Roche edges closer to SMA market as risdiplam hits target in trial in babies

Roche is to begin discussions with regulators about new data from risdiplam, its developmental oral treatment for the rare muscle wasting disease spinal muscular atrophy (SMA) after supportive results in a trial in infants.

The Swiss pharma said Part 2 of the open-label FIREFISH study testing risdiplam in 41 infants aged 1-7 months with type 1 SMA had met its primary goal.

This measured the proportion of infants sitting without support for at least five seconds at 12 months of treatment, using a standardised assessment.

Safety for for risdiplam was consistent with its known safety profile and no new signals were detected.

Results build on positive results from Part 2 of SUNFISH, testing risiplam’s efficacy and safety in people aged 2-25 years with type 2 or type 3 SMA.

The FDA has already granted a priority review for risdiplam and is due to make a decision before a deadline on May 24.

Developed in collaboration with the SMA Foundation and PTC Therapeutics, Risdiplam is a survival motor neuron-2 (SMN2) splicing modifier, designed to increase and sustain SMN protein levels throughout the central nervous system and in peripheral tissues.

Risdiplam is a potential rival to Biogen’s Spinraza (nusinersen), a spinally injected antisense drug that tells the body to produce the SMN protein that is defective in patients with SMA and has halted progression and improved motor function in clinical trials.

Novartis also produces Zolgensma (onasemnogene abeparvovec), a gene therapy approved to treat the genetic cause of SMA.

Both approved drugs are hugely expensive - Spinraza costs $750,000 in the first year and then around $375,000 annually, and Zolgensma costs more than $2.1 million for a single shot making it the most expensive drug ever.

Novartis before Christmas ended development of a rival to risdiplam, saying that it did not see an opportunity for oral therapy for SMA.

Levi Garraway, chief medical officer and head of global product development, said: “This large, global trial confirms the efficacy of risdiplam in an advanced and difficult-to-treat population, including many infants whose disease had already progressed significantly before starting treatment.

“We are very encouraged by these results and we look forward to sharing them with regulators. We also thank the entire SMA community for their continued partnership.”