Alzheimer’s disease is a debilitating and progressive type of dementia, for which there is no known cure. The brains of sufferers are characterised by plaques of tangled masses of ß-amyloid peptide (or “Aß”), and as such the peptide has been a focal point of research into treatment of the disease.

Janssen Alzheimer Immunotherapy is the proprietor of European Patent (UK) No. 1994937 entitled ‘Prevention and treatment of amyloidogenic disease’, which relates to pharmaceutical compositions comprising an antibody to ß-amyloid peptide.

Eli Lilly sought an order to revoke the European Patent (UK) No. 1994937 before the UK High Court, and a declaration that their own antibody for treating Alzheimer's disease called solanezumab, currently in Phase 3 trials, does not infringe the patent.

In ‘Eli Lilly & Co and Janssen Alzheimer Immunotherapy’ [2013] EWHC 1737 (Pat), the Court revoked the patent on the grounds that it was insufficient, and declared Eli Lilly’s antibody would have infringed the patent, had it been valid.

  1. Sufficiency

Article 83 of the EPC concerns sufficiency, and requires that a European application shall disclose the invention in a manner sufficiently clear and complete for it to be carried out by a person skilled in the art.

This concept enshrines one of the fundamental principles in patent law, where an applicant may be rewarded a patent in respect of his invention, in return for disclosing it to the public and thus providing a technical contribution to the art. In turn, the scope of the patent must not exceed the technical contribution the applicant has made to the art in disclosing the invention. Failure to disclose an invention in a sufficiently clear and complete manner may result in refusal of a patent application, or leave a patent, once granted, open to opposition or revocation proceedings.

There are equivalent requirements in most jurisdictions around the world, such as Section 14(3) of the UK Patents Act 1977.

  1. The decision

Claim 1 of the patent read ‘a pharmaceutical composition comprising an antibody to Aß and a pharmaceutically acceptable non-toxic carrier or diluent, for use in preventing or treating a disease characterised by amyloid deposit in a patient, wherein the isotope of the antibody is human IgG1’.

Whilst the decision related to a number of issues including novelty, inventive step and added matter, the most interesting issues surrounded sufficiency.

When assessing sufficiency, the Court set itself a two-stage enquiry. The first stage was to determine whether the disclosure of the patent, read in the light of the common general knowledge of the skilled team, makes it plausible that the invention will work across the scope of the claim. If the disclosure does make it plausible, the second stage was to consider whether the later evidence establishes that in fact the invention cannot be performed across the scope of the claim without undue burden.

In assessing the first stage, the court noted that the claim covered any antibody to Aß (provided the antibody was of the IgG1 subtype). However, based on an analysis of the examples provided in the patent itself, the Court inferred that it would be unlikely that all such antibodies would work. Thus the Court concluded that it was not plausible that any antibody to Aß will be effective, and for this reason, the patent was revoked for insufficiency.

(This brings to mind a recurring concept regarding ‘plausibility’ of an invention, which has also arisen in respect of inventive step. For instance, the Board of Appeal of the EPO stated in T1329/04 that it must be at least plausible from the application that the invention solves the problem embodied in its alleged inventive concept.)

For the sake of completeness, the Court also considered the second stage of the two-stage enquiry; in particular, whether later evidence demonstrated that the patent was insufficient. In this regard, the Court accepted that, ‘despite a very great deal of effort over a decade (and many person years) and despite huge expenditure’, Janssen’s Phase 3 trials of their own antibody drug to Aß (called bapineuzumab) had not succeeded, and that ‘the Patent does no more than invite the skilled team to perform…a “very significant research project with a high prospect of failure” and, if they succeed, claims the fruits of their research’. The Court thus confirmed the patent was insufficient.

  1. Conclusion

The decision highlights the importance of balancing the idea of seeking broad protection for an invention when drafting a patent application, with the realities of what is or is not possible with the technology for which the patent is sought.

Applicants should seek to ensure that an invention is at least plausible across the scope of the claims when drafting an application, and provide supporting data, where possible. Providing basis in the application to allow for the removal of subject matter which is known or suspected not to work may go some way to reduce risks of falling foul of a later allegation that it is not plausible that the invention would work.