FDA Approves At-Home Oral Treatment for Spinal Muscular Atrophy

The FDA has approved risdiplam, the first at-home, oral treatment for spinal muscular atrophy (SMA) in adults and children 2 months and older.

The drug, created by PTC Therapeutics, will be marketed by Genentech as Evrysdi.

The approval was based on “clinically meaningful improvements in motor function and obtainment of developmental milestones,” the companies said.

“Given the majority of people with SMA in the U.S. remain untreated, we believe Evrysdi, with its favorable clinical profile and oral administration, may offer meaningful benefits for many living with this rare neurological disease,” Levi Garraway, MD, PhD, chief medical officer and head of Global Product Development for Genentech, said in a statement.

The approval is based on results from 2 clinical studies with more than 450 participants: FIREFISH in symptomatic infants aged 2 to 7 months; and SUNFISH, in children and adults aged 2 to 25 years, which is the first and only placebo-controlled trial to include adults with types 2 and 3 SMA.

Patients previously treated for SMA with other medications were also included.

Other medications for SMA include Biogen’s nusinersen (Spinraza) and Novartis’ onasemnogen abeparvovec (Zolgensma), with the latter being a 1-time gene therapy.

“Infants achieved key motor milestones not normally seen in the natural course of the disease, such as the ability to sit without support. Evrysdi also preserved vital functions and improved survival at 12 months. In particular, Evrysdi improved survival without permanent ventilation compared to natural history when measured at 12 and 23 months,” PTC said.

"Today marks an incredibly important moment for the broader SMA patient community that had been in dire need of safe and effective treatment options," Stuart W. Peltz, PhD, CEO of PTC Therapeutics, said in a statement.

In the FIREFISH study, 41% of infants treated with the therapeutic dose achieved the ability to sit without support for at least 5 seconds, as measured by the Bayley Scales of Infant and Toddler Development Third Edition (BSID-III). Ninety percent of infants were alive without permanent ventilation at 12 months of treatment and reached 15 months of age or older, according to the study.

In the SUNFISH study, children and adults treated with risdiplam experienced a clinically meaningful and statistical-significant improvement in motor function at 12 months (1.55 point mean difference; P = .0156) compared with placebo (1.36 points [95% CI, 0.61-2.11]; –0.19 points [95% CI, –1.22-0.84], respectively), as measured by a change from baseline in the Motor Function Measure-32 total score.

Risdiplam will be available in the United States within 2 weeks for direct delivery to patients' homes through Accredo Health Group, an Express Scripts specialty pharmacy.