Abcuro raised $66 million through a Series D to advance ulviprubart for inclusion body myositis, a progressive muscle disorder with no approved therapies in the US. The company said the funding will support a registrational clinical study and includes plans to prepare a clinical trial in the fourth quarter of 2026. Ulviprubart is designed as a monoclonal antibody intended to selectively deplete highly cytotoxic T cells implicated in IBM. Abcuro pointed to encouraging signals from a Phase II/III MUSCLE study (NCT05721573), noting a trend in a prespecified subgroup despite not meeting the overall primary endpoint. The financing matters for rare immunology-driven neuromuscular disease—where small patient populations can amplify the importance of subgroup effects and biomarker strategy for future registration.