Keros Therapeutics, Inc. has announced a voluntary halt in dosing for the Tropos trial, a phase 2 clinical trial of cibotercept (ker-012) in combination with background therapy in patients with pulmonary arterial hypertension (PAH). This decision was made based on ongoing safety reviews due to new observations of pericardial effusion adverse events. The company had previously halted the 3.0 mg/kg and 4.5 mg/kg treatment arms on December 12, 2024, due to similar observations.
The Tropos trial, which is a randomized, double-blind, placebo-controlled, global phase 2 clinical trial, is being terminated early. However, the company still expects to present topline data from all treatment arms in the second quarter of 2025.
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. The company believes that cibotercept has the potential to increase the signaling of bone morphogenic protein (BMP) pathways through the inhibition of activin a and activin b signaling, and consequently treat diseases such as PAH that are associated with reduced BMP signaling due to inactivating mutations in the BMP receptors.
This update comes after the company had previously announced the voluntary halt of the 3.0 mg/kg and 4.5 mg/kg treatment arms in December 2024 due to pericardial effusions at those dose levels.
Keros Therapeutics, Inc. continues to prioritize patient safety and is working closely with investigators, the U.S. Food and Drug Administration (FDA), and other relevant regulatory authorities. The company has notified investigators and certain regulatory authorities about the decision to halt dosing in the Tropos trial and is in the process of notifying other relevant regulatory authorities. The market has reacted to these announcements by moving the company's shares -14.7% to a price of $10.64. Check out the company's full 8-K submission here.
