Efficacy of Vinflunine for Patients with Metastatic Urothelial Cancer after Immune Checkpoint Inhibitor Pretreatment—A Retrospective Multicenter Analysis

SIMPLE SUMMARY: With the introduction of immune checkpoint inhibitors (ICI) in recent years, the treatment landscape of metastatic urothelial cancer has undergone a substantial transformation. Nevertheless, disease progression after prior platinum-based chemotherapy and ICI pretreatment remains a challenging clinical situation with little evidence for following therapeutic options. The aim of this multicenter analysis was to examine the efficacy of the vinca alkaloid vinflunine after previous ICI therapy. In our cohort, post-ICI patients showed an overall response rate (ORR) of 22.4% compared to 15.6% within ICI-naïve patients (p = 0.451), and the clinical benefit rate (CBR) was 51.0% vs. 25.0% (p = 0.020), respectively. Post-ICI patients showed longer OS (8.78 vs. 5.72 months; p = 0.467) and longer PFS (3.09 vs. 2.14 months; p = 0.105). Our analysis demonstrates the clinical activity of vinflunine in a third- or later-line post-ICI setting, and the therapeutic benefit may be considerably higher than demonstrated in previous studies. ABSTRACT: Background: Immune checkpoint inhibitors (ICI) are standard of care in patients with metastatic urothelial carcinoma (mUC) ineligible for cisplatin, and as second-line therapy after platinum-based chemotherapy. To date, few data exist about the efficacy of the former second-line chemotherapeutic agent vinflunine after the failure of sequential platinum-based chemotherapy and ICI treatment. The aim of this analysis was to examine the efficacy of vinflunine in a post-ICI third- or later-line setting. Methods: In this retrospective German multicenter study, data of mUC patients treated with vinflunine were reviewed in six centers between February 2010 and December 2021. All of the 105 included patients had radiologic progression after first-line platinum-based chemotherapy. The objective was to describe the efficacy of vinflunine in terms of overall response rate (ORR), clinical benefit rate (CBR), overall survival (OS), and progression-free survival (PFS) for post-ICI and ICI-naïve patients, respectively. Results: In our cohort, 61 patients (58.1%) had preceding immunotherapy before vinflunine administration, and 44 patients (41.9%) were ICI-naïve. Patients with ICI pretreatment showed an ORR of 22.4% compared to 15.6% within ICI-naïve patients (p = 0.451), and CBR was 51.0% vs. 25.0% (p = 0.020), respectively. Post-ICI patients showed longer OS (8.78 vs. 5.72 months; p = 0.467) and longer PFS (3.09 vs. 2.14 months; p = 0.105). Conclusion: This analysis supports the sequential use of vinflunine in post-ICI patients since the vinca-alkaloid retains a measurable clinical activity in these heavily pretreated patients. The therapeutic benefit may be higher than demonstrated in previous studies.