The safety profile of risdiplam (Evrysdi®) used by patients with spinal muscular atrophy (SMA) in an expanded access program (EAP) was found to be similar to that shown in pivotal risdiplam trials, according to a new study published in the Annals of Clinical and Translational Neurology.

The study enrolled 155 pediatric and adult patients with type 1 or 2 SMA who were ineligible for approved SMA treatments. It assessed the safety of risdiplam over a median treatment duration of 4.8 months.

“Prior to the approval of risdiplam by the [US Food and Drug Administration (FDA)] in August 2020, an expanded access program was opened to provide access to risdiplam for eligible individuals with SMA in the US who, at the time, could not receive other [disease-modifying therapies], were ineligible for clinical trial participation, or were at risk of lack/loss of treatment efficacy of the current therapy,” the authors wrote.

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“The program provided an opportunity to collect additional risdiplam safety information beyond the pivotal trials. Overall, safety results in this diverse population were similar to those in previous studies, and no new safety signals were observed.”

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The most common adverse events (AEs) were diarrhea, pyrexia, and upper respiratory tract infection, as has been found in clinical trials of risdiplam. However, just 3 patients withdrew from the EAP due to an AE.

The EAP provided access to risdiplam in patients who otherwise would not have been able to be treated for SMA, highlighting the unmet need for treatment of this condition.

“These safety data provide further support for the use of risdiplam in the treatment of adult and pediatric patients with SMA,” the study authors wrote.


Kwon JM, Arya K, Kuntz N, et al. An expanded access program of risdiplam for patients with type 1 or 2 spinal muscular atrophy. Ann Clin Transl Neurol. Published online May 14, 2022. doi:10.1002/acn3.51560