S19-1035

S19-1035 is a potent and highly selective small molecule inhibitor of aldo-keto reductase 1C3 (AKR1C3). AKR1C3 is an enzyme overexpressed in various hormone-related malignancies, including breast and prostate cancers, where it plays a critical role in tumor progression and the development of resistance to anthracycline-based chemotherapy. By specifically inhibiting AKR1C3, S19-1035 prevents the metabolic inactivation of drugs like doxorubicin, thereby restoring chemosensitivity in resistant cancer cells. In preclinical studies, S19-1035 demonstrated an IC50 of 3.04 nM and over 3000-fold selectivity against other AKR1C isoforms, making it a promising adjuvant candidate for breast cancer treatment.