Salix Pharmaceuticals Ltd said U.S. health regulators have extended the review date by three months for its experimental pill for HIV therapy-related diarrhea.

The U.S. Food and Drug Administration was to review the drug, crofelemer, on June 5.

The FDA has notified Salix that it requires additional time for a full review but did not seek any additional studies, the company said in a statement.

Salix holds the North American and European rights to the drug.

India's Glenmark Pharmaceuticals Ltd holds the rights to sell the drug in 140 other countries but is in arbitration to retain them after initial developer U.S.-based Napo Pharamaceuticals Inc terminated their agreement in November.

Shares of Salix Pharmaceuticals were trading down about 3 percent at $49.28 on Monday afternoon trade on the Nasdaq.