IMR-687 was identified and selected specifically to treat patients with sickle cell disease by both reducing red blood cell sickling and blockage of blood vessels that are underlying causes of the pathology of sickle cell disease.
IMR-687 is a highly potent, selective inhibitor of phosphodiesterase-9 (PDE9i) in blood cells. IMR-687 was developed to target the same biochemical pathway as hydroxyurea, a chemotherapeutic agent, but without its safety issues.
IMR-687 has been shown in cell and animal models to increase fetal globin, which prevents the polymerization of the sickled hemoglobin. This reduces red blood cell sickling, reduces red blood cell death and reduces occlusion of blood vessels. PDE9 inhibition also reduces white blood cell “stickiness” which further reduces the blockage of blood vessels.
IMR-687 is in human clinical studies.