MK-4836

MK-4836 is an investigational, orally bioavailable small molecule soluble guanylate cyclase (sGC) stimulator developed by Merck (known as MSD outside the U.S. and Canada) in collaboration with research institutions such as Thoraxklinik Heidelberg. It was primarily being evaluated for the treatment of pulmonary arterial hypertension (PAH) and other pulmonary vascular diseases. The mechanism of action involves the direct stimulation of sGC and the sensitization of the enzyme to endogenous nitric oxide (NO), leading to increased production of cyclic guanosine monophosphate (cGMP). This signaling pathway results in smooth muscle relaxation and vasodilation within the pulmonary vasculature, which can reduce pulmonary arterial pressure and improve hemodynamics. Clinical development of MK-4836 reached Phase 2 but was terminated by Merck in 2020 for strategic business reasons rather than safety concerns.