All patients (in Part A and B) will receive nab-P intravenously once weekly for 3 weeks out of each 28-day cycle. Palbociclib oral dosing will be once daily on Days 1-21 of each 28-day cycle. To allow for PK evaluation of nab-P administered alone, nab-P will be administered on Day -2 for Cycle 1 only. Subsequent cycles will administer both nab-P and palbociclib on Day 1. Alternate dosing schedules for palbociclib may be explored based on emerging PK, PD, and safety data.