- PTC Therapeutics is pushing its lead candidate down a regulatory pathway almost as rare as the genetic disorder the drug aims to treat.
- The company revealed Monday the Food and Drug Administration had acknowledged its filing over protest, an uncommon decision in the pharmaceutical industry. That kind of filing forces the FDA to review a New Drug Application (NDA) even if the agency had previously decided against such an action, as was the case in October of last year.
- The company looks to get Translarna (ataluren) greenlit as a treatment for patients with Duchenne muscular dystrophy (DMD) who demonstrate nonsense mutations. The disease mainly affects young boys, arising in less than 600 births each year in the U.S. Even fewer, about 10% to 15%, show the nonsense mutations.
The FDA gave PTC's application an action date of Oct. 24, but analysts believe the likelihood of approval is still basically zero.
Translarna is also under investigation for several other rare diseases, including mucopolysaccharidosis Type I and cystic fibrosis (CF).
A history of hiccups has plagued the drug, however, and efficacy data has been sketchy at best.
The medication missed primary endpoints in mid- and late-stage trials testing it in hundreds of patients with DMD, fueling the FDA's decision to reject PTC's NDA for DMD in February 2016 and subsequent appeal later that year. What's more, the drug recently failed a Phase 3 trial testing it in 279 patients with CF.
"While we see this as positive for regulatory process, we believe there is low [probability] of approval, given the unclear drug mechanism and prior failures in multiple large clinical trials in DMD and CF," Jefferies analyst Gena Wang wrote in a Monday note regarding PTC's latest regulatory move.
Wang could only point to two previous instances when drugmakers opted to file in protest. One was Pharmacyclics, which — before AbbVie acquired it — submitted Xcytrin (motexafin gadolinium)as a treatment for lung cancer brain metastases. The other was GlaxoSmithKline's filing of Bexxar (tositumomab and iodine 1131 tositumomabin) as a treatment for non-Hodgkin lymphoma.
The FDA rejected Pharmacyclic's application in 2007, while GlaxoSmithKline withdrew the one for Bexxar.
"We believe that the totality of clinical data in our NDA, which includes the results of two of the largest placebo-controlled DMD clinical trials ever conducted, demonstrates Translarna's benefits to patients and merits a full and fair review by the FDA, including an advisory committee meeting," PTC's CEO Stuart Peltz said in a March 6 statement.
Investors seemed to act positively to the power play. PTC's stock was up more than 4% from Friday, trading at $10.22 by close-of-market Monday.