- Clinically relevant pathologic findings in ECG. 14. Left Ventricle Ejection Fraction (LVEF) by MUGA or ECHO < 55% for patients receiving 2B3-101 in combination with trastuzumab. For patients receiving single agent 2B3-101 treatment. Left Ventricle Ejection Fraction (LVEF) by MUGA or ECHO < 50%.