Over the past decade, three drugs—Biogen’s Spinraza, Roche’s Evrysdi, and Novartis’ gene therapy Zolgensma—have transformed spinal muscular atrophy (SMA) treatment. However, unmet needs remain. Biogen, the first to receive SMA approval in 2016, is addressing this with a higher dose of Spinraza (nusinersen).
In Biogen’s phase 2/3 DEVOTE study, the higher dose significantly improved motor function in treatment-naïve SMA infants, meeting its primary endpoint. This regimen involves two initial 50 mg doses, followed by 28 mg maintenance every four months. Compared to an untreated control group from the earlier ENDEAR study, this high-dose regimen showed superior motor function outcomes, with a favourable trend compared to the standard 12 mg dose.
Biogen plans to seek regulatory approval for this new regimen. Adverse events were consistent with known SMA and Spinraza profiles, with fewer serious events in the high-dose group (60%) compared to the standard dose group (72%).
Spinraza, designed to increase survival motor neuron (SMN) protein levels critical for motor neuron function, faces competition from Novartis’ Zolgensma and Roche’s Evrysdi.
