Avelumab in Combination with Axitinib as First-Line Treatment in Patients with Advanced Hepatocellular Carcinoma: Results from the Phase 1b VEGF Liver 100 Trial

Introduction: Combining an immune checkpoint inhibitor with a targeted antiangiogenic agent may leverage complementary mechanisms of action for the treatment of advanced/metastatic hepatocellular carcinoma (aHCC). Avelumab is a human anti-PD-L1 IgG1 antibody with clinical activity in various tumor types; axitinib is a selective tyrosine kinase inhibitor of vascular endothelial growth factor receptors 1, 2, and 3. We report the final analysis from VEGF Liver 100 (NCT03289533), a phase 1b study evaluating safety and efficacy of avelumab plus axitinib in treatment-naive patients with aHCC. Methods: Eligible patients had confirmed aHCC, no prior systemic therapy, >= 1 measurable lesion, Eastern Cooperative Oncology Group performance status <= 1, and Child-Pugh class A disease. Patients received avelumab 10 mg/kg intravenously every 2 weeks plus axitinib 5 mg orally twice daily until progression, unacceptable toxicity, or withdrawal. Endpoints included safety and investigator-assessed objective response per Response Evaluation Criteria in Solid Tumors (RECIST) 1.1 and modified RECIST (mRECIST) for HCC. Results: Twenty-two Japanese patients were enrolled and treated with avelumab plus axitinib. The minimum follow-up was 18 months as of October 25, 2019 (data cutoff). Grade 3 treatment-related adverse events (TRAEs) occurred in 16 patients (72.7%); the most common (>= 3 patients) were hypertension (n = 11 [50.0%]), palmar-plantar erythrodysesthesia syndrome (n = 5 [22.7%]), and decreased appetite (n = 3 [13.6%]). No grade 4 TRAEs or treatment-related deaths occurred. Ten patients (45.5%) had an immune-related AE (irAE) of any grade; 3 patients (13.6%) had an infusion-related reaction (IRR) of any grade, and no grade >= 3 irAE and IRR were observed. The objective response rate was 13.6% (95% CI: 2.9-34.9%) per RECIST 1.1 and 31.8% (95% CI: 13.9-54.9%) per mRECIST for HCC. Conclusion: Treatment with avelumab plus axitinib was associated with a manageable toxicity profile and showed antitumor activity in patients with aHCC.