The Food and Drug Administration on Thursday approved a new medicine from Sarepta Therapeutics that treats certain patients with Duchenne muscular dystrophy.
The new drug, called Amondys 45, is Sarepta’s third marketed treatment for the rare, inherited muscle-wasting disease. It will be used to treat the approximately 8% of patients with a confirmed mutation to the Duchenne gene that is amenable to exon 45 skipping.
Combined with Sarepta’s currently marketed drugs, Exondys 51 and Vyondys 53, the company’s commercial reach extends to approximately 30% of all Duchenne patients.
All of Sarepta’s drugs have been granted accelerated approval by the FDA based on their ability to produce a tiny amount of the muscle protein dystrophin missing in these patients, even though there is no established proof that more dystrophin improves muscle function or slows the progression of the disease.
Sarepta is required to conduct follow-on studies to confirm that patients benefit from treatment. Exondys 51 was approved in 2016 but Sarepta has not completed its confirmatory study, drawing criticism for taking too long.
The confirmatory study for Amondys 45 is underway, with results expected in 2024.
Amondys 45 is priced “at parity” with Sarepta’s other medicines, the company said. Dosed by weight, Sarepta’s drugs can cost as much as $1 million annually.
Sarepta revenue this year is expected to grow nearly 30% to $686 million, according to consensus analyst estimates.
In January, Sarepta’s effort to develop a one-time gene therapy fix for Duchenne suffered a setback when a mid-stage clinical trial failed to demonstrate improvements in muscle function.