Medimmune Ltd v Novartis Pharmaceuticals UK Ltd & Ors

Obviousness remains a single statutory question: whether it was obvious for the skilled but unimaginative addressee to make the claimed product or carry out the claimed process at the priority date. A structured analysis and such matters as a reasonable expectation of success may assist, but they are not independent legal hurdles. Their significance depends on all the circumstances.

A patent claim is entitled to priority only where the skilled person can derive the same subject matter directly and unambiguously from the priority document as a whole. A claimed method extending to a derivative made after phage-display selection, without a further selection round, lacked that disclosure.

MedImmune Limited alleged that Novartis Pharmaceuticals UK Limited infringed two patents concerning antibody phage display through the sale of ranibizumab. Novartis denied infringement and counterclaimed for revocation.

Arnold J held both patents invalid for obviousness and lack of priority. He also rejected the asserted process infringement. In related proceedings, he held invalid a supplementary protection certificate based on the principal patent.

MedImmune pursued its appeal concerning European Patent (UK) No 0 774 511 and the supplementary protection certificate. Novartis served a respondent’s notice raising insufficiency and a further non-infringement point. The central issue was whether the claimed antibody phage-display method was obvious in light of Professor Smith’s Banbury conference presentation.

1. The appeals were dismissed. The court upheld Arnold J’s finding that the patent was invalid for obviousness. That conclusion disposed of both appeals, so it was unnecessary to determine infringement, insufficiency, or the additional challenge to the supplementary protection certificate.
2. The relevant skilled addressee was a team working in antibody engineering. The court was entitled to identify the team by reference to the practical reality of research in the field and the problem which the invention addressed. The possibility of wider applications did not displace that conclusion.
3. The statutory question was whether the claimed method was obvious at the priority date. The Pozzoli structure was a useful but non-mandatory aid. A reasonable expectation of success, the time needed for a trial, the available research routes, and the effort involved were relevant considerations, not separate conditions.
4. Professor Smith’s presentation expressly proposed antibody phage display, illustrated the essential method, stated that he intended to conduct the experiment, and addressed possible technical difficulties and solutions. It conveyed justified encouragement rather than a prejudice that the proposed method would not work. The skilled team could implement the method by known techniques and would have had a reasonable expectation of success within a reasonable time. Arnold J was entitled to find the claimed invention obvious.
5. The court also upheld the priority ruling. Under Patents Act 1977 section 5, read consistently with Article 87(1) of the European Patent Convention, priority requires direct and unambiguous disclosure of the same invention. The priority document disclosed mutagenesis and selection through phage display, but did not disclose taking the product of phage display, making a derivative, and using it without a further phage-display selection. Claim 1 extended to that undisclosed post-selection derivatisation and was therefore not entitled to priority.
6. Lewison LJ added that fair prospects of success and a reasonable time for experimentation should not be treated as successive hurdles. They interact within the single statutory assessment of obviousness. Moore-Bick LJ agreed with both judgments.

• Court of Appeal (Civil Division): MedImmune’s appeals were dismissed: [2012] EWCA Civ 1234.
• High Court, Chancery Division, Patents Court: Arnold J held the patents invalid for obviousness and lack of priority, rejected the asserted process infringement, and held the related supplementary protection certificate invalid.