Foghorn Therapeutics Delays Breast Cancer Drug Timeline

The Tip Desk · October 18, 2026 · 3 min read

Foghorn’s second-quarter net loss narrowed to $7.2 million, while an operational issue at an outside research organization delayed its breast cancer drug program.

Foghorn Therapeutics Inc. (FHTX), a clinical-stage biotechnology company developing medicines to correct abnormal gene expression, delayed its breast cancer drug timeline after two updates outlining progress toward clinical testing. In May, it had anticipated an investigational new drug application in 2027. Foghorn now says it will provide updated guidance when available, following an unexpected operational issue at a third-party contract research organization supporting animal models.

The affected candidate selectively targeted CBP, a protein involved in regulating gene expression. Foghorn reported anti-tumor activity in preclinical models of heavily pretreated estrogen receptor-positive breast cancer and described the candidate’s tolerability profile as favorable. The company had also developed a long-acting injectable formulation for weekly injections under the skin. Those findings remained preclinical, while the timing of the program’s next regulatory milestone was unresolved.

A revenue adjustment tied to Foghorn’s Lilly collaboration shaped the financial results for the quarter ended June 30. Collaboration revenue was $16.1 million against $7.6 million a year earlier. The increase reflected a $14.2 million cumulative catch-up adjustment for updated future costs, primarily because the collaboration’s research term is scheduled to expire in December 2026. The timing of work performed under the agreement partially offset that adjustment.

Research and development expenses fell to $18.5 million from $21.8 million. The reduction reflected lower Lilly-partnered program costs, facilities and information technology expenses, FHD-286 costs and personnel expenses, partly offset by higher early development and other external costs. General and administrative expenses totaled $6.4 million, with lower facilities and information technology expenses contributing to the decrease.

The quarterly net loss was $7.2 million, compared with $17.9 million a year earlier. Total operating expenses were $24.9 million. The revenue adjustment and lower spending accompanied the narrower loss.

Foghorn’s lead clinical candidate, FHD-909, continued through Phase 1 dose escalation with Lilly, maintaining the progress described in both earlier updates. The trial’s primary target population was patients with non-small cell lung cancer, with an initial focus on tumors carrying SMARCA4 mutations. The oral drug selectively inhibited SMARCA2, a related protein on which SMARCA4-mutant tumors depended in preclinical studies.

The Lilly agreement included equal U.S. co-development and co-commercialization arrangements for the selective SMARCA2 program and another undisclosed oncology target, alongside three discovery programs. Foghorn and Lilly anticipate evaluating FHD-909 with pembrolizumab in lung cancer, contingent on successful Phase 1 dose-escalation results. Foghorn reported complete tumor regression and no regrowth after treatment stopped in animal studies combining FHD-909 with an anti-PD-1 antibody.

Beyond the delayed breast cancer candidate, Foghorn is targeting a 2027 investigational new drug application for its selective EP300 degrader program, focused on multiple myeloma and diffuse large B-cell lymphoma. The company reported complete responses in preclinical myeloma models, with superior anti-tumor activity compared with the dual CBP/EP300 inhibitor inobrodib. It also described superior safety, measured by body weight loss and platelet counts, compared with dual degradation. Foghorn also advanced selective ARID1B degraders in preclinical work, reporting target degradation and evidence suggesting potential oral bioavailability.

The company extended its pipeline beyond oncology with an undisclosed oral small molecule in immunology and inflammation, for which it is targeting a regulatory application in 2027. Cash, cash equivalents and marketable securities totaled $167.6 million at June 30, against approximately $184 million at the first-quarter update. Despite that decline, Foghorn maintained its projection that its cash will fund operations into the first half of 2028, covering the application year targeted for both the inflammation and EP300 programs.