While antibiotics may impair the efficacy of immune checkpoint inhibitors, the detrimental effect does not extend to chemo-immunotherapy combinations in patients with lung cancer, new research shows.
An international multicentre study involving 302 patients with stage IV NSCLC found no effect of prior (n= 47 patients) or current antibiotic therapy on the efficacy of first line chemo-immunotherapy
The study evaluated outcomes in patients treated at eight European cancer centres, mostly with pembrolizumab and histology-based platinum doublets, though some received atezolizumab and histology-based platinum doublets or atezolizumab-bevacizumab/carboplatin-paclitaxel.
In multivariable analysis patients with prior antibiotic use had similar overall survival OS (hazard ratio = 1.42, 95% confidence interval: 0.91-2.22; P = 0.1207) and progression free survival (PFS, HR = 1.12, 95% CI: 0.76-1.63; P = 0.5552), compared to patients unexposed to antibiotics, regardless of performance status.
Similarly, no difference with respect to objective response rate (ORR) was found with prior antibiotic exposure (42.6% versus 57.4%, P = 0.1794).
The study also found no differences in efficacy related to duration of antibiotic exposure (≥7 versus <7 days) or route of administration (intravenous versus oral).
Current antibiotic use was not associated with OS (HR = 1.29, 95% CI: 0.91-1.84; P = 0.149)] and PFS (HR = 1.20, 95% CI: 0.89-1.63; P = 0.222) in multivariable analysis, according to findings published in the Annals of Oncology.
The study investigators said prior antibiotic therapy was known to impair efficacy of single-agent immune checkpoint inhibitors, potentially through the induction of gut dysbiosis, but the effects on chemo-immunotherapy combinations ere unknown until now.