Monsanto Company & Ors v Merck & Company & Anor

On a strike-out application in a patent action, a claim should be struck out only where the alleged infringement is plainly and obviously unsustainable. Construction of a patent claim may require the court to construe the patent as a whole, apply the Protocol on Interpretation and adopt the perspective of the skilled person, often with expert evidence. A Swiss-type claim for the use of a substance in preparing a medicament is a process claim. Its scope is not necessarily confined to the final stage of manufacture or to circumstances where the claimed substance remains in the administered product. Where a wider construction is reasonably arguable, the issue should proceed to trial.

The patentees alleged infringement of European Patent (UK) No 0679157 by Merck’s proposed anti-inflammatory drug. Their alternative case concerned claim 20, a Swiss-type claim for use of a claim 1 compound in preparing a medicament. They alleged that Enol and Enolate forms were present during production abroad, although the imported active ingredient was in Keto form.

Pumfrey J struck out the relevant infringement allegations, holding that claim 20 concerned only preparation of the medicament after manufacture of the active ingredient and was not infringed on the assumed facts. The patentees appealed. The central issues were whether that construction was plainly unarguable at the interlocutory stage and whether claim 20 was a process claim engaging section 60(1)(c) of the Patents Act 1977.

Appeal allowed. The Court of Appeal held that the alternative infringement case was arguable and should not have been struck out.

1. Construction and strike-out. Claim 20, read literally, could cover use of a claim 1 compound during all stages of preparing the medicament, including production of its active ingredient. The court declined to reach a concluded construction at this stage. Section 125 required the patent to be construed as a whole and in accordance with the Protocol on Interpretation. The skilled person’s perspective and expert evidence might materially affect the construction.
2. The court endorsed the caution in Strix v Otter Controls Ltd [1991] FSR 354: summary disposal is inappropriate where patent construction is a sophisticated exercise and the pleaded case is not plainly and obviously unsustainable. The possibility that the claim might ultimately fail did not justify striking it out.
3. Process claim. The relevant invention is identified from the claim under section 125. Claim 20 was a claim for preparation of a medicament and therefore a process claim for the purposes of section 60(1)(c). The court relied on John Wyeth & Brother Ltd’s Application [1985] RPC 545, and on the interpretation of similar claims by the Enlarged Board of Appeal in Eisai (1985) OJ 64.
4. The judge’s order striking out paragraphs 6 and 7 of the statement of case was set aside. The appellants were awarded their costs in the court below and on appeal, with repayment of costs already paid.

• Court of Appeal (Civil Division) [1999] EWCA Civ 1946: appeal allowed; the order striking out the alternative infringement allegations was set aside.
• High Court of Justice, Pumfrey J: on 5 May 1999, construed claim 20 as limited to preparation after manufacture of the active ingredient and struck out paragraphs 6 and 7 of the infringement statement of case.