Intravenous aflibercept in patients with platinum-resistant, advanced ovarian cancer: results of a randomized, double-blind, phase 2, parallel-arm study

Abstract

Background: In this randomized phase 2 study, the authors assessed the efficacy and safety of intravenous aflibercept at 2 different doses (2 mg/kg or 4 mg/kg) in patients with recurrent, platinum-resistant ovarian, peritoneal, or fallopian tube cancer who developed disease progression after receiving topotecan and/or pegylated liposomal doxorubicin.

Methods: Patients were randomized to receive intravenous aflibercept at a dose of either 2 mg/kg or 4 mg/kg every 2 weeks until they developed disease progression or significant toxicity. The primary endpoint was to evaluate Response Evaluation Criteria in Solid Tumor response rates (overall response rate [ORR] = complete responses plus partial responses) and to test the null hypothesis (ORR, >5%). Secondary endpoints included time to tumor progression, safety, progression-free survival/overall survival, drug pharmacokinetics, and immunogenicity. In total, 67 evaluable patients per cohort were planned based on a Simon 2-stage design, and, if those patients responded, then enrollment could extend to 200 patients. Tumor radiographic response was assessed by investigators and by an independent review committee.

Results: After the first 84 evaluable patients, 8 unconfirmed partial responders were noted (ORR, 10%) across both arms; the Independent Data Monitoring Committee recommended continuing blinded accrual. At study completion, 215 evaluable patients were accrued, including 1 responder of 106 patients (0.9%) in the 2-mg/kg cohort and 5 responders of 109 patients (4.6%) in the 4-mg/kg cohort according to the independent review committee. The clinical benefit rate (ORR plus stable disease >6 months) was 12.3% and 11% in the 2-mg/kg and 4-mg/kg cohorts, respectively. Treatment-related grade 3 and 4 adverse events included hypertension (25.5% and 27.5% in the 2-mg/kg and 4-mg/kg cohorts, respectively), proteinuria (9.4% and 7.3%, respectively), and fatigue (5.7% and 3.7%, respectively). The gastrointestinal perforation rate was low (3 patients; 1.4%).

Conclusions: Aflibercept at a dose of either 2 mg/kg or 4 mg/kg was generally well tolerated but did not meet the primary endpoint for response.

Keywords: advanced stage; aflibercept; ovarian cancer; phase 2; platinum resistance.