The case of Actavis UK Ltd. vs. Eli Lilly & Co. is a landmark decision by the UK Supreme Court on the application of the doctrine of equivalents in determining patent infringement. The case revolved around whether Actavis’s products infringed Eli Lilly’s European Patent (UK) No. 1 313 508, which covered a specific use of pemetrexed disodium in cancer treatment. This judgment significantly impacted UK patent law by broadening the scope of patent claims beyond their literal meaning, aligning the UK approach with other European jurisdictions.

Factual Background
Eli Lilly owned a patent for the use of pemetrexed disodium in combination with vitamin B12 to reduce the toxic effects of chemotherapy. The patent explicitly referred to pemetrexed disodium, a specific salt form of the active compound. Actavis sought to market alternative pemetrexed formulations—pemetrexed diacid, pemetrexed dipotassium, and pemetrexed ditromethamine—arguing that these formulations fell outside the literal wording of the patent claims and therefore did not infringe.

Procedural Background
The case was initially heard by the High Court, which ruled in favor of Actavis, holding that its products did not directly or indirectly infringe Eli Lilly’s patent. The Court of Appeal partially reversed this decision, finding indirect infringement but rejecting direct infringement claims. Eli Lilly then appealed to the Supreme Court, arguing that Actavis’s products should be considered infringing under the doctrine of equivalents.

Issues Involved
The key issue in this case was whether Actavis’s products, which did not literally fall within the scope of the patent claims, could still be considered infringing under the doctrine of equivalents. Additionally, the court had to determine whether the prosecution history of the patent could be used as an aid in claim interpretation and whether Actavis’s formulations constituted indirect infringement.

Submissions of the Parties
Eli Lilly contended that despite the literal wording of the patent referring to pemetrexed disodium, the invention was intended to cover all forms of pemetrexed that achieved the same therapeutic effect. It argued that Actavis’s products were functionally equivalent to pemetrexed disodium and that excluding them from the scope of the patent would undermine the purpose of patent protection.

Actavis argued that the claims of the patent specifically mentioned pemetrexed disodium and did not include other salt forms of pemetrexed. It contended that allowing such an expansive interpretation would violate legal certainty and unfairly broaden the patent’s scope beyond what was disclosed and claimed.

Discussion on Cited Judgments
The court relied on several key cases in reaching its decision. The judgment referred to Catnic Components Ltd. v. Hill & Smith Ltd. [1982] RPC 183, where Lord Diplock introduced the concept of purposive construction in patent law, emphasizing that minor variations should not escape infringement if they do not affect the invention’s core function. Another critical reference was Kirin-Amgen Inc. v. Hoechst Marion Roussel Ltd. [2005] RPC 9, where the House of Lords had rejected the doctrine of equivalents in favor of purposive construction.

Additionally, the court considered Improver Corp. v. Remington Consumer Products Ltd. [1990] FSR 181, which introduced a three-step test for determining whether a variant product infringes a patent. The Supreme Court also examined European patent jurisprudence, including decisions from German and Dutch courts, which had consistently applied the doctrine of equivalents to extend patent protection beyond the literal claim wording.

Reasoning and Analysis of Judge
Lord Neuberger, delivering the judgment of the court, held that Actavis’s products infringed Eli Lilly’s patent under the doctrine of equivalents. The court adopted a new test for determining equivalence, asking three questions: whether the variant achieves substantially the same result in substantially the same way, whether this would have been obvious to a person skilled in the art at the priority date, and whether strict compliance with the claim language was an essential requirement. The court ruled that Actavis’s products satisfied these criteria and thus infringed Eli Lilly’s patent.

The judgment also clarified the role of prosecution history in claim interpretation. While generally disfavoring its use, the court acknowledged that it could be considered in exceptional cases where the patentee had made clear representations limiting the claim scope. In this case, the court found that the prosecution history did not preclude a finding of infringement.

Final Decision
The Supreme Court allowed Eli Lilly’s appeal, holding that Actavis’s products directly infringed the patent in the UK, France, Italy, and Spain. The court dismissed Actavis’s cross-appeal, affirming that if the products did not directly infringe, they would still infringe indirectly. This decision marked a significant shift in UK patent law, embracing the doctrine of equivalents and aligning the UK approach with other European jurisdictions.

Law Settled in This Case
The doctrine of equivalents applies in UK patent law, allowing patent claims to cover variants that achieve the same result in substantially the same way. The test for equivalence includes assessing whether the variant is functionally the same, whether this would be obvious to a skilled person, and whether strict compliance with claim language is essential. Prosecution history may be considered in claim interpretation but only in limited circumstances. Indirect infringement remains applicable when a third party supplies an essential element of a patented invention, even if it does not fall within the literal scope of the claims. This case reinforced the balance between fair patent protection and legal certainty, ensuring that minor variations do not allow infringers to escape liability.

Case Title: Actavis UK Ltd. Vs. Eli Lilly & Co.
Date of Order: 12 July 2017
Case No.: [2017] UKSC 48
Neutral Citation: [2017] UKSC 48
Name of Court: Supreme Court of the United Kingdom
Name of Judge: Lord Neuberger, Lord Mance, Lord Clarke, Lord Sumption, Lord Hodge

Disclaimer: The information shared here is intended to serve the public interest by offering insights and perspectives. However, readers are advised to exercise their own discretion when interpreting and applying this information. The content herein is subjective and may contain errors in perception, interpretation, and presentation.

Written By: Advocate Ajay Amitabh Suman, IP Adjutor - Patent and Trademark Attorney
Email: ajayamitabhsuman@gmail.com, Ph no: 9990389539