A Phase Iii Trial Of Neoadjuvant Chemotherapy With Or Without Anthracyclines In The Presence Of Dual Her2-Blockade For Her2+Breast Cancer: The Train-2 Study (Boog 2012-03)

507Background: Neoadjuvant chemotherapy with dual HER2 blockade boosts pathologic complete response (pCR) rates in HER2+ breast cancer. The optimal chemotherapy backbone in this setting is unknown. We conducted a multicenter phase III trial to study whether anthracyclines would improve outcome compared to a carboplatin-taxane regimen (NCT01996267). Methods: We randomly assigned (1:1) patients with stage II-III HER2+ breast cancer to receive 9 cycles paclitaxel (80mg/m2 day 1 and 8) and carboplatin (AUC = 6mg/ml·min) (arm A) or 3 cycles 5-fluoruoracil (500mg/m2), epirubicin (90mg/m2), and cyclophosphamide (500mg/m2) followed by 6 cycles paclitaxel and carboplatin (arm B). Both arms received trastuzumab (6mg/kg, loading dose 8mg/kg) and pertuzumab (420mg, loading dose 840mg) concurrent with all chemotherapy cycles, and cycles were repeated every 3 weeks. The primary endpoint was pCR in breast and axilla (ypT0/is,ypN0). Results: 438 patients were included and 418 (arm A 206 vs arm B 212) were evaluable for t...