Prognostic factors in avelumab maintenance therapy for metastatic urothelial carcinoma

Background In the present study, we evaluated pretreatment prognostic factors for overall survival in patients with metastatic urothelial carcinoma who received maintenance avelumab within the Expanded-Access Program.Patients and methods We retrospectively analyzed 132 patients with metastatic urothelial carcinoma who received at least one cycle of avelumab. Overall survival (OS) was estimated using the Kaplan–Meier method. Univariate analysis was performed to identify pretreatment prognostic factors associated with OS (p < 0.05), and significant variables were included in a multivariate Cox model.Results Median age was 67 years (range, 43–84) and the bladder was the primary tumor site in 78% of patients. Visceral metastases were present in 62.5% of patients, and 32% had lymph node-only disease. ECOG ≥ 1 was observed in 59.1%, and 57% received cisplatin-based chemotherapy. The median follow-up was 24 months, the median OS was 23.8 months, and the 24-month OS rate was 47% (95% CI, 35%–55%).In univariate analysis, liver metastases, bone metastases, and hemoglobin < 10 g/dL were significantly associated with OS. In multivariate analysis, bone metastases (HR = 2.3; 95% CI 1.3–5; p = 0.008) and hemoglobin < 10 g/dL (HR = 2.6; 95% CI 1.2–4.1; p = 0.004) remained independent predictors of worse OS.Conclusions Bone metastases and low hemoglobin are independent predictors of poor survival in patients receiving maintenance avelumab, supporting their role in risk stratification.