This study is consisted of two phase, Phase Ib and II:~Phase 1b includes dose escalation phase and cohort expansion phase. In dose escalation phase, up to 4 dose-escalation cohorts will be sequentially enrolled with regular 3+3 design. DLTs will be evaluated during the first treatment cycle, which is 28 days. In cohort expansion phase, after the RP2D was identified, participants were enrolled in an open-ended manner. Participants were assigned to groups A(3 injections), B (4 injections)and C(6 injections) on a 1:1:1 basis to evaluate the dose frequency.~Phase II:The dose and dosing frequency of M701 drug for the Phase II clinical trial were determined based on a combination of the tolerance1 and efficacy of M701 in the Phase Ib trial. Then the participants were randomly divided into two groups: the test group(M701) and the control group(cisplatin or pleural effusions suctions). The pleural effusions response (ORR) and Puncture Free Survival （PuFS）will be evaluated.
This is a phase 1/phase 2, multicenter, open-label study to evaluate the safety, tolerability, PK, PD, immunogenicity and preliminary efficacy of M701 in patients with treatment of malignant pleural effusions caused by NSCLC.