Pinato DJ, Howlett S, Ottaviani D, et al. - Researchers examined how antibiotic (ATB) therapy, administered concurrently (cATB) or prior (pATB) to ICI therapy, affects overall survival (OS) and treatment response to ICI therapy in patients with cancer treated with ICIs in routine clinical practice. In this observational study, they assessed 196 patients with cancer who were treated with ICI therapy between January 1, 2015, and April 1, 2018, in routine clinical practice. Among these patients, 119 were diagnosed with non–small cell lung cancer, 38 with melanoma, and 39 with other tumor types. The analysis revealed significantly worse overall survival and a higher risk of disease refractory to treatment in correlation to antibiotic treatment administered within 30 days from the commencement of ICI therapy. They observed the association of antibiotic therapy with a reduced response to ICIs in routine practice which was evident irrespective of the tumor site.