ACE-083 is the lead product candidate in our neuromuscular therapeutic program. It is a locally active agent that may be useful for diseases of focal muscle loss such as muscular dystrophies, with a first indication in facioscapulohumeral muscular dystrophy (FSHD). ACE-083 is designed to increase strength and function in specific target muscles for improved patient function and quality of life.

ACE-083 works by binding to and inhibiting select proteins in the TGF-beta protein superfamily that negatively regulate (reduce) muscle growth, such as activins and myostatin (GDF8). This “Myostatin +” approach, is believed to increase muscle mass and strength in the muscle where the drug is administered. Untreated muscles or other organs are not affected, reducing the potential for systemic side effects. Our approach is unique from that of competitors who have attempted to engage the superfamily’s targets selectively, only to receive marginal results. In contrast, we have achieved meaningful clinical results by engaging multiple TGF-beta targets.

In a Phase 1 trial in healthy volunteers, ACE-083 produced substantial dose-dependent increases in muscle volume, with the highest dose level generating an unprecedented 14.5% increase in muscle volume. Based on these results, we initiated a two-part Phase 2 trial in FSHD patients with muscle weakness in the tibialis anterior or biceps. We are also conducting a Phase 2 trial in Charcot-Marie-Tooth disease, in which ACE-083 may benefit patients who suffer from muscle weakness causing foot drop and reduced mobility.