GSK has entered an agreement to acquire a potential best-in-class trispecific T cell-engager (TCE) from Chimagen Biosciences for the treatment of multiple myeloma, with the program expected to enter phase 1 trials in 2027, GSK announced September 15, 2026.¹ The deal has a total potential value of up to $750 million, including an upfront payment for full global rights plus success-based development and commercial milestones.
Key facts
- Asset: Trispecific T cell-engager (TCE); Chimagen Biosciences, acquired by GSK
- Indication: Multiple myeloma
- Mechanism: Binds T cells plus 2 validated tumor-associated antigens
- Deal terms: Upfront payment; up to $750 million total with milestones
- Deal scope: Full global rights to the program
- Milestone: Expected to enter phase 1 trials in 2027
- Disease burden: ~180,000 new multiple myeloma cases globally per year; not curable
- Prior deal: GSK previously acquired CMG1A46 (dual CD19/CD20 TCE) from Chimagen
- Geography: Global development and commercialization rights
"Today's deal secures a promising T cell engager and advances GSK's leadership goals in blood cancer," said Hesham Abdullah, MD, MSc, senior vice president and global head oncology, R&D, at GSK, in a company press release.¹ "The agreement complements our existing portfolio in multiple myeloma, adding a new potential option to address the different needs of patients facing this complex disease."
How is this trispecific TCE designed to differ from existing therapies?
TCEs have shown transformational efficacy in multiple myeloma but have been associated with difficult tolerability profiles, including cytokine release syndrome and elevated infection risk.¹,² Current B-cell maturation antigen-targeted TCEs, for example, have been associated with cytokine release syndrome in roughly half of treated patients in some studies, alongside elevated rates of severe infection, underscoring the rationale for therapies designed with an improved tolerability profile.² The Chimagen asset is designed to address this by binding T cells while simultaneously targeting 2 strategically selected and validated tumor-associated antigens, an approach intended to achieve a deeper and more durable response than existing TCEs along with improved tolerability, potentially enabling broader adoption and earlier use in multiple myeloma treatment.¹
How big is the market opportunity, and what is the disease burden?
The US TCE market for multiple myeloma is expected to exceed $10 billion by 2032.¹ Multiple myeloma is the third most common blood cancer globally, with approximately 180,000 new cases diagnosed each year.¹,³ While generally considered treatable, it is not currently curable, and the disease commonly becomes refractory to available treatments, highlighting the need for new therapeutic options.¹,³
"Our mission has always been to translate cutting-edge innovation into life-changing medicines," said Zhenhao Zhou, founder and CEO of Chimagen Biosciences, in the release.¹ "Working with GSK combines our precision T-cell engager [program] with their global development and commercial capabilities to redefine care for multiple myeloma patients. This agreement also marks another major milestone for our platforms as we continue to build an industry-leading pipeline of multi-specific antibody candidates."
How does this fit into GSK and Chimagen's broader relationship?
This agreement builds on GSK's existing relationship with Chimagen, following an earlier deal to acquire CMG1A46, a clinical-stage dual CD19- and CD20-targeted TCE currently in phase 1 trials for B-cell malignancies and B-cell-dependent autoimmune disorders.¹ The deal also fits GSK's broader oncology strategy of acquiring differentiated assets with validated targets and expanding beyond its current focus on blood and women's cancers into lung, gastrointestinal, and other solid tumors, including priority programs such as the antibody-drug conjugates Ris Rez and Mo-Rez and the KIT inhibitor velzatinib.¹
What are the limitations?
The trispecific TCE has not yet entered clinical trials, and no human safety or efficacy data yet exist. The program is not expected to begin phase 1 testing until 2027. The agreement remains subject to customary closing conditions.
References
- GSK. GSK to acquire potential best-in-class T cell-engager (TCE) for multiple myeloma from Chimagen Biosciences. Press release. Published September 15, 2026. Accessed September 15, 2026. https://www.gsk.com/en-gb/media/press-releases/gsk-to-acquire-potential-best-in-class-t-cell-engager-tce-for-multiple-myeloma-from-chimagen-biosciences/
- Piron B, Moreau P, Touzeau C. Teclistamab for relapsed or refractory multiple myeloma: a review of efficacy, safety, resistance mechanisms and future directions. Biologics. 2026;20:539066. doi:10.2147/BTT.S539066
- Sung H, Ferlay J, Siegel RL, et al. Global cancer statistics 2020: GLOBOCAN estimates of incidence and mortality worldwide for 36 cancers in 185 countries. CA Cancer J Clin. 2021;71(3):209-249. doi:10.3322/caac.21660
