Judge Andrews Issues Claim Construction Opinion Related to Anti-HIV Pharmaceuticals

Judge Richard Andrews recently construed eight disputed claim terms of U.S. Patent No. 6,417,191, which relates to “therapeutic combinations of anti-HIV drug compounds.” Viiv Healthcare UK Ltd. v. Lupin Ltd., C.A. No. 11-576-RGA (D. Del. Nov. 16, 2012); Viiv Healthcare UK Ltd. v. Teva Pharmaceuticals USA, Inc., C.A. No. 11-688-RGA (D. Del. Nov. 16, 2012). Judge Andrews construed the following terms:

• “animal”
• “physiologically functional derivative”
• “symptoms or effects of an HIV infection”
• “a single combined formulation”
Id. at 2-3, 13-15.

Judge Andrews also construed the following terms, which each presented similar issues:

• “(1S, 4R)-cis-4-[2-amino-6-(cyclopropylamino)-9H-purin-9-y1]-2-cyclopentene-1-methanol or a physiologically functional derivative thereof and (2R, cis)-4-amino-1-(2-hydroxymethyl-1,3-oxathiolan-5-yl)-(1H)-pyrimidin-2-one or a physiologically functional derivative thereof”
• “combination”
• “pharmaceutical formulation”/“formulation”
• “therapeutically effective amount”
Id. at 3-12.

For these terms, defendants argued that the ’191 patent specification and prosecution history indicated that “synergism” was an “essential element of the claimed drug combination” and that the patentee “disavowed” non-synergistic combinations. Id. at 5. In response, plaintiffs argued that “synergism” was not an essential element but was an “unexpected result” emphasized to overcome obviousness rejections. Id. at 5-6. The appropriate constructions depended on whether “synergism” limited the scope of the claim terms. See id. at 5.

Despite the patentee’s emphasis on synergy in the title and invention description, Judge Andrews found that the ’191 specification did not “evince[] ‘manifest statements of exclusion or restriction’ giving rise to clear and unmistakable disclaimer.” Id. at 6-9. Among other reasons, he noted that disclaimer “typically occurs through a patentee’s differentiation of prior art.” But in this case, the patentee “at no point . . . criticize[d] a prior art for lacking synergism and then distinguish[ed] [its] drug combination for its synergistic aspect.” Id. at 7-8. Synergism was discussed as an “unexpected result,” not a “component or property of the combination itself.” Id. at 8.

Similarly, despite the patentee’s consistent emphasis on synergism in its correspondence with the PTO, Judge Andrews found that “clear and unmistakable” disclaimer in the prosecution history was absent. Id. at 9-12. He noted that “[c]lassic prosecution disclaimer occurs when an applicant escapes rejection for anticipation through narrowing statements to the examiner differentiating the application from the prior art.” Id. at 11. The patentee in this case, however, never narrowed its claims to avoid an anticipation rejection. Id. Rather, the patentee used “synergism” to overcome obviousness rejections by arguing that “the combined use of the drug compounds [was] not . . . expected to be as effective as proven.” Id. at 12. Judge Andrews did note that “[h]ad the patentee proved the existence of synergistic effects (and thus non-obviousness) via responses that altered the chemical or physical characteristics of the drug combination itself, those responses would arguably limit the scope of the claims, as the invention itself would have been re-characterized.” Id. at 12.

Because the patentee did not disavow non-synergistic combinations in the specification or prosecution history, the claim terms were not limited to synergistic combinations and Judge Andrews gave them their “plain and ordinary meaning[s].” Id. at 3-12.

Viiv Healthcare UK Ltd. v. Lupin Ltd., C.A. No. 11-576-RGA (D. Del. Nov. 16, 2012); Viiv Healthcare UK Ltd….

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