Roche’s risdiplam has come through another late-phase test, triggering improvements in the motor skills of infants with type 1 spinal muscular atrophy (SMA). The clinical success comes months before the FDA is set to decide whether to approve the survival motor neuron-2 splicing modifier.
Risdiplam successfully cleared a pivotal test in patients with the less severe 2 and 3 forms of SMA last year, positioning it to file for approval of the PTC Therapeutics-partnered therapy. The application, which has a PDUFA date of May 24, covers the use of risdiplam in patients with type 1, 2 and 3 forms of SMA.
Roche’s latest update suggests it has a good shot at winning FDA approval with a label that covers all three forms of SMA. The Swiss drugmaker is yet to share numbers from the trial of type 1 patients, but the headline safety and efficacy findings are positive.
The study met its primary endpoint, which assessed whether infants were able to sit without support for at least five seconds after receiving daily doses of risdiplam for one year. Roche also provided a qualitative look at the safety profile, stating no new signals were detected and no subjects withdrew due to treatment-related adverse events.
Unless the detailed data hide red flags not apparent in Roche’s release, risdiplam looks poised to win FDA approval in the coming months. If that happens, risdiplam will become the third new SMA drug to come to market in as many years, turning the previously underserved patient population into the focus of competition between Roche, Biogen and Novartis.
Biogen’s Spinraza was the first of the trio of SMA drugs to come to market, giving the big biotech the time to grow the antisense oligonucleotide into a product that pulled in sales of around $500 million a quarter over the first nine months of the year. However, Zolgensma looks to pose a threat to those sales, with Novartis easily beating analyst expectations in the third quarter in part due to its ability to get patients who were on Spinraza to take its gene therapy.
Roche cannot offer patients the one-shot benefits of Zolgensma, but analysts still have high hopes for the drug, leading to blockbuster sales projections.