MustBio entered into an agreement with Celltrion for the joint research and development and global commercialization of the MB4 program, a next-generation immuno-oncology drug candidate, on October 31, 2025.
αPD-1 x αVEGF x IL-2v fusion protein further potentiates the anti-tumor effect derived from the αPD-1 and IL-2v, through additional functions of the αVEGF, such as anti-angiogenesis, TME reprogramming, and TIL increasing effects.
MB4 selectively activates and expands immune cells in activated hPBMC (TME mimicking condition), with minimal effects on resting hPBMC (PB mimicking condition), enabling strong anti-tumor activity without affecting healthy tissues.
- CD8+ T cell expansion
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- in activated hPBMC (PD-1high)
- in resting hPBMC (PD-1low)
MB4, strong anti-tumor immunity with minimal peripheral effects
αPD-1/αVEGF/IL-2v demonstrates enhanced anti-tumor activity and increased tumor-infiltrating lymphocytes compared to bispecific antibodies, without promoting systemic immune cell expansion.
- Colon cancer syngeneic model
(C57BL/6 mice, MC38 inoculation, TV≈236 mm3 , n=7~8, ip, QWx2) 
- CD8+ T cells in tumor
- CD8+ T cells in periphery
