Sun Pharm. Indus. v. Saptalis Pharm., LLC

Case Name: Sun Pharm. Indus. v. Saptalis Pharm., LLC, No. 18-648, 2019 U.S. Dist. LEXIS 102961 (D. Del. June 19, 2019) (Bryson, J.) 

Drug Product and Patent(s)-in-Suit: Riomet® (metformin HCl); U.S. Pat. No. 6,890,957 (“the ’957 patent”)

Nature of Case and Issue(s) Presented: Sun owned the ’957 patent, which recited a liquid pharmaceutical composition with (i) a therapeutically effective amount of metformin, (ii) a sweetener, (iii) a polyhydroxy alcohol in an amount of about 15% to about 55% by weight, (iv) a mineral acid and bicarbonate salt, and (v) a pharmaceutically acceptable liquid carrier. The parties raised two claim construction disputes.

Why Saptalis Prevailed. First, the court construed the term “about 15 to about 55%” to mean “approximately 15 to approximately 55%. Saptalis argued that because the patent contains separate claims for ranges that differ by only 5% at each end, a POSA would believe that the patentee viewed a weight variation of +5% to be significant. Saptalis further contended that the weight range recited in a sibling patent demonstrated that “the applicant knew how to claim amounts of polyhydroxy alcohol less than 15%, including as low as about 5%, but chose not to do so in the ’957 patent.” In response, Sun argued that Saptalis provided no support for its proposition that “about” denotes a strict numerical or percent variation. The court agreed, explaining that the term “about” should be given its ordinary and accepted meaning of “approximately.” The court further explained that the term “about” was repeatedly and consistently used throughout the written description and patent claims without reference to a particular weight range.

Next, the court found that a single ingredient could not satisfy both the “sweetener” and “polyhydroxy alcohol” limitations: Saptalis argued that (i) the sweetener and the polyhydroxy alcohol were separately recited in the asserted claims, (ii) some dependent claims adjusted the properties of either the sweetener or the polyhydroxy alcohol, but not both, (iii) it would be difficult for a single ingredient to fall within the concentration ranges for both the sweetener and the polyhydroxy alcohol limitations in claim 4, and (iv) the specification consistently described the sweetener and the polyhydroxy alcohol as separate ingredients. In response, Sun argued that the sweetener limitation and the polyhydroxy alcohol limitation “share overlapping functionality” and that one of the functions of the polyhydroxy alcohol is to mask the bitter taste of the API and that the function of the sweetener is to impart a sweet taste to the patient. In other words, “the same ingredient could function both to impart a sweet taste … and mask the bitter taste of metformin.” The court found, however, that in the claims, the “sweetener” and the “polyhydroxy alcohol” are consistently referred to as distinct ingredients. Further, the specification referred to the sweetener and the polyhydroxy alcohol as separate components of the liquid formulation, including in every exemplary formulation that provided for at least one sweetener and at least one separate polyhydroxy alcohol.