Last week, the United States Court of Appeals for the Federal Circuit issued an opinion in Eli Lilly and Company v. Hospira, Inc., Nos. 18-2126, 18-2127 (August 9, 2019). The panel reversed the district court’s literal infringement decision but affirmed the finding of infringement under the doctrine of equivalents.
The patent is directed to an improved method of treating certain types of cancer using pemetrexed disodium with a methylmalonic acid lowering agent and folic acid. The patent owner, Eli Lilly, sued Hospira and Dr. Reddy’s in two separate suits in under the Hatch-Waxman Act. In the Dr. Reddy’s case, the district court construed the third step of method claim 1, “administration of pemetrexed disodium” to mean “liquid administration of pemetrexed disodium,” which “is accomplished by dissolving the solid compound pemetrexed disodium into solution.” Following a bench trial, the court found infringement under the doctrine of equivalents. The court rejected Dr. Reddy’s argument that prosecution history estoppel barred application of the doctrine of equivalents, finding the reason for Eli Lilly’s amendment was to distinguish other antifolates and was therefore only tangential to pemetrexed ditromethamine. In the Hospira case, Eli Lilly asserted literal and equivalents infringement. Following similar reasoning as the Dr. Reddy’s case, the district court found literal and equivalents infringement.
The Federal Circuit reversed the literal infringement determination. The court explained “that to literally practice the ‘administration of pemetrexed disodium’ step under the district court’s claim construction, the pemetrexed disodium salt must be itself administered.” But the panel affirmed the infringement under the doctrine of equivalents. The parties agreed that the amendment changing “an antifolate” to “pemetrexed disodium” was both narrowing and made for a substantial reason relating to patentability. But Eli Lilly argued that the rationale of its amendment “[bore] no more than a tangential relation to the equivalent in question.” Specifically, Eli Lilly argued that the reason for its amendment was to “distinguish pemetrexed from antifolates generally and that the different salt type is a merely tangential change with no consequence for pemetrexed’s administration or mechanism of action within the body.” The Federal Circuit agreed. The court also found the disclosure-dedication rule did not apply because the patent does not disclose methods of treatment using pemetrexed ditromethamine, so Eli Lilly could not have dedicated it to the public. The court concluded that the district court did not clearly err in finding infringement under the doctrine of equivalents.