The technology behind the Targeted Cancer Immunotherapy Program is based on findings in recent years demonstrating that tumors contain specialized cells which are capable of generating new tumors. Colloquially called ‘cancer stem cells’, these cancer initiating (stem) cells typically make up only a small portion of the entire tumor mass (Figure 1). Using the same proprietary technologies used to isolate and grow other stem cell types, we have developed a process to produce large numbers of these cancer initiating cells for use in cancer immunotherapy.
The Immune System and Cancer
A healthy human immune system typically has the ability to recognize and eliminate malignant cells. However, a person’s immune system can be weakened by cancer, thus reducing its ability to mount an effective immune response. Cancer immunotherapy is the process by which a patient’s immune system is stimulated to target the invasive cancer and eliminate it. To be effective, the immune system must be stimulated with a molecule or protein that is expressed by the cancer cells. This molecule or protein is known as an antigen. Other cancer immunotherapy strategies employ antigens that are expressed on some cancer cells, but not all, limiting the effectiveness of those approaches.
Not All Cells are Created Equal
Previous clinical trials have shown that a patient’s own tumor may represent the ideal source of antigens for cancer immunotherapy, since each patient’s individual tumor contains the unique repertoire of antigens of that cancer. However, cancers are made up of many types of cells, most of which are not classified as cancer initiating cells. NeoStem’s strategy uses our unique manufacturing process to isolate and expand the cancer initiating cell population from a patient’s own tumor for use in potentially stimulating the patient’s own immune system. These cells have been shown to represent among the most aggressive type of cells in the cancer and are thought to be the cells that make the cancer lethal. Stimulating the immune system to attack and eliminate these cells could result in prolonged periods of disease free survival. (Figure 2)
The surgical removal and diagnosis of a tumor is a common step in trying to rid a patient’s body of a malignant cancer. In our treatment the excised tumor is used as a means of developing a treatment. A sample of the tumor is sent to our cGMP facility where the cancer initiating cells are isolated, purified, and then inactivated by irradiation. The cell line is then combined with another type of cell, called a dendritic cell, or antigen presenting cell, which is derived from the patient own blood. The antigen presenting cells may have the ability to help train the patient’s immune system to identify and eliminate malignant cells. By combining the cancer initiating cells with the antigen presenting cells, the therapy is believed to target the very cells that have the ability to form new tumors. (Figure 3)