Keros Therapeutics Discontinues PAH Program, Announces Layoffs and Strategic Review

Keros Therapeutics, a Massachusetts-based biotech company, has announced the termination of its pulmonary arterial hypertension (PAH) program and a significant workforce reduction as part of a broader strategic review. The decision comes in the wake of safety concerns observed in a phase 2 clinical trial and marks a pivotal moment for the company as it reassesses its pipeline and corporate direction.

Program Discontinuation and Safety Concerns

Keros has officially ended the development of cibotercept, a TGF-β inhibitor that was being evaluated in a phase 2 trial for the treatment of PAH. The company had previously suspended the Tropos trial in January 2025 after observing several safety signals. Following a comprehensive review of efficacy and safety data, Keros has decided to discontinue the entire PAH program.

The decision to halt the Tropos trial was prompted by the occurrence of pericardial effusion adverse events, which involve an excessive buildup of fluid in the sac surrounding the heart. This safety concern has led to a reassessment of cibotercept's potential in PAH, although the company is considering testing the asset in other indications pending the outcome of its ongoing strategic review.

Workforce Reduction and Financial Implications

As a direct consequence of the program discontinuation, Keros has announced a significant workforce reduction. The company plans to lay off approximately 70 employees, representing 45% of its workforce. Following the cuts, Keros will retain 85 full-time employees.

The layoffs are expected to take place after a 60-day notice period, in compliance with the Worker Adjustment and Retraining Notification Act. Keros anticipates that this reduction in force will result in annual cost savings of about $17 million.

Despite these challenges, Keros reports a strong financial position. As of March 31, 2025, the company stated it had sufficient cash to fund operating costs into 2029. This runway includes a $200 million upfront payment from Takeda, stemming from a hematology partnership established in December 2024.

Strategic Review and Future Focus

Keros Therapeutics is currently undergoing a comprehensive strategic review, which includes an assessment of its ongoing development programs and consideration of all strategic alternatives, including a potential sale of the company. This review was initiated in April 2025, alongside adjustments to the company's stockholder rights plan aimed at preventing rapid accumulations of stock by investors seeking to influence company control.

Moving forward, Keros is shifting its focus to KER-065, a phase 1 neuromuscular disease program with an initial emphasis on Duchenne muscular dystrophy. This repositioning reflects the company's efforts to adapt to recent setbacks and capitalize on promising areas within its pipeline.

As Keros navigates through this period of transition, the pharmaceutical industry will be closely watching to see how the company emerges from its strategic review and whether it can successfully pivot its research and development efforts towards more promising therapeutic areas.