Biogen to Advance Investigational Spinal Muscular Atrophy Asset to Registrational Studies Based on Positive Interim Phase 1 Results

Core Insights - Biogen Inc. announced topline results from the Phase 1 study of salanersen, an antisense oligonucleotide for spinal muscular atrophy (SMA), showing potential for high efficacy and once yearly dosing [1][5] - The Phase 1 study demonstrated substantial slowing of neurodegeneration and clinically meaningful improvements in motor function in children previously treated with gene therapy [2][5] - Biogen is engaging with global health authorities to advance salanersen into registrational studies based on encouraging Phase 1 data [4][5] Study Details - The Phase 1 study included two parts: a randomized placebo-controlled segment in healthy adults and an open-label segment in pediatric SMA participants who had previously received ZOLGENSMA [2][4] - Interim results from the open-label segment (n=24) indicated that both 40 mg and 80 mg doses of salanersen were well-tolerated, with a mean reduction in neurofilament light chain (NfL) of 70% at 6 months [2][4] - Exploratory data showed that half of the participants (4 out of 8) achieved new WHO motor milestones after receiving salanersen [3][4] Safety Profile - The safety profile of salanersen was generally well-tolerated, with most adverse events being mild to moderate, including pyrexia and upper respiratory tract infections [4][5] - The study's findings suggest that salanersen could address critical unmet needs in SMA treatment, building on Biogen's extensive experience in the field [3][5] Industry Context - SMA is a rare genetic neuromuscular disease affecting approximately 1 in 10,000 live births, characterized by progressive muscle atrophy and weakness [7][8] - SPINRAZA, another treatment for SMA, has been approved in over 71 countries and has treated more than 14,000 individuals worldwide, establishing a foundation of care in SMA [9][10]