Roche announced Monday that the FDA granted priority review to a filing seeking approval of the SMN-2 splicing modifier risdiplam for patients with spinal muscular atrophy (SMA). The regulator is expected to make a decision on the application by May 24 next year.
According to Roche, the submission includes 12-month data from the pivotal FIREFISH and SUNFISH trials, which enrolled a broad population of people living with Types 1, 2 or 3 SMA. Earlier this month, the drugmaker reported  that the second part of the SUNFISH study met its primary endpoint, with risdiplam demonstrating significant improvements in motor function using total score of Motor Function Measure 32 (MFM-32) versus placebo.
Roche noted that if authorised, risdiplam, which is an orally administered liquid also known as RG7916, would be the first at-home administered medicine for people with SMA. The company is leading clinical development of risdiplam as part of a collaboration with the SMA Foundation and PTC Therapeutics, and would commercialise the therapy in the US if approved.
Along with the FIREFISH and SUNFISH studies, risdiplam is being investigated in a broad clinical trial programme in SMA, including the JEWELFISH study in patients with SMA aged six months to 60 years who have been previously treated with SMA-directed therapies, and the RAINBOWFISH trial in babies from birth to six weeks of age with genetically diagnosed SMA who are not yet presenting with symptoms.
In 2016, the FDA approved  Biogen and Ionis Pharmaceuticals' Spinraza (nusinersen) for use in children and adults with SMA, making the drug the first treatment approved in the US in this indication. Meanwhile, earlier this year, the regulator authorised  Novartis' gene therapy Zolgensma (onasemnogene abeparvovac-xioi) for the treatment of patients under two years of age with SMA with bi-allelic mutations in the SMN1 gene.
For related analysis, see ViewPoints: PTC, Roche plan to take no prisoners in SMA battle .