Argenx (ARGX) reported Q1 earnings Thursday of $2.58 per diluted share, swinging from a loss of $1.04 a year earlier.

Analysts polled by FactSet expected EPS of $2.41.

Operating income for the quarter ended March 31 was $807.4 million compared with $412.5 million a year earlier.

Analysts surveyed by FactSet expected $817.6 million.

Shares of the company were down nearly 13% in recent premarket activity.