I-Mab provides update on TJ-L14B/ABL503 antibody developments

I-Mab announced multiple recent developments in TJ-L14B/ABL503, a differentiated PD-L1 x 4-1BB bispecific antibody developed in collaboration with ABL Bio. TJ-L14B/ABL503 is designed to address tumors resistant to PD-(L)1 antibodies through its unique ability to conditionally activate 4-1BB upon binding to its target, PD-L1. I-Mab owns 50% of the global rights of TJ-L14B/ABL503. On September 7, 2023, TJ-L14B/ABL503 successfully obtained patent registration in eight Eurasian countries. The patent secures patent rights extending through 2039. Patent examinations are currently underway in over 20 countries, including the U.S., China, and Europe. TJ-L14B/ABL503 is currently being investigated in a Phase 1 dose-escalation study in patients with progressive, locally advanced or metastatic solid tumors who are relapsed or refractory following prior lines of treatment. Currently, I-Mab has observed 1 complete response, 1 partial response, and 2 patients who achieved an unconfirmed objective response upon recent enrollment. The maximum tolerated dose has not yet been reached. The company anticipates presenting the top-line Phase 1 clinical data at a major medical conference in the first half of 2024. Being developed jointly with ABL Bio, TJ-L14B/ABL503 is a differentiated PD-L1-based bispecific antibody. Preclinical studies have demonstrated that the bispecific antibody shows better anti-tumor activity than equimolar doses of single agents alone or in combination. A Phase 1 study is currently being conducted in the U.S. and South Korea.