First-in-Human Trial Shows Experimental Antibody-Drug Conjugate Shrinks Ovarian, Endometrial, and Breast Tumors

A Phase 1/2a clinical trial (BLUESTAR study) of the experimental antibody-drug conjugate AZD8205 (puxitatug samrotecan), which targets the B7-H4 protein, has reported partial tumor responses in patients with advanced or metastatic ovarian, endometrial, and breast cancer. This marks the first human evaluation of this agent. While patient numbers were small and responses partial, the drug demonstrated a manageable toxicity profile and objective responses at biologically active doses, positioning it as a promising agent in early-phase testing for hard-to-treat solid tumors.