Poster Presentation Clinical Oncology Society of Australia Annual Scientific Meeting 2022

Avelumab first-line (1L) maintenance for advanced urothelial carcinoma (aUC): long-term outcomes from JAVELIN Bladder 100 in subgroups defined by response to 1L chemotherapy (#229)

Begoña P. Valderrama 1 , Thomas Powles 2 , Srikala S. Sridhar 3 , Claudia Caserta 4 , Yohann Loriot 5 , Shilpa Gupta 6 , Joaquim Bellmunt 7 , Cora N. Sternberg 8 , David W. Pook 9 , Jing Wang 10 , Nuno Costa 11 , Robert J. Laliberte 12 , Alessandra di Pietro 13 , Se Hoon Park 14 , Petros Grivas 15
  1. Department of Medical Oncology, Hospital Universitario Virgen del Rocío, Seville, Spain
  2. Barts Cancer Institute, Experimental Cancer Medicine Centre, Queen Mary University of London, St Bartholomew’s Hospital, London, UK
  3. Princess Margaret Cancer Centre, University Health Network, Toronto, Ontario, Canada
  4. Medical Oncology Unit, Azienda Ospedaliera S. Maria, Terni, Italy
  5. Gustave Roussy, INSERMU981, Université Paris-Saclay, Villejuif, France
  6. Department of Hematology and Medical Oncology, Cleveland Clinic, Cleveland, Ohio, USA
  7. Department of Medical Oncology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts, USA
  8. Englander Institute for Precision Medicine, Weill Cornell Medicine, Hematology/Oncology, New York, USA
  9. Oncology Department, Monash Health, Melbourne, Victoria, Australia
  10. Pfizer, Cambridge, Massachusetts, USA
  11. Pfizer, Porto Salvo, Portugal
  12. Pfizer, Cambridge, Massachusetts, USA
  13. Pfizer srl, Milano, Italy
  14. Sungkyunkwan University Samsung Medical Center, Seoul, Korea
  15. University of Washington, Fred Hutchinson Cancer Research Center, Seattle Cancer Care Alliance, Seattle, Washington, USA

Aims: In the phase 3 JAVELIN Bladder 100 trial (NCT02603432), avelumab 1L maintenance + best supportive care (BSC) significantly prolonged overall survival (OS) vs BSC alone in patients with aUC that had not progressed with 1L platinum-based chemotherapy. We report exploratory analyses in subgroups defined by response to 1L chemotherapy (complete response [CR], partial response [PR], or stable disease [SD]) after ≥2 years of follow-up.

Methods: Eligible patients had unresectable locally advanced or metastatic UC without progression with 4-6 cycles of 1L gemcitabine + cisplatin or carboplatin. Patients were randomized 1:1 to receive avelumab + BSC (n=350) or BSC alone (n=350), stratified by best response to 1L chemotherapy (CR/PR vs SD) and visceral vs nonvisceral disease at start of 1L chemotherapy.

Results: At data cutoff (June 4, 2021), median follow-up in both arms was ≥38 months. OS and PFS were longer in the avelumab + BSC vs BSC alone arm in all subgroups. HRs for OS (95% CI) were: CR subgroup, 0.72 (0.482-1.076); PR subgroup, 0.70 (0.541-0.914); and SD subgroup, 0.84 (0.596-1.188). HRs for PFS were: CR subgroup, 0.58 (0.410-0.817); PR subgroup, 0.47 (0.367-0.607); and SD subgroup, 0.59 (0.421-0.816). In the avelumab + BSC vs BSC alone arm, respectively, subsequent second-line anticancer drug therapy was received by: CR subgroup, 50.0% vs 74.2%; PR subgroup, 58.3% vs 71.8%; and SD subgroup, 46.4% vs 70.4%. Long-term safety was consistent across subgroups.

Conclusions: Long-term follow-up from JAVELIN Bladder 100 continues to show prolonged OS and PFS with avelumab + BSC vs BSC alone irrespective of response (CR, PR, or SD) to 1L chemotherapy and despite a higher proportion of patients in the BSC alone arm receiving subsequent therapy. These findings further support avelumab 1L maintenance as standard of care for all patients with aUC that has not progressed with 1L platinum-based chemotherapy.

  1. Funding Statement: This trial was sponsored by Pfizer as part of an alliance between Pfizer and Merck (CrossRef Funder ID: 10.13039/100009945). Medical writing support was provided by Jamie Ratcliffe of ClinicalThinking and was funded by Pfizer and Merck.
  2. © 2022 American Society of Clinical Oncology, Inc. Reused with permission. This abstract was accepted and previously presented at the 2022 ASCO Annual Meeting. All rights reserved.