In a study reported in the Journal of Clinical Oncology, Arielle Elkrief, MD, and colleagues found that detection of intratumoral Escherichia was associated with improved overall survival in patients with advanced non–small cell lung cancer (NSCLC) receiving single-agent immune checkpoint inhibitor therapy, but not in those receiving chemoimmunotherapy.
Arielle Elkrief, MD
Study Details
The discovery cohort consisted of patients treated at Memorial Sloan Kettering Cancer Center (MSKCC), including 284 Escherichia-positive and 147 Escherichia-negative patients receiving anti–PD-1/-L1 immunotherapy alone and 215 Escherichia-positive and 312 Escherichia-negative patients receiving chemoimmunotherapy.
Key Findings
In the MSKCC cohort, median overall survival was 16 months (95% confidence interval [CI] = 13–20 months) in Escherichia-positive patients vs 11 months (95% CI = 8.4–14 months) among Escherichia-negative patients treated with single-agent immune checkpoint inhibitors (hazard ratio [HR] = 0.73, 95% CI = 0.59–0.92, P = .0065). The overall survival benefit remained significant in multivariate analysis adjusting for prognostic features including PD-L1 expression (HR = 0.76, P = .026).
Among patients in the MSKCC cohort receiving chemoimmunotherapy, median overall survival was 13 months among Escherichia-positive patients vs 15 months among Escherichia-negative patients (HR = 0.97, 95% CI = 0.78–1.20).
In an independent validation cohort of 772 patients derived from Foundation Medicine Inc, presence vs absence of intratumoral Escherichia was associated with a median overall survival of 16.0 months vs 10.8 months (HR = 0.68, P = .001) among patients receiving single-agent immune checkpoint inhibitors; the benefit remained significant on multivariate analysis (HR = 0.73, P = .032). No significant difference in overall survival (P = .3) was observed between Escherichia-positive and Escherichia-negative patients treated with chemoimmunotherapy.
The investigators concluded, “[Identification of] intratumoral Escherichia was associated with survival to single-agent immune checkpoint inhibitor [therapy] in two independent cohorts of patients with NSCLC.”
Charles M. Rudin, MD, PhD, of the Department of Medicine, Memorial Sloan Kettering Cancer Center, is the corresponding author for the Journal of Clinical Oncology article.
Disclosure: The study was supported by the National Cancer Institute, Canadian Institutes of Health Research, and others. For full disclosures of the study authors, visit ascopubs.org.
