Avelumab treatment for metastatic urothelial carcinoma in the phase Ib JAVELIN Solid Tumor Study: Updated safety and efficacy analysis with ≥ two years of follow-up.

425Background: Avelumab, a human anti‒PD-L1 IgG1 antibody, is approved for the treatment of metastatic urothelial cancer (mUC) progressing after platinum chemotherapy in the US, Canada, and Israel. Here, we report an updated pooled analysis of 2 cohorts of avelumab-treated patients (pts) with mUC from the JAVELIN Solid Tumor study (NCT01772004). Methods: Pts with mUC whose disease had progressed after platinum-based therapy or were cisplatin ineligible received avelumab 10 mg/kg every 2 weeks. Tumors were assessed every 6 weeks by independent review (RECIST v1.1). Endpoints included objective response rate (ORR), duration of response (DOR), progression-free survival (PFS), overall survival (OS), and safety (NCI CTCAE v4.0). Results: As of April 2018, 249 pts had received avelumab and had been followed for ≥2 years (median 2.7 years). Median treatment duration was 12.0 weeks (IQR, 6.0-32.1), and 12 pts (4.8%) remained on treatment. Confirmed ORR in all evaluable pts (n = 242) was 16.5% (95% CI: 12.1%-21.8%...