Randomized phase II trial comparing axitinib with the combination of axitinib and lomustine in patients with recurrent glioblastoma.

ABSTRACT

Axitinib is a small molecule tyrosine kinase inhibitor with high affinity and specificity for the family of vascular endothelial growth factor receptors. It has previously demonstrated anti-tumor activity in a small cohort of patients with recurrent glioblastoma (rGB). We conducted a non-comparative randomized phase II clinical trial investigating axitinib monotherapy versus axitinib plus lomustine (LOM) in patients with rGB. Primary endpoint was 6 month progression-free survival (6mPFS). Patients who progressed on axitinib-monotherapy were allowed to cross-over. Between August 2011 and July 2015, 79 patients were randomized and initiated axitinib monotherapy (n = 50; AXI) or axitinib plus lomustine (n = 29; AXILOM). Median age was 55y [range 18-80], 50M/28F. Baseline characteristics were well balanced between study arms. Nineteen patients in the AXI-arm crossed-over at the time of progression. Treatment was generally well tolerated. AXILOM patients were at higher risk for grade 3/4 neutropenia (0 vs. 21%) and thrombocytopenia (4 vs. 29%). Best Overall Response Rate (BORR) in the AXI-arm was 28 vs. 38% in the AXILOM-arm. 6mPFS was 26% (95% CI 14-38) versus 17% (95% CI 2-32) for patients treated in the AXI versus AXILOM-arms, respectively. Median overall survival was 29 weeks (95% CI 20-38) in the AXI-arm and 27.4 weeks (95% CI 18.4-36.5) in the AXILOM-arm. MGMT-promoter hypermethylation and steroid treatment at baseline correlated significantly with PFS and OS. We conclude from these results that axitinib improves response rate and progression-free survival in patients with rGB compared to historical controls. There is no indication that upfront combination of axitinib with LOM improves results (European Clinical Trials Database (EudraCT) Study Number 2011-000900-16).