Now poised for a speedy trip through the FDA’s regulatory review, Roche’s oral challenger in spinal muscular atrophy (SMA) could soon pick up a nod to cover all patients with the rare genetic disorder, regardless of their age.
Evrysdi, also known as risdiplam, snagged an FDA priority review for its use as a treatment in presymptomatic babies younger than two months old, Roche said Tuesday. The drug is already approved in the neuromuscular disease for adults, kids and babies two months and older. A green light in even younger infants would make Evrysdi the first medicine administered at home for presymptomatic babies with the debilitating disease, Roche said.
The decision leverages interim data from the drug’s RAINBOWFISH study, which showed most infants treated with Evrysdi for at least one year were able to sit, stand and walk within time frames typical of healthy babies, and the infants were also able to maintain swallowing, the Swiss drugmaker said.
“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,” Levi Garraway, M.D., Ph.D., chief medical officer and head of global product development at Roche, said in a statement. “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 works by boosting and sustaining production of the survival motor neuron (SMN) protein in the central nervous system and peripheral tissues. SMN protein is found throughout the body and is needed for the function of nerves that control muscles and movement, Roche explained.
Spinal muscular atrophy, meanwhile, is caused by a mutation of the survival motor neuron 1 (SMN1) gene, which results in patients not producing enough SMN protein. Without the protein, nerve cells cannot function correctly, which eventually results in muscle weakness. Different types of SMA can affect a person’s physical strength. Their ability to walk, eat or breathe can also be reduced or lost, Roche said.
Early interim data from RAINBOWFISH, which was presented at the World Muscle Society Virtual Congress 2021, showed that all five babies on Evrysdi maintained the ability to swallow and were able to feed completely orally after 12 months of treatment. And four of those five infants hit milestones like standing and walking independently within World Health Organization windows for healthy children.
All participants in the study met motor milestones of head control, sitting upright, rolling and crawling after one year on Roche’s drug.
Evrysdi’s safety looked good, too. Four treatment-emergent safety events cropped up during the trial, and “all were resolved or were resolving with ongoing treatment with Evrysdi,” Roche said in its release. Side effects that were most common included nasal congestion, cough, teething, vomiting, eczema, abdominal pain, diarrhea, papule and pyrexia. These events reflected the age of the babies involved in the study rather than their underlying disease, Roche noted.
Roche’s drug is the latest entrant in an SMA field populated by Biogen’s entrenched Spinraza and Novartis’ pricey gene therapy Zolgensma. Analysts have previously noted the drug’s competitive edge, which comes courtesy of its convenient oral dosing, broad label and lower price tag.
Approved in early August 2020, Evrysdi has represented an attractive option for many patients during the pandemic because it doesn’t require a visit to a treatment center.