Myocardial infarction (MI) causes irreversible loss of cardiomyocytes and often leads to ischemic heart failure. To date, there is no effective treatment for ischemic heart failure. The ultimate therapeutic for such disease should replace the lost cardiomyocytes, resolve the fibrotic scar, preferably transdifferentiate the fibroblasts into cardiomyocytes, and increase vascularization to the regenerated myocardium. Therefore, the most promising treatments currently within the experimental phases are induction of existing cardiomyocyte proliferation, direct cardiac reprogramming of the existing fibroblasts to induced cardiomyocytes (iCMs), and increasing angiogenesis. Each approach has been tested individually either in preclinical animal models or in Phase I/II clinical trials with proven efficacy. In this proposal, our central hypothesis is that combining the most powerful three modalities to regenerate the myocardium will synergize to provide a full regeneration of the myocardium to cure ischemic heart failure; therefore, we gathered a team of academic investigators and biotech industry partners to perform a full preclinical testing of the efficacy and toxicity of the triple therapy (Induction of cardiomyocyte proliferation (TNNT2-4F-NIL), direct cardiac reprogramming (TN1-006), and increasing vascularization (XC001)). One of the limiting factors for such gene therapies for heart failure is developing a noninvasive procedure that is suitable for clinical application. Therefore, in this proposal, we are aiming to make this triple therapy less invasive (and thus more clinically applicable) by injecting the viral cocktail into the heart muscle using a novel trans-endocardial injection catheter that was developed by Tenaya Therapeutics (NovoStar Endomyocardial Injection Catheter). Here, building on our published solid preliminary data demonstrating the high efficacy of each individual approach in treating ischemic heart failure in preclinical animal models and clinical trials, we will perform dose-response efficacy and initial toxicity testing in preclinical animal models of heart failure to determine the best dosage for this triple therapy. R61 phase Aim: Determine the optimal dosage and therapeutic window for best in vivo efficacy of the triple therapy in rats. Milestone: Achieve a significant improvement in cardiac ejection fraction by at least 10 points with minimal expression of the reprogramming and cell cycle factors in other tissues. R33 phase Aim: Demonstrate the efficacy and initial safety of the triple therapy injected with the NovoStar catheter in improving cardiac function and systemic congestion in other organs in a pig model of ischemic heart failure and human heart slices. Milestone: Achieve a significant improvement in cardiac ejection fraction by at least 10 points in pigs with no toxicity. Achieve improvement in human heart slice contractile function with no arrhythmia. This project will provide evidence of the efficacy and initial safety of a promising and novel triple therapeutic approach for ischemic heart failure, which combines the three most efficient modalities for cardiac regeneration.

After heart attack the heart loses many muscle cells which leads to the loss of ability to bump blood to the rest of the body. The muscle cells in the heart are not able to regenerate themselves which makes it difficult to treat such disease. Here we are developing a new combination of gene therapies to regenerate these muscle cells in the heart and heal the heart.