Background: Avelumab 1LM is the standard of care for aUC that has not progressed with 1L platinum-based chemotherapy based on level 1 evidence from the JAVELIN Bladder 100 phase 3 trial. Previous results from AVENANCE showed the effectiveness and safety of avelumab 1LM in a real-world population with aUC in France. We report updated data and analyses by subsequent (next-line) treatment. Methods: AVENANCE (NCT04822350) is a noninterventional, ambispective study. Eligible pts had aUC that had not progressed with 1L platinum-based chemotherapy and previous, ongoing, or planned avelumab 1LM treatment. The primary endpoint is overall survival (OS). Data reported are preliminary, and analysis is ongoing. Results: 594 pts were analyzed. At data cutoff (May 31, 2023), median follow-up was 24.2 mo (range, 0.6-43.7); 142 pts (23.9%) remained on avelumab. Median duration of avelumab treatment was 5.6 mo (95% CI, 4.9-6.9). Reasons for discontinuation were disease progression in 330 (73.2%), adverse event in 50 (11.1%), death in 42 (9.3%), and other reasons in 29 (6.4%) pts. 314 pts (52.9%) received subsequent treatment after avelumab: chemotherapy in 238 (75.8%), antibody-drug conjugate (ADC) in 52 (16.6%; enfortumab vedotin, 46 [14.6%]; other, 6 [1.9%]), immunotherapy in 12 (3.8%), and other in 12 (3.8%). Characteristics of pts who received ADC or chemotherapy are shown (Table). In the overall population, median OS from start of avelumab 1LM was 21.1 mo (95% CI, 17.3-23.8), and 1- and 2-y OS rates (95% CI) were 66.58% (62.57%-70.26%) and 45.41% (40.89%-49.82%), respectively. In pts who received subsequent ADC or chemotherapy, median OS (95% CI) from start of avelumab 1LM was 31.3 mo (22.2-not estimable) and 14.0 mo (13.2-15.6), 1-y OS rates (95% CI) were 85.93% (72.72%-93.04%) and 61.68% (55.13%-67.56%), and 2-y OS rates were 66.90% (49.85%-79.29%) and 25.43% (19.17%-32.14%), respectively. Conclusions: Updated results from the AVENANCE study confirm the effectiveness of avelumab 1LM in a real-world population. In pts with subsequent treatment (≈70% of pts who discontinued), a contemporary sequence of ADC after 1L platinum-based chemotherapy and avelumab 1LM treatment showed encouraging OS. Clinical trial information: NCT04822350.

ddMVAC, dose-dense methotrexate, vinblastine, doxorubicin, and cisplatin.