Alexion Pharmaceuticals v Novartis (EPO, G 1/22 and G 2/22, 2023)

Dhenne Avocats · 11 October 2026

Our analysis

Summary

In consolidated cases G 1/22 and G 2/22, the Enlarged Board of Appeal held that the EPO is competent to assess whether a party is entitled to claim priority under Article 87(1) EPC, and that there is a rebuttable presumption, under the autonomous law of the EPC, that an applicant claiming priority in accordance with Article 88(1) EPC is so entitled. Joint filing of a PCT application implies an agreement allowing the co-applicant to rely on the priority, unless there are substantial factual indications to the contrary, which makes challenges to “formal” priority in opposition harder.

Facts and procedure

PCT application WO 2005/110481, filed on 16 May 2005, claimed priority from a US provisional application of 14 May 2004 filed in the name of the three inventors. It named the inventors for the United States only, and Alexion and the University of Western Ontario for the other States. EP 1 755 674 was revoked following oppositions, the priority being held invalid for want of assignment by two of the inventors, so that intervening documents destroyed novelty (points 2 to 4). A divisional application having been refused on the same grounds, Board 3.3.04, hearing consolidated appeals T 1513/17 and T 2719/19, referred two questions on 28 January 2022.

The applicable law

Articles 87 to 89 EPC form a complete, self-contained code of rules on priority (point 25). Article 87(1) EPC, like Article 4A(1) of the Paris Convention, refers to the applicant “or his successor in title” (points 27 and 30). Under Article 60(3) EPC the applicant is deemed entitled to exercise the right to the European patent, disputes on that right being for national courts under the Protocol on Recognition (point 79).

Question

Is the EPO competent to assess whether a party is entitled to claim priority under Article 87(1) EPC and, if so, can party B, named in a PCT application for some States, rely on a priority filed by party A alone?

Decision

Having rephrased the first question (point 34), the Enlarged Board distinguished the title to the subsequent application, governed by national laws and assessed by national courts, from the priority right, an autonomous right created by the EPC and the Paris Convention (points 78, 79 and 84 to 86). The EPO, which already assesses the “where”, “what” and “when” requirements, is also competent for the “who” requirement (points 91 and 92).

No written form is required for the transfer, and even the requirement that the transfer precede the subsequent filing is questionable (points 99 and 100). Entitlement is presumed in favour of the subsequent applicant claiming priority under Article 88(1) EPC, given the cooperation required from the priority applicant (points 104 to 107). It may be rebutted only in rare cases, such as bad faith (point 108); it is assessed at the date priority is claimed (point 109), and the challenging party must demonstrate specific facts supporting serious doubts (point 110).

On the second question, the Board left open the validity of the “PCT joint applicants approach” (points 121 and 136) and held that joint filing establishes, absent substantial indications to the contrary, an implied agreement allowing party B to rely on the priority (points 125 and 136).

Key points for practice

• “Formal” priority is governed by the autonomous law of the EPC, without recourse to conflict of laws rules or national laws (points 85, 86 and 111).
• An opponent challenging entitlement bears the burden of proof and must establish specific facts; speculative doubts do not suffice (point 110).
• Joint filing of a PCT application amounts to an implied agreement on the use of the priority, absent substantial factual indications to the contrary (point 136).
• Practical point: the presumption does not cover the Article 88(1) EPC formalities, compliance with which must still be checked in any file exposed to an intervening publication (point 132).

Relevance before the UPC

The Enlarged Board noted that national courts dealing with validity are not bound by the EPO’s assessment and may examine entitlement to priority (point 115); the same issue arises before the UPC where a revocation action relies on intervening prior art.

Provisions applied

European Patent Convention

Art. 54, 60, 61, 72, 76, 87, 88, 89, 112(1)(a), 118, 139(2); Rule 14, 52, 53

Other instruments

Paris Convention, Arts 4 and 19; PCT, Art. 11(3); Protocol on Recognition; Vienna Convention on the Law of Treaties, Arts 31 and 32; Regulation (EC) No 593/2008 (Rome I)

National law

Germany: § 41 PatG; Netherlands: Patents Act, Art. 9; Switzerland: Patents Act, Art. 18(2)

Case law cited

G 3/92; G 3/93; G 1/97; G 2/98; G 2/04; G 1/15; G 1/19; J 15/80; J 19/87; J 11/95; T 1008/96; T 998/99; T 15/01; T 5/05; T 62/05; T 788/05; T 63/06; T 493/06; T 382/07; T 577/11; T 1933/12; T 2357/12; T 205/14; T 517/14; T 725/14; T 1201/14; T 239/16; T 419/16; T 2431/17; T 844/18; T 1946/21; BGH, X ZR 14/17 (Drahtloses Kommunikationsnetz); BGH, X ZR 49/12 (Fahrzeugscheibe); TGI Valence, 16 February 1962; Gerechtshof Den Haag, Biogen/Genentech v Celltrion, 30 July 2019; Edwards v Cook [2009] EWHC 1304 (Pat); Accord v RCT [2017] EWHC 2711 (Ch)

Related decisions

• Same invention, G 2/98, EPO Enlarged Board of Appeal, 31 May 2001, cited on the self-contained priority rules and on “substantive” priority.

Prepared by Dhenne Avocats from the text of the decision (epo.org, official English text), consulted on 11 October 2026. Only the official text is authoritative.