A Study of RC48-ADC Combination Therapies as First-line Treatment in Advanced Metastatic Gastric Cancer

A Study of RC48-ADC Combine With Toripalimab and Chemotherapy or RC48-ADC Combine With Toripalimab and Trastuzumab as First-line Treatment in Local Advanced or Metastatic Gastric Cancer With the HER2 Expression or Non-expression

This is a Phase II/III, randomized, multicenter, open-label clinical trial designed to evaluate safety and efficacy of RC48-ADC combine with Toripalimab and chemotherapy or RC48-ADC combine with Toripalimab and Trastuzumab as first-line treatment in human epidermal growth factor receptor 2 (HER2)-expression or non-expression participants with locally advanced or metastatic gastric cancer.

Inclusion Criteria:

• Voluntary agreement to provide written informed consent.
• Age:18-75 years（including 18 and 75）.
• Predicted survival ≥ 12 weeks.
• Eastern Cooperative Oncology Group (ECOG) performance status score of 0 or 1.
• Adequate organ function.
• All subjects must have inoperable, advanced or metastatic gastric or or gastroesophageal adenocarcinoma.
• Subject must be previously untreated with systemic treatment; Subject that received neoadjuvant chemotherapy with recurrence >6 months from completion of therapy are permitted;
• HER2-expressing status determined by laboratory to be IHC 1+, 2+ or 3+ or IHC0.

Exclusion Criteria:

• Active central nervous system (CNS) metastases.
• Known active hepatitis B, active hepatitis C, or human immunodeficiency virus (HIV) infection.
• History of other malignancy within the previous 5 years, except for appropriately treated carcinoma in situ of the cervix, thyroid cancer ,etal.
• Known hypersensitivity to antibody-drug conjugate(ADC) or PD-(L)1 or any of its components.
• Assessed by the investigator to be unable or unwilling to comply with the requirements of the protocol.