8-K: Foghorn Therapeutics Advances Oncology Degrader Pipeline

Foghorn Therapeutics announced significant preclinical progress across its Selective ARID1B, CBP, and EP300 degrader programs, highlighting potential new oncology therapies.

Summary

• Foghorn Therapeutics provided pipeline updates for its Selective ARID1B, Selective CBP, and Selective EP300 degrader programs.
• The Selective ARID1B degrader program is advancing towards in vivo proof-of-concept in 2026, demonstrating selective binding and degradation of ARID1B, a target relevant in up to 5% of all solid tumors (e.g., endometrial, gastric, bladder, NSCLC).
• The Selective CBP degrader program, with lead candidate CBPd-171, is on track for non-GLP toxicology studies in Q4 2025 and is expected to be IND-ready in 2026, showing anti-tumor activity in EP300-mutant solid tumors and ER+ breast cancer.
• The Selective EP300 degrader program is on track for IND-enabling studies in 2026, demonstrating efficacy and favorable tolerability in preclinical models for hematological malignancies like multiple myeloma (MM) and diffuse large B-cell lymphoma (DLBCL), including activity in IMiD-resistant MM cell lines.
• The company's proprietary Gene Traffic Control Platform enables the development of precision first-in-class therapeutics by targeting chromatin regulation.

Sentiment

Score: 9

Explanation: The filing presents strong positive preclinical data across multiple pipeline programs, addressing challenging targets with favorable tolerability profiles and clear differentiation from existing approaches. The outlined timelines for IND-enabling studies and IND-readiness in 2026 indicate significant progress and a clear path forward, suggesting high confidence in the company's platform and drug candidates.

Positives

• Demonstrated robust and selective degradation of ARID1B, a previously undruggable target, with both VHL and cereblon based degraders.
• Selective CBP degrader (CBPd-171) shows significant anti-tumor activity in EP300-mutant solid tumors and promising potential in ER+ breast cancer.
• CBPd-171 exhibits no significant preclinical heme toxicity and spares megakaryocytes, addressing a common issue with dual inhibitors.
• Developed a Long Acting Injectable (LAI) formulation for CBPd-171, enabling weekly subcutaneous delivery with comparable efficacy to daily injections.
• Selective EP300 degraders show impressive efficacy in multiple myeloma without thrombocytopenia, a key differentiation from dual CBP/EP300 approaches.
• EP300 degraders maintain full efficacy in IMiD-resistant multiple myeloma cell lines, addressing a significant unmet need.
• Broad anti-tumor activity observed for EP300 degraders in over 70% of tested heme sub-lineages.
• The company's platform has delivered precision first-in-class therapeutics and is poised to unlock new biology, leveraging deep chromatin biology understanding and degrader optimization expertise.

Risks

• Actual results may differ materially from forward-looking statements due to inherent uncertainties, risks, and changes in circumstances.
• Risks related to capital market conditions, business, economy, and other future conditions.
• Regional, national, or global political, economic, business, competitive, market, and regulatory conditions.
• Risks relating to clinical trials, including initiation, timing, progress, and results of research and development programs, preclinical studies, and clinical trials (e.g., Phase 1 dose escalation trial of FHD-909).
• Ability to advance product candidates and successfully complete preclinical and clinical studies.
• Impact of exogenous factors, including macroeconomic and geopolitical circumstances, on business operations.
• Developments related to competitors and the industry.
• Ability to expand target populations and availability of patients for clinical testing.
• Ability to obtain regulatory approval for product candidates from the FDA and other authorities.
• Ability to identify and enter into future license agreements and collaborations.
• Reliance on CDMOs and CROs for manufacturing and research needs.
• Ability to attract and retain key scientific and management personnel.
• Scope of protection for intellectual property rights covering products and the Gene Traffic Control Platform.
• Use of proceeds from capital-raising transactions, estimates of expenses, capital requirements, and needs for additional financing.

Future Outlook

Foghorn Therapeutics anticipates advancing its Selective ARID1B degrader program towards in vivo proof-of-concept in 2026. The Selective CBP degrader program, with lead candidate CBPd-171, is expected to be IND-ready in 2026 following non-GLP toxicology studies in Q4 2025. The Selective EP300 degrader program is also on track for IND-enabling studies in 2026, with an initial focus on multiple myeloma and diffuse large B-cell lymphoma. The company aims to leverage its Gene Traffic Control Platform to develop additional product candidates and expand into new therapeutic areas.

