Background:

PF-592379 is a potent dopamine D3 receptor agonist with an EC50 of 21 nM.

PF-592379 appears to be a full agonist (Emax=95%) when compared with the standard Pramipexole, a D2/D3 receptor agonist for the treatment of Parkinson’s disease[1]. PF-592379 is a potent and selective dopamine 3 agonist with EC50 and Ki of 21 nM and 322 nM, respectively[2]. In vitro binding assays show that PF-592379 (PF-592,379) selectively binds human D3 receptors with a high affinity (Ki=215 nM). Although PF-592379 also binds to human D4 receptors (Ki=4165 nM), it displays a 19-fold binding selectivity for human D3 over D4 receptors. PF-592379 fails to bind human D2 (Ki≥10 μM), D1 (Ki≥10 μM), or D5 (Ki≥10 μM) receptors at concentrations of up to 10 µM, and thus is at least 46-fold selective for D3 over D2, D1, and D5 receptors[3].

PF-592379 is an oral dopamine 3 agonist in rat, and dog. PF-592379 has low-moderate clearance relative to liver blood flow of 6.3 and 8.5 mL/min/kg in dog and 44.8 and 58.2 mL/min/kg in rat. It has high permeability in Caco-2 cells and is completely absorbed in rat and dog pharmacokinetic studies with an oral bioavailability of 28% in both rats and 61 and 87% in the dogs[1].

[1]. Attkins N, et al. Pharmacokinetics and elucidation of the rates and routes of N-glucuronidation of PF-592379, an oral dopamine 3 agonist in rat, dog, and human. Xenobiotica. 2010 Nov;40(11):730-42. [2]. Wager TT, et al. Dopamine D3/D2 Receptor Antagonist PF-4363467 Attenuates Opioid Drug-Seeking Behavior without Concomitant D2 Side Effects. ACS Chem Neurosci. 2017 Jan 18;8(1):165-177. [3]. Collins GT, et al. Lack of abuse potential in a highly selective dopamine D3 agonist, PF-592,379, in drug self-administration and drug discrimination in rats. Behav Pharmacol. 2012 Jun;23(3):280-91.