PTAB

IPR2015-00550

Teva Pharmaceuticals USA Inc v. ViiV Healthcare Co

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Key Events
Petition
petition

1. Case Identification

2. Patent Overview

  • Title: Synergistic Combinations of Zidovudine, 1592U89 and 3TC
  • Brief Description: The ’191 patent discloses pharmaceutical compositions and methods for treating HIV infection. The invention centers on combinations of three known anti-retroviral drugs that are nucleoside analog reverse transcriptase inhibitors (NRTIs): abacavir (also known as 1592U89), zidovudine (AZT), and lamivudine (3TC).

3. Grounds for Unpatentability

Ground 1: Obviousness over Cameron and Daluge - Claims 1-51 are obvious over Cameron in view of Daluge.

  • Prior Art Relied Upon: Cameron (European Patent Application EP 0 513 917 A1) and Daluge (a 1994 conference abstract titled "1592U89 Succinate – A Novel Carbocyclic Nucleoside Analogue with Potent, Selective Anti-HIV Activity").
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner argued that the prior art disclosed all elements of the challenged claims. Cameron taught a highly effective, synergistic combination of AZT and 3TC for treating HIV and expressly suggested that this combination could be used with "other therapeutic and/or prophylactic ingredients." Daluge taught that abacavir was a potent and selective anti-HIV drug, was "equivalent in potency to AZT," and demonstrated synergistic activity when combined with AZT. Petitioner asserted that combining Cameron's foundational two-drug therapy with Daluge's promising third drug rendered the claimed triple-drug combination obvious. This logic was applied to independent claims for both methods of treatment (claim 1) and pharmaceutical formulations (claim 16).
    • Motivation to Combine: A person of ordinary skill in the art (POSA) at the time would have been motivated to add abacavir to Cameron’s established AZT/3TC therapy. This was driven by the well-understood goal of creating more robust three-drug regimens to increase therapeutic efficacy and delay the development of drug resistance, a known problem with HIV treatment. Daluge presented abacavir as an "attractive candidate for clinical evaluation" that was potent, had low toxicity, and worked well with AZT, making it a logical choice for the "other therapeutic ingredient" suggested by Cameron.
    • Expectation of Success: A POSA would have had a reasonable expectation of success in creating an effective triple-drug therapy. All three individual components were known to be useful anti-HIV agents. Furthermore, synergistic effects were already demonstrated in the prior art for the two-drug sub-combinations of AZT/3TC (from Cameron) and AZT/abacavir (from Daluge). Therefore, it was reasonable to expect that the three-drug combination would be, at a minimum, an effective treatment for HIV.
    • Key Aspects: Petitioner extended its obviousness argument to all dependent claims, contending that limitations such as specific drug ratios, dosages, salt forms (abacavir succinate), and administration methods were either directly taught, suggested by the prior art, or would have been the result of routine optimization by a POSA.

4. Key Claim Construction Positions

  • "treatment or prevention" / "therapeutically effective amount": Petitioner argued these terms should be given their plain and ordinary meaning. Crucially, this interpretation does not require any particular magnitude of therapeutic effect or a synergistic outcome, which broadens the claims for the purpose of an obviousness analysis by lowering the bar for what the prior art must teach.
  • "patient pack": For claim 31, Petitioner argued that under the broadest reasonable interpretation, the claim language "comprising 'at least one' active ingredient" only requires a single drug to be physically present in the pack alongside an information insert discussing all three. This construction simplifies the invalidity argument for that claim.
  • Drug Names (e.g., "abacavir"): Petitioner asserted that the chemical names used in the claims should be construed to encompass their common names (e.g., "abacavir," "AZT," "3TC") and their "physiologically functional derivatives" (e.g., salts, esters), as these terms were used interchangeably in the patent and the art.

5. Key Technical Contentions (Beyond Claim Construction)

  • Rebuttal of "Unexpected Synergy": Petitioner preemptively countered the Patent Owner's likely arguments regarding secondary indicia of non-obviousness. It contended that any synergy from the three-drug combination was entirely predictable and not unexpected. The argument was based on prior art showing that the two-drug sub-combinations (AZT/3TC and AZT/abacavir) were already known to be synergistic, making it expected that a combination of all three would also display synergy.
  • Rebuttal of "Unexpected Clinical Superiority": Petitioner asserted that the Patent Owner’s own clinical trial data failed to show that the claimed combinations were unexpectedly superior to existing treatments. Instead, Petitioner argued the data demonstrated that the claimed therapies were merely "non-inferior," "comparable," or showed only "modest" improvement over the prior art "gold standard" AZT/3TC therapy, a level of performance insufficient to overcome a strong prima facie case of obviousness.
  • Lack of Long-Felt Need: Petitioner argued that no long-felt, unmet need was satisfied by the invention. It contended that by the patent's priority date, effective HIV drugs and combination therapies were already available, including the highly successful AZT/3TC combination, which had already addressed the need for improved treatments over monotherapy.

6. Relief Requested

  • Petitioner requests institution of an inter partes review and cancellation of claims 1-51 of Patent 6,417,191 as unpatentable under 35 U.S.C. §103.