In a recent preliminary ruling in relation to Yeda Research and Development Company Limited v Rhone-Poulenc Rorer International Holdings Inc and others [2007] UKHL 43, the House of Lords were required to rule on whether Yeda was able to amend its pleadings so as to continue the case for entitlement. The case concerned a patent covering the drug Erbitant that had revenues of $383.6 million in 2005.

Scientists at the Weizmann Institute of Science in Israel (Weizmann) invented a therapeutic composition involving an antibody and anti-plastic agent that had a synergistic effect in inhibiting growth of cancer cells. Prior to publishing their invention in a scientific paper, Weizmann scientists communicated the invention to Dr. Schelessinger. Dr. Schelessinger had assisted the scientists by providing two of the monoclonal antibodies used in the experiments relating to the invention. At that time, Dr. Schelessinger was on sabbatical from Weizmann and was working with Meloy Laboratories. Before the article was published by Weizmann’s scientists, Meloy Laboratories were taken over by Rhone- Poulenc Rorer International Holdings Inc (Rorer). Subsequently, Rorer made an application to patent the invention in different jurisdictions, naming Dr. Schelessinger and his team at Meloy Laboratories as the inventors. Rorer was subsequently granted a UK patent that it licensed to ImClone for commercial exploitation.

Yeda Research and Development Co Ltd (Yeda) is a company exclusively responsible for the commercial exploitation and technology transfer of inventions created by Weizmann scientists. Once it was aware of the patent obtained by Rorer, Yeda made a reference before the Comptroller in the United Kingdom under s37 of the Patents Act 1977, in which it claimed that the invention was made by the scientists at Weizmann. As an assignee of Weizmann’s rights, Yeda therefore claimed entitlement to joint ownership of the patent.

During the course of the entitlement proceedings, Yeda sought to amend its reference on two accounts: (i) to include a claim of sole ownership based on its experience in parallel litigations in other jurisdictions; and (ii) to account for the requirement laid down by the Court of Appeal in Markem v Zipher [2005] RPC 31 that states that a person who claims entitlement to a patent which has been granted initially to another person must not only prove his entitlement to the invention, but also that the named patentee is guilty of breaching some other rules of law such as that of contract or of confidence. Rorer objected to the first amendment on the ground that a claim to sole entitlement is a new cause of action and could not therefore be made after the expiry of the two year limitation period as prescribed under s37 of the Patents Act.

The Comptroller allowed both set of amendments, but the High Court and the Court of Appeal disallowed them. Through the present appeal, two main questions were raised before the House of Lords: (i) what does a person claiming entitlement of a patent in someone else’s name have to prove? and (ii) does the Comptroller have the power to allow an applicant to amend his claim of joint entitlement to that of sole entitlement after the expiry of the two year limitation period?

In answering the first question, the House of Lords unanimously overruled the principle of Markem v Zipher as stipulated above. According to Lord Hoffman, s7 of the Patents Act provides “an exhaustive code for determining who is entitled to the grant of a patent.” The Lords were of the opinion that laying down additional requirements, such as those determined in Markem v Zipher, confuses the law relating to validity and entitlement. The only requirement for a person seeking joint entitlement to a patent is for him to merely prove that he has contributed to the inventive concept underlying the claimed invention. On the other hand, where a person seeks to be substituted as the sole inventor, he has the additional burden of proving that the inventor named in the patent has not made any contribution to the inventive step.

In relation to the second question, the Lords held that the proceedings for entitlement under s37 of the Patents Act are different from those under ordinary procedural rules, such as the Civil Procedure Rules. The latter requires issuance of a Claim Form and assertion of cause of action, while entitlement proceedings under ordinary procedure rules are exclusively governed through their own limitation period and rules. Therefore, once the Comptroller receives a reference made to him within the prescribed limitation period, the subsequent amendment claiming a full entitlement would not render the present reference a new reference.

Having elucidated the law on the issue of patent entitlement, the House of Lords have now brought clarity and greater certainty to a subject that had become somewhat muddied after the decision of the Court of Appeal in Markem v Zipher. As with most patent entitlement cases, this again emphasises the importance of keeping clear and accurate records of who did what when developing new technologies, particularly when the technology arises out of a collaborative effort.