PTC Therapeutics Inc. announced that following its request for re-examination, the Committee for Medicinal Products for Human Use (CHMP) of the European Medicines Agency (EMA) has adopted a positive opinion regarding the company’s application for a conditional marketing authorization of Translarna (ataluren) for the treatment of nonsense mutation Duchenne muscular dystrophy (nmDMD) in ambulatory patients aged five years and older.
Ataluren is designed to block the effects of so-called “nonsense mutations,” or single-point alterations in certain genes that stop patients from forming fully functioning versions of the proteins encoded by those genes. Such mutations are the catalyst for a number of genetic diseases, but PTC is initially targeting the ones that underlie Duchenne–a degenerative muscle disease—for some patients, and cystic fibrosis for others.
Ataluren, however, has already failed a few trials, and was previously rejected by the same regulators that recommended it today. In 2011, the drug flunked a mid-stage study in Duchenne patients. It also failed a study in a subset of cystic fibrosis patients. PTC still charged ahead into a Phase 3 study in patients with Duchenne, however, feeling that the previous trial helped give it the information needed to design a study to show that ataluren can produce statistically significant results. That phase 3 trial is expected to produce data next year.
So given that there’s no new data here, what caused the CHMP to change its mind? CEO Stuart Peltz didn’t really specifically answer that question on a conference call this morning—he spoke of talking with the agency about additional analyses, and the “consistency” of the drug’s data in various stages of the disease process, which helped get regulators “comfortable that there was truly a drug effect” that ataluren could be approved based on. But he did say the agency didn’t incorporate any information from PTC’s ongoing Phase 3 study as part of its decision.
The European Medicines Agency, meanwhile, said in its own statement that PTCs drug has shown “some evidence of efficacy…in slowing down the loss of walking ability” in patients with Duchenne—and that the company will have to provide “comprehensive” efficacy data from its ongoing Phase 3 study as part of conditional approval of the drug. Will this be enough for various countries in Europe provide reimbursement for the drug? That remains to be seen.