Reversing an earlier negative opinion, the European Medicines Agency (EMA) Committee for Medicinal Products for Human Use (CHMP) gave a qualified endorsement this week to marketing of ataluren (Translarna, PTC Therapeutics) to treat Duchenne muscular dystrophy (DMD). In the drug’s phase IIb and phase III trials, boys with DMD failed to show statistically significant improvements in 6-minute walk distance, which had been the primary endpoint in both studies. Mean improvements with a year of treatment relative to placebo in both trials were approximately 30 meters, which is just barely over the usual threshold for a clinically meaningful difference. In January, the CHMP had reviewed the data and voted against recommending approval, but PTC subsequently requested a re-evaluation. After a recent meeting, the committee announced that the EMA should allow the drug to be marketed on condition that an ongoing phase III trial show a definite benefit. PTC is expected to complete enrollment in the new phase III trial within a few weeks. The outcome of this trial is critical for achieving full approval in the EU as well as the U.S.
