Abstract P4-21-41: Primary analysis of BERENICE: A phase II cardiac safety study of pertuzumab, trastuzumab, and neoadjuvant anthracycline-based chemotherapy in patients with locally advanced, inflammatory, or early-stage, unilateral, and invasive HER2-positive breast cancer

Background: Neoadjuvant pertuzumab (P)+trastuzumab (H)+standard chemotherapy (CT) significantly increases pathologic complete response (pCR) rates v H+CT. However, anti-HER2 therapy following anthracyclines can cause heart failure, and data are limited or lacking on combining P+H after epirubicin or doxorubicin. We report cardiac and overall safety as well as total pCR (tpCR) rates with widely used but understudied anthracycline-containing regimens. Methods: BERENICE (NCT02132949), a non-randomized, open-label, phase II study, enrolled patients (pts) with centrally confirmed HER2-positive, locally advanced, inflammatory, or early-stage, unilateral, and invasive breast cancer, Eastern Cooperative Oncology Group performance status ≤1, and baseline left ventricular ejection fraction (LVEF) ≥55%. In the neoadjuvant period, Cohort A pts received four q2w dose-dense doxorubicin+cyclophosphamide cycles (60 mg/m2/600 mg/m2 with granulocyte-colony stimulating factor support as needed) followed by 12 qw paclitaxel doses (80 mg/m2) + four q3w P+H cycles (P 840 mg, then 420 mg; H 8mg/kg, then 6 mg/kg). Cohort B received four q3w fluorouracil/epirubicin/cyclophosphamide cycles (500 mg/m2/100 mg/m2/600 mg/m2) followed by four q3w docetaxel cycles (75 mg/m2 escalated to 100 mg/m2) + four q3w P+H cycles. Surgery was performed after cycle 8 for both cohorts. The primary objective was to evaluate cardiac safety during the neoadjuvant period, assessed by incidence of 1) New York Heart Association (NYHA) Class III/IV heart failure and 2) significant LVEF declines (≥10% from baseline with a value of Results: Four hundred one pts were enrolled between Jul 2014–Aug 2015. Clinical cutoff was Mar 3, 2016. Demographics and baseline characteristics were generally balanced between cohorts; 64.3% v 61.7% of pts had centrally confirmed hormone receptor (HR)-positive disease and 95.0% v 93.0% had T1–T3 primary tumors. Three pts in Cohort A and none in Cohort B experienced NYHA Class III/IV heart failure during neoadjuvant treatment (table). Thirteen pts in Cohort A v four in Cohort B had significant LVEF declines (table). One Cohort B pt's LVEF decline was prior to anti-HER2 treatment. AE and serious AE (SAE) rates were well balanced between cohorts. The most common AEs were nausea, diarrhea, and alopecia. The most common SAE was febrile neutropenia. tpCR rates were similar between cohorts (table). Neoadjuvant periodCohort ACohort BSafety: Pts, n (%)N=199N=198NYHA Class III/IV heart failure3 (1.5%)0Significant LVEF decline13 (6.5%)4 (2.0%)tpCR (ypT0/Tis ypN0): Pts, n/N (%) Intention-to-treat123/199 (61.8%)122/201 (60.7%)HR-positive66/128 (51.6%)71/124 (57.3%)HR-negative53/65 (81.5%)51/75 (68.0%) Conclusion: Cardiac and general safety of the two anthracycline-containing regimens in BERENICE were as expected and were consistent with the known P+H+CT profiles. Both regimens were active, and tpCR rates were high. Citation Format: Swain SM, Ewer MS, Viale G, Delaloge S, Ferrero JM, Verrill M, Colomer R, Vieira C, Werner TL, Douthwaite H, Bradley D, Waldron-Lynch M, Eng-Wong J, Dang C. Primary analysis of BERENICE: A phase II cardiac safety study of pertuzumab, trastuzumab, and neoadjuvant anthracycline-based chemotherapy in patients with locally advanced, inflammatory, or early-stage, unilateral, and invasive HER2-positive breast cancer [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P4-21-41.