Phase I Trial Of Pegylated Liposomal Doxorubicin And Lapatinib In The Treatment Of Metastatic Breast Cancer (Mbc): Final Results

610 Background: Liposomal formulations including pegylated liposomal doxorubicin (PLD) were developed to improve the therapeutic index of anthracyclines (A). Lapatinib (L) is a selective, highly competitive inhibitor of ErbB1 and ErbB2 tyrosine kinases. Conventional doxorubicin plus trastuzumab was effective but with unacceptable cardiac toxicity. PLD plus L may be effective with less cardiac risk. Methods: This is a phase I, dose-escalation trial of PLD 20, 30, 45 and 60 mg/m2 IV every 4 weeks (maximum of 8 doses) and L, 1500 mg po daily until progression in patients (pts) with MBC. ErbB2 positivity was not required. Prior chemotherapy, endocrine therapy and trastuzumab were allowed. A subsequent amendment allowed prior L. Prior A use was limited to 240 mg/m2 of doxorubicin or 600 mg/m2 of epirubicin. Concomitant CYP3A4 inducers/ inhibitors were not allowed. A left ventricular ejection fraction (LVEF) of u003e 50% was required. The primary objective was to evaluate the safety (particularly cardiac), tolerabi...