Cardiotoxicity of trastuzumab (herceptin) in chick embryos

The cardiac toxicity of trastuzumab was studied in chick embryos. Fertilized eggs of White Leghorns were incubated and investigated. Trastuzumab 5 mg/egg (low dose) or 15 mg/egg (high dose) was injected into the air sac of a fertilized egg on the 16th day of incubation. Electrocardiograms (ECGs) were recorded 0 to 60 min after the injection. After low dosing of trastuzumab, the heart rate was not different compared with the control. However, the heart rate was significantly decreased by high dosing of trastuzumab. In addition, arrhythmia was produced by high dosing of trastuzumab. These findings indicate that trastuzumab has a marked dose- and time-dependent influence on the heart rate in chick embryos.