Merck Shares Slip As 3 Blood-cancer Drug Studies Halted By FDA

Merck & Co. shares declined in the extended session Wednesday after the drugmaker said the Food and Drug Administration halted three clinical studies of a blood cancer drug because of deaths in the studies. Merck shares declined 1.3% to $63.30 after hours. The three studies involve Keytruda, which is being studied to treat blood cancer multiple myeloma patients. Merck said the FDA determined that the risks of the drug in the affected studies outweighed any potential benefits. Patients in the affected studies will no longer receive the drug. Merck said that other clinical studies for Keytruda were unaffected by the FDA clinical hold. Back in June, Merck announced that it was halting new patient enrollment in two of the studies.