Biogen announced it intends to initiate a global phase 3b study to investigate clinical outcomes and safety of a higher dose of Spinraza in patients with later onset spinal muscular atrophy previously treated with Evrysdi.
“We believe that lower drug exposure may be contributing to less-than-optimal treatment outcomes for some patients treated with Evrysdi [risdiplam, Roche],” Maha Radhakrishnan, MD, chief medical officer at Biogen, said in a press release. “The ASCEND study seeks to understand if [Spinraza (nusinersen, Biogen)] may address that unmet medical need and will help inform the future of [spinal muscular atrophy (SMA)] treatment, with the hope of improving patients’ outcomes for the long term.”
Data from prior studies suggested risdiplam exposure decreases as age and weight increase, with adults exhibiting an approximate 40% reduction in drug concentration compared with infants. Upon a patient reaching 20 kg, risdiplam’s dosing is capped at 5 mg.