Drug maker Gilead Sciences has said US health regulators have delayed a decision on whether to approve Truvada as the first pill that prevents HIV infection.
Gilead Sciences said the Food and Drug Administration (FDA) would take an additional three months to review its drug application, after the California company submitted additional materials to the agency earlier this month.
In May, a panel of experts recommended approval of the daily pill for healthy people at high risk of contracting HIV. The group's vote is non-binding, but the FDA often follows its advice.
Gilead said it submitted updated details on its safety materials for patients and doctors using Truvada.
The FDA typically extends its reviews after receiving such information.