The overexpression or amplification of the human epidermal growth factor receptor 2 gene (HER2/neu) is associated with high risk of brain metastasis (BM). The identification of patients at highest immediate risk of BM could optimize screening and facilitate interventional trials. We performed gene expression analysis using complementary deoxyribonucleic acid-mediated annealing, selection, extension and ligation and real-time quantitative reverse transcription PCR (qRT-PCR) in primary tumor samples from two independent cohorts of advanced HER2 positive breast cancer patients. Additionally, we analyzed predictive relevance of clinicopathological factors in this series. Study group included discovery Cohort A (84 patients) and validation Cohort B (75 patients). The only independent variables associated with the development of early BM in both cohorts were the visceral location of first distant relapse [Cohort A: hazard ratio (HR) 7.4, 95 % CI 2.4–22.3; p < 0.001; Cohort B: HR 6.1, 95 % CI 1.5–25.6; p = 0.01] and the lack of trastuzumab administration in the metastatic setting (Cohort A: HR 5.0, 95 % CI 1.4–10.0; p = 0.009; Cohort B: HR 10.0, 95 % CI 2.0–100.0; p = 0.008). A profile including 13 genes was associated with early (≤36 months) symptomatic BM in the discovery cohort. This was refined by qRT-PCR to a 3-gene classifier (RAD51, HDGF, TPR) highly predictive of early BM (HR 5.3, 95 % CI 1.6–16.7; p = 0.005; multivariate analysis). However, predictive value of the classifier was not confirmed in the independent validation Cohort B. The presence of visceral metastases and the lack of trastuzumab administration in the metastatic setting apparently increase the likelihood of early BM in advanced HER2-positive breast cancer.

Introduction Although the human epidermal growth factor receptor 2 (HER2) blocker trastuzumab is generally well tolerated, cardiotoxicity can be an important therapeutic limitation. Objective In this prespecified analysis, we compared the cardiac safety of the trastuzumab biosimilar ABP 980 (KAN-JINTI™) and the trastuzumab reference product (RP; Herceptin ®) in the phase III LILAC study (ClinicalTrials.gov identifier NCT01901146). Methods In the neoadjuvant phase of LILAC, after run-in chemotherapy, 725 patients were randomized 1:1 to ABP 980 (n = 364) or trastuzumab RP (n = 361) plus paclitaxel (every 3 weeks [Q3W] or every week [QW]) for four cycles. After surgery, patients continued treatment Q3W for up to 1 year; ABP 980-treated patients continued ABP 980 (ABP 980/ABP 980; n = 364), and trastuzumab RP-treated patients either continued on the RP (trastuzumab RP/trastuzumab RP; n = 190) or switched to ABP 980 (trastuzumab RP/ABP 980; n = 171). Cardiac safety was monitored by computerized 12-lead electrocardiogram, and left ventricular ejection fraction (LVEF) was assessed by two-dimensional (2D) echocardiogram. LVEF decline was defined as LVEF value decrease from study baseline by ≥ 10 percentage points and to < 50%. Results Over the entire study, 22 (3.1%) patients had protocol-defined LVEF decline; no meaningful between-group differences were observed (ABP 980/ABP 980: 2.8%; trastuzumab RP/trastuzumab RP: 3.3%; trastuzumab RP/ABP 980: 3.5%). The incidence of cardiac adverse events was low and comparable in the treatment groups. One grade 3 cardiac failure event reported in the trastuzumab RP/ABP 980 arm, and another in the trastuzumab RP/trastuzumab RP arm, were coincident with LVEF decline. One patient discontinued the investigational product during the adjuvant phase because of cardiac failure. Conclusion These prespecified analyses confirm the tolerability of ABP 980 and demonstrate clinical similarity of ABP 980 and trastuzumab RP with respect to cardiac safety. No new cardiac safety signals were observed whether patients were receiving ABP 980 or switched from the RP to ABP 980.

Extrahepatic metastasis of HCC represents a progressive phase of the disease with poor prognosis, so the main aim of the treatment should be palliation and care of symptoms.

