UT-105 is an orally active, selective androgen receptor (AR) degrader that binds the AR N-terminal domain, suppresses AR transactivation, blocks AR recruitment to androgen response elements, and promotes AR degradation. It also inhibits the JAK-STAT signaling pathway by reducing interferon-stimulated gene expression, inhibiting STAT1 and STAT3 phosphorylation, and blocking STAT1 recruitment to response elements. UT-105 shows anticancer activity in AR-positive triple-negative breast cancer (TNBC) and is useful for research on selective androgen receptor modulator-resistant ER-positive breast cancer and triple-negative breast cancer.