Avelumab as First-Line Maintenance Treatment in Locally Advanced or Metastatic Urothelial Carcinoma

This work provides a summary of guideline recommendations and an expert position on the use of maintenance avelumab therapy based on a review of current international clinical practice guidelines for locally advanced or metastatic urothelial carcinoma (UC). A PubMed literature search was conducted in March 2022 (updated in July 2023) to identify guidelines for locally advanced or metastatic UC. An expert panel (four oncologists and one urologist) reviewed the guidelines and clinical evidence, and discussed practical questions regarding the use of avelumab maintenance therapy in this clinical setting. The National Comprehensive Cancer Network, European Association of Urology and European Society for Medical Oncology guidelines recommend first-line cisplatin-containing chemotherapy for cisplatin-eligible patients, carboplatin-gemcitabine for cisplatin-ineligible patients who are fit for carboplatin, or immunotherapy with programmed death ligand-1 (PD-L1) inhibitors (e.g. atezolizumab) in platinum-ineligible patients. Maintenance avelumab is recommended in patients with response/stable disease following chemotherapy (regardless of PD-L1 status). In patients who relapse after/during chemotherapy, options include immunotherapy, erdafitinib [in those with fibroblast growth factor receptor (FGFR) mutations], enfortumab vedotin or further chemotherapy. The expert panel provided the following practical guidance: (1) consider maintenance avelumab in all eligible patients; (2) continue avelumab until disease progression/unacceptable toxicity; (3) ideally, administer six cycles of platinum-based chemotherapy prior to maintenance avelumab; (4) perform radiological evaluation after four chemotherapy cycles and prior to maintenance avelumab; (5) carboplatin-gemcitabine followed by maintenance avelumab is preferred in cisplatin-ineligible patients (regardless of PD-L1 expression), but consider first-line immunotherapy in PD-L1-positive patients and platinum-ineligible patients (regardless of PD-L1 status); and (6) for patients who relapse on avelumab, second-line options include enfortumab vedotin, FGFR inhibitors (in those with FGFR mutations) or clinical trial inclusion. In conclusion, avelumab maintenance therapy is recommended following platinum-based chemotherapy in all eligible patients with locally advanced or metastatic UC, continued until disease progression or unacceptable toxicity.