Drug developer Biogen reported a 11.4 percent rise in quarterly revenue as sales of key drugs Tecfidera and Spinraza climbed, albeit at a weaker-than-expected pace.
The company's top-earning multiple sclerosis drug Tecfidera brought in a revenue of $987 million in the quarter, falling short of analyst estimate of $1.02 billion.
Sales of spinal muscular atrophy treatment Spinraza were $364 million, missing estimate of $381.55 million.
Net income attributable to shareholders rose to $1.17 billion in the first quarter ended March 31, or $5.54 per share, from $747.6 million or $3.46 a share, a year earlier.
Revenue rose 11.4 percent to $3.13 billion.
Shares of the company were marginally down at $258.79 in premarket trading.