SIDELINED: Hepatitis C drug developer Idenix Pharmaceuticals Inc. said Thursday that the Food and Drug Administration halted trials of its most advanced drug because of concerns about its effects on patients’ hearts. Idenix said the move is related to side effects of a drug being developed by Bristol-Myers Squibb Co.

EARLIER CONCERN: On Aug. 1, Bristol-Myers said it had stopped giving an experimental drug to patients because one patient suffered heart failure.

PRODUCTS: Idenix is studying several hepatitis C treatments, but none have been approved yet. Shares of Idenix skidded more than 30 percent on the news.