Pazopanib and Fosbretabulin in recurrent ovarian cancer (PAZOFOS): A multi-centre, phase 1b and open-label, randomised phase 2 trial
Vascular co-option is a resistance mechanism to anti-angiogenic agents, but combinations of anti-vascular agents may overcome this resistance. We report a phase 1b and randomised phase 2 trial to determine the safety and efficacy of pazopanib with fosbretabulin. Eligible patients had recurrent, epithelial ovarian cancer with a platinum-free interval (PFI) of 3 to 12 months. Patients were stratified according to PFI (>6 versus ≤6 months) and prior bevacizumab use. Twelve patients were treated in the phase 1b. Commonest grade ≥ 2 adverse events (AEs) were hypertension (100%), neutropenia (50%), fatigue (50%), vomiting (50%). There was one DLT (grade 3 fatigue). The recommended phase 2 dose level was fosbretabulin 54 mg/m It remains unclear whether pazopanib with with fosbretabulin is an efficacious regimen to treat epithelial ovarian cancer. Effective cardiac risk mitigation is needed to increase the tolerability and maximize patient safety in future trials.