Eli Lilly And Company & Ors v Genentech, Inc

In a patent revocation and infringement action, the court construed antibody claims according to the specification as a whole and the technical context. “Specifically binds to” did not require exclusive binding to the claimed cytokine unless the patent so required in the particular embodiment. Claims directed to treatment required a discernible therapeutic effect, and inhibition of the claimed cytokine had to make more than an insignificant contribution to that effect.

For plausibility, the patent had to disclose reasonable scientific grounds for expecting the claimed therapeutic effect. A bare assertion, a mere possibility, or later evidence could not substitute for adequate disclosure. Claims for psoriasis treatment failed this requirement where the patent contained no disease-specific evidence or reasoning, despite being obvious over the prior art in other respects.

Genentech sought to maintain amended claims in European Patent (UK) No 1 641 822 concerning antibodies to the IL-17A/F heterodimer and their therapeutic use. Lilly sought revocation for lack of novelty, obviousness and insufficiency, and declarations concerning infringement by ixekizumab.

The principal issues were claim construction, added matter, obviousness over prior art concerning IL-17A/F and IL-17A/A, plausibility of treatment claims directed to rheumatoid arthritis and psoriasis, and infringement. The court also considered Genentech’s unconditional and conditional amendment applications.

1. Construction. The expression “specifically binds to” was construed in the context of the patent. The definition in paragraph [0118] supported the ordinary antibody meaning of specific binding, rather than a requirement that the antibody bind only IL-17A/F. The patent’s examples did not require negative screening against IL-17A/A or IL-17F/F. Claims directed to treatment required a discernible therapeutic effect, and inhibition of IL-17A/F had to make more than an insignificant contribution to that effect.
2. Amendments. The amendments were allowable except that “comprises” in new claims 1 and 14 extended protection. The conditional substitution of “consists of” was allowable. The added-matter inquiry required comparison of the application and amended patent through the eyes of the skilled team, asking whether the amendment disclosed new technical subject matter. The court rejected a mechanistic approach to selections from multiple lists.
3. Obviousness and novelty. Claims 1, 2, 13, 14 and 15 were novel but obvious over the IL-17A/A prior art, and were also obvious over US344. Claims 12, 20 and 22 were obvious insofar as directed to rheumatoid arthritis. The evidence showed that it was highly probable that obvious implementation of the prior art would produce antibodies binding to and inhibiting both IL-17A/A and IL-17A/F, although inevitability had not been established. The claims were not therefore anticipated.
4. Plausibility. Applying Warner-Lambert Co LLC v Generics (UK) Ltd [2018] UKSC 56, the specification had to disclose reasonable scientific grounds for expecting the claimed therapeutic effect. The claims directed to psoriasis failed this test. The patent contained no experimental evidence or discussion showing a pathogenic role for IL-17A/F in psoriasis, and the cited material supplied only limited support for IL-17A/A. The claim of efficacy was speculative. Later evidence could not cure the insufficiency.
5. Infringement. Ixekizumab satisfied the claims’ construction and, if the claims were valid, infringed claims 1, 2, 14 and 15. If necessary, it would also infringe under the doctrine of equivalents. The use claims were infringed because inhibition of IL-17A/F made more than an insignificant contribution to the therapeutic effect. For claims 13, 14, 15 and 22, knowledge of the relevant intention to use the product arose no later than the last day of trial.
6. The amendments were allowed subject to the stated qualification. The relevant claims were invalid for obviousness or insufficiency. If valid, they had been infringed by Eli Lilly & Co and Eli Lilly & Co Ltd.

First-instance decision. No appellate history is stated in the judgment.