557 Background: Although trastuzumab is generally well-tolerated, cardiotoxicity is the main limitation in its use, leading to a severe heart failure in 2-4% of patients in adjuvant trials. In the phase 3 LILAC trial, trastuzumab biosimilar ABP 980 demonstrated similar efficacy, safety, and immunogenicity to trastuzumab reference product (RP) in women with HER2-positive early breast cancer. Here we report analyses comparing cardiac safety of ABP 980 and RP. Methods: In the neoadjuvant phase, all 725 patients received 4 cycles of chemotherapy with epirubicin + cyclophosphamide Q3W and were then randomized 1:1 to ABP 980 (n = 364) or RP (n = 361) with a loading dose of 8 mg/kg, then 6 mg/kg IV Q3W for 3 cycles plus paclitaxel Q3W (4 cycles) or QW (12 cycles). After surgery, patients received investigational product (IP) Q3W for up to 1 year; ABP 980-treated patients continued ABP 980, and RP-treated patients either continued RP (n = 190) or switched to ABP 980 (RP/ABP 980; n = 171). AEs were assessed every 3 weeks and cardiac safety every 3 months. Cardiac safety was monitored by computerized 12-lead ECG; LVEF was assessed by 2D ECHO. LVEF decline was defined as LVEF value decrease from study baseline by ≥10 percentage points and to < 50%. Results: Treatment groups were well balanced with regard to IP disposition. Over the entire study, 22 (3.1%) patients had LVEF decline by ≥10 percentage points compared to baseline and to < 50%; no meaningful between-group differences were observed (ABP 980:10/359 [2.8%], RP: 6/184 [3.3%], RP/ABP 980: 6/171 [3.5%]). The incidence of cardiac AEs was low and comparable in treatment groups. One grade 3 cardiac failure event was reported in the RP/ABP 980 arm; another in the RP arm was coincident with LVEF decline. No patient discontinued IP during adjuvant phase because of cardiac failure. Conclusions: These pre-specified analyses confirm the tolerability of ABP 980 and demonstrate clinical similarity of ABP 980 and RP with respect to cardiac safety. The incidence of LVEF decline was consistent with the known cardiac safety profile of the RP. No new cardiac safety signals were observed whether patients were on ABP 980 or switched from RP to ABP 980. Clinical trial information: NCT01901146.

505 Background: Brain metastases (BM) of breast cancer constitute an important part of therapeutic failures and are associated with severe morbidity and mortality. The risk of BM is particularly high in HER2+ advanced breast cancer pts. We earlier developed in this group a 13-gene signature strongly predicting for rapid development of BM (J Clin Oncol 2008; 26: 45s). Now, we validated these results in an independent group of pts and on culture model system. Methods: Discovery group included 87 samples analyzed using cDNA synthesis, annealing, selection, extension, ligation and array hybridization (DASL). Independent validation group included 75 samples analyzed using quantitative reverse-transcriptase PCR. 3D culture validation model system used immortal, non-tumorigenic human MCF10A breast epithelial cells with and without ectopic expression of HER-2 and RAD51, a DNA double strand break repair gene (one of the three genes of this group overexpressed in 13-gene signature). The number and morphology of breast acini were scored using indirect immunoflourescence and confocal microscopy. Results: Median brain metastasis-free survival (BMFS) in the discovery group for ‘high’ vs. ‘low’ expression signature tumors was 36 months and 66 months, respectively (P=0.0068), and in the validation group 54 and 86 months, respectively (P=0.032). Short BMFS was also associated with ER-negativity; BMFS in the cohort of ‘high’ 13-gene signature and ER- tumors vs. other 3 groups was 31 months and 66 months in discovery group, and 41 and 77 months in validation group (P<0.0001 and P=0.02, respectively). Overexpression of RAD51 in MCF-10A breast cells altered their three-dimensional acinar morphology and increased the percentage of invasive structures by 6.5 fold, both in the presence and absence of HER2 overexpression. Conclusions: 13-gene signature and ER-negativity predict rapid development of BM in HER+ advanced breast cancer pts. RAD51 may promote aggressiveness in breast epithelial cells. These data may be useful in the design of BM preventive trials and may prompt new treatment strategies.