Biogen’s Salanersen Receives FDA Breakthrough Therapy Designation for Spinal Muscular Atrophy

Designation is supported by an exploratory analysis from the Phase 1b study showing that some children with SMA previously treated with gene therapy who had suboptimal clinical status experienced slowing of neurodegeneration and clinically meaningful improvements in motor function following initiation of salanersen Salanersen is an investigational antisense oligonucleotide dosed once-yearly with the potential to be a meaningful therapy in the future SMA treatment landscape CAMBRIDGE, Mass., June 04, 2026 (GLOBE NEWSWIRE) -- Biogen Inc. (Nasdaq: BIIB) announced today that the U.S. Food and Drug Administration (FDA) has granted salanersen Breakthrough Therapy Designation for the treatment of spinal muscular atrophy (SMA). Breakthrough Therapy designation is a process designed to expedite the development and review of drugs that are intended to treat a serious condition, and preliminary clinical evidence indicates that the drug may demonstrate substantial improvement over available therapy on a clinically significant endpoint(s). Salanersen is an investigational novel antisense oligonucleotide (ASO) and has the potential to offer high efficacy in SMA with once-yearly dosing. “The FDA’s designation of salanersen as a breakthrough therapy recognizes that there is continued unmet need in spinal muscular atrophy, and there is more that can be done for people impacted by the disease,” said Diana Castro, M.D., of the Neurology Rare Disease Center in Flower Mound, Texas. “In the Phase 1b study of salanersen, we saw unexpected improvements on exploratory endpoints in children previously dosed with gene therapy who gained critical functions, such as sitting and walking, after receiving salanersen. We are excited about the potential of salanersen and eager to help advance the Phase 3 program.” The FDA’s decision is based on data from the Phase 1b study of salanersen, which were recently presented at the 2026 Muscular Dystrophy Association (MDA) Clinical & Scientific Conference and the 5th International Scientific Congress on SMA (SMA Europe 2026). After initiation of once-yearly salanersen in children with SMA who had a suboptimal response to prior gene therapy, clinically meaningful improvements in motor function were observed as well as slowing of neurodegeneration, as measured by reduced neurofilament levels. Salanersen was generally well-tolerated in the study. “This designation reflects the FDA's continued commitment to SMA and its recognition of the potential meaningful impact salanersen may offer,” said Kenneth Hobby, President of Cure SMA. “It affirms what our SMA community has recently communicated to the agency: urgent, unmet needs remain, and promising therapies deserve a rapid path forward.” “This designation reflects the FDA’s determination that salanersen has the potential to demonstrate substantial improvement over available therapies,” said Stephanie Fradette, Pharm.D., Head of the Rare Neurology Development Unit at Biogen. “This is a significant milestone for our SMA portfolio as we advance the Phase 3 studies designed to establish the role of salanersen in the future SMA treatment landscape.” The salanersen Phase 3 program consists of three global studies: STELLAR-1 (recruiting), an open-label study, will evaluate the effects of salanersen in young (under 6 weeks old), treatment-naïve and clinically presymptomatic infants with a genetic diagnosis of SMA SOLAR (recruiting), an open-label study, will evaluate the effects of salanersen in teens and adults (aged 15–60 years) with SMA who are either treatment-naïve or previously treated with risdiplam STELLAR-2 (recruitment expected to begin in June 2026), a randomized, double-blind, sham-controlled study, will evaluate the effects of salanersen when initiated ~6 months after onasemnogene abeparvovec-xioi in infants with SMA who received presymptomatic treatment with gene therapy at 6 weeks of age or younger

The release as fetched from its publisher. biogen.com ↗