In patients with NSCLC, the use of antibiotics around immune checkpoint inhibitor (ICI) initiation was linked with reduced overall survival (OS), progression-free survival (PFS), and objective response rate (ORR), according to a study published in Lung Cancer. Gülin Alkan Sen and colleagues conducted a retrospective analysis of 90 patients with advanced NSCLC treated with ICIs as monotherapy or combination with chemotherapy. Patients receiving antibiotics for the first 12 weeks of ICI initiation were compared with those who did not. Among total patients, 30% received antibiotics in the first 12 weeks of ICI treatment. In this patient population, PFS was significantly shorter (4.9 vs 24.8 months; HR, 2.52, 95% CI, 1.52-4.18; P<0.001). The OS was also considerably shorter (5.4 vs 37.8 months; HR, 2.55; 95% CI, 1.48-4.40; P=0.001). In assessing the effect of antibiotics on ORR, researchers found that exposure to antibiotics for the first weeks consistently worsened the response rate; the ORR was 25.9% in the antibiotic group and 55.6% in the no-antibiotic group (P=0.01).
