On September 15, 2026, GSK plc (“GSK”) announced that it agreed to acquire a trispecific T cell-engager (“TCE”) from Chimagen Biosciences (“Chimagen”), a privately held biotechnology company. GSK plans to develop and commercialize the asset for multiple myeloma, with phase I trials expected to begin in 2027.
According to the announcement, TCEs have shown transformational efficacy in multiple myeloma but have been associated with difficult tolerability profiles. The Chimagen trispecific TCE aims to address this by binding to T cells while simultaneously targeting two validated tumor-associated antigens. This targeted approach aims to achieve a more durable response and improved tolerability profile compared to existing TCEs, which could enable broader adoption and earlier use in multiple myeloma treatment.
Under the terms of the agreement, GSK will acquire full global rights to the TCE program and Chimagen will be eligible to receive success-based development and commercial milestone payments. The agreement has a total potential value of up to $750 million.
This is GSK’s second deal with Chimagen. In October 2024, GSK acquired CMG1A46, a dual CD19/CD20-targeted TCE now in Phase I trials for B-cell malignancies and B-cell-dependent autoimmune disorders.