Effect of antibiotic use prior to or concurrent with immune checkpoint inhibitors on outcomes in patients with Hodgkin lymphoma.

Abstract

8030 Background: There is growing interest in the identification of modifiable patient-specific factors that may predict response to immune checkpoint inhibitors (ICIs) in classical Hodgkin lymphoma (cHL). Recently, it has been proposed that antibiotic use could decrease the efficacy of ICIs in the treatment of advanced solid malignancies. The objective of our study is to assess whether antibiotic use prior to or concurrent with ICIs is associated with changes in outcomes in patients with cHL. Methods: Patients who received a PD-1 or CTLA-4 blocker for the treatment of cHL at Mayo Clinic Rochester between January 1, 2011 and October 20, 2018 were identified. We conducted a longitudinal retrospective chart review to identify those who received antibiotics within 30 or 90 days prior to initiation or concurrent with ICI therapy. Univariate cox regression analysis was used to assess for an association between antibiotic use and overall survival (OS) and progression-free survival (PFS) within these groups; a time-dependent variable was used for concurrent antibiotic use. Results: A total of sixty-two patients were identified (61% male, median age at ICI initiation 35 years [range: 19-87]). Median duration of follow up from ICI start was 38 months (range: 4-78). Twenty-one patients (34%) received antibiotics within 90 days of initiation of ICI, of which thirteen (21%) received antibiotics within 30 days. Thirty-five patients (57%) received antibiotics concurrently with ICI. Concurrent and prior antibiotic use within 90 days of ICI were both associated with inferior PFS (concurrent HR = 6.38 [95% CI 3.02-13.47]; 90-day HR = 2.21 [95% CI 1.10-4.47]) and OS (concurrent HR = 8.77 [95% CI 1.91-40.36]; 90-day HR = 2.96 [95% CI 1.09-8.04]). Conclusions: Antibiotic use is associated with inferior outcomes in patients with cHL treated with ICIs in this single institution cohort. This may reflect potential antibiotic effects on the gut microbiome (GMB) and immune system as has been suggested in prior studies. Further confirmatory studies and examination of potential confounding covariates are needed.