P-IL-2 injection was injected intravenously, the screening period was 28 days, and the DLT observation period was 28 days from the beginning of the first infusion (including the day of administration). After the end of the DLT observation period, subjects can continue to receive treatment on a voluntary basis. The safety follow-up after drug withdrawal was carried out 28 days after the last medication. During the survival follow-up after drug withdrawal, imaging examination and survival information were collected every 12 weeks as far as possible within 2 years after drug withdrawal, until the subjects developed disease or received other anti-tumor specific therapy. Subjects with disease progression or other treatment received telephone survival follow-up every 12 weeks. After 2 years of drug withdrawal, telephone survival follow-up was conducted every 12 weeks according to the wishes of the subjects.
Phase Ia: single-dose escalation study: accelerated titration combined with traditional 3+3 dose. Sample size is correlated with the DLT occurring in each dose group. 4 dose groups are expected; the first dose group is the accelerated titration group, which includes only 1 subject; subsequent dose groups are in traditional 3+3 dose increments, with 3-6 subjects in each group; a total of 10-19 subjects are expected in all dose groups. If the DLT is still not present in the highest dose ,the safety monitoring committee(SMC) to determine if it is necessary to continue incrementally to a higher dose.