Orsini Specialty Pharmacy Now Provides Vyondys 53 to Treat Duchenne

Orsini Pharmaceutical Services is now providing Sarepta Therapeutics’ newly approved therapy Vyondys 53 (golodirsen) to treat people with Duchenne muscular dystrophy (DMD) responsive to exon 53 skipping.

Orsini, which also distributes Sarepta’s other DMD therapy, Exondys 51 (eteplirsen), is an independent specialty pharmacy in the U.S. focused on supporting patients with rare and complicated diseases. It services patients in all 50 states.

According to the company, its selection was due to a clinical model that focuses on the specific needs of people with complex disorders requiring frequent patient-provider encounters (called “high touch”).

“We are excited to continue our successful partnership with Sarepta and serve the needs of the DMD community and the specialists who treat this unique genetic condition,” said Orsini’s CEO Mike Fieri, in a press release. “DMD and other diseases we treat require a high touch level of interaction and coordination with the clinical team, payers, as well as patients and their support network.”

“Our philosophy of ‘no patient left behind’ drives our unique pharmacy care model and consistently addresses the needs of patients and families challenged with very rare chronic disorders,” Fieri added.

People with DMD have impaired production of dystrophin, a key protein for muscle integrity, due to mutations in the DMD gene.

Vyondys 53 (also known as SRP-4053) works by masking exon 53 in the messenger RNA produced from DMD to make a shorter but functional version of dystrophin. Injected directly into the bloodstream, the therapy is intended for the nearly 8% of DMD cases amenable to skipping exon 53 — one of the 79 bits of DNA that contain information to make dystrophin.

As it makes the cell machinery “skip” over a part of the gene, the treatment is designed to enable the production of a shorter but functional dystrophin protein.

After it rejected Sarepta’s application due to safety concerns, the U.S. Food and Drug Administration (FDA) conditionally approved Vyondys 53 in December 2019. Full approval is now based on the Phase 3 ESSENCE trial (NCT02500381), a “post-marketing confirmation trial” as typically required in the FDA’s conditional approvals.

The trial, which is still recruiting, will evaluate the effectiveness and safety of Vyondys 53 and of an additional investigational exon-skipping therapy by Sarepta, called casimersen (SRP-4045). This potential treatment is designed to mask exon 45.

Expected to be completed by 2024, ESSENCE is enrolling up to 222 patients at locations in Canada and Europe, with sites yet to open in the U.S. 

Participants will be split into two equal-sized groups, each receiving either Vyondys 53 or casimersen. The primary goal is to assess muscular strength and function, as measured by the six-minute walk test, after nearly two years of treatment (96 weeks). Safety will be evaluated throughout the trial.

According to a Sarepta spokeswoman, the price of Vyondys 53 will be similar to that of Exondys 51, and will be based on a patient’s weight, with an estimated cost of $300,000 per year to treat a child weighing 20 kg (44 pounds).