Neutrophil-to-Eosinophil Ratio Predicts the Efficacy of Avelumab in Patients With Advanced Urothelial Carcinoma Enrolled in the MALVA Study (Meet-URO 25).

BACKGROUND: Neutrophil-to-eosinophil ratio (NER) has been described to be associated with outcomes to immune checkpoint inhibitors (ICI) in several tumor types, but less is known about its role of in the response to avelumab in advanced urothelial cancer (aUC). Thus, we reported outcomes by NER of aUC patients treated with avelumab as maintenance after initial response to platinum-based chemotherapy and enrolled in the Maintenance with AVeLumAb ([MALVA] in advanced urothelial neoplasms in response to first-line chemotherapy: an observational retrospective study) study (Meet-URO 25).

PATIENTS AND METHODS: Median NER at baseline and after 3 cycles of avelumab were calculated. Progression-free survival (PFS) and overall survival (OS) by NER were reported.

RESULTS: At the cutoff date (April 15, 2023), a total of 109 patients were included. The median NER was 28.05 at baseline and 24.46 after 3 cycles of avelumab, respectively. Median PFS was not reached for patients with baseline NER less than the median (<median) compared to 5.1 months for patients with baseline NER greater than the median (≥median) (P = .0005). Median OS was significantly longer for patients with baseline NER <median compared with patients with baseline NER ≥median (not reached vs. 11.7 months, respectively; P = .0016). Significantly better PFS and OS were confirmed for NER after 3 cycles of avelumab <median compared with NER ≥median at the same timepoint.

CONCLUSION: NER <median may be predictive of PFS in aUC patients treated with avelumab, and prognostic for OS regardless of treatment. Prospective studies are warranted to validate NER as a readily available and reproducible laboratory-biomarker for efficacy outcomes of avelumab in aUC.