TJ-L14B + ABL503

**TJ-L14B + ABL503** is an investigational **PD-L1 x 4-1BB bispecific monoclonal antibody** co-developed by **I-Mab** and **ABL Bio** for the treatment of **progressive, locally advanced or metastatic solid tumors** that have relapsed or are refractory after prior therapy. The molecule was designed using ABL Bio's Grabody-T platform to provide **conditional 4-1BB co-stimulation in the presence of PD-L1-expressing tumor cells**, aiming to enhance tumor-directed T-cell activation while reducing the systemic hepatotoxicity and off-tumor immune activation historically associated with 4-1BB agonism. Its PD-L1-binding arm localizes the antibody to the tumor microenvironment and blocks the PD-L1 checkpoint axis, while its 4-1BB-binding arm acts as a tumor-dependent agonist to promote T-cell activation. The program has been reported in Phase 1 clinical development in the United States and South Korea for advanced solid tumors.

Brand names

ragistomig

Other names

PD-L1 x 4-1BB bispecific antibodyPD-L-1 x 4-1BB bispecific antibodyPD-L 1 x 4-1BB bispecific antibody