HER2 targeted therapies have substantially improved the prognosis of patients with breast cancer however they can be associated with cardiac toxicity.
SAFE-HEaRt is the first investigator-initiated trial that prospectively tests whether HER2 therapies may be safely administered in patients with reduced left ventricular ( LV ) function in the setting of ongoing cardiac treatment and monitoring.
Eligibility criteria were: stage I-IV HER2 positive breast cancer candidates for non-Lapatinib therapy; LV ejection fraction ( LVEF ) greater than or equal to 40% and less than 50% and no symptoms of heart failure.
All patients had cardiology visits and echocardiograms at baseline, during treatment and 6 months after treatment, and received beta blockers and ACE inhibitors unless contraindicated.
Primary endpoint was completion of planned oncologic HER2 therapy without development of a cardiac event, defined as heart failure symptoms or asymptomatic decline in LVEF greater than or equal to 10% points from baseline and/or to LVEF less than or eqaul to 35%.
Of 31 enrolled patients, 30 were evaluable. Mean age was 54 years, 18 had early stage and 13 metastatic disease.
Seventeen patients had prior exposure to anthracyclines and 13 had hypertension.
On study 15 patients were treated with Trastuzumab ( Herceptin ), 14 Trastuzumab / Pertuzumab ( Perjeta ) and 2 ado-Trastuzumab emtansine ( Kadcyla ).
Mean LVEF was 45% at baseline and 46% at the end of treatment.
Twenty-two patients completed HER2 therapy as defined per protocol without development of a cardiac event and 5 are still on study.
Three patients met cardiac event criteria: 2 developed symptomatic heart failure ( at 24 and 36 weeks ) and 1 had protocol defined LVEF decline to 35% at 12 weeks, all were taken off study.
Two of these 3 patients are alive and in follow up and 1 died of disease progression.
Demographics, previous anthracyclines and baseline LVEF did not predict development of cardiac events.
Elevation of highly sensitive troponin preceded 2 of 3 cardiac events which was significant ( p=0.003 ).
In conclusion, patients with breast cancer and mildly reduced LVEF can safely receive HER2 therapies in the setting of regular cardiac monitoring and treatment with beta-blockers and ACE inhibitors.
The results provide new safety data in this unique population and have potential to contribute to clinical practice changes. ( Xagena )
Source: American Society of Clinical Oncology - ASCO Meeting, 2018