X0508 4 2026-02-02 0001733294 Generation Bio Co. GBIO 0002051408 Conway Kevin John C/O GENERATION BIO CO. 301 BINNEY ST, SUITE 401 CAMBRIDGE MA 02142 false true false false Chief Financial Officer 0 Common Stock 2026-02-02 4 M 0 235 A 2144 D Common Stock 2026-02-02 4 F 0 72 5.64 D 2072 D Restricted Stock Units 2026-02-02 4 M 0 235 0 D Common Stock 235 0 D Each restricted stock unit represents the right to receive one share of the company's common stock. 2. The grant of 9,390 restricted stock units was made on January 20, 2023. Pursuant to the terms of that certain Agreement and Plan of Merger, by and among the Issuer, XOMA Royalty Corporation ("Parent") and Parent's wholly-owned subsidiary, XRA 7 Corp., dated as of December 15, 2025 (the "Merger Agreement"), prior to the effective time of the merger as contemplated by the Merger Agreement, each restricted stock unit of the Issuer that was outstanding and unvested became vested in full on February 2, 2026. /s/ Shawna-Gay White, Attorney-in-Fact 2026-02-04