Shares of Progenics Pharmaceuticals (PGNX) - Get Report rose 6% to $10.20 in premarket trading on Thursday. The New York company will join the S&P SmallCap 600 effective Feb. 21. Earlier this week, Progenics said it started a phase 1 study of 1095 for the treatment of metastatic prostate cancer.  

Meanwhile, shares of Alexion Pharmaceuticals (ALXN) - Get Report were up 4.6% to $138.05. The New Haven, Conn.-based company on Thursday reported fourth quarter and full-year 2016 results.

Other biotech stock movers include BioCryst Pharmaceuticals (BCRX) - Get Report , whose shares were up 5% to $6.47.