Disease Team Therapy Development - Research
Stem Cell Use:
Embryonic Stem Cell
Patients with end-stage heart failure have a 2-year survival rate of only 50% with conventional medical therapy. This dismal survival rate is actually significantly worse than patients with AIDS, liver cirrhosis, stroke, and other comparable debilitating diseases. Currently available therapies for end stage heart failure include drug and device therapies, as well as heart transplantation. While drug and device therapies have proven effective at reducing symptoms, hospitalizations and deaths due to heart failure, new approaches are clearly required to improve this low survival rate. Organ transplantation is highly effective at increasing patient survival, but is severely limited in its potential for broad-based application by the very low number of hearts that are available for transplantation each year. Stem cell therapy may be a promising strategy for improving heart failure patient outcomes by transplanting cells rather than a whole heart. Several studies have convincingly shown that human embryonic stem cells can be differentiated into heart muscle cells (cardiomyocytes) and that these cells can be used to improve cardiac function following a heart attack. The key objective of this CIRM Disease Team Therapy proposal is to perform the series of activities necessary to obtain FDA approval to initiate clinical testing of human embryonic stem cell-derived cardiomyocytes in end stage heart failure patients.
Statement of Benefit to California:
Coronary artery disease (CAD) is the number one cause of mortality and morbidity in the US. The American Heart Association has estimated that 5.7 million Americans currently suffer from heart failure, and that another 670,000 patients develop this disease annually. Cardiovascular disease has been estimated to result in an estimated $286 billion in direct and indirect costs in the US annually (NHLBI, 2010). As the most populous state in the nation, California bears a substantial fraction of the social and economic costs of this devastating disease. In recent years, stem cell therapy has emerged as a promising candidate for treating ischemic heart disease. Research by our group and others has demonstrated that human embryonic stem cells (hESCs) can be differentiated to cardiomyocytes using robust, scalable, and cGMP-compliant manufacturing processes, and that hESC-derived cardiomyocytes (hESC-CMs) can improve cardiac function in relevant preclinical animal models. In this proposal, we seek to perform the series of manufacturing, product characterization, nonclinical testing, clinical protocol development, and regulatory activities necessary to enable filing of an IND for hESC-CMs within four years. These IND development activities will be in support of a Phase 1 clinical trial to test hESC-CMs in heart failure patients for the first time. If successful, this program will both pave the way for a promising new therapy to treat Californians with heart failure numbering in the hundreds of thousands, and will further enhance California’s continuing prominence as a leader in the promising field of stem cell research and therapeutics.
Patients with end-stage heart failure (ESHF), which can result from heart attacks, have a 2-year survival rate of 50% with conventional medical therapy. Unlike cells of other organs, the billions of cardiomyocytes lost due to damage or disease do not regenerate. Recently, implantable mechanical pumps that take over the function of the failing left ventricle (left ventricular assist devices; LVADs) have been used to prolong the lives of heart failure patients. However, these devices carry an increased risk of stroke. The only current bona fide cure for ESHF is heart transplantation, but the shortage of donor organs and the risks associated with life-long use of powerful immunosuppressive drugs limit the number of patients that can be helped. Human embryonic stem cells (hESCs) have the unique properties of being able to grow without limit and to be converted into all the cell types of the body, including cardiomyocytes. Our project seeks to find ways to treat patients by replacing their lost cardiomyocytes with healthy ones derived from hESC. The ultimate goal of this 4 year project is to evaluate the feasibility, safety, and efficacy of this approach in both small and large animal models of heart disease and to use this data to initiate a clinical trial to test the therapy in patients. In our first year, we developed methods for producing essentially unlimited quantities of cardiomyocytes from hESCs using a process that is compatible both with clinical needs and large-scale industrial cell production. We have also developed models of heart disease in both rats and pigs, and have begun transplanting the stem cell-derived cardiomyocytes into the rat model. We have demonstrated that stem cell-derived cardiomyocytes can engraft in this animal model and we are testing their effects on the pumping function of the heart, the growth of replacement blood vessels lost during a heart attack, and the size of the scar that typically forms after injury. In the next several years, we will continue to evaluate the safety and function of these cells and will start to transplant in our large animal model of heart disease, which will enable us to test these cells in a heart with very similar characteristics to humans, delivered in a minimally invasive way that would be ideal for clinical use.