Actavis v Eli Lilly (UKSC, [2017] UKSC 48, 2017)

Dhenne Avocats · 11 October 2026

Our analysis

Summary

The UK Supreme Court held that Actavis’s products, combining vitamin B12 with the free acid or other salts of pemetrexed, directly infringed Eli Lilly’s patent claiming the use of pemetrexed disodium only, in the United Kingdom and also in France, Italy and Spain. Lord Neuberger separated normal interpretation of the claim from the question of immaterial variants, reformulated the Improver questions and allowed limited recourse to the prosecution file.

Facts and procedure

European Patent (UK) No 1 313 508, with a priority date of 30 June 2000, claims in Swiss form the use of pemetrexed disodium in the manufacture of a medicament to be administered with vitamin B12 (paras 4, 12 and 21). The Actavis products contain pemetrexed diacid, ditromethamine or dipotassium (para 8). Arnold J found no direct or indirect infringement in any of the four states; the Court of Appeal found indirect but not direct infringement. Lilly appealed on direct infringement and Actavis cross-appealed on indirect infringement (para 9).

The applicable law

Direct infringement falls under section 60(1) of the Patents Act 1977, read under section 130(7) consistently with the EPC: Article 69 EPC and its Protocol, Article 2 of which requires due account to be taken of equivalent elements (paras 28 to 33). The Court reviewed Catnic, Improver and Kirin-Amgen and the approaches of other contracting states (paras 35 to 52). Indirect infringement falls under section 60(2) (para 104).

Question

Does a claim clearly limited to pemetrexed disodium extend to other forms of pemetrexed, and does the prosecution history, in which the limitation followed the examiner’s objections, stand in the way?

Decision

Infringement is approached through two issues: does the variant infringe as a matter of normal interpretation and, if not, does it nonetheless infringe because it varies from the invention in an immaterial way (para 54)? The second is not one of interpretation (paras 55 and 56); on the first, the Actavis products are not covered (para 58). The Court reformulated the Improver questions (para 66): does the variant achieve substantially the same result in substantially the same way as the inventive concept; would it be obvious to the skilled person, knowing that the variant achieves that result, that it does so in substantially the same way; would the reader have concluded that the patentee intended strict compliance with the literal meaning to be an essential requirement? The second question now assumes that the variant works (paras 61 and 62) and also applies to post-priority developments (para 63). Here the first two questions were answered yes (paras 68 and 69), and the third no: the limitation to the disodium salt reflected the fact that only that salt had been tested in the patent, which confuses disclosure with scope of protection (paras 70 to 75). The prosecution file may be referred to only where the point is truly unclear and the file unambiguously resolves it, or where ignoring it would be contrary to the public interest (paras 87 and 88); here the examiner’s objections concerned disclosure and added matter and had no bearing on equivalents (paras 89 to 91). Direct infringement was also found in France, as a case of moyens généraux, and in Italy and Spain (paras 92 to 102). The cross-appeal failed: once diluted in saline, the product contains pemetrexed disodium (paras 105 to 113).

Key points for practice

• Scope of protection is determined in two distinct steps, normal interpretation then equivalents (para 54).
• The reformulated second question assumes that the variant works, which lightens the patentee’s burden (para 62).
• Practical point: a claim limitation accepted in answer to a disclosure or added matter objection does not, of itself, deprive the patentee of equivalents (para 89).

Relevance before the UPC

As the UPC applies Article 69 EPC and its Protocol, the reformulated test and the comparative review of national approaches (paras 44 to 52) may inform arguments on equivalents before it.

Provisions applied

European Patent Convention

Art. 69; Art. 128; Protocol on the Interpretation of Article 69, Arts 1 and 2

National law

Patents Act 1977, sections 60(1), 60(2) and 130(7)

Case law cited

Catnic Components v Hill & Smith [1982] RPC 183; Improver v Remington [1990] FSR 181; Kirin-Amgen v Hoechst Marion Roussel [2005] RPC 9; Wood v Capita Insurance Services [2017] 2 WLR 1095; BGH, X ZR 168/00 (Schneidmesser I); BGH, X ZR 29/15; OLG Munich, 6 U 3039/16; Hoge Raad, Ciba-Geigy v Oté Optics

Related decisions

• Pemetrexed, BGH, 14 June 2016, German decision on the same patent, cited on the prosecution history (paras 84 and 91).

Prepared by Dhenne Avocats from the text of the decision (UK Supreme Court website, PDF of the judgment), consulted on 11 October 2026. Only the official text is authoritative.