Teva et al. v Boehringer Ingelheim (EPO, T 251/25, 2026)

Dhenne Avocats · 23 October 2026

Our analysis

Summary

In a decision of 29 June 2026, published online on 29 September 2026 (T 0251/25), Technical Board of Appeal 3.3.04 of the EPO set aside the opposition division’s decision maintaining Boehringer Ingelheim’s EP 2 981 255 in amended form and revoked the patent, as the claimed therapeutic use of empagliflozin in preventing cardiovascular events was not made credible by the application as filed (Article 83 EPC).

Facts and procedure

EP 2 981 255, entitled « Therapeutic uses of empagliflozin », claims empagliflozin for use in preventing, reducing the risk of or delaying a cardiovascular event (cardiovascular death or heart failure requiring hospitalisation) in patients with type 1 or type 2 diabetes or pre-diabetes. Ten oppositions had been filed, including by Teva, Polpharma, Sandoz, Zentiva and STADA. The opposition division maintained the patent on the basis of auxiliary request 1, whose claim 1 is identical to claim 1 as granted. Dr Reddy’s Laboratories (UK) intervened in the appeal after being sued for infringement before the High Court of England and Wales, and the appeal was accelerated. The Board was chaired by M. Pregetter, with R. Hauss and A. Bacchin.

Question

Can data on cardiovascular biomarkers (oxidative stress, endothelial dysfunction, arterial stiffness) make credible, at the effective date, a therapeutic use aimed at preventing cardiovascular death and heart failure requiring hospitalisation?

Decision

Therapeutic effect is a functional technical feature of a further medical use claim and must be taken into account for sufficiency of disclosure (Reasons 3.2 and 3.3). It must be credible at the effective date on the basis of the application and common general knowledge. Clinical data are not always necessary, but may be required where credibility cannot be established otherwise, and post-filed evidence can only corroborate (Reasons 5.2 to 5.5). Interpreting point 77 of G 2/21, the Board holds that, absent conclusive data in the application, an opponent may discharge its burden with convincing arguments (Reasons 5.7). Examples 1 (diabetic rats) and 8 (type 1 diabetic patients) only concern biomarkers, and neither the application nor common general knowledge (review article D79) establishes the direct mechanistic link between improving them and reducing the claimed cardiovascular events (Reasons 5.13 and 5.14). The rosiglitazone example, with favourable biomarker effects but unfavourable cardiovascular safety, reinforces that doubt (Reasons 5.19). Post-filed evidence cannot fill the gap (Reasons 5.22). Auxiliary request 17, limited to cardiovascular death, fails for the same reason (Reasons 7.1 to 7.7). The decision under appeal is set aside and the patent revoked.

Key points for practice

• For a further medical use claim, the claimed efficacy must be made credible by the application itself: prognostic biomarkers are not enough without an established link between their improvement and the claimed clinical outcome (Reasons 5.14.4 to 5.14.6).
• The Board rejects the view that clinical data are never required: they may be needed where credibility cannot rest on another basis (Reasons 5.4).
• Where the application contains no conclusive data, an opponent may establish insufficiency through convincing arguments alone, the Board observing that the decisions cited in the Guidelines for requiring serious doubts substantiated by verifiable facts do not support that requirement (Reasons 5.7).
• The decision comes while infringement proceedings are pending in the UK against Dr Reddy’s, the intervener on appeal, and deprives Boehringer of the patent in all designated states.

Provisions applied

European Patent Convention

Articles 54(5), 83, 100(b) and 105 EPC

Rules of Procedure of the Boards of Appeal

Articles 10(3) and 13(2) RPBA

Case law cited

G 1/03, G 2/08, G 2/21, T 609/02, T 19/90, T 294/20, T 853/22

Prepared by Dhenne Avocats from the official decision (epo.org), consulted on 23 October 2026. Only the official text is authoritative.