Mitral regurgitation (MR) is the most prevalent valvular heart disease in the U.S., affecting approximately 1.7% of the population. There are 4.1 million patients in the US with moderate to severe MR requiring treatment. However, only approximately 30,000 patients in the U.S. undergo surgery for MR each year due to concerns about procedural complexity and patient safety. There is great enthusiasm among the heart valve industry and clinicians to develop transcatheter mitral valve repair (TMVRep) or replacement (TMVR), offering less invasive treatment options for MR patients. However, after more than a decade of development, the field of transcatheter mitral valve therapy is still in its infancy. Many of the current TMVRep and TMVR devices have dismal clinical results. Current transcatheter treatment methods face serious roadblocks: TMVRep devices are safe but not very effective, while TMVR devices can be effective, but are not yet safe. In this proposal, Dura Biotech proposes to develop the novel Sutra TMVR system which combines the best aspects of surgical MV replacement, TMVR, and TMVRep approaches to pose an elegant and effective solution for MR. The Sutra TMVR system is delivered and anchored at the mitral annulus in a three-step procedure that closely mimics the surgical valve replacement process with clinically proven long-term efficacy. The implanted Sutra TMVR system replaces the native posterior mitral leaflet with a novel tri-leaflet prosthetic valve that mimics the native posterior mitral leaflet in design and function, to provide predictable and consistent MR reduction. Because the Sutra TMVR system only covers the posterior portion of the MV, it eliminates left ventricular outflow tract obstruction seen commonly with other replacement devices, and enables a smaller device profile for safe, trans-septal access and delivery. The feasibility and short-term efficacy of the Sutra valve via surgical implantation have been demonstrated through in an early proof-of-concept 60-day animal study. The goal of this SBIR project is to develop and commercialize the novel Sutra TMVR system. To achieve this goal, in Phase 1 of this study we will finalize the Sutra system valve and stent designs through a series of engineering analyses and experimental tests. In Phase 2 of this study we will first perform preclinical animal studies of the Sutra system via transcatheter implantation, then perform verification-and-validation tests on the final Sutra system design, and finally compile the data for Investigational Device Exemption (IDE) submission to the FDA. Successful completion of this project will yield an innovative hybrid TMVR and TMVRep device to treat the largely underserved MR patient population.