The Efficiency of Concomitant Antibiotic Usage On Survival Outcomes of Nivolumab-Treated Metastatic Renal Cell Carcinoma Patients: A Multicenter Experience

Aim: Immunotherapy has brought a new perspective to cancer treatments. However, the response of patients to the novel drug is heterogeneous. It is essential to reveal the factors that may affect the outcomes. It was aimed to evaluate the effect of antibiotherapy (Abx) on overall survival (OS) and progression-free survival (PFS) in patients with metastatic renal cell carcinoma (mRCC) receiving second-line nivolumab treatment. Method: The study is a multicentre, retrospective, multicentre design that included patients with metastatic renal cell carcinoma who used nivolumab in second-line treatment. One hundred and two patients with mRCC were divided into two groups according to whether they used Abx with nivolumab: concurrent Abx users and non-users. Overall survival (OS) and progression-free survival (PFS) were compared between the groups with and without concurrent Abx. Results: Of the 102 patients included in the study, 67 (65.7%) of the patients did not receive Abx treatment, while 35 (34.3%) of the patients used Abx. Quinolones were the most commonly used Abx group (57.2 %). This was followed by beta-lactams Abx (42.8%). Median PFS was 9.4 (4.4-14.4) months in non-Abx users and 6.7 (5.9-7.5) months in Abx users (p=0.04). mOS was 29.8 (23.6-35.9) months in non-Abx users and 22.04 (16.4-27.7) months in Abx users (p=0.96). Conclusion: Concurrent Abx usage in mRCC patients treated with nivolumab negatively affects immunotherapy efficacy and treatment response. Clinicians should be cautious about the concomitant use of immunotherapy and Abx in such patients.