GSK plc (NYSE: GSK) announced on Tuesday that it has entered into an agreement with Chinese biotech firm Chimagen Biosciences to acquire global rights to a trispecific T-cell engager (TCE), with a total transaction value of up to $750 million.

Under the terms, GSK will make an upfront payment, while Chimagen remains eligible for additional payments tied to drug development and commercialization milestones. The trispecific TCE is an engineered protein designed to bring T cells into proximity with tumor cells while simultaneously blocking immune checkpoints, thereby enhancing the ability to kill cancer cells and reducing off-target effects.

GSK intends to develop this asset for the treatment of multiple myeloma, with a Phase I clinical trial expected to begin in 2027. Notably, this marks the second trispecific TCE that GSK has acquired from Chimagen. In October 2024, GSK announced the acquisition of CMG1A46, a clinical-stage CD19- and CD20-targeting TCE, from the same company.

GSK plans to develop and commercialize CMG1A46 for B-cell-driven autoimmune diseases such as systemic lupus erythematosus (SLE) and lupus nephritis (LN), with potential expansion into related autoimmune indications. Per the earlier agreement, GSK paid $300 million upfront to secure global rights to CMG1A46, and Chimagen is also entitled to development and commercialization milestone payments totaling $550 million.

Tuesday's latest deal is part of GSK's broader strategy under new CEO Luke Miels to expand its oncology franchise, addressing the looming patent expiration risk for its top-selling HIV drug. Earlier this year, GSK completed a $10.6 billion acquisition of lung cancer drug developer Nuvalent, marking the company's largest purchase in over a decade. In October 2025, the U.S. Food and Drug Administration (FDA) approved GSK's blood cancer drug Blenrep for use in combination regimens, allowing the therapy to return to the market after nearly three years off it.