Key Takeaways:
The Food and Drug Administration granted Breakthrough Therapy Designation to Biogen Inc.'s salanersen for spinal muscular atrophy, a status that could speed development of the once-yearly treatment for the rare genetic neuromuscular disease.
"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," Diana Castro, M.D., of the Neurology Rare Disease Center in Flower Mound, Texas, said.
The designation is based on a Phase 1b study of 24 children aged six months to 12 years who received either 40 mg or 80 mg of salanersen. Among participants with elevated baseline neurofilament light chain, a marker of ongoing neurodegeneration, levels fell 75 percent at six months and were sustained through follow-up. Twelve of the 24 children achieved at least one new World Health Organization motor milestone, and all maintained milestones documented at baseline. The 80 mg dose will be evaluated in Phase 3 studies. Salanersen was generally well-tolerated at both doses, with most adverse events mild to moderate.
Salanersen is an investigational antisense oligonucleotide designed to correct splicing of SMN2 pre-mRNA to increase production of SMN protein. Its new chemistry enables high potency with once-yearly intrathecal dosing. Biogen licensed global development, manufacturing and commercialization rights from Ionis Pharmaceuticals Inc., which discovered the drug. The treatment is a potential successor to Biogen's Spinraza, which generated about $1.55 billion in worldwide sales last year and requires dosing three times a year.
The Phase 3 program includes three global studies: STELLAR-1, STELLAR-2 and SOLAR, evaluating 80 mg administered once-yearly across a broad spectrum of SMA patients. SMA affects approximately one in 10,000 live births and is a leading genetic cause of infant death, characterized by progressive muscle atrophy and weakness due to loss of motor neurons.
"This designation reflects the FDA's continued commitment to SMA and its recognition of the potential meaningful impact salanersen may offer," Kenneth Hobby, President of Cure SMA, said. "It affirms what our SMA community has recently communicated to the agency: urgent, unmet needs remain, and promising therapies deserve a rapid path forward."
The breakthrough designation shows the FDA's view that salanersen may offer substantial improvement over available therapies, including gene therapy. Investors will watch for enrollment data from the Phase 3 program, which will determine whether the once-yearly dosing advantage can establish salanersen as a competitive option in the evolving SMA treatment market.
This article is for informational purposes only and does not constitute investment advice.
