hIgG8.8-MTI1

hIgG8.8-MTI1 is a control antibody-drug conjugate (ADC) developed by Pfizer for use in preclinical oncology research. It consists of a non-targeting humanized monoclonal antibody (hIgG8.8) conjugated to MTI1, a proprietary microtubule inhibitor. In studies evaluating ADCs against targets such as the IL-13 receptor alpha 2 (IL-13Rα2), hIgG8.8-MTI1 serves as a negative control to demonstrate that the antitumor activity of target-specific ADCs (like hAB08-MTI1) is mediated by specific binding to the receptor rather than non-specific toxicity of the payload. Preclinical data has shown that while target-specific ADCs significantly reduce tumor growth in models like PC3MM2 and A375, the hIgG8.8-MTI1 control group typically shows tumor progression similar to vehicle controls.