Background: Targeting HER-2/neu with Trastuzumab has been associated with development of cardiac toxicity.
Methods: Twenty-seven patients with ductal carcinoma in situ (DCIS) of the breast completed an IRB approved clinical trial of a HER-2/neu targeted dendritic cell based vaccine. Four weekly vaccinations were administered prior to surgical resection. All subjects underwent pre- and post-vaccine cardiac monitoring by MUGA/ECHO scanning allowing for a comparison of cardiac function.
Results: In 3 of 27 vaccinated patients (11%) transient asymptomatic decrements in ejection fraction of greater than 15% were noted after vaccination. Notably, evidence of circulating anti-HER-2/neu antibody was found prior to vaccination in all three patients, but cardiac toxicity was not noted until induction of cellular mediated immune responses.
Conclusions: This is the first description of HER-2/neu targeted vaccination associated with an incidence of cardiac changes, and the induction of cellular immune responses combined with antibody may contribute to changes in cardiac function.