Updated efficacy and tolerability of durvalumab in locally advanced or metastatic urothelial carcinoma.

Abstract

286 Background: Anti-PD-L1 immunotherapy has shown promising clinical activity in urothelial carcinoma (UC). We report on a planned update of efficacy and follow-up in patients (pts) receiving durvalumab for the treatment of locally advanced or metastatic UC. Methods: Pts received durvalumab 10 mg/kg Q2W up to 12 months (mo), unacceptable toxicity or confirmed progressive disease. Tumor PD-L1 expression was assessed using the validated Ventana SP263 assay (PD-L1 high = TC ≥ 25% or IC ≥ 25%). Primary endpoints were confirmed ORR by RECIST v1.1 with blinded independent central review (BICR) and safety. Duration of response (DoR) and overall survival (OS) were key secondary endpoints. Results: As of July 24, 2016 (data cutoff [DCO]), the primary efficacy population included 103 pts who were followed for at least 13 weeks (median duration of follow up 7.3 mo); 37% had ≥ 2 prior regimens; 97% had prior platinum treatment; 95% had visceral metastases; and 49% had liver metastases at baseline. As of the DCO, 21 pts (20.4%) had a confirmed response per BICR (including 5 pts [4.9%] with a complete response) and an additional 3 pts had an unconfirmed response. Responses were seen in both PD-L1 high and PD-L1 low/negative subgroups (Table). Responses occurred early (median time to response 1.4 mo) and were durable. Median DoR has not been reached. Of the 21 confirmed responders, 18 pts had an ongoing response, 16 pts had DoR ≥ 6 mo and 7 pts had DoR ≥ 9 mo. Treatment-related Grade 3/4 AE rates were low (5.2%; as treated population, n = 191); Grade 3/4 immune-mediated AEs (imAEs) occurred in 3 pts, and 1 pt discontinued treatment due to an imAE of acute kidney injury. Conclusions: Durvalumab administered at 10 mg/kg Q2W showed clinical activity and an excellent safety profile in pts with locally advanced or metastatic UC. Clinical trial information: NCT01693562. [Table: see text]