Hemangioblast (HG) Program

Hemangioblasts for the Treatment of Vascular Diseases

ACT’s hemangioblast (HG) program for the treatment of blood and cardiovascular diseases is currently in preclinical development.

Hemangioblasts are newly-characterized stem cells capable of differentiating into both hematopoietic (blood cell-forming) and angiogenic (blood vessel endothelium-forming) cells. The latter comprise the single layer of tissue that lines the interior of the entire circulatory system, from the heart to the smallest capillary. Blood vessel endothelial cells are involved in control of blood pressure by constricting and dilation of blood vessels, clotting of blood, formation of new blood vessels and inflammation and swelling.

These bipotential progenitor cells can be efficiently and reproducibly generated from human embryonic stem cells (hESCs). Hemangioblasts have multiple potential therapeutic applications for the repair of vascular tissue and could be a promising treatment option for a variety of diseases including cardiovascular diseases, diabetes and stroke.

Preclinical Development

A paper published in Nature Methods documented ACT’s successful generation of functional hemangioblast cells from human embryonic stem cells, and a paper published earlier this year in Cell Research indicated that hESCs could be a potentially unlimited source of platelets for transfusion.

Preclinical data have demonstrated that hemangioblasts, when injected into animals with retinal damage due to diabetes or ischemia-reperfusion injury (lack of adequate blood flow) of the retina, participate in the repair of the damaged vasculature at the site of the injury. Moreover, the cells homed to the site of injury and showed robust reparative function of the entire damaged vasculature within 24-48 hours.

Promising preclinical data were also seen in animal models of both myocardial infarction (50% reduction in mortality rate) and hind limb ischemia, with restoration of blood flow to near normal levels.