Introduction:

First-line (1L) platinum-based chemotherapy (PBT) is recommended for patients with locally advanced or metastatic urothelial carcinoma (la/mUC). Among patients without disease progression following 1L PBT, avelumab maintenance (maintA) is recommended based on a survival benefit versus best supportive care in the JAVELIN Bladder 100 trial. However, there are limited data on the proportion of patients who are eligible for maintA in clinical practice. This study assessed the proportion of patients with la/mUC who are eligible for and who received maintA in US clinical practice.

Methods:

This retrospective, observational study used the US nationwide Flatiron Health longitudinal electronic health record-derived database comprising de-identified patient-level structured and unstructured data. Adults diagnosed with la/mUC who received ≥1 dose of 1L PBT between April 2020 to January 2022 were included. MaintA eligibility and utilization and patient disposition were assessed. MaintA eligibility was defined as complete response, partial response, or stable disease following 1L PBT.

Results:

In total, 336 patients with la/mUC were included in the analysis. Mean age (SD) was 70.1 (9.3) years and 72.6% were male. 186 (55.4%) received a cisplatin-based regimen and the remainder a carboplatin-based regimen; 181 patients (53.9%) were eligible for maintA. Of 138 evaluable maintA-ineligible patients, the primary reason for maintA ineligibility was disease progression (71.7% of patients, 99/138), followed by death during/post 1L PBT (28.3%, 39/138). Of maintA-eligible patients, 37.0% (67/181) received maintA, representing 19.9% (67/336) of the 1L PBT-treated population. Among patients who initiated maintA, mean (SD) time to initiation from end of 1L PBT was 1.0 (0.74) month and duration of maintenance was 5.5 (3.9) months.

Conclusion:

Of patients initiating 1L PBT, almost half were not eligible for maintA, primarily due to disease progression (71.7%) or death (28.3%) and >80% of the overall 1L PBT-treated population did not receive maintA. These data highlight the need for novel 1L treatments for patients with la/mUC.

Funding: Seagen Inc., and Astellas Pharma Inc