PF-06447475 is a highly potent, selective and brain penetrant LRRK2 inhibitor with an IC50 of 3 nM.
PF-06447475 inhibits LRRK2 enzyme and LRRK2 in the whole cell assay with IC50s of 3 and 25 nM, respectively[1]. Cells incubated with PF-06447475 alone (0.5, 1, 3 μM) or in the presence of ROT significantly reduces (S935)-LRRK2 kinase phosphorylation to control. PF-06447475 significantly preserves the nucleus morphology and ΔΨm of NLCs exposed to ROT compared to untreated and control. PF-475 significantly diminishes ROT-induced ROS generation to a similar extent to cells exposed to PF-475 alone[2].
In G2019S+ rats treated with PF-06447475, a significant reduction in microgliosis to levels found in wild-type rats could be observed. The proinflammatory marker MHC-II expressed on myeloid cells but not neurons also appears to be less abundant in confocal sections in G2019S+ rats treated with PF-06447475. PF-06447475 treatment in G2019S+ rats significantly lowers the number of CD68 cells recruited to the SNpc. PF-06447475 successfully blocks the enhanced neuroinflammation associated with G2019S-LRRK2 expression. Treatment of G2019S+ rats with PF-06447475 preserves TH expression in the dorsal striatum, consistent with drug attenuating neurodegeneration in the SNpc[3]. PF-06447475 is well tolerated in rats[1].
References:
[1]. Henderson JL, et al. Discovery and preclinical profiling of 3-[4-(morpholin-4-yl)-7H-pyrrolo[2,3-d]pyrimidin-5-yl]benzonitrile (PF-06447475), a highly potent, selective, brain penetrant, and in vivo active LRRK2 kinase inhibitor. J Med Chem. 2015 Jan 8;58(1):419-32.
[2]. Mendivil-Perez M, et al. Neuroprotective Effect of the LRRK2 Kinase Inhibitor PF-06447475 in Human Nerve-Like Differentiated Cells Exposed to Oxidative Stress Stimuli: Implications for Parkinson's Disease. Neurochem Res. 2016 Oct;41(10):2675-2692.
[3]. Daher JP, et al. Leucine-rich Repeat Kinase 2 (LRRK2) Pharmacological Inhibition Abates α-Synuclein Gene-induced Neurodegeneration. J Biol Chem. 2015 Aug 7;290(32):19433-44.