GSK plc (LSE/NYSE: GSK) and Chimagen Biosciences (Chimagen), a privately held biotechnology company, announced an agreement for GSK to acquire CMG1A46, a clinical-stage dual CD19 and CD20-targeted T cell-engager (TCE), from Chimagen for $300 million upfront. 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.

For over a decade, GSK has been a pioneer in the treatment of lupus. This agreement underscores the importance of novel therapeutic approaches to address the heterogeneity of lupus manifestations and the continued burden, particularly in patients who suffer from severe disease and are refractory to current standard of care.¹

Tony Wood, Chief Scientific Officer, GSK, said: “Through our work in systemic lupus erythematosus and lupus nephritis, we increasingly understand the underlying drivers of B cell-driven diseases. As a novel therapeutic option directed at deep B cell depletion, CMG1A46 offers exciting potential which we are pleased to take forward to address unmet need in lupus and related autoimmune conditions.”

CD20 is an established target in the treatment of autoimmune diseases and there is growing clinical evidence that CD19 shows promise as a differentiated therapeutic approach given its presence on more B cell types.² 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.

Zhenhao Zhou, Chief Executive Officer, Chimagen, said: “We are excited by the potential of CMG1A46 to improve the lives of patients suffering from autoimmune conditions and grateful to have GSK accelerate that vision. This agreement provides further validation of our proprietary T cell-engager platform, and we are eager to continue our mission of developing novel multi-specific antibody therapeutics.”

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.