Merck Sharp & Dohme Limited v Ono Pharmaceutical Co. Limited & another, and Bristol Myers Squibb Company, Ono Pharmaceutical Co. Limited & another v Merck & Co. Inc. & another, High Court (Patents Court), Mr Justice Birss, 22 October 2015
The UK Patents Court has upheld the validity of Ono’s patent EP (UK) 1 537 878 (under which BMS is an exclusive licensee), which concerns antibodies to the PD-1 receptor for the treatment of all cancers.
Ono and BMS alleged that Merck’s anti-PD-1 antibody pembrolizumab (Keytruda), which it proposes to market as a treatment for unresectable/metastatic melanoma, infringed the patent. Merck accepted that if the patent was valid, its product fell within the scope of the claims. Merck raised a wide variety of attacks on the patent, including added matter, insufficiency, loss of priority, anticipation and obviousness. Ono admitted that if priority was lost, the claims were invalid. Ono further stated that it would not seek an injunction in the UK if its claim to infringement was successful.
Interestingly, the judge held that plausibility forms part of the law of novelty as part of the enablement assessment. In this case, the question was whether the prior art plausibly enabled the claimed therapeutic effect. This issue is frequently raised in cases concerning second medical use claims where there is an issue of whether the disclosure of the therapeutic effect in the prior art is sufficient to be novelty destroying. Birss J’s approach can be contrasted with the approach of Arnold J in Hospira v Genentech  EWHC 1796 (Pat) in which this issue was instead dealt with by asking whether the claimed therapeutic effect was properly disclosed in the prior art (i.e. you must know from the prior art that the claimed therapeutic effect will be obtained).
Other interesting aspects of the judgment include how the judge dealt with Merck’s plausibility attack (which was raised under the heads of priority, sufficiency and AgrEvo obviousness) and his analysis of whether the invention was ‘obvious to try’.