Combination of combretastatin A4 phosphate and doxorubicin-containing liposomes affects growth of B16-F10 tumors.

The study aimed to check the effectiveness of anticancer therapy combining a vascular-disruptive drug (combretastatin phosphate, CA4P) and a liposomal formulation of a chemotherapeutic (doxorubicin). CA4P was synthesized in our laboratory according to a previously described procedure. The antivascular drug and long-circulating doxorubicin-loaded liposomes were used to treat B16-F10 murine melanoma experimental tumors. Seventy-four hours after drug administration, a decrease in the number of tumor blood vessels was apparent and necrotic areas within tumors were visible. Combination therapy consisting of alternate administrations of CA4P and liposomal doxorubicin yielded greater inhibition of tumor growth than monotherapies alone. The best therapeutic results were obtained with the antivascular drug administered intratumorally every second day at 50 mg/kg body mass. In the case of combined therapy, the best results were obtained when the vascular-disruptive agent (CA4P) and the antineoplastic agent (liposomal doxorubicin) were administered in alternation.