For this study, NECTIN4 expression data from seven muscle-invasive bladder cancer clinical cohorts (n = 1,912 total patients) were used to compare relative NECTIN4 expression across molecular subtypes. The outcome of the gene expression analysis was relative NECTIN4 expression in the consensus molecular subtypes of bladder cancer. Expression of NECTIN4 was validated in multiple bladder cancer cell lines. NECTIN4 was stably overexpressed or knocked down in basal (TCCSUP and UMUC-3) and luminal (HT-1376, HT-1197, and UMUC-9) bladder cancer cell lines, respectively, and enfortumab vedotin dose-response assays were performed, as measured by cell proliferation and clonogenic assays.
Dr. Chu and colleagues found that NECTIN4 expression is heterogeneous across molecular subtypes of bladder cancer and significantly enriched in luminal subtypes (p < 0.001):
Additionally, NECTIN4 expression is positively correlated with the luminal transcription markers GATA3, FOXA1, and PPARG across cohorts (Spearman’s rank correlation r = 0.57 p < 0.0001 for GATA3, r = 0.37 p < 0.0001 for FOXA1, and r = 0.56 p < 0.0001 for PPARG):
NECTIN4 expression is both necessary and sufficient for enfortumab vedotin sensitivity in luminal and basal subtypes of urothelial bladder cancer cells. Downregulation of NECTIN4 led to enfortumab vedotin resistance and enfortumab vedotin-resistant cell lines expressed decreased levels of Nectin-4.
Dr. Chu concluded this study assessing Nectin-4 expression across molecular subtypes with the following take-home messages:
- Results of this pre-clinical study suggest that sensitivity to enfortumab vedotin is mediated by expression of NECTIN4, which is significantly enriched in luminal subtypes of bladder cancer
- Downregulation of NECTIN4leads to resistance to enfortumab vedotin
- These findings have implications for biomarker development, patient selection, and the inclusion of molecular subtyping in ongoing and future enfortumab vedotin clinical trials
- Further investigation into Nectin-4 loss as a mechanism of resistance in patients treated on enfortumab vedotin is warranted
Written by: Zachary Klaassen, MD, MSc – Urologic Oncologist, Assistant Professor of Urology, Georgia Cancer Center, Augusta University/Medical College of Georgia Twitter: @zklaassen_md during the 2021 American Society of Clinical Oncology Genitourinary Cancers Symposium (#GU21), February 11th-February 13th, 2021
- Rosenberg J, Sridhar SS, Zhang J, et al. EV-101: A Phase I study of single-agent enfortumab vedotin in patients with nectin-4-positive solid tumors, including metastatic urothelial carcinoma. J Clin Oncol 2020 Apr 1;38(10):1041-1049.
- Rosenberg JE, O’Donnell PH, Balar AV, et al. Pivotal trial of Enfortumab Vedotin in Urothelial Carcinoma after Platinum and Anti-Programmed Death 1/Programmed Death Ligand 1 Therapy. J Clin Oncol. 2019 Oct 10;37(29):2592-2600.
- Powles T, Rosenberg JE, Sonpavde GP, et al. Enfortumab Vedotin in Previously Treated Advanced Urothelial Carcinoma. N Engl J Med 2021 Feb 12 [Epub ahead of print].