Safety and clinical activity of durvalumab monotherapy in patients with hepatocellular carcinoma (HCC).

4071 Background: Durvalumab, an anti-PD-L1 mAb, has shown early and durable clinical activity with manageable safety in an ongoing Phase 1/2, multicenter, open-label study in pts with advanced solid tumors. Interim analyses from the HCC cohort in the dose-expansion part of this study are reported here. Methods: Patients with HCC (Child-Pugh class A) received durvalumab 10 mg/kg i.v. q2w for 12 months or until confirmed progressive disease, whichever occurred first. The primary objective was to evaluate the safety profile; secondary objective was to assess the antitumor activity (investigator-assessed RECIST v1.1). Clinical activity was evaluated for the total HCC population and by viral status. Results: As of Oct 24 2016, 40 HCC pts with median 23.9 (range 2.4–34.7) weeks follow-up received durvalumab. 93% had prior sorafenib. Treatment-related AEs occurred in 80.0% of pts, most commonly fatigue (27.5%), pruritus (25.0%) and elevated aspartate aminotransferase (AST) (22.5%). Grade 3–4 treatment-related AEs were reported in 20.0% of pts, most commonly elevated AST (7.5%) and elevated alanine aminotransferase (5.0%). 7 (17.5%) pts completed the initial 12-month treatment and 7 (17.5%) pts discontinued treatment because of an AE (none related to treatment). There were no deaths due to treatment-related AEs. Clinical activity is presented in the table. 4 pts achieved a PR; 2 were ongoing at data cut-off. Conclusions: Durvalumab had an acceptable safety profile and showed promising antitumor activity and OS in pts with HCC, particularly HCV+ pts. Clinical trial information: NCT01693562. [Table: see text]