# Outcomes with Avelumab Maintenance Treatment for Advanced Urothelial Cancer in a US Patient Cohort

## TL;DR

This study examines how avelumab, a cancer treatment, performs in patients with advanced bladder cancer in the US and finds it effective when used after initial chemotherapy.

## Contribution

The study provides real-world evidence supporting avelumab as a first-line maintenance treatment for advanced urothelial cancer.

## Key findings

- Avelumab maintenance treatment showed similar outcomes to previous studies in patients with no disease progression after first-line chemotherapy.
- Second-line enfortumab vedotin after avelumab maintenance was effective, with median overall survival of 11.6 months.
- Most patients who completed first-line platinum-based chemotherapy had no disease progression.

## Abstract

In this study, we looked at medical records showing treatment patterns and outcomes in people with advanced urothelial cancer in the United States following the approval of avelumab for first-line maintenance treatment. Most people who completed first-line treatment received platinum-based chemotherapy (66%), and 89% of these people had no evidence of disease progression. Most people who went on to receive first-line maintenance received avelumab (62%). Outcomes with avelumab maintenance were similar to previous studies. Our study also demonstrates that, after disease progression on avelumab maintenance, second-line enfortumab vedotin appears to be an effective treatment option. Overall, available data support the use of avelumab maintenance as a standard treatment in people whose disease has not progressed following first-line platinum-based chemotherapy. Further research is needed to look at additional available treatment options and their associated outcomes when received outside of a clinical trial.

Background: This study describes treatment patterns and clinical outcomes in patients with advanced urothelial carcinoma (aUC) in the US following the approval of avelumab for first-line maintenance treatment. Methods: This retrospective cohort study used deidentified patient data from the Tempus database. Eligible patients had completed first-line systemic anticancer treatment for aUC between July 2020 and March 2023. Results: In total, 974 eligible patients were identified; most (72%) were male. Median age at diagnosis was 70 years. Among patients who completed first-line platinum-based chemotherapy (644 [66%]), 574 (89%) had no evidence of disease progression. Of 219 patients who received first-line maintenance, 135 (62%) received avelumab. Median (95% CI) overall survival (OS) and progression-free survival (PFS) from avelumab maintenance start were 14.9 months (13.1—not estimable [NE) and 6.4 months (4.6—NE), respectively. Enfortumab vedotin (EV) was the most common second-line treatment after avelumab (70%). Median (95% CI) OS and PFS from second-line EV start were 11.6 months (6.1—NE) and 6.6 months (4.1—NE), respectively. Conclusions: Results provide insights into the impact of avelumab first-line maintenance treatment in patients with aUC in the US. Effectiveness data are consistent with previous findings, supporting the use of avelumab maintenance in patients without disease progression following first-line platinum-based chemotherapy. Second-line EV after progression on avelumab maintenance had similar effectiveness to results from other real-world studies.