Study shows efficacy of PEGylated liposomal doxorubicin in intracranial model of breast cancer

Breast cancer brain metastases present a challenge to clinicians because there are few systemic therapies capable of crossing the blood-brain barrier to control the disease. An international team, led by scientists at the University of North Carolina Lineberger Comprehensive Cancer Center, reports pre-clinical research showing improved efficacy of a PEGylated liposomal (encapsulated) anti-cancer agent compared with a non-liposomal formulation of the same drug in an intracranial model of breast cancer. The study results were published online in the May 1, 2013 issue of PLOS ONE.

Carey Anders, MD, assistant professor of medicine and study first author, says, "To our knowledge this study is the first of its kind in brain cancer metastases and offers an informed foundation for the development of early-phase clinical trials. It also offers the potential to improve the current treatment paradigm for patients with intracranial breast cancer recurrence." Dr. Anders is co-director of the UNC Multidisciplinary Brain Metastases Specialty Clinic.

In this study, the scientists used an intracranial model of aggressive triple negative breast cancer to evaluate the pharmacokinetics of a chemotherapy drug, anthracycline doxorubicin in a PEGYlated liposomal-formulation, compared to a non-liposomal formulation. They augmented the liposomal doxorubicin with ABT-888, an inhibitor of an enzyme involved in many cellular functions, called poly (ADP-ribose) polymerase (PARP).

Their results showed that treatment with PEGylated liposomal doxorubicin resulted in a 1500-fold higher plasma and 20-fold higher intracranial tumor bioavailability compared with the non-liposomal doxorubicin. In addition, PEGylated liposomal doxorubicin was detected in in plasma and the intracranial tumor 96 hours following treatment compared to the drug being undetectable in plasma and the tumor after 24 hours in the non-liposomal doxorubicin. Survival rates for the PEGylated liposomal doxorubicin treatment were significantly prolonged as compared to non-liposomal doxorubicin.