Abstract
An objective of DDS in cancer chemotherapy is to find methods by which anticancer agents selectively target solid tumors. Two main concepts constitute selective tumor targeting, active targeting and passive targeting. The former involves monoclonal antibodies or ligands to tumor related receptors which can target the tumor by utilizing specific binding ability between the antibody and antigen or between the ligand and its receptor. The latter system can be achieved by the so-called “EPR effect, the enhanced permeability and retention effect”. Regarding passive targeting, doxil, a pegylated liposomal doxorubicin, received Food and Drug Administration approval for Kaposi's sarcoma or ovarian cancer. Recent clinical trials including phase III randomized trial have shown clear clinical benefits of doxil. In comparison to doxorubicin, doxil has a significantly smaller volume of distribution, larger AUC, slower clearance, and longer elimination half-life. These different pharmacokinetic profiles likely contribute to the different toxicity profiles and improved therapeutic benefit observed with doxil. NK 911 is a doxorubicin entrapped in a polymer micelle. A phase I clinical trial of NK 911 has just initiated in the National Cancer Center. Miceller encapsulated taxol, KRN 5500 or cisplatin have been developed recently. These will be also evaluated in clinical trials in the near future.
