Astellas licenses MyoAAV capsid for XLMTM — low‑dose gene therapy enters clinic

Astellas Gene Therapies licensed Kate Therapeutics’ MyoAAV capsid and is developing ASP2957 (MyoAAV3.8‑MHCK7‑hMTM1) as a capsid‑engineered gene therapy for X‑linked myotubular myopathy (XLMTM). The program aims to improve uptake into muscle cells and enable lower systemic doses than prior AAV approaches; Astellas plans a Phase I/II VALOR trial to assess safety and preliminary efficacy. The move follows tragic outcomes in earlier XLMTM AAV trials and reflects an industry focus on capsid engineering to mitigate dose‑related risks. Astellas said the MyoAAV platform could allow substantially lower vector doses while achieving therapeutic protein expression; the VALOR trial is now recruiting under the IND for first‑in‑human testing.