A total of nine (Q3W, the first day of intravenous administration every three weeks) dose groups were designed in the dose escalation period. The dose groups were 1.0, 2.1, 4.2, 5.3, 6.3, 7.3, 8.4, 9.4 and 10.5 mg/kg, respectively. The BOIN design with accelerated titration was used, and the DLT observation period was 21 days.~The specific steps for conducting a clinical trial using the BOIN design are as follows:~Perform the accelerated titration as follows: Assign the first patient to dose level 1. If this patient does not develop dose-limiting toxicity (DLT), the second patient will be treated at the next higher dose level. Treat one patient at a time and continue the dose-climbing process until the first DLT is observed, or a second grade 2 toxicity occurs, or the highest dose is reached. Two more patients were then treated on the current dose. After that, follow steps 2 and 3 and take the number of cases in each group as 3 to treat the follow-up patients.~Assign the dose to the next group of subjects according to the dose rise and fall rule shown in the Bayesian Optimal interval (BOIN) decision table.~Repeat Step 2 until the set maximum sample size of 45 or the number of evaluable subjects treated at the current dose reaches 12 and the current decision is to maintain the current dose according to the rise and fall rule of the dose rise and fall decision table.~After the dose escalation period was completed, order preserving regression was used to determine MTD. Once MTDS have been identified and the maximum sample size of 45 patients has not been reached, sponsors may enroll up to 12 additional patients in the selected MTDS to obtain more information on the safety and efficacy of the selected dose. In the additional extension process, the cull boundary in the decision table is used for toxicity monitoring.~The Safety Monitoring Committee (SMC) will conduct an ongoing safety assessment during the dose escalation period. The safety data of each dose group should be reviewed and decided by the SMC before starting the administration of the next dose group. If additional safety, efficacy, and PK data are required for a dose group by SMC resolution, subjects will be allowed to continue to be enrolled in this dose group after completing the BOIN dose increment; If the SMC has decided that a dose group can proceed to the cohort extension phase, it is permitted to proceed directly to the cohort extension phase in that dose group (i.e. to Phase Ib). The composition and responsibilities of the SMC will be further detailed in the SMC Constitution.~The recommended dose for cohort expansion (RDE) will be determined by the SMC based on safety/tolerability, PK data, and preliminary antitumor activity, as well as other available data. RDE can be at the same dose level as MTD or at a lower dose level than MTD; Rdes may also be different for different indications.
This is an open, multicenter study of stage Ia/Ib in Chinese subjects with unresectable locally advanced/metastatic solid tumors. It is divided into dose escalation period and cohort expansion period. A total of 9 dose groups (Q3W on the first day of intravenous administration every three weeks) were designed in the dose escalation period. The initial dose was 1.0mg/kg, Q3W, and the observation period of DLT was 21 days. In the dose expansion phase, 5 cohorts were set up.