Randomized, double-blind, phase III trial of pazopanib versus placebo in women who have not progressed after first-line chemotherapy for advanced epithelial ovarian, fallopian tube, or primary peritoneal cancer (AEOC): Results of an international Intergroup trial (AGO-OVAR16).

Abstract

LBA5503 Background: Pazopanib is an oral, multikinase inhibitor of VEGFR-1, -2, -3, PDGFR-α and -β, and c-Kit. Preclinical and clinical studies support VEGF(R) and PDGF(R) as targets for AEOC treatment. This study evaluated the efficacy, safety, and tolerability of pazopanib maintenance therapy in patients who have not progressed after first-line chemotherapy for AEOC. Methods: Patients with histologically confirmed AEOC, FIGO II-IV, and no evidence of progression after surgery and ≥ 5 cycles of platinum-taxane chemotherapy were randomized 1:1 to receive 800 mg pazopanib once daily or placebo for up to 24 months. Primary endpoint was progression-free survival (PFS) by RECIST. Secondary endpoints included overall survival, PFS by GCIG criteria, safety, and quality of life. Results: Most of the 940 randomized patients had stage III/IV disease (91%) at initial diagnosis, and no residual disease after surgery (58%). The median time from diagnosis to randomization was 7.1 months in the placebo arm and 7.0 months in the pazopanib arm. The median follow-up was 24 months. Patients in the pazopanib arm had a prolonged PFS vs placebo (HR = 0.766; 95% CI: 0.64-0.91; p = 0.0021; medians 17.9 vs 12.3 months, respectively). Sensitivity and subgroup analyses of PFS, and analysis of PFS by GCIG criteria, were consistent with the primary analysis. The first interim analysis for OS (only 189 OS events = 20.1% of population) showed no difference between arms. Pazopanib mean exposure was shorter vs placebo (8.9 vs 11.7 months). Pazopanib treatment was associated with a higher incidence of adverse events (AEs) and serious AEs (26% vs 11%) vs placebo. The most common AEs were hypertension, diarrhea, nausea, headache, fatigue, and neutropenia. Fatal SAEs were reported in three patients on pazopanib and one patient on placebo. Conclusions: Pazopanib maintenance therapy provided a statistically significant and clinically meaningful PFS benefit in patients with AEOC; OS data are not mature. The safety profile of pazopanib in this setting was consistent with its established profile. Clinical trial information: NCT00866697.