Response and Outcomes of Maintenance Avelumab After Platinum-Based Chemotherapy (PBC) in Patients With Advanced Urothelial Carcinoma (aUC): "Real World" Experience

Clin Genitourin Cancer. 2023 Oct;21(5):584-593. doi: 10.1016/j.clgc.2023.06.008. Epub 2023 Jun 20.

Abstract

Background: Platinum-based chemotherapy (PBC) followed by avelumab switch maintenance in nonprogressors is standard first line (1L) treatment for advanced urothelial carcinoma (aUC). We describe clinical features and outcomes in a "real-world' cohort treated with avelumab maintenance for aUC.

Materials and methods: This was a retrospective cohort study of patients (pts) who received 1L switch maintenance avelumab after no progression on PBC for aUC. We calculated progression-free survival (PFS) and overall survival (OS) from initiation of maintenance avelumab. We also described OS and PFS for specific subsets using Cox regression and observed response rate (ORR).

Results: A total of 108 pts with aUC from 14 sites treated with maintenance avelumab were included. There was a median of 6 weeks1-30 from end of PBC to avelumab initiation; median follow-up time from avelumab initiation was 8.8 months (1-42.7). Median [m]PFS was 9.6 months (95%CI 7.5-12.1) and estimated 1-year OS was 72.5%. CR/PR (vs. SD) to 1L PBC (HR = 0.33, 95% CI 0.13-0.87) and ECOG PS 0 (vs. ≥1), (HR = 0.15, 95% CI 0.05-0.47) were associated with longer OS. The presence of liver metastases was associated with shorter PFS (HR = 2.32, 95% CI 1.17-4.59). ORR with avelumab maintenance was 28.7% (complete response 17.6%, partial response 11.1%), 29.6% stable disease, 26.9% progressive disease as best response (14.8% best response unknown).

Conclusions: Results seem relatively consistent with findings from JAVELIN Bladder100 trial and recent "real world" studies. Prior response to platinum-based chemotherapy, ECOG PS 0, and absence of liver metastases were favorable prognostic factors. Limitations include the retrospective design, lack of randomization and central scan review, and possible selection/confounding biases.

Keywords: Anti-PD(L)1; Bladder cancer; Immune Checkpoint Inhibitors; Immunotherapy; Urinary tract cancer.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Antibodies, Monoclonal / therapeutic use
  • Carcinoma, Transitional Cell* / drug therapy
  • Humans
  • Platinum
  • Retrospective Studies
  • Urinary Bladder Neoplasms* / chemically induced
  • Urinary Bladder Neoplasms* / drug therapy

Substances

  • avelumab
  • Antibodies, Monoclonal
  • Platinum