple myeloma (MM); non-Hodgkin’s lymphoma (NHL) Hematopoietic Stem Cell Common Myeloid Progenitor Cell Common Lymphoid Progenitor Cell Neutrophil Platelets T-Cell B-Cell Plasma Cell Oncogenic Mutations/Aberrations T-Cell Lymphoma B-Cell Lymphoma Multiple Myeloma IKZF1/3 IRF4 ↑ IKZF1/3 and IRF4 Key Roles of IKZF1/3: • Multiple myeloma and lymphoma cells rely on IKZF1/3 and IRF4 for survival • Degrading IKZF1/3 leads to down regulation of IRF4, promoting myeloma and lymphoma cell death and on-target neutropenia • IKFZ1/3 degradation combined with MM immune-based regimens have potential to enhance activity through T-cell activation and cancer cell death by downregulation of IRF4 Advantages of Cemsidomide: Cemsidomide is more potent than approved and development stage IKZF1/3 degraders Increased selectivity for IKZF1/3 resulting in reduced off-target toxicity © 2025 C4 Therapeutics, Inc. 9 Multiple Myeloma

 
Cemsidomide Enrollment and Dose Escalation Complete in MM 100 µg QD 75 µg QD 62.5 µg QD 37.5 µg QD 50 µg MWF DOSE ESCALATION CEMSIDOMIDE 14/14 + DEX* Utilizing a Bayesian logistic regression model until determination of the MTD and/or RP2D © 2025 C4 Therapeutics, Inc. KEY INCLUSION CRITERIA • Adults with MM, R/R to at least 3 prior lines of therapy that have included lenalidomide, pomalidomide, a proteasome inhibitor, a glucocorticoid, and an anti-CD38 monoclonal antibody • Nonresponsive to or progressed within 60 days of prior therapy • Creatinine clearance ≥40 mL/min • ECOG ≤2 Phase 1 Study Endpoints • Primary: assess safety, tolerability and define the RP2D/MTD • Secondary: assess PK, PD, and preliminary anti-tumor activity *Cemsidomide administered as 14 days on/14 days off in a 28-day cycle; Dex was dosed on days 1, 8, 15, and 22 at doses of 40 mg orally for patients ≤75 years old and 20 mg orally for patients >75 years old; 2 patients at 100 µg are excluded as they had not completed Cycle 1 as of the data cut off date. Eastern Cooperative Oncology Group (ECOG); maximum tolerated dose (MTD); Monday Wednesday Friday (MWF); multiple myeloma (MM); once daily (QD); pharmacodynamics (PD); pharmacokinetic (PK); recommended Phase 2 dose (RP2D); relapsed refractory (R/R) 10 Trial is Fully Enrolled with Multiple Dose Levels Studied, Including Expansion at Each Dose Level Multiple Myeloma

 
11© 2025 C4 Therapeutics, Inc. Cemsidomide MM Data Further Demonstrate Potential Best-in-Class Profile Cemsidomide continued to be well-tolerated with manageable neutropenia1 0% 25% 50% 75% 100% All Dose Cohorts (N=63) 75 µg Cohort (N=20) 100 µg Cohort (N=10) R e sp o n se R a te ORR 33% ORR 40% ORR 50% Compelling anti-myeloma activity observed across multiple doses1 1. Data cut-off date as of April 30,2025; C4T data on file Source: Data presented at ASH with data cutoff date as of 10/11/24, can be found here: https://ir.c4therapeutics.com/static-files/32ae4fdb-d4d9-4a17-a77d-83289c66e91f Overall Response Rate (ORR); minimal residual disease (MRD); complete response (CR); once daily (QD) Cemsidomide +Dex - Overall Response Rates Multiple Myeloma At the 100 µg dose level: • One patient achieved an MRD negative CR • Eight patients (80%) received prior CAR-T or T-cell engager therapy

 
TEMRA TEM 0 20 40 60 80 100 % positive cells (C1D21 vs C1D1) % p o s it iv e c e ll s C1D1 C1D21 © 2025 C4 Therapeutics, Inc. Clinical Evidence of Immune T-cell Activation With Cemsidomide Monotherapy ** **** TEMRA: Terminally differentiated T-cells TEM: Effector memory T-cells Peripheral blood mononuclear cells (PBMCs); daily dosing (QD); Monday, Wednesday, Friday dosing (MWF); multiple myeloma (MM) Source: C4T data on file as of 11/28/2023 (https://ir.c4therapeutics.com/static-files/ec59b02e-3074-484d-ad88-e81831bf37ed) • 19 patient samples (PBMCs) analyzed by flow cytometry • Aggregate data of 25 µg, 50 µg, and 75 µg Supports potential of cemsidomide as a maintenance therapy option and in combination with other MM agents to improve efficacy: ✓ Cemsidomide induces CD8+ T- cell activation by increasing effector memory T-cell subset ✓ T-cell activation is observed at well-tolerated monotherapy clinical doses ✓ Clinical data consistent with the preclinical in vitro data reported for cemsidomide Multiple Myeloma 12

