Prognostic factors in avelumab maintenance therapy for metastatic urothelial carcinoma

Abstract

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. Advanced bladder cancer is often treated first with platinum-based chemotherapy. If the disease is controlled after chemotherapy, some patients may continue treatment with a drug called avelumab to help delay progression and improve survival. However, not all patients benefit equally from this treatment. In this study, we examined 132 patients with advanced urothelial carcinoma (the most common type of bladder cancer) who received maintenance avelumab in routine clinical practice in Turkey. Our goal was to identify simple clinical factors that could help predict how long patients might survive. We found that patients with cancer spread to the bones and those with low hemoglobin levels (a blood test related to anemia) had shorter overall survival compared with other patients. These factors remained important even after adjusting for other clinical variables. Our findings suggest that bone metastases and anemia may help doctors identify patients with a poorer prognosis before starting maintenance avelumab. This may support closer monitoring and help guide treatment decisions. Because this was a retrospective study, some limitations exist, including missing biological markers and possible differences in previous treatment responses. Despite these limitations, our results provide useful real-world information that may improve personalized treatment planning in advanced bladder cancer.