PF-05180999 is a phosphodiesterase 2A (PDE2A) inhibitor, with an IC50 of 1.6 nM. PF-05180999 binds to the rat, dog and monkey PDE2A, with Kis of 4.2, 8.4, and 5.5 nM and IC50s of 2.6, 5.2, and 3.4 nM, respectively. PF-05180999 shows weak activity against PDE, with IC50s of 2.03 μM (PDE10A1), 26.969 μM (PDE7B), 50.09 μM (PDE11A4), and >56.25 μM (PDE1B1, PDE3A1, PDE4D3, PDE5A1, PDE6 (bovine), PDE8B, PDE9A1), respectively. PF-05180999 is also a weak inducer of CYP3A4, and with no direct inhibition of human recombinant cytochrome P450 (CYP) enzymes (1A2, 2B6, 2C8, 2C9, 2C19, 2D6, and 3A) and no induction of CYP1A2.