Keros Therapeutics Halts All Dosing In Phase 2 TROPOS Trial For PAH Due To Safety Concerns

(RTTNews) - Providing additional update on the Phase 2 TROPOS trial on Wednesday, biopharmaceutical company Keros Therapeutics, Inc. (KROS) announced Wednesday that it has voluntarily halted all dosing in the TROPOS trial, 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, 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.

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.

TROPOS is a randomized, double-blind, placebo-controlled, global Phase 2 clinical trial to evaluate cibotercept (KER-012) in combination with background therapy in patients with pulmonary arterial hypertension or PAH.

The primary objective of this trial is to evaluate the effect of cibotercept on pulmonary hemodynamics compared to placebo in participants on background PAH therapy. The key secondary objective of this trial is to evaluate the effect of cibotercept on exercise capacity compared to placebo on participants on background PAH therapy.

Cibotercept is designed to bind to and inhibit the signaling of TGF-ß ligands that stimulate smooth muscle hypertrophy and fibrosis, including activin A, activin B and myostatin.