A review of market access for Duchenne muscular dystrophy treatments shows that under the pharmacy benefit, about 39% of the lives under commercial formularies are covered with utilization management restrictions. Around 28% of the lives under health exchange formularies are not covered for at least one of the drugs.
Under the medical benefit, about 57% of the lives under commercial policies are covered with utilization management restrictions. Almost 81% of the lives under Medicare policies have access to at least one of the drugs without utilization management restrictions.
For about 77% of the covered lives, payer pharmacy benefit formularies do not require step therapy (ST). Of the lives that require ST, only 1% of the lives require multiple steps. Around 84% of payer-controlled pharmacy benefit covered lives require prior authorization.
In May 2022, the FDA granted orphan drug designation to Stealth BioTherapeutics Corp.’s elamipretide for the treatment of patients with Duchenne muscular dystrophy. The FDA’s division of neurology also granted the company’s request for a pre-investigational new drug (IND) meeting to discuss a development path for elamipretide in combination with products within the approved therapeutic class of exon-skipping phosphorodiamidate morpholino oligomers, according to the company.
In February 2021, the FDA gave accelerated approval to Sarepta Therapeutics, Inc.’s Amondys 45 (casimersen) for the treatment of Duchenne muscular dystrophy (DMD) in people with a confirmed mutation amenable to exon 45 skipping. The agency gave the drug priority review, as well as fast track and orphan drug designations. Dosing for the intravenous infusion is 30 mg/kg of body weight once weekly over 35 to 60 minutes via an in-line 0.2 micron filter. The company says the drug is priced at parity with its other DMD therapies, which are around $750,000 for an average patient per year.
In August 2020, the FDA gave accelerated approval to NS Pharma, Inc.’s Viltepso (viltolarsen) for people with Duchenne muscular dystrophy who have a mutation amenable to exon 53 skipping. The agency gave the application priority review. Recommended dosing is 80 mg/kg once weekly as an intravenous infusion over 60 minutes. Its annual price is about $733,000 for a 66-pound person.
Market Events Drive Changes
In February 2021, the FDA gave accelerated approval to Sarepta Therapeutics, Inc.’s Amondys 45 (casimersen) for the treatment of Duchenne muscular dystrophy (DMD) in people with a confirmed mutation amenable to exon 45 skipping. In August 2020, the agency gave accelerated approval to NS Pharma, Inc.’s Viltepso (viltolarsen) for people with DMD who have a mutation amenable to exon 53 skipping. In December 2019, the FDA gave accelerated approval to Sarepta’s Vyondys 53 (golodirsen) for the same indication.
Competitive Market Landscape
There are multiple products in Phase III or later of clinical trials. Treatments in the development pipeline include therapeutic approaches that restore or replace dystrophin and those that treat Duchenne symptoms, such as those that protect muscles by reducing fibrosis and inflammation.
Pharmacy, Medical Benefit Implications
Drugs for this indication are generally covered under both the pharmacy and medical benefits. Payers require prior authorization, and step therapy requirements may have patients try prednisone and prednisolone first.