- Antibiotic use is associated with worse survival outcomes in patients with locally advanced/metastatic urothelial carcinoma treated with atezolizumab.
Why this matters
- Future research should explore the effect of antibiotics on other immune checkpoint inhibitors.
- The findings suggest a need for extra caution with immune checkpoint inhibitors.
- Post hoc analysis of single-group, phase 2 IMvigor210 (n=429) and randomized phase 3 IMvigor211 (n=467) trial including patients with advanced/metastatic urothelial carcinoma.
- Funding: None disclosed.
- In pooled cohort, antibiotic use within 30 days before and after immune checkpoint inhibitor was associated (all HRs; 95% CIs) with significantly worse:
- OS: 1.44 (1.19-1.73).
- PFS: 1.24 (1.05-1.46).
- In patients treated with chemotherapy in IMvigor211, no significant association was observed between antibiotic use and:
- OS: 1.15 (0.91-1.46).
- PFS: 1.09 (0.88-1.36).
- In IMvigor211 cohort, atezolizumab vs chemotherapy was associated with:
- Similar OS in antibiotic users: 0.95 (0.71-1.25).
- Improved OS in nonusers: 0.73 (0.60-0.88).
- Post hoc analysis.