Real-world Study of Avelumab First-line Maintenance Treatment in Patients with Advanced Urothelial Carcinoma in France: Overall Results from the Noninterventional AVENANCE Study and Analysis of Outcomes by Second-line Treatment

In this noninterventional study of avelumab first-line maintenance treatment in France, results were consistent with JAVELIN Bladder 100 phase 3 trial findings. In exploratory subgroup analyses, patients treated with avelumab followed by second-line enfortumab vedotin had encouraging long-term outcomes. Avelumab first-line maintenance treatment was approved for patients with advanced urothelial carcinoma (aUC) without progression following platinum-based chemotherapy (PBC), based on the results from the JAVELIN Bladder 100 phase 3 trial. To report the results from AVENANCE, a real-world study of avelumab first-line maintenance treatment. This is a retrospective and prospective, noninterventional study (NCT04822350). Eligible patients with aUC without progression on first-line PBC were enrolled at 82 centers in France between July 2021 and May 2022. The effectiveness population included 595 patients. The median follow-up was 26.3 mo. Previous, ongoing, or planned avelumab first-line maintenance treatment. Overall survival (OS) from avelumab initiation (primary endpoint) and safety were evaluated. The median age was 73.0 yr, and performance status was 0/1 in 91% of patients and ≥2 in 9.3%. The most common prior first-line chemotherapy regimen was carboplatin plus gemcitabine (61%). At data cutoff (December 7, 2023), the median duration of avelumab treatment was 5.6 mo, 125 patients remained on avelumab, and 55% had received second-line treatment. The median OS from avelumab initiation was 21.3 mo (95% confidence interval [CI], 17.6–24.6), and the median progression-free survival was 5.7 mo (95% CI, 5.2–6.5). In exploratory analyses of this population without disease progression on PBC, the median OS from the start of first-line PBC was 26.5 mo overall, and in subgroups that received second-line enfortumab vedotin (n = 55) or PBC (n = 79), it was 41.5 and 24.5 mo, respectively. Real-world data from AVENANCE confirm the effectiveness and safety of avelumab first-line maintenance treatment in a heterogeneous population, supporting its recommendation for cisplatin-eligible and cisplatin-ineligible patients with aUC who are progression free after first-line PBC. In an exploratory analysis, a small subgroup that received a treatment sequence of first-line PBC without disease progression followed by avelumab first-line maintenance and second-line enfortumab vedotin had a median OS of >3 yr. A French real-world study, called AVENANCE, looked at avelumab maintenance