Clinical Trial: Combination Chemotherapy With or Without Atezolizumab in Treating Patients With Stage III Colon Cancer and Deficient DNA Mismatch Repair or Microsatellite Instability

Study Status: Not yet recruiting
Recruit Status: Not yet recruiting
Study Type: Interventional

Official Title: Randomized Trial of FOLFOX Alone or Combined With Atezolizumab as Adjuvant Therapy for Patients With Stage III Colon Cancer and Deficient DNA Mismatch Repair or Microsatellite In

Brief Summary: This randomized phase III trial studies combination chemotherapy and atezolizumab to see how well it works compared with combination chemotherapy alone in treating patients with stage III colon cancer and deficient deoxyribonucleic acid (DNA) mismatch repair or microsatellite instability. Drugs used in combination chemotherapy, such as oxaliplatin, leucovorin calcium, and fluorouracil, work in different ways to stop the growth of tumor cells, either by killing the cells, by stopping them from dividing, or by stopping them from spreading. Monoclonal antibodies, such as atezolizumab, may interfere with the ability of tumor cells to grow and spread. Giving combination chemotherapy with atezolizumab may work better than combination chemotherapy alone in treating patients with colon cancer.

Detailed Summary:

PRIMARY OBJECTIVES:

I. To determine whether atezolizumab combined with oxaliplatin, leucovorin calcium, and fluorouracil (FOLFOX) and its continuation as monotherapy can significantly improve disease-free survival (DFS) compared to FOLFOX alone in patients with stage III colon cancers and high-frequency microsatellite instability (MSI-H) or deficient DNA mismatch repair (dMMR).

SECONDARY OBJECTIVES:

I. To determine whether atezolizumab combined with FOLFOX and its continuation as monotherapy can significantly improve overall survival compared to FOLFOX alone in patients with stage III colon cancers and MSI-H or dMMR.

TERTIARY OBJECTIVES:

I. To determine the impact of the addition of atezolizumab to FOLFOX on patient health-related quality of life (QOL), functional domains of health-related QOL, and disease- and treatment-related symptoms.

II. To determine if the "immunoscore" can predict the efficacy of atezolizumab for disease-free survival among patients with stage III colon cancer.

III. To assess whether circulating immune cell populations can predict the efficacy of atezolizumab as adjuvant therapy for stage III colon cancer.

IV. To explore the associations of genomic alterations identified in cell-free (cf)DNA with DFS in patients treated with FOLFOX with or without atezolizumab.

V. To assess whether soluble markers of systemic inflammation in blood can predict the efficacy of atezolizumab as adjuvant therapy for stage III colon cancer.

DFS will be compared between treatment arms using the stratified log rank test at one-sided level 0.025. The hazard ratio (HR) for DFS will be estimated using a stratified Cox proportional hazards model and the 95% confidence interval (CI) for the HR will be provided. Results from an unstratified analysis will also be provided. Kaplan-Meier methodology will be used to estimate the median DFS for each treatment arm, and Kaplan-Meier curves will be produced. Brookmeyer Crowley methodology will be used to construct the 95% CI for the median DFS for each treatment arm.