Management Comments

• "We have made significant progress across our degrader portfolio, further highlighting our ability to address challenging and prevalent targets." Adrian Gottschalk, President and CEO.
• "Earlier this week, we presented new preclinical data at the TPD and Induced Proximity Summit demonstrating significant progress for our first-in-class Selective ARID1B degrader, with potential as a new therapy for endometrial, gastric, gastroesophageal junction, bladder and non-small cell lung cancer." Adrian Gottschalk, President and CEO.
• "Our Selective CBP degrader, with potential in EP300-mutant cancers and ER+ breast cancer, is advancing towards IND in 2026 and on track for non-GLP toxicology studies this quarter." Adrian Gottschalk, President and CEO.
• "Additionally, our Selective EP300 degrader shows encouraging anti-tumor efficacy with favorable tolerability in hematological malignancies in preclinical studies. This is particularly exciting in multiple myeloma where we believe we are significantly differentiated versus dual CBP/ EP300 programs." Adrian Gottschalk, President and CEO.
• "These advancements along with our continued innovation and disciplined execution are positioning Foghorn at the forefront in the field of targeted protein degradation." Adrian Gottschalk, President and CEO.
• "ARID1B has long been difficult to selectively drug due to its high homology to ARID1A, lack of enzymatic activity, and its largely unstructured nature. Our demonstration of selective degradation of ARID1B represents a major scientific breakthrough that underscores the strength of our protein degrader capabilities to overcome challenges that have historically limited the field." Steven Bellon, Chief Scientific Officer.

Industry Context

The announcement positions Foghorn Therapeutics as a leader in chromatin biology and targeted protein degradation, addressing historically challenging targets like ARID1B, CBP, and EP300. The company's focus on selective degraders aims to overcome limitations of dual inhibitors, such as dose-limiting toxicities (e.g., thrombocytopenia seen with dual CBP/EP300 inhibitors like Inobrodib), and to provide effective treatments for cancers with high unmet needs, including IMiD-resistant multiple myeloma and various solid tumors with specific mutations.

Comparison to Industry Standards

• Selective CBP degrader (CBPd-171) shows no significant impact on platelet counts and spares megakaryocytes, differentiating it from dual CBP/EP300 inhibitors like Inobrodib (CCS1477), which has shown significant impact on platelet counts in preclinical studies.
• Selective EP300 degraders achieve deeper responses at tolerated doses with no thrombocytopenia, contrasting with Inobrodib, whose clinical use is limited by thrombocytopenia requiring dosing holidays.
• EP300 degraders demonstrate full efficacy in IMiD-resistant multiple myeloma cell lines, addressing a critical challenge where existing immunomodulatory drugs (IMiDs) like lenalidomide, pomalidomide, iberdomide, or mezigdomide face resistance.

Stakeholder Impact

• Shareholders: Positive impact due to significant preclinical pipeline progress, de-risking of programs, and clear development timelines, potentially increasing company valuation.
• Patients: Potential for new, more effective, and better-tolerated therapies for various cancers, including those with high unmet needs like IMiD-resistant multiple myeloma and ARID1A-mutant solid tumors.
• Investment Professionals: Provides detailed scientific and strategic insights into the company's drug development capabilities and future prospects, aiding investment decisions.

Next Steps

• Advance Selective ARID1B degrader program towards in vivo proof-of-concept in 2026.
• Conduct non-GLP toxicology studies for CBPd-171 in Q4 2025.
• Prepare Selective CBP degrader program to be IND-ready in 2026.
• Initiate IND-enabling studies for Selective EP300 degrader program in 2026.
• Further characterize LAI formulation for CBPd-171 in additional pharmacology studies to refine human dose predictions.

Key Dates

Recommendation

The filing details substantial and highly positive preclinical advancements across three distinct, first-in-class degrader programs targeting challenging oncology pathways. The demonstrated selective degradation, robust anti-tumor activity, favorable tolerability profiles (especially the absence of hematological toxicities compared to dual inhibitors), and efficacy in drug-resistant settings (IMiD-resistant MM) represent significant de-risking events. The clear timelines for IND-enabling studies and IND-readiness in 2026 for multiple programs indicate strong execution and a promising near-term clinical pipeline. This progress, coupled with the company's proprietary Gene Traffic Control platform, suggests a high potential for future value creation and makes the stock a compelling 'strong buy' for long-term investors.

Keywords

Targeted Protein Degradation, Oncology, ARID1B degrader, CBP degrader, EP300 degrader, SMARCA4 mutant cancers, ER+ breast cancer, Multiple Myeloma, Non-Small Cell Lung Cancer, Chromatin Biology, Biotechnology, Preclinical data, IND-ready, Hematological Malignancies