Urogenit Tract Infect.  2023 Dec;18(3):75-81. 10.14777/uti.2023.18.3.75.

Impact of Antibiotics on the Efficacy of Immune Checkpoint Inhibitors in Metastatic Urothelial Carcinoma

• Lim DG
• Lee HY
• Chung HS
• Hwang EC
• Jung SI
• Kwon DD

• KMID: 2550591
• DOI: http://doi.org/10.14777/uti.2023.18.3.75

Abstract

Purpose
Emerging evidence has suggested that prior or concurrent antibiotic (ATB) use may be associated with a poor response to immune checkpoint inhibitors (ICIs) in patients with some solid tumors. This study examined the effects of ATB use on the oncological outcomes of patients receiving ICIs for mUC.
Materials and Methods
Patients receiving ICIs for mUC between 2018 and 2020 were assessed retrospectively. Those with over three cycles of atezolizumab or pembrolizumab were included. ATB use, defined as ≥ three days within 60 days before or three months after ICI administration, was compared between groups for oncological outcomes.
Results
Thirty-one patients were examined. The ATB-use and no-ATB-use groups consisted of 15 (48.4%) and 16 patients (51.6%), respectively. The ATB-use group showed a lower disease control rate (56.3% vs. 13.3%, p=0.023) than the no-ATB-use group. The objective response rate in the ATB-use group was lower than the no-ATB-use group, but the difference was statistically insignificant (43.7% vs. 13.3%, p=0.113). The ATB-use group had shorter progression-free survival (median three vs. six months, log-rank p=0.045) and shorter overall survival (median three vs. 14 months, log-rank p=0.023) than the no-ATB-use group. The most commonly used antibiotics were fluoroquinolones (46.7%), cephalosporins (40.0%), non-cephalosporin beta-lactams (6.7%), and nitrofurantoin (6.7%).
Conclusions
ATB may be associated with poorer oncological outcomes in patients with mUC who received ICI therapy. Hence, further research will be needed to understand the relationship between the modulation of ATB-related dysbiosis and gut microbiota composition with the oncological outcomes in patients with mUC.

Keyword

Immunotherapy; Antibiotics; Immune checkpoint inhibitors; Metastatic urothelial carcinoma; Oncological outcomes