Trial Outcomes & Findings for Immunosurveillance for Metastatic Colorectal Cancer (NCT NCT06509880)

Patients with histologically confirmed metastatic colorectal cancer (stage M1 only) were recruited at oncology centers affiliated with university clinics in 4 regions of Kazakhstan. Active enrollment began on July 15, 2022 and was completed in July 2024.

Of 200 patients screened, 187 met eligibility criteria, provided informed consent, and were enrolled (randomized). Thirteen patients were screening failures: 8 did not meet inclusion/exclusion criteria, 5 withdrew consent before randomization.

All 187 randomized participants were included in the age analysis. No participants were excluded. The number of participants analyzed matches the overall number of baseline participants for each arm.

Relative Dose Intensity (RDI) over cycles 1-4 of FOLFOX, calculated as (delivered dose intensity / planned dose intensity) × 100. Dose intensity accounts for both dose reductions and treatment delays for oxaliplatin (mg/m²/week) and infusional 5-fluorouracil (mg/m²/week).

Global health status/quality of life subscale from the EORTC QLQ-C30. Scores are linearly transformed to a 0-100 scale. Higher scores indicate better global health status/quality of life (better outcome). Minimum = 0, maximum = 100. This is a subscale score, not a total scale score.

Mitochondrial activity of neutrophils assessed in peripheral blood as the percentage (%) of neutrophils with preserved mitochondrial function among 200 counted neutrophils per participant. Range 0-100%. Higher percentages indicate better preserved neutrophil mitochondrial function. Primary metric: change from baseline to 1 month after completion of chemotherapy.

Metabolic response to treatment assessed by \[18F\]FDG PET/CT using EORTC PET response criteria based on the change in tumor FDG uptake (e.g., SUV metric) between baseline and follow-up. Participants were classified into mutually exclusive categories: partial metabolic response (PMR) (≥25% decrease in tumor FDG uptake), stable metabolic disease (SMD) (does not meet PMR or PMD), or progressive metabolic disease (PMD) (≥25% increase in tumor FDG uptake and/or new FDG-avid lesions). Higher metabolic activity and PMD indicate worse disease activity.

Serum CEA concentration measured in peripheral blood and reported in ng/mL. Higher CEA values generally indicate higher tumor burden and are used to monitor treatment response in conjunction with imaging. CEA response defined as a ≥50% decrease in serum CEA concentration from baseline to 1 month after completion of chemotherapy.

CA 19-9 response defined as a ≥50% decrease in serum CA 19-9 concentration from baseline to 1 month after completion of chemotherapy. CA 19-9 measured in U/mL. Higher CA 19-9 values indicate higher tumor burden (worse outcome). Normal range approximately 0-27 U/mL.

CD4+/CD8+ T-cell ratio measured in peripheral blood (unitless ratio). The prespecified metric is the change in CD4+/CD8+ ratio from baseline to 1 month after completion of chemotherapy.

Left ventricular ejection fraction (LVEF) ≥50% by echocardiography at baseline was required for study inclusion. Patients with LVEF \<50% were excluded.