FDA chief says Avandia data still inconsistent

WASHINGTON (Reuters) - All studies to date provide inconsistent data about the potential contribution of GlaxoSmithKline Plc's diabetes drug Avandia to heart attack risk, the head of the Food and Drug Administration said in testimony prepared for a congressional hearing on Wednesday.

Dr. Andrew von Eschenbach also told lawmakers the agency has asked for a stronger "black box" warning about the risk of congestive heart failure for some patients on the labels of Avandia and rival drug Actos, made by Takeda Pharmaceutical Co. Ltd. Both drugs already have a less prominent warning about that issue.