A recent FDA approval of a label expansion put the three marketed therapies for spinal muscular atrophy (SMA) on equal footing for the youngest patients. A recent survey found that many payers are covering sequential use of the costly agents, including a gene therapy.
The FDA initially approved Evrysdi (risdiplam) from Roche Group member Genentech USA, Inc. on Aug. 7, 2020, for the treatment of SMA in people at least 2 months old. On May 30, 2022, the agency expanded the drug’s label to include the treatment of babies less than 2 months old. The medication is an oral solution administered by mouth or feeding tube and can be administered by a patient or caregiver at home after a recommended consultation with a health care professional prior to the first dose.
That label expansion meant that Evrysdi joined two other therapies in being indicated for infants with the most severe type of SMA. The first SMA drug on the market was Biogen’s Spinraza (nusinersen), which the FDA approved on Dec. 23, 2016, for the treatment of SMA in pediatric and adult patients. The agent is administered by or under the direction of health care professionals over one to three minutes as an intrathecal injection. That drug was followed by the May 24, 2019, approval of Novartis Pharmaceuticals Corp. subsidiary AveXis, Inc.’s Zolgensma (onasemnogene abeparvovec-xioi) for the treatment of patients less than 2 years old with SMA with bi-allelic mutations in the SMN1 gene. Dosing for the gene therapy is a one-time 60-minute intravenous infusion.
People with SMA cannot produce enough survival motor neuron (SMN) protein, leading to the loss of motor neurons, which results in problems breathing, swallowing, speaking and walking. Before a therapy was available to treat SMA, the condition was the No. 1 genetic cause of infant death.
The condition is not inexpensive to treat. The first-year price of Spinraza is $765,000 and then $382,500 for subsequent years. The price of Evrysdi is tied to a person’s weight and is capped at $340,000 per year once someone reaches 44 pounds. For a 15-pound patient, the price would be less than $100,000 per year. And Zolgensma’s price is $2.125 million.
For the Managed Care Biologics and Injectables Index: Q1 2022, between March 3, 2022, and April 7, 2022 — before Evrysdi’s label expansion — Zitter Insights polled 36 commercial payers with 117.1 million covered lives and 26 Medicare payers with 38.6 million lives. While respondents covering 92% of commercial lives said that they do not allow the use of more than one SMA therapy at the same time, those with 82% of lives said they allow sequential use of the agents (see chart below).
Zitter Insights and AIS Health are both MMIT companies.
Among the 25 neurologists also surveyed during the same time frame, 80% had prescribed Spinraza over the 12 months prior to the survey, 68% had prescribed Evrysdi, and 44% had written a script for Zolgensma.
For more information on the Zitter Insights data, contact Jill Brown Kettler at firstname.lastname@example.org.