Merck Sharp & Dohme Ltd v Ono Pharmaceutical Co Ltd & Anor  EWHC 2973 (Pat)
In Merck Sharp & Dohme v Ono & BMS  EWHC 2973 (Pat), Birss J held that Ono’s patent (under which BMS is the exclusive licensee), with claims to anti-PD-1 antibodies which inhibit the immunosuppressive signal of PD-1 for cancer treatment, is valid. Merck sought to challenge the validity of the patent, raising a wide variety of attacks on the patent, including added matter, insufficiency, loss of priority, anticipation and obviousness. The case raised a number of points of legal interest including the role of plausibility in priority, novelty and sufficiency.
Merck had admitted that, if the patent were found valid, its proposed dealings in its product for treating melanoma would infringe. Unusually, Ono indicated that if it won its infringement case, it would not seek an injunction in the UK provided an appropriate royalty was paid by Merck, to be agreed or decided by the court.
In concluding that the patent was valid, Birss J held that the mouse models for cancer in the priority document (and the patent) provided support for the claimed invention, such that the Patent was entitled to its priority date. Further, because the skilled person would appreciate that these results would have broad application in treating cancer (because the PD-1 blockade effects the immune system, rather than being directed to an attribute of any particular type of cancer) it was plausible that the invention would be effective for treating a wide variety of cancers and so the claims were sufficient. The Judge also held that the Patent was novel over the mouse models for autoimmune disease contained in the prior art as these did not amount to a ‘disclosure’ of the claimed invention.
The judge applied the ‘obvious to try’ guidance set out by the Court of Appeal in its recent decision in Teva v Leo  EWCA Civ 780, holding that although it would not have been inventive to the skilled person to carry out tests which would have led to the invention, the skilled person would not have had a sufficient expectation that the outcome would be successful to render the claimed invention obvious.
 EWHC 2973 (Pat)