Atezolizumab Added to FOLFOXIRI and Bevacizumab Safe, Effective for Metastatic Colorectal Cancer

Adding anti-PD-L1 agent atezolizumab to first-line fluorouracil, leucovorin, oxaliplatin, and irinotecan (FOLFOXIRI) plus bevacizumab is safe and effective for patients with metastatic colorectal cancer, according to findings from the phase 2 AtezoTRIBE trial.

The trial enrolled 218 patients with previously untreated metastatic colorectal cancer from 22 oncology centers in Italy, between November 20, 2018, and February 26, 2020. Patients were stratified according to treatment center, Eastern Cooperative Oncology Group (ECOG) performance status, primary tumor site, and previous adjuvant therapy.

Patients were randomized in a 1:2 ratio to receive either first-line FOLFOXIRI plus bevacizumab (n = 73) or FOLFOXIRI plus bevacizumab with the addition of atezolizumab (n = 145), administered up to eight 14-day cycles, followed by maintenance with fluorouracil and leucovorin plus bevacizumab with or without atezolizumab, according to randomization. Maintenance continued until disease progression, unacceptable adverse events (AEs), or consent withdrawal. The primary end point for the trial was progression-free survival (PFS).

At the data cutoff of August 1, 2021, the median follow-up duration was 19.9 months. Median PFS for the atezolizumab group was 13.1 months compared to 11.5 months in the control group.

The most common grade 3 to 4 AEs were neutropenia (42% in the atezolizumab group vs 36% in the control group), diarrhea (15% vs 13%), and febrile neutropenia (10% in both groups). Serious AEs were reported in 39 (27%) patients in the atezolizumab group, and 19 (26%) patients in the control group. There were also 2 treatment-related deaths (caused by acute myocardial infarction and bronchopulmonary hemorrhage) in the atezolizumab group. No deaths were reported in the control group.

The study authors concluded, “the addition of atezolizumab to first-line FOLFOXIRI plus bevacizumab is safe and improved progression free survival in patients with previously untreated metastatic colorectal cancer.”

Source:

Antoniotti C, Rossini D, Pietrantonio F, et al. Upfront FOLFOXIRI plus bevacizumab with or without atezolizumab in the treatment of patients with metastatic colorectal cancer (AtezoTRIBE): A multicentre, open-label, randomised, controlled, phase 2 trial. Lancet Oncol. Published online: May 27, 2022. doi:10.1016/S1470-2045(22)00274-1.