Merck Sharp & Dohme (UK) Limited v Halozyme Inc

A statement of case must contain a concise statement of the facts relied upon and sufficient detail to enable the opposing party to understand the case advanced. In patent infringement proceedings involving functional claim features, this may require identification of the relevant comparator sequence and, where material, the conditions of comparison. Those matters are pleaded facts, not merely evidence. A case management order requiring a statement of case is not diluted by the refusal of wider requests for information. Where provision of experimental samples depends on third-party or governmental action, an order may require best endeavours rather than impose an absolute obligation.

This was a case management judgment in patent revocation and infringement proceedings concerning modified PH20 hyaluronidase enzymes. The defendant relied on infringement allegations relating to functional features of two patents and required a sample of the claimant’s proposed product for experiments.

The court considered whether the defendant’s draft amended statement of case complied with an earlier order requiring a statement of case on infringement, whether an order should be made requiring provision of a product sample, and whether permission to appeal should be granted.

1. Pleading requirements. The order requiring a statement of case on infringement required a document satisfying the objective requirements of a pleading. By analogy with CPR 16.4(1)(a), it had to contain a concise statement of the facts relied upon. It also had to contain sufficient detail to enable the opposing party to understand the case advanced, as stated in Habibsons Bank Ltd v Standard Chartered Bank (HK) Ltd [2011] QB 943.
2. The draft pleading was inadequate because it did not identify the relevant comparator sequence for either patent. Identifying that sequence was part of the infringement case, since it was necessary to assess whether the claimed modification and increased activity or stability were present.
3. For the patent claim concerning increased stability, the pleading also had to identify the relevant conditions in which the comparison was said to establish increased stability. These were factual assertions necessary to make the infringement case comprehensible. They were not merely evidence concerning the perspective of the skilled person.
4. The refusal of broader requests for information under CPR Part 18 did not excuse compliance with the separate requirement to plead the facts supporting the infringement case. The draft amended statement of case therefore did not comply, and permission to amend was not granted on that version. The defendant was given until 4 February 2026 to comply, allowing time to seek a stay from the Court of Appeal.
5. Sample provision. The claimant was ordered to use best endeavours to provide the agreed sample. An absolute obligation was inappropriate because export licences depended on third parties and governmental agencies. The costs of the sample application were costs in the case.
6. Permission to appeal. Applying the first-appeal test of a realistic, rather than fanciful, prospect of success or another compelling reason, permission to appeal was refused.

First-instance case management judgment. Permission to appeal was refused, subject to the defendant’s opportunity to apply to the Court of Appeal for a stay before the compliance deadline.