Neoadjuvant Chemotherapy With Nonpegylated Liposome-Encapsulated Doxorubicin (Npld) Plus Cyclophosphamide Followed By Trastuzumab Plus Nabpaclitaxel For Her2-Positive Breast Cancer (Bc).

648 Background: Using a liposomal delivery system NPLD has shown similar efficacy and less cardiac toxicity compared to conventional anthracyclines. Similarly albumin-bound paclitaxel (nabpaclitaxel) has demonstrated higher response rates and improved tolerability compared to conventional taxanes. This study aimed to evaluate the activity and safety of neoadjuvant chemotherapy with NPLD, nabpaclitaxel and trastuzumab for early or locally advanced HER2 positive BC. Methods: Preoperative treatment included NPLD (60 mg/mq iv) plus cyclophosphamide (600 mg/mq iv) every 3 weeks for 4 cycles followed by nabpaclitaxel (260 mg/mq iv) plus trastuzumab (8 mg/mq loading dose iv, then 6 mg/mq iv) every 3 weeks for 4 cycles. All patients received granulocyte colony-stimulating factor as prophylaxis of febrile neutropenia. Primary objective of the study was pathologic complete response (pCR) defined as the absence of residual invasive cancer both in the breast and regional nodes. Also, breast MRI, Contrast-Enhanced-Spectral-Mammography (CESM) and Ki-67 after 1 cycle of chemotherapy were exploratory investigated to assess the ability to predict pCR. Results: 15 pts were treated from September 2011 to November 2013. 14 pts were evaluable for response and completed the planned treatment. Median age was 52 years (range: 28-70), the majority of pts had T2 stage (64%), clinical nodes involvement N+ (71%), ER positive (64%). 6 out of 14 pts had clinical stage III BC. All tumours were grade 3 and 93% had Ki-67 ≥20%. pCR was reported in 64% (9 of 14). The most frequent grade 3 adverse event was myalgia (21%). Breast MRI after 1 cycle showed a significant difference on “signal-intensity/time” (SIT) curve between pCR pts and no-pCR pts, with an increase (type-II to type-III) in 50% of pCR pts and 0% of no-pCR pts. Conclusions: The nanoparticle formulations, nabpaclitaxel and NPLD, combined with trastuzumab seem to be an active and manageable regimen. It may represent an attractive and promising option in neoadjuvant treatment for HER2 positive BC. The role of Breast MRI, CESM and Ki-67 needs further exploration to predict pathologic response.