INTERACT Stomach-II

Intraperitoneal Irinotecan Combined With Systemic Therapy for Patients With Gastric Peritoneal Metastases: A Phase II, Multicenter Study

This is a phase II study conducted in three hospitals in the Netherlands (Erasmus MC in Rotterdam, Catharina Hospital in Eindhoven, and the Netherlands Cancer Institute in Amsterdam). A total of 55 patients will take part. The aim is to test whether a new combination treatment is feasible for patients with gastric peritoneal metastases (PM). The treatment includes chemotherapy (intraperitoneal irinotecan and standard systemic therapy such as CAPOX or FOLFOX), and may also include nivolumab or trastuzumab, depending on biomarker results.

Inclusion Criteria:

• Histologically confirmed gastric cancer or gastroesophageal junction adenocarcinoma
• Pathologically and clinically confirmed diagnosis of macroscopic peritoneal metastases (defined as PCI score ≥ 1)
• WHO-performance score of 0 to 1 with a life expectancy greater than or equal to three months
• Aged 18 years or older
• Written informed consent according to the ICH-GCP and national/local regulations

Exclusion Criteria:

• Distant metastases other than peritoneal metastases or metastatic lymph nodes
• Prior palliative systemic therapy for gastric cancer
• Prior (neo)-adjuvant systemic therapy for gastric cancer within the six months before enrolment in this study
• Severe symptomatic ascites requiring monthly recurrent therapeutic paracentesis
• Homozygous dihydropyrimidine dehydrogenase (DPD) deficiency
• Any contra-indication for the (planned) systemic chemotherapy (e.g. active infection, serious concomitant disease, severe allergy, persistent neurologic toxicity after (neo-)adjuvant oxaliplatin based systemic therapy), as determined by the treating medical oncologist
• Inadequate organ functions (defined as a hemoglobin <5.0 mmol/l, an absolute neutrophil count <1.5 x 109/l, platelet count <100 x 109/l, creatinine clearance <30 ml/min, bilirubin >2x ULN and liver transaminases >2.5x ULN)
• Pregnant or lactating women
• Concomitant participation in any clinical study that could modify the outcomes relevant to this study
• Absence of assurance of compliance with the protocol