 
Immune T-Cell Activation Has Potential to Enhance Activity of Bispecific T-cell Engager Therapies Validated Biology Precedent Clinical Evidence 2 Preclinical Cemsidomide Data Cemsidomide enhances the activity of bispecific T-cell engagers through immunomodulation Talquetamab +/- IKZF1/3 Degraders Independent Clinical Trials; PI, anti-CD38, & IKZF1/3 Degrader Exposed R/R MM Patients 16% 6% 22% 25% 9% 19% 26% 44% 73% 94% 0% 25% 50% 75% 100% Talq (N=100) Talq + Pom (N=16) R e sp o n se R a te sCR CR VGPR PR Duration of response (DOR); stringent complete response (sCR); complete response (CR); very good partial response (VGPR); partial response (PR); multiple myeloma (MM); Relapsed refractory (R/R) Sources: 1. Talq FDA label; 2. Matous ASH 2023. 1 2 DOR Median: 9.5 months 100% at 9 months 0.001 0.01 0.1 1 10 10 20 30 40 50 60 70 Cemsidomide + Bispecific T-cell Engagers T-cell Dependent Cellular Cytotoxicity Assay (TDCC) Assay [Cemsidomide] (nM) N C I- H 9 2 9 L y s is (% ) Cmin Cmax Talquetamab: 2.5 ng/mLTeclistamab: 25 ng/mL“Long-term exposure to bispecific antibodies with chronic T-cell stimulation further aggravates T-cell dysfunction, which could contribute to failure of disease control” Multiple Myeloma © 2025 C4 Therapeutics, Inc. 13

 
Phase 2 (Single Arm) Cemsidomide + Dex For registrational intent Cemsidomide Development Plan Addresses Multiple Lines of Therapy I 2L ~56,000 1L ~65,000 3L ~49,000 4L ~42,000 5L+ ≥23,000 U.S. + EU4 + UK Addressable Patients (2024)1 Treatment Line Phase 1b Cemsidomide / BCMA Bispecific Combo Studies Currently Being Enabled for Early 2026 Future Study to be Initiated INITIAL CEMSIDOMIDE DEVELOPMENT PATH IN MM Source: 1. EvaluatePharma (accessed 1/8/25), consulting engagements with Health Advances and Clearview. Germany, Italy, France, and Spain (EU4). B-cell maturation antigen (BCMA); dexamethasone (Dex); T-Cell engager (TCE); multiple myeloma (MM) Multiple Myeloma © 2025 C4 Therapeutics, Inc. Development Rationale Potentially enhances response durability and treatment duration of BCMA bispecific by preventing T-cell exhaustion Potential to provide highly refractory patients, including patients who have received prior anti-BCMA, a treatment option that is tolerable and efficacious where there are limited options 14 Potential Accelerated Approval Potential Accelerated Approval Randomized Phase 2/3 Cemsidomide / BCMA Bispecific Combo (1-3 prior lines) For registrational intent

 
With a Potential Best-in-Class Profile, Cemsidomide Is Positioned to Be an IKZF1/3 Degrader of Choice Across Various Combinations Post-Transplant Maintenance1 Anti-CD38 Combos Proteasome Inhibitor Combos CAR-Ts (+/- Maintenance Therapy) Other MOAs2 1Approximately 30% of multiple myeloma patients undergo a hematopoietic stem cell transplant and receive post-transplant maintenance therapy. 2 Other MOAs approved in MM include dexamethasone combos, anti-SLAMF7 mAbs and XPO1 inhibitors. Potential future treatment options include FcRH5 bispecific T-cell engagers, BCL-2 inhibitors, and others. Sources: EvaluatePharma (accessed 1/8/25), NCCN guidelines, consulting engagements with Health Advances and Clearview. B-cell maturation antigen (BCMA); dexamethasone (dex); G protein-coupled receptor, class C, group 5, member D (GPRC5D); monoclonal antibodies (mAbs); mechanism of action (MOA); Germany, Italy, France, and Spain (EU4) BCMA/GPRC5D T-cell Engagers and ADC Combos © 2025 C4 Therapeutics, Inc. CEMSIDOMIDE OPPORTUNITY • Potential to address a growing patient population as current 5L+ treatment options start to be used in earlier lines • Cemsidomide has the potential to become the IKZF1/3 degrader of choice in numerous regimens across lines of therapy given its potent anti-myeloma activity, differentiated safety profile, and immunomodulatory effects EVOLVING MULTIPLE MYELOMA TREATMENT LANDSCAPE Multiple Myeloma 2L ~56,000 1L ~65,000 3L ~49,000 4L ~42,000 5L+ ≥23,000 U.S. + EU4 + UK Addressable Patients (2024) Treatment Line 15

