Sales of a leading rare-disease drug produced by Biogen slipped a bit at the end of last year, amid intensifying competition.
The Cambridge pharmaceutical company said Thursday that revenue from Spinraza, which treats spinal muscular atrophy (SMA), totaled $543 million in the fourth quarter. That's down about 1% from the third quarter.
Swiss drug maker Novartis reported a day earlier that Zolgensma, an SMA therapy launched last June, grew sales by 16%, to $186 million, in the fourth quarter.
SMA attacks nerve cells that control basic movements, like breathing and swallowing. The disorder, which affects roughly one in every 6,000-10,000 babies born around the globe, is the leading genetic cause of death for infants.
The patient populations for Biogen's Spinraza and Novartis' Zolgensma are overlapping but not identical, meaning the rivals don't compete for every prescription.
With more than 10,000 patients on Spinraza, Biogen's share of the SMA market still dwarfs Novartis'. Approximately 200 patients have been treated with Zolgensma.
And despite the small decline in the fourth quarter, Spinraza revenue increased 22% in 2019, overall.
In a statement, Biogen Chief Executive Michel Vounatsos touted “continued strong worldwide growth for Spinraza.”
Still, with a record list price of $2.1 million, Zolgensma can generate revenue in bigger chunks than Spinraza, which bears a sticker price of $750,000 in the first year of treatment and $375,000 annually thereafter. Zolgensma is a one-time treatment, which accounts for much of its value.