Updated

U.S. drug reviewers have raised questions about safety issues with an experimental Merck & Co hepatitis drug, including anemia and reports of psychiatric problems, documents released on Monday said.

A main issue for discussion is the increase in anemia in patients treated with boceprevir, Food and Drug Administration staff said in a summary prepared for an advisory panel that will review the drug on Wednesday.

Another "potential safety signal" is a higher number of patients who reported psychiatric symptoms such as suicidal and homicidal thoughts, the FDA reviewers said. But they added it was "difficult to make any meaningful clinical conclusions" about the cases.

FDA staff said they generally agreed with Merck's assessment that boceprevir was effective in treating hepatitis C, a disease that destroys the liver. Analysts project the drug could generate blockbuster sales if approved.