Biogen Inc.'s Spinraza (nusinersen) is the company's big near-term growth driver, so the fact that sales of the drug for the life-threatening neurodegenerative condition spinal muscular atrophy (SMA) plateaued in the first quarter is worrying to investors. First quarter sales of Spinraza totaled $364m, roughly flat with the fourth quarter, Biogen reported April 24.
Nonetheless, Spinraza is on track to exceed 2017 revenues and become a blockbuster in its second full year on the market, no easy feat for any drug, let alone one targeting an ultra-rare condition
