Law applied:
Patent Act (PatG) § 81, § 99 (1); Code of Civil Procedure (ZPO) § 263
Summary:
a) A change of party and thus also the joinder of another party as plaintiff can be declared as long as the legal dispute is pending.
b) An effective declaration of accession does not lose its effect if the first plaintiff withdraws the complaint and the declaration of withdrawal is served on the defendant before the declaration of accession.
EPÜ Art. 87
There is a rebuttable but strong presumption in favor of the right to claim priority (confirmation by the EPO, decision of October 10, 2023 - G 1/22, para. 86, para. 101 et seq. and para. 122 - right to priority; Federal Supreme Court (BGH), judgment of November 28, 2023 - X ZR 83/21, GRUR 2024, 374 para. 110 et seq. - Sorafenib-Tosylat; Judgment of January 9, 2024 - X ZR 74/21, GRUR 2024, 603 para. 67 et seq. - Happy Bit).
Federal Supreme Court, judgment of July 15, 2025 - X ZR 98/23, GRUR-RS 2025, 20249
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