Today, the U.S. Food and Drug Administration (FDA) has approved a label extension for Evrysdi® (risdiplam) to include babies under two months old with spinal muscular atrophy (SMA). This means that risdiplam is now approved in the US to treat SMA in children and adults of all ages.
The approval is based on interim (preliminary) efficacy and safety data from the RAINBOWFISH study in newborns, which showed that the majority of pre-symptomatic babies treated with risdiplam achieved key milestones such as sitting and standing with half the participants walking after 12 months of treatment. In more detail, the initial analysis included 6 infants with 2 or 3 copies of SMN2 that were treated with risdiplam for at least 12 months. The patients achieved the following motor milestones as measured by the HINE-2 (motor function test) at Month 12:
- 6 (100%) patients achieved sitting (5 patients could pivot/rotate and 1 patient achieved the ability to sit),
- 4 (67%) patients could stand (3 patients could stand unaided and 1 patient could stand with support), and
- 3 (50%) patients could walk independently.
All 6 patients were alive at 12 months without permanent ventilation. The safety profile for pre-symptomatic patients is consistent with the safety profile for symptomatic SMA patients treated with Evrysdi® in clinical trials.
Finally, and as shared previously, the interim (preliminary) data from the RAINBOWFISH study have also been submitted to the European Medicines Agency (EMA) as part of an application to extend risdiplam's currently approved indication in Europe for patients younger than 2 months old. This application was accepted by the EMA on 17th January, which means that EMA’s Committee for Medicinal Products for Human Use (CHMP) is now conducting a formal scientific evaluation.
A positive decision by the CHMP would expand the approved use of risdiplam to infants with SMA across all 27 European Union member states, as well as Iceland, Norway and Liechtenstein.