Biogen Wins FDA Approval for High-Dose Version of Spinraza

US regulators have approved a high-dose version of Biogen Inc.’s drug for a rare muscle disorder, giving the company a boost as it competes with a gene therapy from Novartis AG.

The Food and Drug Administration has cleared the new version of Spinraza for spinal muscular atrophy, or SMA, a rare inherited condition that hobbles production of a protein that muscles need to function properly. The severe form of the disease is fatal by the age of two if left untreated.