No Charm: PTC’s Duchenne Drug Rejected by FDA for Third Time

Xconomy New York — 

The FDA on Wednesday rejected a Duchenne muscular dystrophy drug from PTC Therapeutics, marking the third time that the regulator has quashed the company’s attempts to bring its drug to the market.

Early this year, South Plainfield, NJ-based PTC (NASDAQ: PTCT) invoked a little-used rule to force an FDA decision. That strategy looked ill-advised last month when a panel of FDA advisors gave the data a vote of no confidence.

One month later, PTC says it has received the FDA’s formal rejection letter, which questioned the efficacy of ataluren (Translarna). The agency called for more evidence from one or more clinical trials, and it also cited manufacturing problems, according to PTC. PTC said it would address those problems, and it is appealing the FDA’s decision.

“We are extremely disappointed for the Duchenne community and strongly disagree with the agency’s conclusions,” CEO Stuart Peltz said in a prepared statement.

PTC shares actually rose on Wednesday, trading as high as $17.40 per share, up 7.8 percent from Tuesday’s closing price. But that’s still well shy of the company’s 52-week high of $22 per share.

Duchenne is a rare muscle-wasting disease in which boys lose the ability to walk and eventually die of the disease at a young age. The disorder is caused by genetic defect that prevents boys from producing the muscle-boosting protein dystrophin. PTC describes its drug as a protein restoration therapy.

Ataluren failed in clinical trials in 2011 and 2016, and the FDA refused to review the drug’s marketing application following each failure. European regulators approved ataluren in 2014 with conditions: PTC must provide more data from another placebo-controlled clinical trial in order to confirm the safety and efficacy of the treatment.

In the U.S., PTC used the rare “over protest” rule to force a decision because it did not want to run another clinical trial. PTC contended that the “totality of the data” from the two earlier failed trials was sufficient to show the drug helped patients. San Rafael, CA-based BioMarin Pharmaceuticals (NASDAQ: BMRN) used the same argument for its Duchenne drug drisapersen, which had failed in Phase 3 studies. After an independent advisory panel to the FDA questioned the clinical trial data, BioMarin decided to stop work on the drug.

Peltz said PTC will file a dispute resolution request with the regulator next week.

Photo by Flickr user Joel Kramer via a Creative Commons license.