GSK acquires autoimmune T cell engager from Chimagen for $300M upfront

GSK is making a strategic acquisition by purchasing an antibody from Chimagen Biosciences to potentially treat autoimmune diseases. The UK-based pharmaceutical company will pay $300 million upfront for global rights to Chimagen's antibody, CMG1A46, with additional milestone payments that could total $550 million. GSK aims to test this T cell engager in conditions such as lupus erythematosus and lupus nephritis.

This move by GSK follows Merck's recent $700 million acquisition of a bispecific antibody from Curon, which targets CD3xCD19 for treating B cell cancers and autoimmune diseases. GSK has prior experience in the lupus treatment space, having developed and marketed Benlysta, a medication widely used for managing lupus.

Chimagen Biosciences, founded in 2016 by Zhenhao Zhou and Jie Zhang in Shanghai, specializes in multi-specific antibodies. CMG1A46, their leading compound, is currently undergoing early-stage clinical trials in the US and China for leukemia and lymphoma. GSK plans to initiate Phase 1 trials for lupus with this antibody in 2025. Although CMG1A46 is Chimagen’s sole compound in clinical trials, the company is also working on other preclinical candidates.

CMG1A46 is a trispecific antibody that targets CD19 and CD20 proteins on B cells, as well as CD3 on T cells. The concept is that T cells can attack the unregulated B cells, which are significant contributors to the disease process. Pharmaceutical companies are exploring the use of T cell engagers and cell therapies as potential treatments for various autoimmune disorders.

In the oncology field, the safety profile of T cell engagers has raised some concerns. However, GSK claims that CMG1A46 has a low affinity for CD3, which could mitigate the toxicities typically associated with T cell engagers.