Antibiotic Exposure Does Not Impact Immune Checkpoint Blockade Response in MSI-H/dMMR Metastatic Colorectal Cancer: A Single-Center Experience

Authors

Victoria Serpas Higbie
Jane Rogers
Hyunsoo Hwang
Wei Qiao
Lianchun Xiao
Arvind Dasari
Kerri Mola-Rudd
Van K Morris
Robert A Wolff
Kanwal Raghav
Ryan Huey
Christine Parseghian
Jason Willis
Scott Kopetz
Michael J Overman
Benny Johnson

Publication Date

11-3-2022

Journal

The Oncologist

Abstract

BACKGROUND: Immune checkpoint blockade (ICB) has improved outcomes for patients with microsatellite instability high (MSI-H)/deficient mismatch repair (dMMR) tumors. However, not all MSI-H/dMMR patients will exhibit the same ICB efficacy. Previous studies suggest that concomitant antibiotic use while receiving ICB may result in poorer outcomes. We aimed to evaluate this association in patients with MSI-H/dMMR metastatic colorectal cancer (mCRC).

MATERIALS AND METHODS: A single-site, retrospective review of 57 patients with MSI-H/dMMR mCRC that received ICB was completed. Data collected included patient demographics, ICB information, and antibiotic use. Antibiotic exposure was considered from 90 days prior to ICB through 6 weeks after initiation. Primary endpoint was overall response rate (ORR).

RESULTS: The majority of patients received pembrolizumab (27 [47%]) or nivolumab (17 [30%]) monotherapy as their ICB agent. Of the 57 patients, 19 (33.3%) had antibiotic exposure from 90 days prior to ICB initiation through 6 weeks after initiation with most (13 [68%]) having antibiotic use in the 30 days preceding ICB initiation. Similar ORRs were seen in both groups (P-value > .99). No difference was observed in OS (P-value .29) or PFS (P-value .36) between groups.

CONCLUSION: Our data show no association of lower response rates or survival in those MSI-H/dMMR patients with mCRC who receive antibiotics around the initiation of ICB. This information needs to be confirmed in a larger prospective cohort.

Keywords

Humans, DNA Mismatch Repair, Immune Checkpoint Inhibitors, Prospective Studies, Anti-Bacterial Agents, Colorectal Neoplasms, Microsatellite Instability, Colonic Neoplasms

Comments

Supplementary Material

Data Availability Statement

PMID: 35946836

DOI

10.1093/oncolo/oyac162

PMID

35946836

PMCID

PMC9632313

PubMedCentral® Posted Date

August 2022

PubMedCentral® Full Text Version

Post-print

Published Open-Access

yes