This is a Phase 1a/1b open-label, multicenter study with dose escalation and dose expansion cohorts to evaluate the safety, tolerability, PK and preliminary efficacy of HS-20089 in patients with advanced solid tumors.~The Dose Escalation will include an initial accelerated titration design followed by a Bayesian optimal interval (BOIN) design. Enrollment into Dose Expansion will begin after identification of the MTD and/or MAD in Phase 1a. In Phase 1b, preliminary efficacy will be evaluated in planned expansion cohorts that include patients with specific tumor types that are B7-H4+ advanced solid tumors.
HS-20089 is a novel DAR-6 antibody-drug conjugate （ADC） targeting B7-H4. In preclinical studies, it inhibited tumor cell growth expressing B7-H4 in vitro and in vivo. The first-in-human trial is conducted to assess the maximum tolerated dose (MTD) and dose limiting toxicity (DLT), to evaluate the pharmacokinetics, safety and preliminary anti-tumor activity of HS-20089 in Patients With Advanced Solid Tumors.