AstraZeneca Loses Appeal against Dr. Reddy's for generic Prilosec

The U.S. Court of Appeals for the Federal Circuit has rejected AstraZeneca AB’s appeal of a lower court decision that Dr. Reddy's Laboratories Ltd.’s generic version of popular over-the-counter antacid Prilosec did not infringe (omeprazole delayed-release) capsules OTC did not infringe two US patents, Nos 5,900,424 and 5,690,960. Judge Colleen McMahon of the U.S. District Court for the Southern District of New York dismissed the suit in March, finding thatDr. Reddy’s drug used a different form of omeprazole magnesium (with less than 1 percent crystallinity), the primary ingredient in Prilosec, than that covered in the AstraZeneca patents.

Astra argued that Dr. Reddy’s had infringed its patents based on the doctrine of equivalents, but Judge McMahon deflated that line of reasoning, as well. “Because AstraZeneca argued to the USPTO that its patented product could be distinguished from other products because it was more than 70 percent crystalline, it cannot now argue that a product less than 70 percent crystalline infringes under the doctrine of equivalents,” she said.