Prospective evaluation of the cardiac safety of HER2-targeted therapies in patients with HER2-positive breast cancer and compromised heart function: the SAFE-HEaRt study

Purpose

HER2-targeted therapies have substantially improved the outcome of patients with breast cancer, however, they can be associated with cardiac toxicity. Guidelines recommend holding HER2-targeted therapies until resolution of cardiac dysfunction. SAFE-HEaRt is the first trial that prospectively tests whether these therapies can be safely administered without interruptions in patients with cardiac dysfunction.

Methods

Patients with stage I–IV HER2-positive breast cancer candidates for trastuzumab, pertuzumab or ado-trastuzumab emtansine (TDM-1), with left ventricular ejection fraction (LVEF) 40–49% and no symptoms of heart failure (HF) were enrolled. All patients underwent cardiology visits, serial echocardiograms and received beta blockers and ACE inhibitors unless contraindicated. The primary endpoint was completion of the planned HER2-targeted therapies without developing either a cardiac event (CE) defined as HF, myocardial infarction, arrhythmia or cardiac death or significant asymptomatic worsening of LVEF. The study was considered successful if planned oncology therapy completion rate was at least 30%.

Results

Of 31 enrolled patients, 30 were evaluable. Fifteen patients were treated with trastuzumab, 14 with trastuzumab and pertuzumab, and 2 with TDM-1. Mean LVEF was 45% at baseline and 46% at the end of treatment. Twenty-seven patients (90%) completed the planned HER2-targeted therapies. Two patients experienced a CE and 1 had an asymptomatic worsening of LVEF to ≤ 35%.

Conclusion

This study provides safety data of HER2-targeted therapies in patients with breast cancer and reduced LVEF while receiving cardioprotective medications and close cardiac monitoring. Our results demonstrate the importance of collaboration between cardiology and oncology providers to allow for delivery of optimal oncologic care to this unique population.

Electronic supplementary material

The online version of this article (10.1007/s10549-019-05191-2) contains supplementary material, which is available to authorized users.

Abstract P4-14-09: Cardiac safety of trastuzumab without an anthracycline in patients with HER2-positive early stage breast cancer: A single center experience

Background: Trastuzumab (H) improves disease-free survival and overall survival in HER2+ early breast cancer (EBC) but is associated with risk of treatment-induced cardiotoxicity especially when administered after an anthracycline. We performed a single center retrospective study to assess the cardiac safety of adjuvant trastuzumab therapy without anthracyclines in a real-world clinical setting.

Methods: Patients (pts) with HER2+ early breast cancer (EBC) who received H without anthracycline-based chemotherapy between January 2010 and June 2014 were studied. Patients enrolled in a clinical trial were excluded. Tumor characteristics, chemotherapy regimen, cardiovascular risk factors, left ventricular ejection fraction (LVEF), and treatment interruption data were collected. A cardiac event (C.E.) was defined as New York Heart Association class III or IV heart failure with LVEF decline of > 10% to < 55% or possible/probable cardiac death, as previously defined by the NSABP B-31 trial.

Results: In total, 174 pts with HER2+ EBC treated with H-based therapy without anthracyclines were identified. Median age was 59 years (range, 32 to 85 years), 72 (41%) had hypertension, 55 (32%) had hyperlipidemia, 29 (16%) had diabetes, and 5 (3%) had coronary artery disease. At baseline, all pts had a LVEF > 50% (median, 66%; range, 50% to 81%). Two (1.1%) pts developed a C.E. Both pts had risks factors for C.E. (1 - age > 60 years, hypertension, and prior history of anthracycline exposure; 1- age > 60 years, hypertension, hyperlipidemia, and baseline LVEF of 50-55%). After discontinuation of H, both patients had recovery of LVEF to > 50% and resolution of heart failure symptoms. Twelve (6.9%) pts developed asymptomatic LVEF decline of > 10% points to < 55% during H therapy. Of the 14 patients who developed cardiotoxicity, H was prematurely interrupted or discontinued in 8 patients.

Conclusion: In our single center experience of patients being treated off study, the incidence of C.E.s and asymptomatic LVEF decline during H therapy without an anthracycline was 1.1% and 6.9%, respectively. These appeared higher than events reported in clinical trials possibly due to the inclusion of an older group of women with a higher prevalence of cardiovascular risk factors. Overall, the incidence of symptomatic heart failure is low for H without an anthracycline even in this older group.

Citation Format: Mukku RB, Verma S, Liu J, Steingart R, Hudis C, Yu AF, Dang C. Cardiac safety of trastuzumab without an anthracycline in patients with HER2-positive early stage breast cancer: A single center experience. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P4-14-09.

Metabolic changes in women using a long-acting monthly oral contraceptive and return of ovulation on discontinuation

Metabolic changes were investigated in two groups of women using oral contraceptives for 5 to 16 years. Blood samples were taken during the last cycle of oral contraceptive use and three months post-treatment. One group had used a monthly oral contraceptive (MOC, 3mg quinestrol and 10mg 16-methylene chlormadinone acetate) and the second group a daily oral contraceptive (DOC, 35 micrograms ethynylestradiol and 0.625 mg norethisterone). During treatment there were increases in serum total cholesterol and triglycerides but not HDL-C, in plasma total cortisol but not in renin activity, angiotensin II or urinary free cortisol excretion, in hemoglobin and some coagulation factors but not Factor X or antithrombin III, platelet function or fibrinolysis. The area under the blood glucose concentration-time curve, but not that for serum insulin, was slightly increased and there was no change in fasting blood sugar concentrations. All metabolic parameters, except plasma cortisol, which had shown an increase on treatment, had decreased to control levels within 3 months. Ovulation returned promptly in all women, the mean time being 70 days for Group MOC and 44 days for Group DOC. Thus, in spite of the long duration of use of the oral contraceptives, metabolic changes were minor.