Dolutegravir - USA

Claim Construction (District of Delaware): Sep 26, 2019

This patent litigation dispute involves seven consolidated patent infringement and invalidity lawsuits, all arising under the Hatch-Waxman Act. Plaintiffs [Viiv/Shinogi] filed each of these actions for patent infringement of US 9,246,986 alleging violation of 35 U.S.C. § 271, based upon Defendants’ [Lupin; Apotex; Cipla ; Sandoz; Lek Pharmaceuticals and Laurus Labs] submissions of Abbreviated New Drug Applications (“ANDAs”) with the Federal Drug Administration (“FDA”). Those ANDAs seek FDA approval of generic versions of one or both of two brand-name drugs, “TIVICAY®” and “TRIUMEQ®.” Defendants responded with counterclaims for noninfringement and invalidity.

Plaintiffs and Defendants dispute the appropriate construction of two claim terms:

(1) “A crystal form of a sodium salt of a compound of formula AA,” contained in Claims 1 through 6 of the ’986 Patent.

Claim 1: A crystal form of a sodium salt of a compound of formula AA having characteristic diffraction peaks at 6.4°±0.2°, 9.2°±0.2°, 13.8°±0.2°, 19.2°±0.2°, and 21.8°±0.2° degrees two-theta in an X-ray powder diffraction pattern.

(2) “A crystal form of a hydrate of a sodium salt of a compound of formula AA,” contained in Claims 7 through 12 of the ’986 Patent.

Claim 7: A crystal form of a hydrate of a sodium salt of a compound of formula AA having characteristic diffraction peaks at 8.0°±0.2°, 9.3°±0.2°, 11.3°±0.2°, 16.0°±0.2°, and 22.8°±0.2° degrees two-theta in an X-ray powder diffraction pattern.

What the parties dispute is whether the term “crystal form” in each of the claims should be further construed to identify the particular hydration state of the claimed crystal forms—in light of the specific measurement data set out in both of the claims and the specification. Thus, for Claims 1 through 6, Defendants contend that the term “a crystal form” of dolutegravir sodium should be construed as “an anhydrate crystalline form of dolutegravir sodium”—because the measurement data shows that the crystal form is an anhydrate. Likewise, for Claims 7 through 12, Defendants argue that the term “a crystal form of a hydrate of” dolutegravir sodium should be further construed as “a monohydrate crystalline form of dolutegravir sodium".

Defendants’ position relies on the specification, which identifies, as examples of the invention, two crystal forms of dolutegravir sodium: Compound 13, which is an anhydrate, and Compound 13b, which is a monohydrate. Defendants contend that these two crystal forms of dolutegravir sodium are, in fact, the entirety of the invention, because—as the specification itself reveals—these two crystal forms yield the same measurement data that is listed in the twelve claims. Specifically, Compound 13 yields the same measurement data listed in Claims 1 thorough 6; and Compound 13b yields the same measurement data listed in Claims 7 through 12.

Court, however, sided with Plaintiff & said that Defendants’ proposed construction impermissibly imports limitations from the specification into the claims. Court said that the appropriate inquiry is whether the claim language, the specification, and the prosecution history of the ’986 Patent “clearly indicate that the invention encompasses no more” than Compounds 13 and 13b. Court further said that while it is true that the ’986 Patent claims specific crystal forms by way of certain measurement data, and that Compounds 13 and 13b exhibit that exact same data, it does not follow that Plaintiffs intended Compounds 13 and 13b to constitute the entirety of the invention. As Plaintiffs note, a crystalline form of dolutegravir sodium may exist that exhibits the same crystal structure as Compound 13 or Compounds 13b—and thus exhibits the measurement data set out in the ’986 Patent’s claims—but yet differs in hydration state. Specifically, Plaintiffs point out that non-stoichiometric crystalline compound can lose water (thus changing hydration state) without changing the crystal structure. It therefore makes sense that a patent applicant—like Plaintiffs here—seeking to claim a particular crystalline structure as the invention, would define the invention by reference to the measurement data, rather than by reference to the hydration state.

Court therefore, denied Defendants claim construction because claim language, specification, and prosecution history of the ’986 Patent are not ambiguous& they do not clearly indicate that Compounds 13 and 13b are the entirety of the invention.