Shares of Jazz Pharmaceuticals plc
JAZZ,
+0.18%
gained 3.5% in premarket trading on Thursday, the day after the Food and Drug Administration said it had approved the company's acute lymphocytic leukemia treatment Rylaze. The therapy is an orphan drug, meaning it affects less than 200,000 people in the U.S. The drug is expected to be available later this month; a spokesperson for the company said that's when the price will be made public. Jazz's stock is up 7.6% so far this year, while the broader S&P 500
SPX,
+0.75%
is up 14.4%.