The first oral treatment option
Risdiplam is the third SMA treatment approved by the Food and Drug Administration, “and has the potential to expand access to treatment for people with SMA,” commented Mary Schroth, MD, chief medical officer of Cure SMA, who was not involved in the research. She added that the exploratory outcomes of the FIREFISH study represent “a significant milestone for symptomatic infants with SMA type 1.”
While the other two approved SMA therapies – nusinersen and onasemnogene abeparvovec – have led to improvements in survival and motor function, they are administered either intrathecally or intravenously respectively, while risdiplam is an oral therapy.
Dr. Schroth says there are currently no studies comparing the different SMA treatments. “Cure SMA is actively collecting real-world experience with risdiplam and other SMA treatments through multiple pathways,” she said. “Every individual and family, in collaboration with their health care provider, should discuss SMA treatments and make the decision that is best for them.”
Writing in Neuroscience Insights, a few months after risdiplam’s FDA approval last summer, Ravindra N. Singh MD, from the department of biomedical sciences, Iowa State University, Ames, wrote that, as an orally deliverable small molecule, risdiplam “is a major advancement for the treatment of SMA.”
Now, the FIREFISH study is “welcome news,” he said in an interview. “The results look promising so far,” he added. “I am cautiously optimistic that risdiplam would prove to be a viable alternative to the currently available invasive approaches. However, long-term studies (with appropriate age and sex-matched cohorts) would be needed to fully rule out the potential side effects of the repeated administrations.”
The therapy “is particularly great news for a group of SMA patients that might have tolerability and/or immune response concerns when it comes to nusinersen and gene therapy,” he noted in his article, adding that the ability to store and ship the drug at ambient temperatures, as well as its comparatively low cost are added benefits.
The study was supported by F. Hoffmann–La Roche. Dr. Baranello disclosed that he serves as a consultant for AveXis, F. Hoffmann-La Roche, and Sarepta Therapeutics, as well as PTC Therapeutics, from whom he also receives speaker honoraria. Dr. Schroth disclosed no personal conflicts and is an employee of Cure SMA. Cure SMA works to develop strategic relationships with corporate partners with the goal of working together to lead the way to a world without SMA. In advancement of that mission, Cure SMA has received funding from multiple corporate sources including Aetna, Biogen, Blue Cross Blue Shield, Genentech, Kaiser Permanente, Novartis Gene Therapies, Scholar Rock, and United HealthCare. Cure SMA has no financial stake in any treatment and does not advocate for one treatment over another. Dr. Singh disclosed that Spinraza (Nusinersen), the first FDA-approved SMA drug, is based on the target (US patent # 7,838,657) that was discovered in his former laboratory at UMASS Medical School, Worcester, Mass.