GSK to Acquire Autoimmune Drug Candidate CMG1A46 from Chimagen Biosciences

GSK plc announced on October 29, 2024, an agreement to acquire CMG1A46, a clinical-stage T cell-engager, from the privately held biotechnology company Chimagen Biosciences for an upfront payment of $300 million. The company plans to develop and commercialize CMG1A46 for B cell-driven autoimmune diseases, including systemic lupus erythematosus (SLE) and lupus nephritis (LN).

CMG1A46 targets both CD19 and CD20 on B cells, aiming for deep depletion of these cells which are implicated in autoimmune conditions. This acquisition is intended to strengthen GSK's existing portfolio and research in lupus and related autoimmune diseases, addressing a significant unmet need for patients who do not respond to current treatments.

Preclinical studies suggest CMG1A46 can achieve rapid and deep B cell depletion in both blood and tissues, potentially leading to more durable patient responses. The drug candidate is currently in Phase I clinical trials for leukemia and lymphoma in the U.S. and China. GSK aims to initiate a Phase I trial in lupus patients in 2025.

Under the terms of the agreement, GSK will pay $300 million upfront for global rights to CMG1A46. Chimagen is also eligible to receive up to $550 million in success-based development and commercial milestone payments, bringing the potential total transaction value to $850 million.