Avelumab first-line (1L) maintenance for advanced urothelial carcinoma (UC): Long-term follow-up results from the JAVELIN Bladder 100 trial.

Abstract

487 Background: The phase 3 JAVELIN Bladder 100 trial (NCT02603432) showed significantly longer overall survival (OS) with avelumab + best supportive care (BSC) vs BSC alone in patients (pts) with advanced UC that had not progressed with 1L platinum-containing chemotherapy. Avelumab 1L maintenance is now considered standard of care in treatment guidelines. We report trial data with ≥2-years follow-up in all pts (additional 19 months from the initial analysis). Methods: Pts with unresectable locally advanced or metastatic UC without disease progression with 4-6 cycles of 1L gemcitabine + cisplatin or carboplatin were randomized 1:1 to receive avelumab + BSC or BSC alone. The primary endpoint was OS, assessed from randomization in all pts and in pts with PD-L1+ tumors (Ventana SP263 assay). Secondary endpoints included progression-free survival (PFS) and safety. Results: 700 pts were randomized (350 per arm); 358 (51.1%) had PD-L1+ tumors. With extended follow-up (median, ≥38 months in both arms for all pts; data cutoff, June 4, 2021), OS remained significantly longer in the avelumab + BSC vs BSC alone arm in all randomized pts and in pts with PD-L1+ tumors (Table). An OS benefit was observed across prespecified subgroups. PFS (by investigator) was longer with avelumab + BSC vs BSC alone in all randomized pts and in pts with PD-L1+ tumors (Table). In the avelumab + BSC and BSC alone arms, respectively, 185 (52.9%) vs 252 (72.0%) pts received a subsequent anticancer drug therapy, including a PD-(L)1 inhibitor in 40 (11.4%) vs 186 (53.1%) pts. Long-term safety was consistent with previous avelumab monotherapy studies, with no new safety signals. Conclusions: Long-term follow-up from the JAVELIN Bladder 100 trial continues to show prolonged OS with avelumab + BSC vs BSC alone. These results further support the standard-of-care role for avelumab as 1L maintenance in pts with advanced UC that has not progressed with 1L platinum-containing chemotherapy. Clinical trial information: NCT02603432. [Table: see text]