Preclinical Metabolism, Pharmacokinetics and In Vivo Analysis of New Blood-Brain-Barrier Penetrant Fingolimod Analogues: FTY720-C2 and FTY720-Mitoxy.
Parkinson's disease (PD) is a neurodegenerative aging disorder in which postmortem PD brain exhibits neuroinflammation, as well as synucleinopathy-associated protein phosphatase 2A (PP2A) enzymatic activity loss. Based on our translational research, we began evaluating the PD-repurposing-potential of an anti-inflammatory, neuroprotective, and PP2A stimulatory oral drug that is FDA-approved for multiple sclerosis, FTY720 (fingolimod, Gilenya®). We also designed two new FTY720 analogues, FTY720-C2 and FTY720-Mitoxy, with modifications that affect drug potency and mitochondrial localization, respectively. Herein, we describe the metabolic stability and metabolic profiling of FTY720-C2 and FTY720-Mitoxy in liver microsomes and hepatocytes. Using mouse, rat, dog, monkey, and human liver microsomes the intrinsic clearance of FTY720-C2 was 22.5, 79.5, 6.0, 20.2 and 18.3 μL/min/mg; and for FTY720-Mitoxy was 1.8, 7.8, 1.4, 135.0 and 17.5 μL/min/mg, respectively. In hepatocytes, both FTY720-C2 and FTY720-Mitoxy were metabolized from the octyl side chain, generating a series of carboxylic acids similar to the parent FTY720, but without phosphorylated metabolites. To assess absorption and distribution, we gave equivalent single intravenous (IV) or oral doses of FTY720-C2 or FTY720-Mitoxy to C57BL/6 mice, with two mice per time point evaluated. After IV delivery, both FTY720-C2 and FTY720-Mitoxy were rapidly detected in plasma and brain; and reached peak concentrations at the first sampling time points. After oral dosing, FTY720-C2 was present in plasma and brain, although FTY720-Mitoxy was not orally bioavailable. Brain-to-plasma ratio of both compounds increased time-dependently, suggesting a preferential partitioning to the brain. PP2A activity in mouse adrenal gland increased ~2-fold after FTY720-C2 or FTY720-Mitoxy, as compared to untreated controls. In summary, FTY720-C2 and FTY720-Mitoxy both (i) crossed the blood-brain-barrier; (ii) produced metabolites similar to FTY720, except without phosphorylated species that cause S1P1-mediated-immunosuppression; and (iii) stimulated in vivo PP2A activity, all of which encourage additional preclinical assessment.
In Vitro and Molecular Metabolism Laboratory, Ricerca Biosciences LLC, Concord, Ohio, United States of America.
Julius O
JO
Enoru
Department of Biomedical Sciences, Graduate School of Biomedical Sciences, Center of Emphasis in Neurosciences, Paul L. Foster School of Medicine, Texas Tech University Health Sciences Center El Paso, El Paso, Texas, United States of America.
Barbara
B
Yang
Department of Biomedical Sciences, Graduate School of Biomedical Sciences, Center of Emphasis in Neurosciences, Paul L. Foster School of Medicine, Texas Tech University Health Sciences Center El Paso, El Paso, Texas, United States of America.
Sesha
S
Krishnamachari
Department of Biomedical Sciences, Graduate School of Biomedical Sciences, Center of Emphasis in Neurosciences, Paul L. Foster School of Medicine, Texas Tech University Health Sciences Center El Paso, El Paso, Texas, United States of America.
Ernesto
E
Villanueva
In Vitro and Molecular Metabolism Laboratory, Ricerca Biosciences LLC, Concord, Ohio, United States of America.
William
W
DeMaio
In Vitro and Molecular Metabolism Laboratory, Ricerca Biosciences LLC, Concord, Ohio, United States of America.
Adiba
A
Watanyar
Department of Chemistry and Biochemistry, New Mexico State University, Las Cruces, New Mexico, United States of America.
Ramesh
R
Chinnasamy
Department of Chemistry and Biochemistry, New Mexico State University, Las Cruces, New Mexico, United States of America.
Jeffrey B
JB
Arterburn
Department of Biomedical Sciences, Graduate School of Biomedical Sciences, Center of Emphasis in Neurosciences, Paul L. Foster School of Medicine, Texas Tech University Health Sciences Center El Paso, El Paso, Texas, United States of America.
Ruth G
RG
Perez
D000818:Animals; D001812:Blood-Brain Barrier / Q000378:metabolism*; D000068876:Fingolimod Hydrochloride / Q000493:pharmacokinetics*; D022781:Hepatocytes / Q000378:metabolism; D006801:Humans; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D008862:Microsomes, Liver / Q000378:metabolism; D054648:Protein Phosphatase 2 / Q000378:metabolism; D051381:Rats
D054648:Protein Phosphatase 2; D000068876:Fingolimod Hydrochloride