Auxilium Pharms., Inc. v. Upsher-Smith Laboratories, Inc.

Case Name: Auxilium Pharms., Inc. v. Upsher-Smith Laboratories, Inc., Civ. No. 13-148-SLR, 2013 U.S. Dist. LEXIS 170770 (D. Del. Dec. 4, 2013) (Robinson, J.) (Plaintiffs cannot use the doctrine of equivalents to reach beyond what is claimed and described in the patents-in-suit, therefore summary judgment of non-infringement was appropriate.) 

Drug Product and Patent(s)-in-Suit: Testim® (testosterone); U.S. Patent Nos. 7,320,968 (“the ’968 patent”), 7,608,605 (“the ’605 patent”), 7,608,606 (“the ’606 patent”), 7,608,607 (“the ’607 patent”), 7,608,608 (“the ’608 patent”), 7,608,609 (“the ’609 patent”), 7,608,610 (“the ’610 patent”), 7,935,690 (“the ’690 patent”), 8,063,029 (“the ’029 patent”), and 8,178,518 (“the ’518 patent”)

Nature of the Case and Issue(s) Presented: On January 28, 2013, Plaintiffs filed an infringement action against Upsher-Smith alleging infringement of the patents-in-suit. Upsher-Smith filed a motion for summary judgment of non-infringement. The parties agreed that Upsher-Smith’s formulation did not literally infringe the asserted claims of the patents-in-suit, as each of the patents required a specific formulation with specific ingredients, not contained in Upsher-Smith’s ANDA product formulation. Plaintiffs argued that Upsher-Smith’s formulation infringed under the doctrine of equivalents. The Court disagreed. Starting with the premise that the claims and the specification of a patent serve an important public notice function, the court found that plaintiffs cannot use the doctrine of equivalents to reach beyond what is claimed and described in the patents-in-suit, particularly where the specification and prosecution history included statements and arguments distinguishing over the alleged equivalent components.

Why Upsher-Smith Prevailed:  The court rejected plaintiffs’ assertion that its narrow claims directed to specific cyclic enhancers should cover Upsher-Smith’s ANDA product formulation, which uses three straight chain enhancers. Each of the patents-in-suit claims priority to the same application which issued as the ’968 patent. All of the patents, except for the ’518 patent, claim a method for treating hypogonadism using a pharmaceutical composition that contains a specific formulation of testosterone gel. The ’518 patent claims the composition. The claimed compositions each contain an “enhancer” which is “a material which is capable of increasing the rate of passage of androgen through the skin or other body membrane.” The court found that the claims of the patents-in-suit focus narrowly on one or a subset of five cyclic “Hsieh” enhancers. The specification describes the family of cyclic “Hsieh” enhancers and recites the cyclic structures. Plaintiffs argued that they could rely on the doctrine of equivalents because they contended that they can prove “Hsieh” enhancers are equivalent to straight chain enhancers. After reviewing the specification and the prosecution history, the court rejected this argument because a large number of enhancers were known in the art and many were referenced in the specification. The court found that the patentees specifically discussed the straight chain enhancers in the specification and differentiated the claimed cyclic “Hsieh” enhancers. The court further found that the patentees argued during prosecution that their invention was not obvious in light of straight chain enhancers, because of the differences between the types of enhancers and the superiority of the claimed “Hsieh” enhancer compositions. According to the court, those enhancers were foreseeable alternatives to “Hsieh” enhancers and a competitor would reasonably believe the patentee had surrendered enhancers other than “Hsieh” enhancers. Thus, the court granted Upsher-Smith’s motion for summary judgment of non-infringement of the patents-in-suit.