PhaseRx, Inc. announced positive results from the company's single escalating dose response study in non-human primates. The administration of mRNA delivered using the company's proprietary Hybrid mRNA TechnologyTM platform in a large animal model was safe and well tolerated at all dose levels tested – an important step prior to advancing its lead mRNA drug candidate towards clinical development. The company has previously shown therapeutic effect in its lead program, PRX-OTC, in the preclinical model of Ornithine Transarbamylase Deficiency ("OTCD"), including both lowering of blood ammonia and rescue of 100% of treated mice.    In the non-human primate study, human Erythropoietin ("hEPO") mRNA dosed at 0.1, 0.3 and 1.0 mg/kg delivered with the Hybrid mRNA TechnologyTM platform demonstrated dose-dependent increases in levels of hEPO protein with a very favorable safety profile. Elevations of hEPO protein levels at three orders of magnitude above normal physiological levels were achieved. In addition, a commensurate increase was also seen in reticulocyte count, a cell type expressed in response to hEPO which was robust and seen in all dose groups. The formulation was extremely well tolerated in non-human primates with no statistically significant dose-related changes in liver enzymes or cytokines, including IL-6, TNF-a, IFN-g, IL-12, or IP-10.