Avelumab first-line (1L) maintenance for advanced urothelial carcinoma (UC): Results from patients with >= 12 mo of treatment in JAVELIN Bladder 100

In the phase 3 JAVELIN Bladder 100 trial (NCT02603432), patients (pts) with aUC that had not progressed with 1L platinum-based chemotherapy had significantly prolonged overall survival and progression-free survival with avelumab 1L maintenance + best supportive care (BSC) compared with BSC alone. Results led to avelumab 1L maintenance being approved worldwide and adopted into international treatment guidelines as standard of care. Here, we report long-term data from pts with ≥12 mo of avelumab 1L maintenance treatment as part of the JAVELIN Bladder 100 trial. Eligible pts had unresectable locally advanced or metastatic UC that had not progressed with 1L platinum-based chemotherapy. This analysis included pts randomized to receive avelumab + BSC. Study treatment continued until confirmed progression, unacceptable toxicity, or withdrawal of consent. After a median follow-up of 38.0 mo in the avelumab arm (data cutoff June 4, 2021; ≥2 y in all pts), 118/350 pts (33.7%) had received ≥12 mo of treatment. Characteristics of these pts were similar to those in the overall avelumab arm (Table). Among all treated pts in the overall avelumab arm (N=344), grade ≥3 treatment-related adverse events (TRAEs) occurred in 67 (19.5%) and grade ≥3 immune-related AEs (irAEs) occurred in 26 (7.6%). Among pts treated for ≥12 mo (n=118), grade ≥3 TRAEs occurred after ≥12 mo in 14 (11.9%) and grade ≥3 irAEs occurred after ≥12 mo in 5 (4.2%). Efficacy outcomes will be presented. In the JAVELIN Bladder 100 trial, prolonged avelumab 1L maintenance treatment was associated with a safety profile consistent with prior avelumab monotherapy studies, with no new safety signals identified with longer treatment duration. These results further support the use of avelumab 1L maintenance until progression for pts with aUC that has not progressed with 1L platinum-based chemotherapy.Table: 1760PPts with ≥12 months of avelumab treatment (n=118)Overall avelumab arm (N=350)Median age (range), years69 (43-86)68 (37-90)Sex, n (%)MaleFemale91 (77.1)27 (22.9)266 (76.0)84 (24.0)ECOG PS, n (%)01283 (70.3)35 (29.7)0213 (60.9)136 (38.9)1 (0.3)Site of metastasis at start of chemotherapy, n (%)VisceralNonvisceral56 (47.5)62 (52.5)191 (54.6)159 (45.4)Best response to 1L chemotherapy, n (%)CR or PRSD87 (73.7)31 (26.3)253 (72.3)97 (27.7)PD-L1 status, n (%)PositiveNegativeUnknown72 (61.0)39 (33.1)7 (5.9)189 (54.0)139 (39.7)22 (6.3)CR, complete response; PR, partial response; SD, stable disease. Open table in a new tab