Keros Therapeutics voluntarily halts all dosing of Phase 2 TROPOS trial

Keros Therapeutics (KROS) announced that it has voluntarily halted all dosing in the TROPOS trial, a Phase 2 clinical trial of cibotercept in combination with background therapy in patients with pulmonary arterial hypertension, including the 1.5 mg/kg and placebo treatment arms, based on the ongoing safety review due to new observations of pericardial effusion adverse events. On December 12, 2024, the company announced that it had voluntarily halted the 3.0 mg/kg and 4.5 mg/kg treatment based on the observation of pericardial effusions at those dose levels. “While we are disappointed in this new development, patient safety is always our top priority. We continue to work with the investigators, the U.S. FDA and other relevant regulatory authorities, and we look forward to analyzing and presenting TROPOS topline clinical data in the future,” said Jasbir Seehra, PhD., Chair and CEO. The company has notified investigators and certain regulatory authorities, including the FDA, about this decision, and is in the process of notifying other relevant regulatory authorities. The TROPOS trial is being terminated early, and patients are expected to be monitored through the end-of-trial visits. The company continues to expect to present topline data from all treatment arms in this trial in the second quarter of 2025.