The Court disagreed with the FDA, holding that
the FDA’s requirement that a generic manufacturer’s patent challenge give rise to litigation as a condition of retaining exclusivity when a patent is delisted is inconsistent with the Act, which provides that the first generic manufacturer to file an approved application is entitled to exclusivity when it either begins commercially to market its generic drug or is successful in patent litigation.The six month exclusivity period is lucrative for generic manufacturers particularly in the case of a blockbuster drug like Zocor. Merck continues to sell brand name Zocor at a price that is lower than that charged before its patent expired. Merck also has made a contract with Dr. Reddy's Laboratories Ltd. of India to sell a so-called authorized generic version of Zocor.
A copy of the opinion in Ranbaxy Laboratories v. Leavitt, No. 06-5154 is available here.