Ionis Pharmaceuticals Inc. (IONS)/Biogen Inc. (BIIB) have sought FDA approval for a higher dose regimen of Spinraza for spinal muscular atrophy, and a decision is due on September 22, 2025. Spinraza was approved in the U.S. for the treatment of spinal muscular atrophy (SMA) in pediatric and adult patients at a recommended dose of 12mg in December 2016.The currently approved 12 mg regimen is comprised of four loading doses administered over approximately 60 days, followed by maintenance dosing every four months thereafter.The proposed higher dose regimen of Spinraza comprises a more rapid loading regimen, two 50 mg doses 14 days apart, and a higher maintenance regimen, 28 mg, every 4 months.According to the company, the higher dose regimen can enable meaningful clinical benefits while maintaining a safety profile broadly consistent with the approved 12 mg regimen.Biogen acquired the global rights to develop, manufacture, and commercialize Spinraza from Ionis Pharmaceuticals in August 2016 and has since then been responsible for all development, regulatory, and commercialization activities and costs for Spinraza. IONS closed Wednesday’s (Aug.27, 2025) trading at $42.69, down 1.26%.