CANCER THERAPIES
Cancer is a disease of uncontrolled cell growth. When detected early and still confined to a single location, cancer may be cured by surgery or irradiation. However, neither surgery nor irradiation can cure cancer that has spread throughout the body. Chemotherapy can sometimes effectively treat cancer that has spread throughout the body, however, a number of non-cancerous cells, such as bone marrow cells, are also highly susceptible to chemotherapy. As a result, chemotherapy often has fairly significant side effects. Finally, it is common to see cancer return after apparently successful treatment by each of these means.
Immunotherapy, using the patient's own immune system, may have advantages over surgery, irradiation, and chemotherapy in the treatment of cancer. Many cancers appear to have developed the ability to "hide" from the immune system. A treatment that can augment the immune response against tumor cells by making the cancer more "visible" to the immune system would likely represent a significant improvement in cancer therapy. Immune-enhancing proteins such as IL-2 and interferon-alpha, or IFN-a, have shown encouraging results. However, these agents often require frequent doses that regularly result in severe side effects.
We have researched delivery enhancements that may complement our core DNA delivery technology. Our current clinical-stage approach consists of injecting directly into lesions certain plasmids, which, upon uptake into cells, direct the production of the encoded immunostimulatory proteins. The plasmids may be complexed with a cationic lipid-based delivery system.
The ease of manufacture, outpatient treatment with minimal discomfort, and the excellent tolerability profile suggest that cancer therapies using non-viral DNA delivery may offer advantages over current modalities of therapy. In addition, cancer therapies using non-viral DNA delivery may offer an added margin of safety compared with viral-based delivery, as no viral DNA/RNA or viral particles are contained in the formulation.
Preclinical studies in animals have demonstrated the safety and potential efficacy of this approach. Subsequently, in human studies, a very low incidence of treatment-related adverse events has been observed.
Our Allovectin-7® and IL-2/EP cancer immunotherapeutics are currently under development.