EP-4144736-B1 - AZABENZIMIDAZOLES AND THEIR USE AS AMPA RECEPTOR MODULATORS

Inventors

• BERRY, Cynthia G.B
• WU, DONGPEI
• ZHANG, WEI
• AMERIKS, MICHAEL K.
• CHEN, GANG
• JOURDAN, Fabrice Loic
• LEBOLD, Terry Patrick
• LIN, David Wei
• PENA PIÑÓN, Miguel Angel
• RAVULA, SUCHITRA
• SAVALL, Bradley M.
• SWANSON, DEVIN M.

Dates

Publication Date

20260506

Application Date

20160428

Claims (4)

1. 2-(2-Fluoro-4-pyridyl)-3-(7-methyl-1H-indazol-5-yl)-5-(trifluoromethyl)imidazo[4,5-b]pyridine, or a pharmaceutically acceptable salt, N-oxide, or solvate thereof.
2. A pharmaceutical composition comprising the compound of claim 1 and a pharmaceutically acceptable excipient.
3. 2-(2-[ 18 F]fluoro-4-pyridyl)-3-(7-methyl-1H-indazol-5-yl)-5-(trifluoromethyl)imidazo[4,5-b]pyridine, or a pharmaceutically acceptable salt, N-oxide, or solvate thereof.
4. A pharmaceutical composition comprising the compound of claim 3 and a pharmaceutically acceptable excipient.

Description

Field of the Invention The present invention is related to compounds having AMPA receptor modulating properties and pharmaceutical compositions comprising these compounds. Background of the Invention Glutamate is the primary excitatory neurotransmitter in mammalian brain. Glutamatergic signaling participates in a wide range of neural functions including learning and memory, long-term potentiation and synaptic plasticity. Glutamate receptors can be divided into two families. The ionotropic glutamate receptors form ion channels that activate upon binding agonist, opening a pore through the plasma membrane through which cations can flow. The metabotropic glutamate receptors are G-protein-coupled receptors, activating intracellular signal transduction cascades. The ionotropic glutamate receptors can be further subdivided into four sub-families, based upon sequence homology and selectivity to exogenous agonists. These sub-families are the AMPA (α-amino-3-hydroxyl-5-methyl-4-isoxazole-propionic acid), NMDA (N-methyl-D-aspartate), kainate, and delta receptors. The AMPA subtype of glutamate receptors are glutamate-gated ion channels expressed primarily on postsynaptic membranes of excitatory synapses in the central nervous system. AMPA receptors assemble as tetramers of subunits. Mammals express four AMPA-receptor subunits, called GluA1-GluA4. Each GluA subunit can be expressed in multiple splice variants; the two most prominent splice variants are called flop and flip. GluA subunits freely form functional homo- and hetero-tetramers. The majority of RNA encoding GluA2 subunits is edited post-transcriptionally, altering a genetically-encoded glutamine to arginine. This RNA editing causes AMPA receptors to preferentially form with two GluA2 units, and also prevents calcium entry through the activated receptor. In their native environment, the pore-forming GluA tetramers directly or indirectly associate with numerous auxiliary proteins which modify the trafficking, localization, gating characteristics, and pharmacology of the AMPA receptor (AMPAR). These auxiliary subunits include cytoskeletal and anchoring proteins, other signaling proteins, and several intracellular and transmembrane proteins with unknown function. The wide variety of proteins which can participate in AMPA receptor complexes vastly increases the ability of a neuron to tune the response characteristics of its synapses. Transmembrane AMPA Receptor Regulatory Proteins (TARPs) are a fairly recently discovered family of proteins that have been found to associate with and modulate the activity of AMPA receptors. (Gill and Bredt., Neuropsychopharmacology 36(1): 362-363 (2011). Several TARPs exhibit regiospecific expression in the brain, leading to physiological differentiation of the AMPA receptor activity. For example, TARP y2-dependent AMPA receptors are primarily localized in the cerebellum and cerebral cortex while TARP y8-dependent AMPA receptors are localized primarily in the hippocampus. AMPA receptors mediate the majority of fast neurotransmission across synaptic gaps. Thus, inhibition or negative modulation of AMPA receptors is an attractive strategy for therapeutic intervention in CNS disorders characterized by excessive neuronal activity. However, since AMPA receptor activity is so ubiquitous within CNS, general antagonism affects most areas of the CNS resulting in undesired effects, such as ataxia, sedation, and/or dizziness, which are shared by all known general AMPA receptor antagonists. Epilepsy affects over 50 million people world-wide, with 30-40% of treated patients being resistant to current pharmacotherapies and only about 8% of treated patients being maintained seizure free. Epilepsy is often defined as when a person has two or more unprovoked epileptic seizures. The International League Against Epilepsy (ILAE) defines an epileptic seizure as "a transient occurrence of signs and/or symptoms due to abnormal excessive or synchronous neuronal activity in the brain." Seizures are thought to have a number of underlying causalities which adds to the difficulty in treating epilepsy. Seizures have been divided according to their clinical presentation including generalized seizures (absence, atonic, tonic-clonic (grand mal), and myoclonic), simple and complex partial onset seizures, gelastic seizures, dacrystic seizures, and status epilepticus. Current therapies target a variety of mechanisms including GABA y - aminobutyric acid) receptor agonism, T-type calcium channel blockers, sodium channel modulators, synaptic vesicle protein SV2A modulation, and inhibition of GABA transaminase. More recently, AMPA receptor antagonists have been investigated for treatment of seizures as well. AMPA receptor antagonists are known anticonvulsant agents. Typically, AMPA receptor antagonists have very narrow therapeutic dosing windows; the doses needed to obtain anticonvulsant activity are close to or overlap with doses at which undesired effects are observed.