Goal: We will develop and validate 3D engineered muscular tissues (EMTs) as an enabling ?clinical trial-on-a- chip? platform to determine cardiac and skeletal muscle deficiencies in human Duchenne and Becker muscular dystrophy (DMD/BMD), and test the efficacy of novel therapeutics. We leverage state-of-art techniques developed by our team: (1) a method to differentiate and mature iPSC-derived cardiomyocytes and skeletal myoblasts. (2) phenotype-confirmed hiPSCs from DMD patients (3) 3D-tissue engineering technique using decellularized extracellular matrix (dECM) (4) Protocols to construct a multicellular architecture (5) non-invasive, high-throughput screening system allowing parallel electrophysiological and contractile assessment. (6) Novel antagonist of the cation channel ? TRPC6 that displays in vivo potential in a severe mouse model of DMD. We integrate these techniques and methods into an assay that recapitulates the major hallmarks of DMD, enabling real-time assessment of treatment efficacy. To demonstrate the utility of our EMT assay as a ?clinical trial-on-a- chip,? the new TRPC6 blocker is tested through Phase I safety/toxicity, Phase II dosing/ efficacy in EMT from a few DMD patients, and Phase III outcomes in EMTs from a larger heterogenous population of DMD/BMD patients. Focus/Aim: The UG3 phase establishes protocols to engineer optimized, hiPSC-derived cardiac and skeletal muscle tissues using our magnetic sensing platform and integrating this platform with our high- throughput imaging capabilities. The developed platform will be used to characterize the functional phenotypes of engineered muscle tissues generated from hiPSC-derived cardiomyocytes and skeletal myoblasts from dystrophic patients or healthy controls. This will verify that the ?clinical trial-on-a-chip? assay possesses sufficient sensitivity to recapitulate DMD phenotypes, stratify disease severity, and define contractility and electrophysiological outcomes that can be used to inform therapy efficacy testing in the UH3 phase. The UH3 phase will use the EMT assay to simulate protocols for running a 3-phase clinical trial. The therapeutic to be tested is BI 749327, a novel and promising selective and potent inhibitor of TRPC6 (Transient Receptor Potential- Canonical channel 6). The drug is the first orally bioavailable TRPC6 blocker, and we have already reported efficacy in pressure-load and renal fibrosis models in vivo. New data shows efficacy in DMD.
In Aim 1, the toxicity profile and dose range of BI 749327 is determined in healthy EMTs.
In Aim 2, mechanical and electrical effects of BI 749327 over a range of doses is applied to DMD-derived EMTs to identify an optimal dose and pharmacodynamic profile to move forward to broader testing.
In Aim 3, we will use the prior information to perform a Phase 3-style study that will involve iPSC-derived EMTs from DMD patients with varying mutations causing total dystrophin deletion, and from BMD patients that express mutant dystrophin resulting in varying clinical phenotypes. The goal is to establish the clinical trial-on-a-chip to inform and support human DMD clinical trial design, optimizing dosing and personalizing therapy for patients.
This project will establish a clinical trial-on-a-chip for testing novel therapies for dystrophin deficient muscular dystrophy (Duchenne or Becker). Cardiac and skeletal engineered muscle tissues from human induced pluripotent stem cells are tested and the efficacy of a novel inhibitor of the cation channel -TRPC6 assessed. Blocking TRPC6 in mice with severe DMD shows promise for improving heart and skeletal muscle function, and the new assay system should provide a high-throughput method to screen efficacy among different patients, test drug safety, and optimize clinical trial design.
