Introduction

The case of Eli Lilly v Actavis UK Ltd & Ors ([2017] UKSC 48) represents a significant milestone in the interpretation and enforcement of patent laws within the United Kingdom and across multiple European jurisdictions. The core of the dispute revolved around whether Actavis's alternative formulations of an anti-cancer drug infringe upon Eli Lilly's patent for pemetrexed disodium. This comprehensive commentary delves into the intricacies of the case, elucidating the background, judicial findings, and the broader implications for patent law.

Summary of the Judgment

The United Kingdom Supreme Court, led by Lord Neuberger, upheld Eli Lilly's appeal against Actavis, determining that Actavis's products directly infringed Lilly's patent not only in the UK but also in France, Italy, and Spain. The Supreme Court dismissed Actavis's cross-appeal, which contested the finding of indirect infringement. The judgment centered on the application of the doctrine of equivalents and the proper interpretation of patent claims, particularly in the context of equivalent compounds used in pharmaceutical formulations.

The patent in question, European Patent (UK) No 1 313 508, claimed the use of pemetrexed disodium combined with vitamin B12 for cancer treatment. Actavis introduced alternative salts of pemetrexed, arguing that since their products did not specifically contain pemetrexed disodium, they did not infringe the patent. However, the Supreme Court found that these alternatives were equivalent and thus fell within the scope of the patent's protection.

Analysis

Precedents Cited

The judgment extensively referenced pivotal cases that have shaped the doctrine of equivalents in the UK and other European jurisdictions. Notably:

• Catnic Components Ltd v Hill & Smith Ltd [1982] RPC 183: Established the foundational approach to determining equivalence beyond literal infringement.
• Improver Corporation v Remington Consumer Products Ltd [1990] FSR 181: Introduced the three-question test for assessing equivalence.
• Kirin-Amgen Inc v Hoechst Marion Roussel Ltd [2005] RPC 9: Reinforced the purposive construction of patent claims and criticized the extension of monopoly through the doctrine of equivalents.
• Epilady Cases in Germany, Italy, and the Netherlands: Demonstrated how equivalent assessments are approached differently across European courts, influencing the Supreme Court's analysis.

These precedents collectively informed the Supreme Court's approach to interpreting patent claims and assessing infringement through equivalence, emphasizing a balance between patentee protection and legal certainty for third parties.

Legal Reasoning

The Supreme Court's legal reasoning hinged on two primary issues: direct infringement through equivalent compounds and the applicability of the doctrine of equivalents in a multi-jurisdictional context. The Court redefined the Improver test, adapting it to align more closely with practices in Germany, Italy, and the Netherlands. The reformed questions focus on whether the variant achieves the same result in the same way, whether this would be obvious to a skilled person, and whether strict compliance with the literal claim language was intended by the patentee.

Importantly, the Court emphasized that the prosecution history—i.e., the amendments made during the patent application process—should be considered cautiously and only in specific circumstances to avoid altering the claim scope improperly. This nuanced approach ensures that patents are interpreted based on their claims and specifications while allowing for flexibility through the doctrine of equivalents.

Impact

The judgment has profound implications for patent holders and pharmaceutical companies operating within and across European jurisdictions. By clarifying the application of the doctrine of equivalents, the Supreme Court has reinforced the protection of patented inventions against slight variations that do not materially change their function or efficacy.

Additionally, the alignment of the UK's approach with that of Germany, Italy, and the Netherlands fosters greater consistency in patent law enforcement across Europe, reducing ambiguity and enhancing predictability for businesses. This harmonization is particularly crucial in the pharmaceutical sector, where minor chemical variations can lead to significant legal disputes over patent infringement.

Complex Concepts Simplified

Doctrine of Equivalents

The doctrine of equivalents allows a patent holder to claim infringement even when an accused product or process does not fall within the literal wording of the patent claims, provided that the differences are insubstantial. This ensures that slight modifications by competitors do not circumvent patent protections.

Improver Test

Originally established in Improver Corp v Remington Consumer Products, the three-question test assesses whether:

1. The variant achieves the same result in the same way as the patented invention.
2. The modification would have been obvious to a skilled person at the time of the patent.
3. The patentee intended the claims to cover the variant.

Prosecution History

Prosecution history refers to all documents and communications between the patent applicant and the patent office during the application process. While typically used sparingly in claim interpretation, it can influence the understanding of the scope of patent protection.

Conclusion

The Supreme Court's decision in Eli Lilly v Actavis UK Ltd & Ors underscores the delicate balance patent law must maintain between protecting inventors and ensuring market competition. By refining the doctrine of equivalents and aligning it with broader European practices, the Court has provided clearer guidelines for assessing patent infringement. This not only fortifies the rights of patent holders like Eli Lilly but also sets a robust framework for future litigation, promoting fairness and legal certainty in the pharmaceutical industry and beyond.