Avelumab first-line maintenance treatment for advanced urothelial carcinoma: review of evidence to guide clinical practice

The JAVELIN Bladder 100 phase III trial led to the incorporation of avelumab first-line (1L) maintenance treatment into international guidelines as a standard of care for patients with advanced urothelial carcinoma (UC) without progression after 1L platinum-based chemotherapy. JAVELIN Bladder 100 showed that avelumab 1L maintenance significantly prolonged overall survival (OS) and progression-free survival in this population compared with a 'watch-and-wait' approach. The aim of this manuscript is to review clinical studies of avelumab 1L maintenance in patients with advanced UC, including long-term efficacy and safety data from JAVELIN Bladder 100, subgroup analyses in clinically relevant subpopulations, and 'real-world' data obtained outside of clinical trials, providing a comprehensive resource to support patient management. Extended follow-up from JAVELIN Bladder 100 has shown that avelumab provides a long-term efficacy benefit, with a median OS of 23.8 months measured from start of maintenance treatment, and 29.7 months measured from start of 1L chemotherapy. Longer OS was observed across subgroups, including patients who received 1L cisplatin + gemcitabine, patients who received four or six cycles of 1L chemotherapy, and patients with complete response, partial response, or stable disease as best response to 1L induction chemotherapy. No new safety signals were seen in patients who received >1 year of avelumab treatment, and toxicity was similar in those who had received cisplatin or carboplatin with gemcitabine. Other clinical datasets, including noninterventional studies conducted in Europe, USA, and Asia, have confirmed the efficacy of avelumab 1L maintenance. Potential subsequent treatment options after avelumab maintenance include antibodyedrug conjugates (enfortumab vedotin or sacituzumab govitecan), erdafitinib in biomarker-selected patients, platinum rechallenge in suitable patients, nonplatinum chemotherapy, and clinical trial participation; however, evidence to determine optimal treatment sequences is needed. Ongoing trials of avelumab-based combination regimens as maintenance treatment have the potential to evolve the treatment landscape for patients with advanced UC.