 
Cemsidomide Enrollment and Dose Escalation Is Complete in NHL © 2025 C4 Therapeutics, Inc. KEY INCLUSION CRITERIA • Adults with NHL, R/R to prior therapy • PTCL patients must have received at least 1 prior alkylator-based chemotherapy • ALCL patients must have also received a CD-30 mAb • Nonresponsive to or progressed within 60 days of prior therapy • Creatinine clearance ≥40 mL/min • ECOG ≤2 Phase 1 Study Endpoints • Primary: assess safety, tolerability and define the RP2D/MTD • Secondary: assess PK, PD, and preliminary anti-tumor activity DOSE ESCALATION CEMSIDOMIDE 14/14 Utilizing a Bayesian logistic regression model until determination of the MTD and/or RP2D Anaplastic large cell lymphoma (ALCL); Angioimmunoblastic T-cell lymphoma (AITL); Eastern Cooperative Oncology Group (ECOG); monoclonal antibody (mAb); maximum tolerated dose (MTD); Monday Wednesday Friday (MWF); non-Hodgkin’s lymphoma (NHL);once daily (QD); pharmacodynamic (PD); pharmacokinetic (PK); peripheral T-cell lymphoma (PTCL); recommended Phase 2 dose (RP2D); relapsed refractory (R/R) Source: ASH 2024; C4T data as of 10/11/2024.(https://ir.c4therapeutics.com/static-files/32ae4fdb-d4d9-4a17-a77d-83289c66e91f) 100 µg QD 87.5 µg QD 75 µg QD 62.5 µg QD 37.5 µg QD 50 µg QD 25 µg MWF NHL 16 Trial is Fully Enrolled With Multiple Dose Levels Studied Data presented at ASH 2024 demonstrated: • Cemsidomide is well-tolerated with manageable neutropenia • Compelling and deep responses achieved across PTCL subtypes ✓ Cemsidomide monotherapy produced responses in all four PTCL subtypes ✓ All AITL patients (4/4) experienced a metabolic response Cemsidomide Data in NHL Expected in Q4

 
CFT8919 EGFR L858R Degrader Non-Small Cell Lung Cancer

 
CFT8919 Is a Potent, Oral, Allosteric, Mutant-selective Degrader of EGFR L858R With Potential to Improve Outcomes for NSCLC Patients CFT8919 Orthosteric Inhibitor Potential Degrader Advantages of CFT8919: CFT8919 exploits an allosteric binding site created by the L858R mutation, thereby avoiding resistance mutations to the orthosteric site Potent and selective against L858R regardless of secondary mutations with potential for more durable activity in this setting Does not hit wild-type, potentially resulting in better tolerability Non-small cell lung cancer (NSCLC); epidermal growth factor receptor (EGFR) Current Approved EGFR Inhibitors Have Limitations: • Patients become refractory due to secondary mutations • NSCLC patients with L858R have inferior clinical outcomes • Toxicities associated with inhibition of wild-type EGFR limit tolerability © 2025 C4 Therapeutics, Inc. 18

 
CFT8919 Binds to Allosteric Site, Avoiding Impact of L858R Non-classical Co-mutations in the Orthosteric Binding Pocket Sources: 1. From Black Diamond’s analyses of 94,939 sequencing reports from treatment naive NSCLC (Guardant Health) presented at AACR 2024 (https://blackdiamondtherapeutics.com/assets/files/AACR_2024__BDTX-1535_FINAL_Presentation_20240405.pdf) 2. Gitenbeek, et al. 2023 Progression free survival (PFS) CFT8919 binds to the allosteric site, potentially avoiding the impact of non-classical co-mutations with L858R, where inhibitors demonstrate lower PFS in this patient population than those with EXON 19 deletion 1 2 Overall survival by type of mutation in patients with Stage IV EGFR mutated NSCLC and brain metastasis who received first-line treatment with osimertinib EGFR-L858R Tumors More Frequently Co-express Non-classical EGFR Mutations Before Exposure to EGFR TKI1 Patients with L858R Do Less Well on Osimertinib Therapy vs Ex19del © 2025 C4 Therapeutics, Inc. 19

