A Study of SI-B003, a PD-1/CTLA-4 Bispecific Antibody, in Patients With Advanced Solid Tumors

In phase Ia study, the safety and tolerability of SI-B003 in patients with recurrent or metastatic solid tumors will be investigated to determine the dose-limiting toxicity (DLT), maximum tolerated dose (MTD) or maximum administered dose (MAD) for MTD is not reached of SI-B003.
In the phase Ib study, the safety and tolerability of SI-B003 in specific tumors will be further investigated by selecting multiple doses based on the results of phase Ia study or/and the fixed-dose administration method with the closest exposure level, and recommended phase II dose (RP2D) for phase II clinical studies will be determined.