This is an open, multi-center, dose escalation and expansion phase I/II study. The Phase I study will explore the tolerability and safety of RC118 in combination with Toripalimab for the treatment of patients with Claudin 18.2-positive, locally advanced unresectable or metastatic malignant solid tumors, and to establish the maximum tolerated dose (MTD) and the recommended dose in phase II clinical trials (RP2D); The Phase II study will evaluate the efficacy and safety of RC118 in combination with Toripalimab or RC148 in patients with locally advanced or metastatic Gastric cancer/Gastro-esophageal junction cancer.
Be able to participate in the study voluntarily and willing to provide written informed consent.
male or female 18 ≤ age ≤ 75 years old.
Must have an Eastern Cooperative Oncology Group (ECOG) Performance Status of 0 or 1.
The expected survival ≥12 weeks.
Pregnant women, breastfeeding women or women with a positive blood pregnancy test result during the screening period (non-fertile women do not need to undergo a pregnancy test, such as women with a previous hysterectomy and/or bilateral oophorectomy or amenorrhea ≥12 months).
Subjects with active hepatitis B (HBsAg positivity and HBV DNA titre higher than the normal upper limit), active hepatitis C (HCVAb positivity and HCV RNA titre higher than the normal upper limit), and positive human immunodeficiency virus antibody (HIV-Ab) results during the screening period.
Subjects with a history of other acquired or congenital immunodeficiency diseases, or who have undergone organ or bone marrow transplantation.
Subjects who have previously received monoclonal antibody, double antibody targeting drugs, ADC, CAR-T and other therapeutic drugs targeting Claudin 18.2 or other ADCs with MMAE payload; or have participated in clinical trials and received investigational drugs within 4 weeks before the first dose.