RP2D decision
PD, DLTs, TRAEs
Two patients receiving 10 mg/kg QL1706 experienced DLTs, and 7.5 mg/kg per 3 weeks was amended in the protocol as an additional escalation dose. As no DLTs occurred, 7.5 mg/kg per 3 weeks was the MTD. In phase I, the TRAEs (grade ≥ 3) of the 0.3-, 1-, 3-, 5-, 7.5-, and 10-mg/kg groups were 0%, 33.3%, 0%, 12.2%, 19.4%, and 50%, respectively. There were fewer severe TRAEs in the 5-mg/kg group compared to the 10-mg/kg group, and there was no significant dose-exposure correlation among doses of 1–7.5 mg/kg. The ORRs of the 0.3-, 1-, 3-, 5-, 7.5-, and 10-mg/kg groups were 0%, 33.3%, 16.7%, 22.9%, 10.7%, and 40% in phase I. In terms of PK, the 5-mg/kg group had a lower exposure level than the 7.5-mg/kg and 10-mg/kg groups. According to the PD analysis, Ki67 in CD8