GSK has reached an agreement with Chimagen Biosciences, a privately held biotechnology company, to acquire CMG1A46, a clinical-stage dual CD19 and CD20-targeted T cell-engager (TCE), from Chimagen for $300 million. GSK plans to develop and commercialise CMG1A46 with a focus on B cell-driven autoimmune diseases, such as systemic lupus erythematosus (SLE) and lupus nephritis (LN), with potential to expand into related autoimmune diseases.

CD20 is an established target in the treatment of autoimmune diseases whilst there is growing clinical evidence that CD19 shows promise as a differentiated therapeutic approach given its presence on more B cell types. In preclinical studies, CMG1A46, designed to target both CD19 and CD20, has shown rapid, deep B cell depletion both in the bloodstream and in tissues which could lead to more durable responses in patients.

CMG1A46 is currently in phase I clinical trials in leukaemia and lymphoma in both the US and China. GSK aims to begin a phase I trial in lupus in 2025.