Genentech today touted two-year data evaluating the use of its Evrysdi therapeutic in infants with symptomatic Type 1 spinal muscular atrophy (SMA).
South San Francisco, Calif.-based Genentech’s Firefish Phase 2/3 global study for Evrysdi (risdiplam) in infants between 1-7 months old showed that the orally administered (liquid or feeding tube) therapeutic continued to improve motor function between months 12 and 24, including the ability to sit without support, according to a news release.
Additionally, Evrysdi continued to improve survival and the ability to feed orally while reducing the need for permanent ventilation, Genentech said. The drug was consistent with its established safety profile, too. Evrysdi has been FDA approved for treating SMA in adults and children two months of age and older since August 2020 and is approved in 39 countries overall.
The primary endpoint of the study was the percentage of infants able to sit without support for at least five seconds at month 12. After demonstrating improved ability to sit without support at one year, 24-month data showed continued improvements, with 61% (25/41) vs. 29% (12/41) able to sit without support for at least five seconds and 44% (18/41) vs. 17% (7/41) able to sit without support for at least 30 seconds.
On top of that, 92% of infants treated with Evrysdi maintained the ability to feed orally (35/38) at month 24, while exploratory data showed similar maintenance in the ability to swallow (95%; 36/38). Genentech said that the natural course of the disease typically leads to infants with Type 1 SMA who are older than 12 months requiring feeding support.
Among the 41 infants treated, 38 were alive after 24 months, while 83% (34/41) were alive and free from permanent ventilation after 24 months. No new deaths occurred between months 12 and 24.
The adverse events observed were consistent with previous studies, as the most common adverse events included upper respiratory tract infection (54%), pneumonia (46%), pyrexia (44%), constipation (29%), nasopharyngitis (17%), bronchitis (15%), diarrhea (15%) and rhinitis (12%).
Serious pneumonia incidence declined by approximately three times between the first and second 12-month periods of the trial. Still the most common serious adverse events were pneumonia (39%) and respiratory distress (7%). There were no drug-related adverse events leading to withdrawal or treatment discontinuation.
“These data highlight the real-world impact of this transformative medicine in babies with the most severe form of SMA. For example, all infants alive after 24 months of treatment were able to swallow which can help them to feed orally rather than through a tube,” Genentech CMO & head of global product development Dr. Levi Garraway said in the release. “These results increase our understanding of how this first-of-its-kind treatment can extend the lives of babies with Type 1 SMA, providing much needed hope for their families.”