- The Food and Drug Administration has expanded approval of Roche's spinal muscular atrophy drug Evrysdi to include infants younger than 2 months old, the company announced Tuesday, providing an oral alternative in that population to a gene therapy from Novartis and a drug from Biogen that is administered through a spinal injection.
- The broadened approval permits doctors to use Evrysdi in babies whose disorder is identified through newborn screening tests. A small trial of six babies showed use of the drug helped all six sit without support after one year of treatment, while four could stand and three could walk.
- Evrysdi was the last of the three SMA drugs available in the U.S to gain regulatory approval, but use has steadily grown since its launch in 2020. The new approval will help Roche better compete with Novartis and its gene therapy Zolgensma, which is often administered soon after birth, and with Biogen's drug Spinraza.
Treatment of SMA has transformed over the six years since Biogen first gained approval for Spinraza. The disease was previously considered fatal for many babies born with the mutation that causes it. Even for those with less severe forms of the disorder, there were lifelong disabilities that often required use of a wheelchair or mechanical ventilation.
Until Evrysdi's latest approval, Spinraza was the only drug approved for all patients. Novartis' Zolgensma, which replaces the defective genes to stimulate production of an important muscle protein, is approved for children younger than 2 years old. The company has faced setbacks in trying to complete the clinical studies necessary to win approval in patients older than that.
With SMA's incidence estimated as once per every 10,000 births, the three drugmakers are all targeting a small group of patients with their treatments. While oral and therefore more convenient, Evrysdi must be taken every day. Spinraza, by comparison, is administered once every four months after a two-month loading period through the more invasive intrathecal injection. Zolgensma is intended to be a one-time treatment, although with the long-term safety of gene therapy still unclear, some parents could be more cautious about using it for their babies.
Spinraza is the biggest seller, with $473 million in sales in the first quarter of 2022, compared to $363 million for Zolgensma and about $236 million for Evrysdi. When the two Swiss drugmakers reported earnings, Novartis disclosed that Zolgensma had been used in about 2,000 patients worldwide and Roche said Evrysdi had been used in more than 5,000. (Roche's number includes those treated in clinical trials and compassionate use, however.)
Sales of both Zolgensma and Evrysdi are growing, at the apparent expense of Spinraza, sales of which shrank by 9% in the first quarter compared to the same period last year.
With all three drugs now approved for use in the youngest infants and two of the three available more widely, a new question is how these treatments might be used in sequence. All three, however, are costly: Zolgensma's one-dose list price is around $2 million, while Spinraza's list price is $375,000 a year at the maintenance dose and Evrysdi costs $340,000 annually.