Oxford Gene Technology Ltd v Affymetrix Inc & Ors

A patentee seeking post-grant amendment must disclose the material facts relevant to the stated reason for amendment, but is not required to waive legal professional privilege or conduct an unrestricted document trawl. Disclosure of privileged documents to an opponent’s solicitors on strictly confidential terms does not waive privilege where the proposed disclosure is never accepted and the documents remain confidential. The court retains power to control disclosure to professional advisers, applying justice and fairness, but exclusion of a party from information relevant to the case is exceptional. The discretion under section 75 of the Patents Act 1977 is not fettered by Article 138 of the European Patent Convention when the proposed amendment would validate an otherwise invalid patent.

Oxford Gene Technology Ltd brought patent infringement proceedings against Affymetrix Inc, Affymetrix UK Ltd and Beckman Coulter Inc. Oxford Gene Technology sought amendment of its European patent under section 75 of the Patents Act 1977. Following an order for disclosure relevant to the court’s discretion, it listed documents claimed to be legally privileged and permitted confidential inspection by Affymetrix’s English solicitors and counsel, but not disclosure to the clients or United States advisers.

Pumfrey J held that privilege had been lost, refused wider disclosure, and restricted use of the documents to the amendment proceedings. The defendants appealed. Oxford Gene Technology cross-contended that privilege had not been waived and argued that Article 138 of the European Patent Convention required the amendments to be permitted.

The appeal was dismissed. A declaration was made that Oxford Gene Technology had not disclosed the Schedule B documents to Affymetrix so as to waive privilege. The relevant paragraphs of Pumfrey J’s order were set aside, and there was no order as to costs.

1. Disclosure and privilege. The patentee’s duty of good faith requires disclosure of the material facts relevant to the reason advanced for amendment. It does not require disclosure of every potentially relevant document, nor waiver of legal professional privilege. The decision whether to waive privilege belongs to the patentee.
2. Whether privilege has been waived is determined by the court according to justice and fairness. Disclosure of part of a document will generally waive privilege in the whole, but disclosure for a limited purpose may preserve it. Here the list, correspondence and inspection arrangements showed that disclosure to the adversary was never intended or accepted. The documents remained confidential, so privilege was not waived.
3. Article 138. Article 138 does not require the court to allow amendments under section 75. Section 63 and Article 138(2) concern a patent which is partly valid, whereas section 75 permits amendment to validate an invalid patent. Refusal of amendment does not itself revoke the patent and therefore does not create an additional ground of revocation.
4. Wider disclosure. Although unnecessary to the result, Aldous LJ considered that the judge had given insufficient weight to Affymetrix’s need to consult its representatives. The ordinary rule is that a party should know the facts underlying its advisers’ advice, subject to exceptional protection for trade secrets or genuinely unintelligible technical material. Restricting use to amendment proceedings would also be unworkable because amendment and validity formed part of the same litigation.

• Court of Appeal (Civil Division): appeal from Pumfrey J’s judgment dated 1 August 2000. Appeal dismissed; declaration made that privilege had not been waived; specified paragraphs of the order set aside; permission to appeal to the House of Lords refused.