Real-world (rw) treatment (tx) patterns, sequencing, and outcomes in US patients (pts) with locally advanced or metastatic urothelial cancer (la/mUC) treated with avelumab first-line maintenance (1LM)

ASCO 2024 Abstract
Authors Kenneth Robert Carson, Chiemeka Ike, Seyed Hamidreza Mahmoudpour, Sebastian Monzon, Stamatina Fragkogianni, Mairead Kearney

Background: In June 2020, avelumab 1LM was approved in the US for pts with la/mUC without progressive disease (PD) after 1L platinum-based chemotherapy (PBC). This rw study describes pt characteristics, tx patterns, and outcomes in pts who received avelumab 1LM. We report exploratory analyses by baseline metastatic site.

Methods: A retrospective cohort of pts diagnosed with la/mUC (T4b, N2/3, and/or M1) who received systemic tx after approval of avelumab 1LM was identified from deidentified records in the Tempus database. Pts with no evidence of PD after completing 1L PBC were considered eligible for 1LM. 1LM was differentiated from second-line (2L) tx based on recorded clinical intent or algorithmically based on immuno-oncology tx initiated within 180 days of 1L PBC completion without recorded PD. Rw overall survival (OS), progression-free survival (PFS), and time to next tx (TTNT) were estimated using Kaplan-Meier methods.

Results: By data cutoff (Nov 2023), 1485 pts had received 1L tx after approval of avelumab 1LM. Median age at diagnosis was 70 y, 74% were men, 62% were White, 88% had transitional cell carcinoma, and 62% had metastatic/stage IV disease. 1L tx was PBC in 63% (942/1485), which included cisplatin in 62% (581/942), carboplatin in 34% (326/942), and oxaliplatin in 4% (35/942), alone or in combination. 87% (820/942) were eligible for 1LM after completing 1L PBC, of whom 38% (313/820) had recorded 1LM tx, which was avelumab in 58% (180/313). Median follow-up from 1LM start was 13.5 months. Median (95% CI) rwOS and rwPFS from avelumab 1LM start was 20.6 (17.6-25.3) and 6.2 (4.6-13.7) months, respectively. Analysis by metastatic site is shown in the table. After avelumab 1LM, 37% (67/180) received 2L tx, most commonly with enfortumab vedotin (EV; 64% [43/67]); median rwOS from start of 2L EV was 13.5 months (95% CI, 11.6-NE).

Conclusions: Despite limited follow-up, this study demonstrates the rw effectiveness of avelumab 1LM in pts whose disease has not progressed on 1L PBC. Results corroborate JAVELIN Bladder 100 data and recent rw studies from multiple countries. Our study also provides early evidence of the use and effectiveness of 2L EV after the JAVELIN Bladder regimen of 1L PBC without PD followed by avelumab 1LM. Understanding OS outcomes in pts with specific metastatic patterns is important for improving individualized care. Future studies with longer follow-up are warranted to evaluate rw benefits of the avelumab 1LM in selected pt groups.

Metastatic Site Median (95% CI) Months from Start of Avelumab 1LM
No visceral or thoracic lesions (n=86) 20.9 (19.7-NE) 10.6 (6.0-NE) 11.0 (8.2-20.4)
Liver (n=34) 14.7 (9.1-NE) 4.8 (3.5-NE) 7.1 (4.8-9.8)
Brain (n=10) 6.1 (4.2-NE) 3.7 (3.6-NE) 4.6 (4.2-NE)
No metastatic lesions (n=26) 17.2 (11.5-NE) 3.5 (2.3-NE) 8.1 (4.8-NE)

NE, not estimable.