Medimmune Ltd v Novartis Pharmaceuticals UK Ltd & Anor

A patent claim must be construed purposively in context, while giving effect to deliberate limitations in its language. For obviousness, the question is whether the skilled team would have taken the relevant steps with a reasonable expectation of success within a reasonable time. A broad claim is insufficient where its scope exceeds the technical contribution made by the invention. Priority requires the claimed subject matter to be disclosed directly and unambiguously, and in an enabling manner, by the priority document. A process claim extends to a product obtained directly by the process where the product retains its identity and essential characteristics. The Biotech Directive does not restrict process claims directed to producing binding molecules merely because biological materials are used in carrying them out.

MedImmune, exclusive licensee of the Medical Research Council, sued Novartis for infringement of European Patents (UK) Nos 0 774 511 and 2 055 777. The patents concerned antibody phage display, including selection of binding molecules from phage or phagemid libraries. Novartis counterclaimed for revocation, alleging lack of priority, obviousness, insufficiency and added matter.

The disputed product was ranibizumab, sold as Lucentis. The court considered construction of claims relating to ranges of binding specificities, phagemid genomes and gene III fusion proteins; entitlement to priority from the third priority document; obviousness over Parmley & Smith and a talk at the Banbury Conference; sufficiency and added matter; and infringement under section 60(1)(c) of the Patents Act 1977 and Article 8(2) of the Biotech Directive.

1. Disposition. None of claims 5–8 of patent 511 or claim 1 of patent 777 was entitled to priority from PD3. As MedImmune accepted that loss of priority made the patents invalid, both patents were invalid. In any event, the process used to produce ranibizumab did not fall within the claims, so Novartis had not infringed.
2. The claims were construed purposively. “A range of binding specificities” referred to specificities for different epitopes or antigens, not merely different affinities for one antigen. In claim 5 of 511, “each” particle required the relevant phagemid genome to encode the binding molecule displayed by the particle, effectively confining the claim to the gene III-deletion helper-phage system. “A gene III protein” in claim 1 of 777 meant a complete or substantially complete gene III protein, not merely its C-terminal domain.
3. Under section 5(2)(a) of the Patents Act 1977, priority required direct and unambiguous, enabling disclosure of the same subject matter. PD3 disclosed use of a phagemid, but did not clearly and unambiguously disclose a phagemid encoding both chains of a Fab fragment. It also did not disclose post-display mutation of the selected antibody. The claims therefore lacked priority.
4. Applying the structured obviousness approach, the claims were not obvious over Parmley & Smith because that paper concerned antigen display, warned against large inserts and gave no reason to expect correct antibody folding. They were, however, obvious over Professor Smith’s Banbury Conference disclosure, which expressly proposed antibody phage display and gave the skilled team a reasonable expectation of success within a reasonable time.
5. The claims were not insufficient. The invention was a general technique for selecting binding molecules from diverse populations, and its implementation for different molecules or applications did not impose undue burden. The added-matter objection also failed because the application disclosed binding fragments and derivatives possessing binding specificity.
6. On the assumed hypothesis that the relevant process claims had been used, ranibizumab would have been a product obtained directly by the process under section 60(1)(c). Article 8(2) of the Biotech Directive did not provide a defence because the claims were directed to producing binding molecules, not to producing biological material.