Indian drugmaker Ranbaxy Laboratories Ltd said the U.S. Food and Drug Administration has revoked the previously granted tentative approvals to the company for launching the first cheaper generic forms of AstraZeneca's heartburn drug Nexium and Roche's antiviral Valcyte. The FDA wrote to Ranbaxy saying that while there were no data integrity issues related to the company's filings for these two drugs, the agency's original decisions granting approval were "in error," the company said on Thursday. Ranbaxy added that it has lost its six-months exclusivity on launching a generic version of Valcyte. "Ranbaxy is disappointed with this development and is actively evaluating all available options to preserve its rights," the company said in a statement. (Reuters)