Phase I Study of SYS6043 in Patients With Advanced/Metastatic Solid Tumors

This is a multicenter, open-label, Phase I study of dose escalation, PK expansion, and cohort expansion, aiming to evaluate the safety, tolerability, PK characteristics, and preliminary anti-tumor efficacy of SYS6043 (a B7-H3-targeted antibody-drug conjugate) in patients with advanced/metastatic solid tumors. It includes three parts, namely dose escalation, PK expansion, and cohort expansion. Phase Ia dose escalation is the first part (Part 1) of this study. The dose escalation is carried out using BOIN design, to evaluate the MTD/maximum administered dose (MAD) and the RP2D. Phase Ia PK expansion (Part 2) will be conducted at 2-3 dose levels deemed acceptable (≤MTD) in terms of safety/tolerability as assessed by the SMC, to further evaluate the safety, tolerability, PK characteristics, and preliminary anti-tumor activity of SYS6043. Phase Ib cohort expansion (Part 3) will further evaluate the safety and efficacy of SYS6043 at the selected RP2D dose (1-2 dose levels). A safety monitoring committee (SMC) will be established for this study. The SMC will continuously review safety during the study period and make decisions on adjustments to dose escalation, addition of new dose groups, recommended doses, and recommended exploratory cohorts. For details, please refer to the SMC Charter.