Acceleron Drops Drug for Rare Muscle Disease After Mixed Phase 2 Data

Xconomy Boston — 

An experimental Acceleron Pharma drug for rare neuromuscular diseases has failed to distance itself from a placebo in a mid-stage study, spelling the end for that program.

Acceleron (NASDAQ: XLRN) drug ACE-083 was being developed as a treatment for Charcot-Marie-Tooth disease, a hereditary nerve disorder that leads to the progressive loss of muscle function. The Cambridge, MA-based company develops drugs that target TGF-beta, a family of proteins that regulate cellular growth and repair. ACE-083 was designed to block myostatin, a protein that suppresses muscle growth.

In the Phase 2 clinical trial, Acceleron reported that patients treated with its drug showed, on average, an increase in total muscle volume—which was the study’s main goal. But that muscle volume increase did not translate into statistically significant improvements in function or quality of life compared to a placebo. Based on those results, Acceleron says it will discontinue further work on ACE-083.

The clinical trial results in Charcot-Marie-Tooth disease come six months after disappointing Phase 2 data for ACE-083 in facioscapulohumeral muscular dystrophy, another rare neuromuscular disorder. In that study, Acceleron reported an increase in muscle volume but no statistically significant improvement in muscle function.

Given the facioscapulohumeral muscular dystrophy results, disappointing data in Charcot-Marie-Tooth was not a surprise, SVB Leerink analyst Geoffrey Porges wrote in a research note. He added the results confirm the importance to the company of sotatercept, a drug being developed to treat pulmonary arterial hypertension. In January, Acceleron reported positive preliminary data from a Phase 2 study, prompting Porges to say that the drug has the potential to become a blockbuster seller.

Acceleron plans to present results of the Charcot-Marie-Tooth study at the American Academy of Neurology Annual Meeting in April. Going forward, the company will focus on luspatercept (Reblozyl) in anemia and sotatercept in pulmonary arterial hypertension, as well as ongoing preclinical TGF-beta research, CEO Habib Dable said in a prepared statement.

Image: iStock/Vasyl Dolmatov