Roche’s Evrysdi (risdiplam) granted FDA priority review for treatment of pre-symptomatic babies under 2 months of age with spinal muscular atrophy (SMA)

Roche announced that the U.S. Food and Drug Administration (FDA) has granted priority review of a supplemental new drug application (sNDA) for the use of Evrysdi (risdiplam) to treat pre-symptomatic babies under two months of age with spinal muscular atrophy (SMA). The sNDA submission incorporates interim data from the RAINBOWFISH study, which shows the majority of pre-symptomatic babies treated with Evrysdi achieved key milestones such as sitting, standing, walking and maintained the ability to swallow following 12 months of treatment.

“Treating very young babies with Evrysdi before SMA symptoms arise may help them to achieve milestones such as standing and walking within timeframes typical of healthy infants,” said Levi Garraway, M.D., Ph. D., Roche’s Chief Medical Officer and Head of Global Product Development. “Extending treatment access for the youngest members of the SMA community is crucial and we look forward to working with the FDA on this application.”

Evrysdi is designed to treat SMA by increasing and sustaining production of the survival motor neuron (SMN) protein in the central nervous system (CNS) and peripheral tissues. SMN protein is found throughout the body and is critical for maintaining healthy motor neurons and movement. Evrysdi’s existing FDA label is for the treatment of SMA in adults, children and babies two months and older. If approved, Evrysdi would be the first medicine administered at-home for pre-symptomatic babies with SMA.

Initial interim data from the RAINBOWFISH study, presented at the World Muscle Society (WMS) Virtual Congress 2021, showed that of the babies included in the interim efficacy analysis, all (5/5), maintained the ability to swallow and were able to feed exclusively orally after 12 months of treatment. Eighty per cent (4/5) treated with Evrysdi for at least 12 months achieved milestones such as standing and walking independently within World Health Organization windows for healthy children. All participants (n=5) met HINE-2* motor milestones of head control, sitting upright, rolling and crawling after 12 months of treatment with Evrysdi.

No treatment related serious adverse events were reported in any of the babies treated with Evrysdi through the interim safety analysis period (n=12). Four treatment emergent adverse events were reported, and all were resolved or were resolving with ongoing treatment with Evrysdi. The most common adverse events (AEs) were nasal congestion (33%), cough (25%), teething (25%), vomiting (25%), eczema (17%), abdominal pain (17%), diarrhoea (17%), gastroenteritis (17%), papule (17%) and pyrexia (17%). The AEs were reflective of the age of the babies rather than the underlying SMA. The RAINBOWFISH study is currently recruiting.

The latest results from the RAINBOWFISH study will be presented at the Muscular Dystrophy Association (MDA) Clinical and Scientific Conference in March 2022.

Roche leads the clinical development of Evrysdi as part of a collaboration with the SMA Foundation and PTC Therapeutics.

*Hammersmith Infant Neurological Examination, Section 2