WASHINGTON (AP) — Drugmaker Vivus Inc. said Monday that regulators will take another three months to make a decision on its closely-watched obesity drug Qnexa, which could become the first new prescription drug to reach the market in more than a decade.

Vivus said the Food and Drug Administration pushed back its decision date to July 17 to review a new drug safety plan submitted by the company. Previously the agency was scheduled to make a decision by April 17. Vivus said the three-month extension is standard when companies submit additional risk management information for a drug.

The FDA has rejected three experimental drugs for obesity in the last three years, including Qnexa, raising questions about whether any new weight loss drugs can win approval. The agency has not approved a new prescription diet pill since 1999.