Brief Summary
This is a double-blind, randomized, multiregion, comparative phase Ⅲ clinical study designed to evaluate the efficacy and safety of HLX22 in combination with trastuzumab and chemotherapya cancer treatment that uses drugs to kill or slow the growth of cancer cells, while minimising damage to healthy cells as first-line treatment in patients with HER2-positive locally advancedat a late stage, far along/metastatic adenocarcinomacancer arising from mucus-producing glands in organs of the gastric and/or gastroesophageal junction (G/GEJ).Eligible subjects will be randomized to the two groups based on a 1:1 ratio. Enrolled subjects shall be treated with the study drug until the loss of clinical benefit, death, intolerable toxicity, withdrawal of informed consenta process in which a patient receives detailed information about a procedure or treatment, including its potential risks, benefits, and alternatives. The patient then has the opportunity to understand the information and voluntarily agree to the procedure or treatment., or other reasons specified by the protocol (whichever occurs first).
Intervention / Treatment
- Drug: HLX22
- Drug: Pembrolizumab
- Drug: Trastuzumab
- Drug: Oxaliplatin
- Drug: Capecitabine
Inclusion Criteria:
- Male/female who are at least 18 years of age on the day of signing the informed consent.
- With histologically or cytologically confirmed diagnosisthe process of identifying a disease based on signs and symptoms, patient history and medical test results of previously untreated, locally advanced unresectable or metastatic HER2-positive gastric or gastroesophageal junction adenocarcinoma.
- Had measurable disease as assessed by IRRC according to the RECIST v1.1, the target lesion must not be a bone metastatic lesion only.
- HER2-positive tumor defined as either IHC 3+ or IHC 2+ in combination with ISH+ or FISH, as assessed by a central laboratory on a primary or metastatic tumor.
- ECOG PS within 7 days before randomization: 0-1.
- Expected survival ≥ 6 months.
- Had adequate organ function