IMMU-132 in TROP-2 Overexpressed Advanced and Relapsed Ovarian Cancer

Trophoblast cell surface antigen-2 (TROP-2) is overexpressed in a variety of epithelial-derived tumor tissues and represents a promising antitumor therapeutic target. Novel antibody-drug conjugates (ADCs) targeting TROP-2, such as IMMU-132 (SG), Datopotamab Deruxtecan (Dato-DXd), and Sacituzumab Tirumotecan (MK-2870), are under active development. In ovarian cancer, efficacy data for TROP-2 ADCs mainly derive from pan-solid tumor clinical studies. TROP-2 expression exhibits intratumoral heterogeneity. Currently, there is no standardized or internationally accepted guideline for evaluating TROP-2 expression. TROP-2 expression status can be assessed using the H-score scoring system: 0-100 as low expression, 100-200 as moderate expression, and \>200 as high expression. An exploratory analysis of the ASCENT study in triple-negative breast cancer, which categorized TROP-2 expression as high, moderate, or low based on H-score, found that patients with high expression had double the efficacy compared to those with moderate expression (44% vs 22%). Therefore, subsequent studies are warranted to explore effective screening criteria for TROP-2 ADC drugs to achieve more precise diagnosis and treatment. Our center has observed that among 3 patients with heavily pretreated recurrent ovarian cancer and high TROP-2 expression in tumor tissue, 1 achieved a complete response (CR) and 2 achieved partial responses (PR) following SG monotherapy. Safety was favorable, with main side effects being grade 1-2 gastrointestinal reactions and no grade 3-5 adverse reactions. Accordingly, this study will prospectively observe the efficacy of IMMU-132 monotherapy in patients with advanced or recurrent ovarian cancer characterized by high TROP-2 expression in tumor tissue.