PTC abandons CF indication after latest failure
- PTC Therapeutics announced this morning that its Phase 3 ACT study testing ataluren in patients with nonsense mutation cystic fibrosis did not meet its primary or secondary endpoints.
- While the drug had a positive safety profile, the company has chosen to discontinue development of ataluren in cystic fibrosis. The company will end all ongoing extension studies and withdraw its application for approval in Europe.
- PTC’s stock dropped nearly 17% in early morning trading on March 2 to trade just under $11 per share. Despite the bad news, the stock is well off its 52-week low of $4.03.
The Phase 3 study of 279 patients showed that ataluren failed to improve lung function in the treatment of cystic fibrosis compared with a placebo at 48 weeks.
This is just the latest failure for the company’s lead compound. While the second failure in cystic fibrosis, the company has shown spotty results in Duchenne muscular dystrophy as well.
The Food and Drug Administration rejected the company’s application in DMD last year. While PTC appealed the decision, the rejection has stood. After the approval of Sarepta Therapeutics’ drug for DMD, PTC said it would fight the decision again. Unlike Sarepta's drug, PTC's ataluren is based on a different genetic mutation called a nonsense mutation.
The drug is currently approved in Europe under a conditional approval and is known by the brand name Translarna. The company has five years to prove the drug works in DMD or it will be taken off the market.
While Jefferies analyst Gena Wang said in a note to investors that the failure in cystic fibrosis was expected, she added that it could hurt further review of the drug. "We assign no value to ataluren in the US and we see the CF failure could create additional hurdles for the regulatory process," the analyst wrote.
- PTC Therapeutics Statement
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