Cardiac safety of pegylated liposomal doxorubicin (PLD) in combination with trastuzumab (T) in patients with metastatic breast cancer (MBC): Results from a multicenter phase II study

1106 Background: Combination therapy of doxorubicin and trastuzumab is highly effective for Her2 positive MBC but characterized by frequent cardiac toxicity (CT). PLD can significantly reduce CT compared to conventional doxorubicin. Patients and Methods: 15 patients were enrolled in a phase II trial to evaluate cardiac safety of T (4 mg/Kg loading dose day 2, followed by weekly 2 mg/Kg) in combination with PLD (40 mg/m2 IV bolus day 1, q 28 d). 75% of pts. presented with more than 1 metastatic site and 40% for second line treatment. PLD was administered for 6 or 9 cycles, respectively, T until disease progression. To assess CT, all pts were evaluated with electrocardiogram (ECG) and echocardiograms (E) for Left Ventricular Ejection Fraction (LVEF) at baseline, every cycle during PLD and T, and every three months during T therapy alone. CT was defined as appearance of signs/ symptoms of congestive heart failure and/or an absolute decrease in LVEF > 10 units (below 50%) or decrease in LVEF > 15 units (above...