Association of neutrophil to eosinophil ratio (NER) with clinical outcomes in patients with metastatic renal cell carcinoma (mRCC) treated with first-line (1L) immune checkpoint inhibitors (ICI) –based regimens.

Abstract

4557 Background: ICI-based regimens (ICI + ICI or ICI + VEGF targeted therapy [VEGF-TT]) represent current standard of care systemic therapies for the management of patients with mRCC. Robust biomarkers capable of predicting the therapeutic efficacy and safety of such regimens are still lacking. Eosinophils have been shown to play an important role in the response to immunotherapy. While recent investigations in RCC evaluated NER as a biomarker of poor response to immunotherapy, they did not fully account for the impact of different lines of therapy and the therapeutic classes of ICI-based regimens. We aimed to comprehensively evaluate the association of NER with clinical outcomes in patients with mRCC treated with 1L ICI regimens. Methods: We retrospectively reviewed data from patients with mRCC treated with first line ICI-based regimens (dual ICI or ICI + VEGF-TT) at Dana-Farber Cancer Institute. Clinicodemographic information was collected, including tumor histology, ECOG performance status, IMDC risk score. We examined NER at baseline and at 6, 12, and 24 weeks while patients were still receiving treatment. The primary endpoint was overall survival (OS). Time to treatment failure (TTF) was a secondary endpoint. The association of NER with OS and TTF was evaluated using Cox regression models, adjusted for age, gender, BMI, histology, IMDC risk score and autoimmune disease. Results: Overall, 156 patients were included in the current analysis, with a median age of 61 years (IQR: 54-67). 60 patients received dual ICI therapy, while 96 were treated with ICI + VEGF-TT combinations. In the ICI+ICI group, a higher NER at baseline, 6 and 12 weeks was associated with worse OS. In the ICI + VEGF group, a higher NER only at 6 weeks appeared to be associated with worse OS. No association between NER and TTF was found. Conclusions: To our knowledge, this is the first study to investigate, across therapeutic classes, the association of NER with clinical outcomes in patients with mRCC treated with 1L ICI-based regimens. Higher NER was linked to poor survival outcomes, especially in patients receiving dual ICI therapy. Future translational studies are needed to clarify these findings. [Table: see text]