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Federal Circuit Again Invalidates Prozac® Patent

99-1262
May 30, 2001

Decision icon Decision

Last Month at the Federal Circuit - June 2001

Judges: Gajarsa (author), Mayer, and Friedman

In Eli Lilly & Co. v. Barr Laboratories, Inc., No. 99-1262 (Fed. Cir. May 30, 2001), a Federal Circuit panel, for the second time, affirmed the district court’s SJ that the patents-in-suit were not invalid for failure to disclose the best mode of carrying out the invention, but reversed the district court’s holding that one of the asserted claims was not invalid for double patenting.

Eli Lilly and Company (“Lilly”) charged Barr Laboratories, Inc. (“Barr”) with infringement of its U.S. Patent Nos. 4,314,081 (“the ‘081 patent”) and 4,626,549 (“the ‘549 patent”) by Barr’s filing of an Abbreviated New Drug Application with the Food and Drug Administration seeking approval to market a generic version ofLilly’s Prozac®. The ‘081 patent claims the compound fluoxetine hydrochloride, the active ingredient in Lilly’s Prozac® pharmaceutical. The ‘549 patent claims a method of blocking the uptake of serotonin by brain neurons in animals by administering the compound fluoxetine hydrochloride. The district court had granted Lilly’s motions for SJ that the patents-in-suit were not invalid for failure to disclose the best mode of practicing the invention and were not invalid for double patenting.

On August 9, 2000, the Federal Circuit affirmed the district court’s holding that the patents-in-suit were not invalid for violating the best-mode requirement, but reversed with respect to double patenting, finding claim 7 of the ‘549 patent invalid. In response to Lilly’s petition for rehearing or rehearing en banc, the Federal Circuit, acting en banc, vacated the panel’s earlier decision and reassigned the opinion to the panel for revision of the double-patenting section. In its second opinion, the panel again held that both the ‘081 patent  claim and the ‘549 patent claim were invalid, but on a new and different legal basis.

On appeal, Barr submitted two bases for its allegation that Lilly had violated the best-mode requirement. First, Barr argued that Lilly had violated the best-mode requirement by failing to disclose the preferred method of synthesizing the starting material used to make fluoxetine hydrochloride. Second, Barr contended that Lilly had failed to disclose the preferred recrystallization solvent used to remove impurities during the manufacturing process. With regard to the method of synthesizing the starting material used to manufacture fluoxetine hydrochloride, the Federal Circuit held that since neither of the patents-in-suit claimed the starting material or a method of synthesizing the starting material, and that the method of making the starting material was not necessary to carry out the claimed invention, Lilly was not required to disclose its preferred method. With regard to the recrystallization solvent, the Federal Circuit held that the recrystallization solvent was both an unclaimed element as well as a routine detail and, thus, did not need to be disclosed.

Turning to the question of obviousness-type double patenting, the panel again held claim 7 of the ‘549 patent invalid, but this time in view of claim 1 of U.S. Patent No. 4,590,213 (“the ‘213 patent”). Claim 1 of the ‘213 patent claims a method for treating activity in a human by administering an effective amount of fluoxetine or a pharmaceutically acceptable salt thereof.

The Court concluded that serotonin uptake inhibition is an inherent property of the administration of fluoxetine hydrochloride. Therefore, the only difference between the two claims is that the ‘213 patent claim is directed to humans while the ‘549 patent claim is directed to animals. Because humans are a species of the animal genus, the Court found no patentable distinction between the claims and held claim 7 of the ‘549 patent invalid for double patenting.