The FDA has approved Sarepta’s eteplirsen ( Exondys 51) for the treatment of patients Duchenne muscular dystrophy (DMD) who have a confirmed mutation of the dystrophin gene amenable to exon 51 skipping.
During the conference call about the recent approval of Exondys 51, the Sarepta team has given information on what the drug will cost.
Exondys 51 will cost around $300,000 annually for patients with Duchenne muscular dystrophy. That estimate is the average cost per year but it will vary per patient based on their body weight. A 2ml vile of Exondys 51 will cost $1,600 and a 10ml vile will cost $8,000.
Serepta also has a Rare Pediatric Disease Designation which allows Sarepta to sell their ‘priority review voucher’ to another company (which go for around $300+ million).
Shares of Sarepta increased 75% following the FDA approval.
About Exondys 51
Serepta’s Exondys 51 should be administered once a week at 30mg, once weekly. It is advised that each patient should know their genotype mutation before administering Exondys 51.
Duchenne muscular dystrophy
Duchenne muscular dystrophy is caused by lack of a functional dystrophin protein, a protein that helps keep muscle cells intact. Patients with progressive muscle disorder experience symptoms in early childhood, losing the ability to walk as early as age 10. These patients, mostly boys, experience life-threatening heart and lung complications in their late teens and twenties.
There are many subsets of the Duchenne population based on the type of mutation found in the dystrophin gene. There are currently no drugs approved in the US to directly treat any of these groups.
Eteplirsen is designed to enable RNA to skip over the part of the DNA with a problematic mutation, enabling a functional (though shorter) dystrophin protein to be produced. Specifically, the drug skips a portion of the DNA known as exon 51. About 13% of the 35,000 DMD patients in the US and Europe have a mutation that might theoretically respond to a drug such as eteplirsen.