Acceleron has abandoned a drug for facioscapulohumeral muscular dystrophy (FSHD), even though it hit the mark on the primary endpoint in its phase 2 trial.
The US biotech took the decision to pull ACE-083 after a sift through the secondary endpoint data from the study convinced it that its clinical profile wasn’t strong enough to support a push into costly late-stage clinical testing.
FSHD is a genetic muscle disorder in which the muscles of the face, shoulder blades and upper arms are among the most affected.
TGF beta protein inhibitor ACE-083 – which inhibits proteins involved in muscle breakdown such as myostatins and activins – was shown to build muscle in patients with FSHD in the study. However the increase in muscle bulk didn’t translate to functional improvements in muscle strength.
“As we have stated consistently, for ACE-083 to become an important new therapy for patients with FSHD, it would have to deliver a meaningful functional benefit on top of an ability to grow muscle,” said Habib Dable, Acceleron’s chief executive.
“Unfortunately, in this case, the data shows no evidence of such a benefit,” he added.
ACE-083 is the lead candidate in Acceleron’s neuromuscular therapeutic programme, and its most advanced drug after Celgene-partnered luspatercept for chronic anaemias. The latter has been tipped as a future blockbuster, which likely helped insulate Acceleron from the news of ACE-083’s demise – shares fell a little under 7% in after-hours trading in the wake of its announcement.
It’s not the end of the road for ACE-083 however, as it is still being tested in a mid-stage trial in patients with Charcot-Marie-Tooth (CMT) disease – another disease that causes muscle atrophy – with results due in the first quarter of 2020.
Dable said he is still optimistic for a positive outcome for that trial, as CMT is a neuromuscular disorder with a different pathophysiology. On the plus side, ACE-083 was generally well-tolerated in the FSHD trial with most adverse reactions mild to moderate and occurring at the injection site.
Along with luspatercept and ACE-083, Acceleron is also developing sotatercept for pulmonary arterial hypertension (PAH) in a phase 2 trial. It picked up an orphan drug designation for sotatercept (formerly ACE-011) from the FDA this week.