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

Background: 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.

Objective: To report the results from AVENANCE, a real-world study of avelumab first-line maintenance treatment.

Design, setting, and participants: 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.

Intervention: Previous, ongoing, or planned avelumab first-line maintenance treatment.

Outcome measurements and statistical analysis: Overall survival (OS) from avelumab initiation (primary endpoint) and safety were evaluated.

Results and limitations: 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.

Conclusions: 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.

Patient summary: A French real-world study, called AVENANCE, looked at avelumab maintenance treatment in people with advanced urothelial cancer whose tumor disappeared, shrank, or stopped growing with chemotherapy. Overall, results were consistent with those seen in a previous clinical trial, and on average, people treated with avelumab maintenance lived for 26.5 mo from the start of chemotherapy. Analyses of different groups of people found that survival varied, with people living for an average of 18-42 mo depending on what treatment they received after they finished avelumab treatment.