MQI-191

MQI-191 is a preclinical-stage antibody-drug conjugate (ADC) being developed for the treatment of solid tumors, specifically prostate cancer. Jointly discovered by Mabqi and Syndivia, the candidate was generated using Mabqi's LiteMab© Antibody Discovery Studio to identify a highly specific fully human antibody, which was subsequently conjugated using Syndivia's GeminiMab™ site-specific conjugation platform. This platform enables hinge-region site-specific conjugation of native antibodies to achieve a precise drug-to-antibody ratio (DAR) of 1, preserving native glycosylation, antibody flexibility, and structural integrity. In preclinical models, MQI-191 has demonstrated robust antitumor activity, including complete tumor regression, alongside an excellent safety profile. In early 2026, Syndivia exercised its option on the candidate, which was subsequently out-licensed to an undisclosed pharmaceutical company for further clinical development.