The first clinical trial of a biologic nanoparticle designed to give back to cancer patients the tumor-busting gene they have lost is expected to start in September at Georgetown University Medical Center. The phase I clinical study will enroll 20 patients with advanced solid cancers (including most common tumor types), and is the culmination of more than a decade of work by a team of researchers led by Professor Esther H. Chang, Ph.D. at the Lombardi Comprehensive Cancer Center. Their research has led to development of a tiny structure -- measuring a millionth of an inch across -- that resembles a virus particle that can penetrate deeply into the tumor and move efficiently into cells. The device is a “liposome” -- a microscopic globule made of lipids -- that is spiked on the outside with antibody molecules that will seek out, bind to, and then enter cancer cells including metastases wherever they hide in the body. These molecules bind to the receptor for transferrin that is present in high numbers on cancer cells. Once inside, the nanoparticle, which the researchers call a “immunolipoplex,” will deliver its payload -- the p53 gene whose protein helps to signal cells to self-destruct when they have the kind of genetic damage characterized by cancer and by cancer therapies. More than half of all cancer patients have cancer cells that have lost normal functioning of the p53 gene, so-called “guardian of the genome,” and the Georgetown researchers believe that restoring the gene will improve the tumor-killing ability of traditional treatments.
