GSK to acquire trispecific T cell engager for multiple myeloma from Chimagen

GSK plc announced on September 15, 2026 that it has entered an agreement to acquire a potential best-in-class trispecific T cell-engager from Chimagen Biosciences, a privately held biotechnology company.¹ The company said it plans to develop and commercialize the asset for multiple myeloma, with the program expected to enter phase I trials in 2027.¹

The asset is designed differently from existing T cell engagers. GSK said TCEs have shown transformational efficacy in multiple myeloma but have been associated with difficult tolerability profiles, and the Chimagen trispecific asset is designed to address this by binding to T cells while simultaneously targeting two strategically selected and validated tumour-associated antigens.¹

On financial terms, GSK will pay an upfront fee to acquire full global rights to the TCE program, with Chimagen eligible for success-based development and commercial milestone payments, and the agreement has a total potential value of up to $750 million.¹ The deal remains subject to customary closing conditions.¹

This is not GSK's first deal with Chimagen. The agreement builds on GSK's existing relationship with Chimagen, following a previous agreement to acquire CMG1A46, a clinical-stage dual CD19 and CD20-targeted TCE currently in phase I trials for B-cell malignancies and B-cell dependent autoimmune disorders.¹

Chimagen describes itself as a clinical-stage biotechnology company focused on the discovery and development of novel multi-specific T cell-engagers and NK cell-engagers generated by proprietary antibody engineering platforms.¹