|PTC Therapeutics CEO Stuart Peltz|
After missing a key trial goal and getting a rare second chance from EU regulators, PTC Therapeutics' ($PTCT) ataluren is now the world's first approved therapy for Duchenne muscular dystrophy (DMD), picking up a conditional European OK as the company awaits results from a late-stage study.
The drug, to be marketed as Translarna, is cleared to treat the roughly 13% of DMD sufferers whose disease is caused by a nonsense mutation. That works out to about 2,500 patients in Europe, PTC said. The conditional approval allows the company to sell the treatment in all 28 EU member countries for one year, at which point regulators will want to see results from an ongoing Phase III trial before conferring a permanent green light.
The nod comes after a surprising reversal of fortune for PTC. In 2010, ataluren missed its primary endpoint in a 174-patient Phase IIb trial, failing to significantly improve patient performance on a 6-minute walk test compared to placebo and leading a committee of European Medicines Agency advisers to rule against recommending early approval for the drug in January. PTC appealed that ruling, however, and, on a second look, the same group noted "some evidence of effectiveness" at certain doses, factoring in DMD patients' serious unmet need and changing its recommendation.
The EMA committee's change of heart more than doubled PTC's share value back in May, and Monday's expected approval sent the biotech up about 4% in early trading.
"We are moving rapidly to make this product available to patients in the EU as we continue our global efforts to fulfill our vision of making Translarna available to all the boys it may benefit," PTC CEO Stuart Peltz said in a statement. "... The DMD community has been waiting a long time for treatment options and this conditional approval marks an important day for us all."
But PTC's long-term success with ataluren is contingent upon success in a 220-patient Phase III trial called ACT DMD. The company kicked off enrollment last year, hoping to avoid a repeat of its mid-stage flop as it tests whether the drug can top placebo in 6-minute walk test performance over 48 weeks. PTC expects to complete the trial next summer, just in time to make its case for a full European approval.
Meanwhile, in the U.S., PTC is racing with Sarepta Therapeutics ($SRPT) and Prosensa ($RNA) to commercialize the country's first DMD treatment. Each is hoping for an early FDA nod, and recent comments from the agency's head of drug research have stoked hopes for success. Last week, in a letter to a DMD patient group, CDER Director Janet Woodcock said regulators plan to "explore the use of all potential pathways for the approval of drugs for Duchenne muscular dystrophy, including accelerated approval, as appropriate."
- read the release
Editor's note: An earlier version of this story misstated the timing of ataluren's Phase IIb study. We regret the error.