Update: 29 March 2019
Developed for sickle cell disease, IMR-687 is a highly potent, selective inhibitor of phosphodiesterase-9 (PDE9i) in blood cells. It targets 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.
The drug is currently being tested in a mid-stage study, which is expected to be concluded by June. Initial data is expected by the second half of this year, and the full readout in the first quarter of 2020.