Arm A: Paclitaxel 90 mg/m² IV QW (3 on/1 off) + bevacizumab 10 mg/kg IV Q2W + AMG 386 10 mg/kg IV QW Arm B: Paclitaxel 90 mg/m² IV QW (3 on/1 off) + bevacizumab 10 mg/kg IV Q2W + AMG 386 3 mg/kg IV QW Arm C: Paclitaxel 90 mg/m² IV QW (3 on/1 off) + bevacizumab 10 mg/kg IV Q2W + AMG 386 placebo IV QW Arm D: Paclitaxel 90 mg/m² IV QW (3 on/1 off) + Open Label AMG 386 10 mg/kg IV QW To maintain the double-blind in arms A, B, and C, each subject will be infused weekly with a volume of investigational product equivalent to 10 mg/kg AMG 386 IV. Arm D will receive open label AMG 386 and will not receive a placebo for bevacizumab.