Immune Cell Therapy for Cancer
Cancers are usually characterized by rapid cell growth. In the early years of cancer research, this rapid growth was used as a marker to recognize cancer cells. Drugs, developed to target and kill all fast-growing cells (chemotherapy), often lead to undesired side effects, such as gastrointestinal toxicity, hematological toxicity and other problems, such as hair loss. In some cases, toxicity from conventional chemotherapy drugs can cause serious harm or even be fatal.
Thanks to major advances in the understanding of the molecular biology of cancers specific cellular features have been discovered that are associated with certain cancers. These discoveries have allowed for the development of targeted cancer therapies. Targeted cancer therapies generally have fewer side effects compared to older chemotherapies.
We take this tactic even further by using living immune cells to target specific cancer molecules. This approach may bring two advantages:
- The immune cells have a prolonged life and can replicate in the patient, providing long term protection against newly developing cancer cells.
- The cells become part of the patient’s own immune system, making this a natural approach to the treatment of cancer.
Cancer cells express molecules either inside the cell or on the surface of the cancer cells that may be used as targets by anti-cancer immune cells. The challenge for us is to train the immune cells to recognize and exclusively target the cancer cells and not recognize and attack normal tissues in the patient.
We basically use two different approaches to generate immune cells that can recognize and specifically targeting cancer cells.
- For cancer target molecules that are localized on the outside of the cancer cell, chimeric antigen receptor (CAR) technology is used to train the immune cells to recognize cancer specific molecules. CAR technology involves combining different elements of normal immune system molecules in a way that allows immune cells to recognize specific cancer molecules on the outside of a cell. Our CAR technology is unique in that we use a special type of immune cell, called a NKT lymphocyte to deliver the CAR to the tumor. We have data to indicate that NKT lymphocytes are very efficient at getting to tumors in the body.
- To reach cancer molecules inside the cancer cell, we modify the T cell receptor (TCR) of immune cells called T lymphocytes. The TCR technology is necessary for cancer molecules inside the cell because TCRs have evolved to recognize small parts of internal molecules that are presented on the surface of the cell by special immune molecules that recognize the TCR. We have engineered TCRs to increase their numbers on the surface of lymphocytes, which should make them more active against cancer. We call this technology “dominant TCR”.