FDA approves Roche, PTC Therapeutics' oral spinal muscular atrophy drug Evrysdi

The FDA on Friday cleared Roche and partner PTC Therapeutics' Evrysdi (risdiplam), making it the first at-home, orally administered treatment for all types of spinal muscular atrophy (SMA) in adult and paediatric patients aged two months and older. The SMN2 splicing modifier, also known as RG7916, will be available within two weeks for direct delivery to patients' homes through an Express Scripts specialty pharmacy, and will be sold in the US by Roche's Genentech unit.

"Evrysdi is the first drug for this disease that can be taken orally, providing an important treatment option for patients with SMA, following the approval of the first treatment for this devastating disease less than four years ago," remarked Billy Dunn, director of the Office of Neuroscience in the FDA's Center for Drug Evaluation and Research. Biogen and Ionis Pharmaceuticals' Spinraza (nusinersen), which requires infusion into the spinal canal every four months, was approved by the US regulator in 2016, while Novartis' gene therapy Zolgensma (onasemnogene abeparvovec-xioi) was cleared last year for SMA patients under two years with bi-allelic mutations in the SMN1 gene.

The FDA decision on Evrysdi was based on results from the FIREFISH and SUNFISH studies. In January, Roche reported that the FIREFISH trial involving infants aged one to seven months with Type 1 SMA had achieved its primary endpoint. Part 1 of the study evaluated several doses of Evrysdi and determined the therapeutic dose of 0.2 mg/kg for Part 2.

Results after 12 months in Part 1 of the study showed that 41% of infants treated with the therapeutic dose achieved the ability to sit without support for at least five seconds as measured by the Bayley Scales of Infant and Toddler Development Third Edition (BSID-III) gross motor scale. In addition, 90% of infants were alive without permanent ventilation and reached at least 15 months of age, while 81% were alive without permanent ventilation after a minimum of 23 months of treatment and reached an age of 28 months or older.

More recently, Roche reported data from FIREFISH Part 2, which also met its main goal, with 29% of infants able to sit without support for five seconds by month 12, as assessed by BSID-III. "No infants achieve this milestone in the natural history of Type 1 SMA," the drugmaker noted in April when the findings were released.

The SUNFISH trial of patients aged two to 25 years with type 2 or 3 SMA also met its primary endpoint, with results showing a significant 1.55-point mean improvement from baseline on the primary endpoint of the Motor Function Measure (MFM-32) scale at 12 months, compared with placebo.

Meanwhile, PTC indicated that a marketing application to the European Medicines Agency "is imminent." Roche holds global commercialisation rights to the drug outside the US. According to PTC, Roche has submitted applications for approval in Brazil, Chile, China, Indonesia, Russia, South Korea and Taiwan.

To read more Top Story articles, click here.