This study is composed of two stages:Part I is mono-therapy dose escalation and dose expansion study, and Part II is the study of combination therapy.~The dose escalation study will be conducted using Part I for testing optimal doses at 0.3,1, 3, 10, 20, 30 mg/kg every 3 weeks (Q3W). An accelerated titration followed by traditional 3+3 design will be used in this study with a 21-day dose-limiting toxicity (DLT) observation period. Based on the data of dose escalation study, determine whether to carry out dose escalation at frequency of every 2 weeks(Q2W) and how many cohorts will be added in dose expansion study.~Based on the data of Part I, one or two doses will be conducted in the study of combination therapy. The study of PART II is composed of two cohorts. Cohort 1:Subjects with untreated CLDN18.2 positive gastric/gastroesophageal junction adenocarcinoma(G/GEJAC) will be treated with MIL93 and standard first-line chemotherapy.Cohort 2:Subjects with untreated CLDN18.2 positive pancreatic cancer will be treated with MIL93 and standard first-line chemotherapy.
MIL93 is a recombinant humanized anti-Claudin 18.2 (CLDN18.2) IgG1 monoclonal antibody. This is an open label Phase I study to evaluate safety, tolerability, pharmacokinetics and efficacy of MIL93 in Advanced or Metastatic solid tumors.