PTC's Emflaza to face generics this month after Aurobindo's final FDA nod

After a series of regulatory setbacks in Europe, PTC Therapeutics will soon find itself under a generic attack in the U.S.

Monday, India's Aurobindo said (PDF) it has received a final FDA approval for its generic form of PTC's Emflaza for the treatment of Duchenne muscular dystrophy (DMD) in patients 5 and older.

Aurobindo plans to launch generic deflazacort tablets at various dosage strengths this month, the company said in a release.

In the first nine months of 2023, Emflaza generated around $188 million, according to PTC's quarterly releases from last year. The company has yet to report full-year 2023 results.

The drug has no remaining patents, according to FDA records. Its lone remaining period of FDA exclusivity covers DMD patients ages 2 to 5 and expires in June 2026.

Emflaza got off to a controversial start after its 2017 FDA approval to treat DMD. Marathon Pharma, which had previously acquired rights to trial data on the decades-old drug, priced it at $89,000 per year, attracting heat from lawmakers. 

Long before the nod, the corticosteroid had been available in other countries for about $1,000 per year, Sen. Bernie Sanders and the late U.S. Rep. Elijah Cummings wrote in a letter to the FDA at the time.

Under congressional scrutiny, Marathon halted the launch and then sold the product to PTC Therapeutics.

Emflaza is one of PTC's two commercial products. On the other side of the Atlantic, the company's other DMD drug, Translarna, faces a likely market withdrawal after a series of regulatory setbacks.

In the placebo-controlled Study 041, the drug failed to meet statistical significance on its primary endpoint in a selected patient subgroup, but it did turn in "nominally statistically significant results on several key endpoints," PTC previously said. Still, the results weren't enough to convince European regulators that Translarna should remain on the market.

After a September decision against recommending renewing the drug's authorization, regulators last month reached the same conclusion after a reexamination process.

Besides those two medicines, PTC records royalties from sales of Roche's spinal muscular atrophy drug Evrysdi.

In the third quarter of 2023, PTC's Translarna generated $69 million, while Emflaza pulled down $67 million. Evrysdi royalties topped $50 million during the quarter.