To explore the safety and clinical efficacy of cisplatin combined with RC48 and anti-PD-1 antibodies AK105 in Her-2 positive advanced gastric cancer.

Although anti-PD-1 antibody could prolong the survival of patients with adanced gastic cancer, there are relatively few reports on anti-PD-1 antibody therapy in Her2-positive gastric cancer. RC48 is a primary anti-HER2 antibody-drug conjugate, which has been approved by the Chinese NMPA for the later-line treatment of Her2-positive gastric cancer. This study was to explore the safety and clinical efficacy of RC48 combined with cisplatin and AK105 in previously untreated patients with HER2-positive gastric cancer.

Inclusion Criteria:

• Age ≥18 years old, ≤75 years old, regardless gender
• Pathologically confirmed gastric adenocarcinoma, Her2 immunohistochemical examination of 2+ or 3+
• ECOG PS scores 0-1
• Stage IV according to AJCC 8.0 and no systemic therapy previously
• Expected lifespan ≥ 3 months
• Adequate organ function
• At least one measurable lesion according to RECIST 1.1
• Asymptomatic intracranial metastasis
• No history of other malignancies
• Women of childbearing age must have a negative blood pregnancy test within 7 days, and subjects of childbearing age must use appropriate contraception during the trial and for 6 months after the trial
• Agreed to participate in this clinical study and signed the Informed Consent

Exclusion Criteria:

• Currently participating in an interventional clinical investigational treatment, or have received other investigational drugs or treatment with an investigational device within 4 weeks prior to the first dose
• Received anti-PD-1, anti-PD-L1, anti-CTLA-4, and other checkpoint inhibitor
• Received traditional Chinese medicines or immunomodulatory drugs with anti-gastric cancer indications within 2 weeks before the first administration
• Active autoimmune diseases or immunodeficiency diseases
• Allergy to any test drug and its excipients, or a history of severe allergy, or contraindication to the test drug
• Severe mental disorder
• Receiving systemic corticosteroids within 7 days prior to the first dose of the study
• Clinically apparent cardiovascular and cerebrovascular disease
• Others investigators evaluated not meet the inclusion criteria

all IPD that underlie results in a publication

starting 6 months after publication

The IPD will be shared with researhers who plan to do meta-analysis or other reasonable requests.