 
Mean plasma concentration shown for n > 2 Mean plasma concentration shown for n > 2 CFT8919 Is Selective for EGFR L858R and Active in a Setting of Osimertinib Resistance in Preclinical Models Source: C4T data on file; Presented at Keystone Symposium 2021 (https://c4therapeutics.com/wp-content/uploads/Preclinical-Evaluation-of-CFT8919-as-a-Mutant-Selective-Degrader- of-EGFR-with-L858R-Activating-Mutations-for-the-Treatment-of-Non-Small-Cell-Lung-Can.pdf) Investigational new drug application (IND) EGFR-L858R EGFR-L861Q 0 5 10 15 0 500 1000 1500 2000 Days of Treatment B a F 3 E G F R L 8 5 8 R /T 7 9 0 M /C 7 9 7 S T u m o r v o lu m e ( m m 3 ) Vehicle PO BID Osimertinib 25 mpk PO QD CFT8919 10 mpk PO BID CFT8919 25 mpk PO BID CFT8919 50 mpk PO BID Specific for EGFR Exon 21 Mutants Active in Setting of EGFR C797S © 2025 C4 Therapeutics, Inc. 20

 
Mean plasma concentration shown for n > 2 Mean plasma concentration shown for n > 2 Mean plasma concentration shown for n > 2 CFT8919 Demonstrates Activity in Brain Metastasis Model Source: C4T data on file; presented at TPD Summit 2021 (https://c4therapeutics.com/wp-content/uploads/C4_CFT8919_TPD_Summit_Presentation.pdf) By mouth (PO); twice daily (BID) 4 6 8 10 12 10 100 1000 10000 Time (hr) C F T 8 9 1 9 c o n c e n tr a ti o n in p la s m a ( n g /m l) a n d t u m o r (n g /g ) Plasma Tumor in brain Plasma clearance t1/2 = 3.1 hrs 0 5 10 15 0 200 400 600 Study Day B L I (p h o to n s /s × 1 0 6 ) Vehicle CFT8919 (50mg/kg PO BID) 0 5 10 15 -20 -10 0 10 20 Study Day B o d y W e ig h t C h a n g e ( % ) * *Body weight loss due to tumor burden 50 mg/kg single dose PO Mean Plasma & Tumor Concentration In vivo Efficacy In vivo Body Weight Change © 2025 C4 Therapeutics, Inc. 21

 
CFT8919 Has the Potential to Address Multiple Opportunities With High Unmet Needs CFT8919’s Fastest Path to Market Is in 2L+ With Potential to Expand Into Front-Line Development Rationale: • Fast path to market • Lack of therapies after patients relapse with secondary mutation (i.e., C797S) 2L+ Development Rationale: • Large patient opportunity • Potential to increase responses and durability in L858R patients Front-line Dose escalation in Greater China is advancing; C4T to utilize data to inform ex-China clinical development 2024 Annual Incidence of EGFR L858R Mutated NSCLC1: • U.S.: ~17,000 • China: ~189,000 • EU4 + UK: ~13,000 Source: 1. EvaluatePharma (accessed on 1/10/25), consulting engagements with Health Advances and Clearview. Germany, Italy, France, and Spain (EU4) © 2025 C4 Therapeutics, Inc. 22

 
Prioritized Portfolio With Multiple 2025 Milestones © 2025 C4 Therapeutics, Inc. Cemsidomide IKZF1/3 2Q 2025: Completed Phase 1 dose escalation in MM September 2025: Present data from full Phase 1 dose escalation in MM at IMS Annual Meeting 4Q 2025: Present data from Phase 1 dose escalation data in NHL 2025: Enable initiation of the next phase of cemsidomide clinical development in MM with new studies expected to initiate in early 2026 CFT8919 EGFR L858R Year-end 2025: Utilize data from Phase 1 dose escalation trial in Greater China to inform ex-China clinical development 2Q 2025: Advanced two programs to preclinical milestones through the Roche collaboration 3Q 2025: Advanced one project to preclinical milestones through the MKDG collaboration 2025: Advanced internal and collaboration programs to key discovery milestones 2025: Present and publish preclinical work from internal pipeline and TORPEDO platform Discovery Multiple myeloma (MM); peripheral T-cell lymphoma (PTCL), a subtype of NHL; International Myeloma Society (IMS); non-Hodgkin’s Lymphoma (NHL) 23 2Q 2025: Complete monotherapy Phase 1 dose escalation trial in BRAF V600 mutant solid tumors 2Q 2025: Generate sufficient data from Phase 1 cohorts to inform next stepsCFT1946 BRAF V600 Mutant