Cardiac safety of liposomal anthracyclines

Anthracyclines have demonstrated antitumor activity in a variety of cancers; however, irreversible cardiac damage is a major dose-limiting toxicity, restricting lifetime cumulative dose. The most successful strategy to improve the cardiac safety of anthracyclines to date involves liposomal encapsulation, which alters the tissue distribution and pharmacokinetics of these agents. The cardiac safeties of liposomal daunorubicin, liposomal doxorubicin (D-99), and pegylated liposomal doxorubicin have been studied in several clinical trials. The lack of published data comparing liposomal daunorubicin with conventional daunorubicin makes it difficult to draw meaningful conclusions regarding the relative cardiac safeties of these formulations. Studies indicate that the risk of anthracycline-induced cardiotoxicity is considerably lower with liposomal doxorubicin formulations than with conventional doxorubicin. Pegylated liposomal doxorubicin has been studied most extensively and has demonstrated the most significant reductions in risk for cardiotoxicity. Compared with conventional doxorubicin, pegylated liposomal doxorubicin has shown similar efficacy with a significantly lower incidence of cardiotoxicity and significantly fewer cardiac events. Although the long-term cardiac safety of these agents is unknown, data suggest that liposomal anthracyclines, particularly pegylated liposomal doxorubicin, may offer a significant clinical benefit for patients with higher risks for anthracycline-induced cardiotoxicity.