Shares of Alexion Pharmaceuticals Inc. (ALXN) - Get Report were up 0.8% to $122.10 in premarket trading on Friday, July 7, after ending Thursday's trading session at $121.09, down 3%. Bloomberg reported on Thursday that the U.S. Department of Health and Human Services' Office of Inspector General was investigating Alexion in connection with a probe by the U.S. Attorney's Office in Massachusetts of the company's support for charities that help Medicare patients.

In other news, Endo International plc  (ENDP) - Get Reportsaid Thursday it has opted to voluntarily pull its opioid pain medication, Opana ER, from the market and expects to post a pre-tax impairment charge of about $20 million in the second quarter of 2017. The move came after the U.S. Food and Drug Administration in June requested that Endo remove reformulated Opana ER from the market due to the agency's concern that "the benefits of the drug may no longer outweigh its risks."

Endo shares closed at $11.17 on Thursday, down 1.9%, and were unchanged ahead of the open on Friday.

Biotech movers in premarket trading include Arena Pharmaceuticals Inc. (ARNA) - Get Report , up 4.8% to $18.86 and Novavax Inc. (NVAX) - Get Report , up 3.4% to $1.22.

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