Post hoc analyses from JAVELN Bladder 100 that will be presented at the American Society of Clinical Oncology 2023 Annual Meeting shed light on the long-term safety profile of avelumab first-line maintenance for patients with advanced urothelial carcinoma (UC).
The phase 3 trial enrolled patients with advanced UC who had not progressed after first-line platinum-based chemotherapy. Results showed significantly prolonged overall survival and progression-free survival with avelumab first-line maintenance plus best supportive care (BSC) compared with BSC alone.
Additionally, the safety profile of avelumab was consistent with prior avelumab monotherapy studies; no new safety signals were identified and no detrimental impact on quality of life was noted.
Joaquim Bellmunt, MD, PhD, and colleagues reported post hoc safety analyses in the avelumab-plus-BSC arm after a minimum of 2 years of follow-up. They noted that trial treatment continued until disease progression, unacceptable toxicity, or withdrawal of consent.
Median follow-up at data cutoff was 38 months. In the 344 patients who received at least 1 dose of avelumab, median treatment duration was 5.8 months and median number of infusions was 11.5.
Treatment-related adverse events (AEs) of any grade were reported in 269 patients, and 19.5% of patients experienced events grade 3 or higher. Forty patients had a treatment-related AE that led to treatment discontinuation.
Immune-related AEs of any grade occurred in 111 patients, and 7.6% of patients experienced events grade 3 or higher. Serious immune-related AEs occurred in 18 patients, of which immune-related nephritis or renal dysfunction was the most common. Twenty-one patients had an immune-related AE that led to treatment discontinuation.
Among the 118 patients treated with avelumab for at least 12 months, immune-related AEs occurred after 12 months in 27 patients, including grade 3 or higher events in 4.2% of patients. Immune-related rash was the most common immune-related AE of any grade after 12 months of treatment.
Researchers concluded that the acceptable long-term safety profile of avelumab first-line maintenance is confirmed. “These results further support the use of avelumab first-line maintenance until progression as standard of care for patients with advanced urothelial carcinoma without progression after first-line platinum-based chemotherapy,” they added.