Keros Therapeutics, Inc. (KROS), a biopharmaceutical firm, announced on Wednesday an update regarding its Phase 2 TROPOS trial. The company has decided to voluntarily cease all dosing in the trial, including the 1.5 mg/kg and placebo groups, due to a safety review that identified new incidents of pericardial effusion as adverse effects.
Previously, on December 12, Keros Therapeutics had already stopped the 3.0 mg/kg and 4.5 mg/kg dose levels following similar pericardial effusion concerns. The company has informed trial investigators and certain regulatory bodies, such as the FDA, of this decision and is in the process of updating additional relevant regulatory entities.
With the decision to terminate the TROPOS trial early, the participants will continue to be monitored until their respective end-of-trial visits. Despite the early termination, Keros remains on track to deliver topline results from all treatment arms of the trial in the second quarter of 2025.
The TROPOS trial was structured as a randomized, double-blind, placebo-controlled Phase 2 study conducted globally to assess the effectiveness of cibotercept (KER-012) in conjunction with standard therapy on patients with pulmonary arterial hypertension (PAH).
The main goal of the trial was to compare the impact of cibotercept on pulmonary hemodynamics against a placebo in patients receiving standard PAH treatment. A critical secondary objective was to examine the effects of cibotercept on exercise capacity versus the placebo in these patients.
Cibotercept is engineered to bind and inhibit the signaling of TGF-β ligands, which contribute to smooth muscle hypertrophy and fibrosis, including activin A, activin B, and myostatin.
