(Reuters) - Biogen Inc’s (BIIB.O) shares dived 8 percent on Tuesday after U.S. sales of Spinraza, a potential blockbuster drug it is banking on to offset slowing sales of multiple sclerosis drugs, fell short of Wall Street estimates in the latest quarter.
Spinraza, a spinal muscular atrophy (SMA) drug, generated $197.6 million in U.S. sales in the third quarter, lagging analysts’ average estimate of $242 million, according to broker SunTrust Robinson Humphrey.
The shortfall was due to the dosing regimen of the drug, which was approved in December, as fewer patients took the more frequent “loading”, or initial, dose, Biogen Chief Executive Michel Vounatsos said on an earnings call.
The treatment starts with four loading doses, followed by maintenance doses once every four months. The first three loading doses are taken at 14 day intervals and the last 30 days after the third, meaning all four can be taken in one quarter.
Many patients who took the loading doses in the second quarter did not get a loading dose in the latest quarter and instead took a maintenance dose, Vounatsos said.
He estimated that the impact of the dosing schedule likely means that Spinraza’s revenue growth in the current quarter would be driven mostly by non-U.S. markets.
Spinraza costs $750,000 for the first year and $375,000 a year after that to treat SMA, a rare disorder that is the leading genetic cause of death in infants.
Biogen is banking on Spinraza to offset slowing growth of its bestselling multiple sclerosis (MS) drug, Tecfidera, which is facing stiff competition from Roche AG’s (ROG.S) Ocrevus and Sanofi SA’s (SASY.PA) Aubagio.
Vounatsos estimated Ocrevus would have a “modest net negative impact” on Biogen’s MS portfolio, which also includes Tysabri, for the rest of 2017.
Separately, Biogen said it would pay Neuimmune Holding AG $150 million to reduce the royalty payment on potential sales of its experimental Alzheimer’s disease treatment, aducanumab. The move would improve Biogen’s economics in its Alzheimer’s pipeline, analysts said.
Tecfidera’s sales dipped 3.5 percent to $1.07 billion in the quarter, and also missed analysts’ estimates of $1.09 billion.
Biogen’s profit rose 18.7 percent to $1.23 billion in the quarter ended Sept. 30. Excluding one-time items, it earned $6.31 per share.
Total revenue climbed 4.1 percent to $3.08 billion.
Analysts on average had estimated a profit of $5.73 per share and revenue of $3.04 billion, according to Thomson Reuters I/B/E/S.
Biogen’s shares fell as much as 8.1 percent, before easing to trade 3.3 percent lower at $317.84.
Reporting by Akankshita Mukhopadhyay and Manas Mishra in Bengaluru; Editing by Martina D'Couto, Sai Sachin Ravikumar and Savio D'Souza