Keros Reorganizes TROPOS Trial For Safety, Results Expected In 2025

Keros Therapeutics, Inc. is a clinical-stage biopharmaceutical company focused on developing treatments for dysfunctional TGF-β protein signalling conditions. The company has announced it has voluntarily paused dosing in the 3.0 mg/kg and 4.5 mg/kg treatment arms of its Phase 2 TROPOS trial. The trial, which evaluates cibotercept (KER-012) in combination with background therapy for pulmonary arterial hypertension (PAH), identified unexpected cases of pericardial effusion adverse events, prompting the decision.

Jasbir S. Seehra, Ph.D., Chair and CEO, said in a statement, “We are working diligently to gain a better understanding of these unanticipated findings. Above all, patient safety is our top priority when conducting any clinical trial. We will work with the investigators, the U.S. Food and Drug Administration (“FDA”) and other relevant regulatory authorities to address this as quickly as possible.”

The trial remains fully enrolled, and dosing continues in the 1.5 mg/kg arm following a risk-benefit assessment conducted by an independent Data Monitoring Committee (DMC) and a select group at Keros. The decision to adjust dosing was made in consultation with the DMC, and Keros will continue collecting safety and efficacy data across all treatment arms. The company has informed the FDA, investigators, and other regulatory authorities of this update and anticipates sharing topline results from all treatment arms in the second quarter of  2025. Keros is actively investigating the issue and will provide updates as new information becomes available.