Innovent Biologics, Inc. announced that the first patient was dosed in Australia for its proprietary anti-Claudin18.2 monoclonal antibody-drug conjugate(ADC) (R&D code: IBI343) in Phase I clinical trial for the treatment of patients with advanced solid tumors. It is the first ADC candidate drug to enter clinical phase in Innovent's pipeline. The study (NCT05458219) is an open-label, multi-center Phase I study evaluating the safety, tolerability, and preliminary efficacy of IBI343 in subjects with advanced solid tumors, and to determine the maximum tolerated dose (MTD) and/or the recommended Phase 2 dose (RP2D).

IBI343 is a recombinant human anti-Claudin 18.2 monoclonal ADC. After IBI343 binds to the Claudin 18.2-expressing tumor cells, the Claudin 18.2 dependent ADC internalization occurred and the drug is released resulting in DNA damage and eventually apoptosis of the tumor cells. The freed drug can also diffuse across the plasma membrane to reach and kill the neighboring cells, resulting in "bystander killing effect".

In both Claudin 18.2 high and low expression mice tumor bearing models, IBI343 exhibited potent tumor growth inhibition efficacy, and it also demonstrated tolerable safety profile in preclinical in vivo models.