Of the 5 evaluable pts with MEL in Arm A and 7 in Arm B, ORR was 20.0% (1 PR) and 42.9% (1 CR, 2 PR) respectively. Of the 9 evaluable pts with HCC, ORR was 11% (1 PR)...The combination of CS1002 and CS1003 demonstrated a promising anti-tumor activity and favorable safety profile in pts with pretreated MSI-H/dMMR tumors, anti-PD-(L)1-refractory MEL and anti-PD-(L)1-refractory HCC at two dose levels of CS1002.