Stem cells are naturally occurring cells within the human body that have the potential to develop, or differentiate, into other types of cells with individual characteristics and specific functions. While the existence of stem cells was first postulated over 100 years ago, they were not specifically observed until 1964, when scientists illustrated the presence of self-renewing cells in mouse bone marrow. The first medical use of stem cells — and still the most common — was in the transplant of bone marrow where a patient’s own bone marrow is either not working properly or has been intentionally destroyed by chemotherapy or radiation to kill cancer cells.
Many researchers believe that stem cells hold significant promise in the treatment of a wide variety of diseases. However, the broader application of stem cell therapy still faces a number of hurdles. One hurdle is the proper selection of the cells that are expected to have the greatest therapeutic effect, and we believe that the isolation of those specific cells is critical to the successful development of any regenerative therapy based on stem cells. Our proprietary technology allows us to identify and isolate specific adult stem cells expressing high levels of an enzyme known as aldehyde dehydrogenase, or ALDH, which we refer to as ALDHbright, or ALDHbr, cells. ALDHbr cells represent a very small fraction, typically less than 1%, of all cells in bone marrow. ALDH is a key enzyme in the synthesis of retinoids, which are molecules that control the regulation of gene activities. In preclinical studies, ALDHbr cell populations exhibited a variety of activities that we believe may promote the regeneration of multiple types of cells and tissues.
Another key issue with stem cell treatments is the potential rejection of the injected cells by the patient’s immune system. We seek to address this issue in our product candidates by using a patient’s own stem cells collected from the patient’s bone marrow. Stem cells collected in this manner and injected back into the same patient are referred to as autologous stem cells. To date, the only cell therapies approved by the FDA have been based on autologous cells. Some stem cell therapies being developed require the manipulation, culturing or addition of growth factors to the cells. These processes can create manufacturing and regulatory risk, add additional costs and delay treatment of the patient. In some cases, the time between the collection of the stem cell source and the delivery of the cell therapy to the patient can be many weeks. We produce ALDHbr cell populations without any of these additional steps. In addition, our technology allows for the sorting of the ALDHbr cell populations and their return to the clinician for administration to the patient typically within 36 hours, which is shorter than many other treatments involving autologous cells.