KN026-001 is a two-stage study (Open-label stage/Randomized stage). Open-label stage is designed to evaluate the safety and efficacy of KN026 and chemotherapy when given together. Randomized stage is designed to evaluate the OS and PFS in patients receiving KN026 and chemotherapy compared to patients receiving placebo and chemotherapy.
Age ≥18 years;
Histologically or cytology-confirmed HER2-positive locally advanced, recurrent, or metastatic gastric cancer (including adenocarcinoma of the gastro-esophageal junction); HER2 positive is defined as IHC 3+, or IHC 2+ with ISH test positive (HER2/CEP17 ratio ≥ 2.0, or mean HER2 copy number ≥ 6.0 signals/cell);
Failure of at least first-line standard therapy (trastuzumab plus chemotherapy); Note: Neoadjuvant/adjuvant therapy previously administered with a trastuzumab-containing regimen can be considered first-line therapy if the subject has progressed disease during neoadjuvant/adjuvant therapy or within 6 months of completion of treatment;
Stage 1 : At least one measurable lesion at baseline according to RECIST 1.1; Stage 2: At least one evaluable lesion at baseline according to RECIST 1.1; the area must not have received previous radiotherapy, or there must be evidence of significant progression after the end of radiotherapy;
Subjects with untreated active brain metastases; Subjects will be admitted if their brain metastases have been treated and the metastases are stable (brain imaging at least 4 weeks prior to the first dose showed stable lesions with no new CNS symptoms, or CNS symptoms have returned to baseline and no hormonal therapy is required at least 14 days prior to the first dose of the investigational treatment), and there is no evidence of new or enlarged original brain metastases;
Other investigational medications received within 4 weeks prior to the first study treatment, based on the time of the last trial dose;
Antineoplastic therapy such as chemotherapy, small molecule inhibitors, immunotherapy (such as interleukin, interferon, or thymosin) within 4 weeks or 5 half-lives (whichever is shorter but at least 2 weeks) prior to the first study treatment; Have received Chinese herbal treatment with antitumor activity within 14 days before administration;
Subjects recieved major surgery (e.g., transabdominal, transthoracic, etc.) within 28 days prior to the first study treatment; does not include minor procedures such as diagnostic puncture or infusion device implantation), or major surgery is expected to be required during the study;