Accord Healthcare Limited & Ors v The Regents of The University of California & Anor

Obviousness remains the statutory question whether the claimed invention was obvious having regard to the state of the art. Structured approaches such as Pozzoli and the problem-and-solution approach assist that inquiry but cannot replace it.

In pharmaceutical cases, routine research and testing may establish obviousness where the research has a defined target. However, a small structural change is not necessarily trivial, and medicinal chemistry requires close attention to the actual teaching of the prior art, motivation, expectation of success and hindsight.

A patent may make a sufficient technical contribution by disclosing a plausible new compound or an alternative solution. It need not establish that the compound is superior to the prior art.

Three actions were brought by pharmaceutical companies seeking revocation of EP (UK) 1 893 196 B2 and invalidation of the related supplementary protection certificate. The patent claimed enzalutamide, identified in the prior art as RD162′, for treating prostate cancer, including hormone-refractory prostate cancer.

The claimants relied on conference Slides and a Poster disclosing related androgen-receptor antagonists, particularly RD162. They alleged that replacing RD162’s cyclobutyl substituent with a geminal dimethyl substituent was obvious. They also alleged that the patent lacked a plausible technical contribution because it contained limited data for RD162′, including no pharmacokinetic data.

The central issues were whether claim 1 was obvious over either disclosure and whether the patent plausibly disclosed a technical contribution.

1. Obviousness. The statutory question was whether claim 1 was obvious having regard to the state of the art at the relevant date. The approaches in Pozzoli and the problem-and-solution approach were useful analytical tools, but neither displaced the statutory question. The assessment remained fact-specific and had to avoid hindsight.
2. Motivation and routine testing. Motivation was relevant but not an indispensable condition of obviousness. Routine testing could establish obviousness where it was obvious to undertake the testing and the target was substantially predetermined. The existence of several possible routes did not itself make an obvious route non-obvious. However, a skilled team was not assumed to undertake technical work for idle curiosity. The purpose, scope and likely direction of the research had to be established.
3. Poster. The Poster disclosed RD162 as a promising compound with useful activity and pharmacokinetic properties. The skilled team would have been motivated to conduct a structure-activity relationship investigation starting from RD162 and to seek a novel compound for competitive and patenting reasons. However, the evidence did not establish that the investigation would lead to RD162′, or that making and testing it would arise as a defined step rather than through hindsight. The allegation that the cyclobutyl-to-dimethyl change was immediately obvious was hindsight-tainted. Claim 1 was not obvious over the Poster.
4. Slides. The Slides identified RD162 as the most promising disclosed compound and showed a pharmacophore in which the substituents corresponding to the cyclobutyl group participated in hydrophobic interactions. Although the technical case for a dimethyl analogue was cogent, the evidence did not adequately establish the context, objective and planned testing by which the skilled team would arrive at RD162′. Claim 1 was not obvious over the Slides.
5. Perceived prejudice and superiority. A patentee could not rely on a perceived problem in taking a course unless the patent itself overcame that problem. A claimed invention did not have to be better than the prior art. A plausible non-obvious alternative could constitute a technical contribution.
6. Plausibility and sufficiency. The patent was not a bare assertion or abstract possibility. The cell-based data comparing RD162′ with RD162, together with the placement of RD162′ in Tier 1, gave the skilled team a reasonable basis for expecting therapeutic activity. The absence of pharmacokinetic data for RD162′ did not require invalidity. The suggested insufficiency and plausibility squeeze failed because the disclosures in the prior art and the patent were not comparable.
7. Disposition. Claim 1 was not obvious over either the Poster or the Slides. The insufficiency and plausibility attack also failed. Each of the three actions was dismissed.