IMR-687 inhibits PDE9A with more than 800-fold greater potency than PDE1A3, PDE1B, PDE1C, PDE5A2, with IC50 values of 88.4 μM, 8.48 μM, 12.2 μM, and 81.9 μM, respectively.
IMR-687 (0.1-10 μM) treatment in erythroid K562 cells for 72 hours induces hemoglobin (HbF) in a dose-dependent manner.
IMR-687 (0.03-10 μM) treatment for 6 hours in erythroid K562 cells increases cGMP in a dose-dependent manner.