SBI-183 is an orally active inhibitor of QSOX1 (Kd value of 20 μM), thereby suppressing the proliferative and invasive phenotype of two renal cancer cell lines (786-O and RCJ-41T2), a triple negative breast cancer (TNBC) cell line (MDA-MB-231), a lung adenocarcinoma cell line (A549), and a pancreatic ductal adenocarcinoma (MIA PaCa2). Moreover, SBI-183 inhibits tumor growth in two independent human xenograft mouse models of renal cell carcinoma.