WO2020061211A1 - Use of highly-selective adenosine 3a receptor subtype agonists - Google Patents

Abstract

The disclosure provides methods and compositions for treating cognitive impairment due to traumatic brain injury, for treating the neurological sequelae of traumatic brain injury, and for treating or preventing chemotherapy-induced cognitive impairment by administering to a subject in need thereof an A3AR agonist.

Description

USE OF HIGHLY-SELECTIVE ADENOSINE 3A RECEPTOR SUBTYPE AGONISTS

CROSS-REFERENCE

[0001] This application claims the benefit of U.S. Provisional Patent Application No. 62/732,766, filed September 18, 2018, and U.S. Provisional Patent Application No. 62/732,777, filed September 18, 2018, the entire contents of each of which are incorporated herein by reference.

BACKGROUND

[0002] The present disclosure relates generally to the field of medicine. More specifically, the disclosure describes the use of a drug that is a selective agonist for the human adenosine A_? receptor subtype (A₃AR) in the treatment of cognitive impairment due to traumatic and toxic brain insults. Such brain insults include but are not limited to traumatic brain injury (TBI) and its neurological sequelae (including post-concussion syndrome and“shell-shock”), and chemotherapy-induced cognitive impairment (CIO;“chemo-brain”,“chemo-fog”). The present disclosure is directed to the use of drugs that are highly-selective agonists for the human adenosine A3 receptor (A₃AR) subtype in the prevention and treatment of cognitive impairment due to diverse brain insults such as TBI and CIO.

[0003] Traumatic brain injury (TBI) is major health issue, with particular relevance to sports injuries and injuries resulting from military operations. TBI is defined as damage to the brain resulting from external mechanical force, such as rapid acceleration or deceleration, impact, blast waves, or penetration by a projectile. Brain function is temporarily or permanently impaired. Structural brain damage may or may not be detectable with current technology. TBI can be classified based on severity, mechanism (closed or penetrating head injury), or other features (e.g., occurring in a specific location or over a widespread area). The neurological sequelae of TBI include physical, cognitive, social, emotional, and behavioral symptoms.

Outcome can range from complete recovery_' to permanent disability. The past few decades have produced developments in diagnosis and treatment that have decreased death rates and improved outcomes. This has resulted in an increased number of long-term TBI survivors suffering from TBX-induced cognitive impairment.

[0004] TBI is often followed by months or years of cognitive impairment (post concussion syndrome;“shell shock”). The neurological sequelae to TBI may last for decades and include mild-to-severe cognitive impairment. Cognitive deficits that can fol low TBI include impaired attention; disrupted insight, judgement, and thought; reduced processing speed;

distractibility; and deficits in executive functions such as abstract reasoning, planning, problem- solving, and multi-tasking. Memory loss, the most common cognitive impairment with TBI, occurs in 20-79% of patients with closed head trauma, depending on severity. People who have suffered TBI may also have difficulty with understanding or producing spoken or written language, or with more subtle aspects of communication such as body language. Post-concussion syndrome, a set of lasting symptoms experienced after mild TBI, can include physical, cognitive, emotional and behavioral problems such as headaches, dizziness, difficulty concentrating, and depression. TBI may cause emotional, social, or behavioral problems and changes in personality.

[000SJ TBI is due to a primary and a secondary injury. The primary⁷ injury is the initial tissue trauma. This is followed by a secondary injury due to a neuro-inf!aramatory response that contributes to secondary cell death in areas of the brain distant to the init al trauma. These neuroinflammatory processes promote cell death during the early phase after TBI and contribute to subsequent neurological impairments during later stages. Neurodegeneration and neuroinflammation are believed to be key factors leading to neurological sequelae associated with TBI

|0006] Secondary injury events include damage to the blood-brain barrier, a neurolnilammaiory response involving formation of the Nod-like receptor protein 3 (NLRP3) inflammasome. The inflammasome is a large multi-protein complex that forms in the cytoplasm of neurons, astrocytes, microglia and other cell types in response to innate immune signaling inflammasome activity coupled to caspase-1 cleaves the inactive precursor forms of interleukin- 1-beta (IL-Ib) and interleukin- 18 (IL-18) and thus leads to increased levels of IL-Ib and other pro-inflammatory cytokines. Moreover, as cells die, they release various harmful substances, including the neurotransmitter, glutamate, which produces an excitotoxic effect involving the influx of calcium and sodium ions into neurons, and the dysfunction of mitochondria and free radical overload. Injured axons in the brain’s white matter may separate from their cell bodies as a result of secondary⁷ injury, potentially killing those neurons. Other factors in secondary injury⁷ are changes in the blood flow to the brain; ischemia; cerebral hypoxia; cerebral edema; and raised intracranial pressure. Intracranial pressure may rise due to swelling or a mass effect from a lesion, such as a hemorrhage. As a result, cerebral perfusion pressure (the pressure of blood flow in the brain) is reduced and ischemia results.

[QQ07] Treatment in the acute stage (the period lasting until a few days to w eek after TBI) focuses on stabilizing basic physiological function and wound healing. Nevertheless, it. is recognized that secondary injury phenomena begin during this period, indicating that early intervention to reduce or prevent later stage sequelae is appropriate.

[QQ08] No medication is FDA-approved for the treatment or prevention of the secondary inj ury processes that generate the neurological sequelae of TBI, including TBI- induced cognitive impairment. Accordingly, there exists a need for compounds and methods for treating and preventing secondary injury following TBI.

[0009] The present disclosure also provides methods of treating cognitive impairment following chemotherapy (CIO; also known as“chemo-bram”;“chemo-fog”), which is a major side-effect of cancer therapy. Cognitive impairment is estimated to affect >50% of patients. However, little is known about the mechanisms underlying CIO. The phenomenon first came to light because of the large number of breast cancer survivors who complained of changes in memory, fluency, and other cognitive abilities that impeded their ability to function as they had pre-chemotherapy. While many cancer patients experience temporary cognitive impairment while undergoing chemotherapy, some patients continue to experience these symptoms long after chemotherapy has been completed. CIO is often seen in patients treated for breast cancer, ovarian cancer, prostate cancer, and other reproductive cancers, as well as other types of cancers. The cause of CIO is unknown, hut there is evidence from experiments in animal models suggesting that it is secondary to a neuroinfiamrnatory response in the brain that includes increased levels of pro-inflammatory cytokines and impaired function of neuronal and glial mitochondria. Evidence suggests that the n euroinflaramatory response begins when

chemotherapy commences, or within hours-to-days thereafter, and that it may persist for weeks, months or years after chemotherapy is completed.

[0010] CIO has a strong negative impact on quality of life in cancer patients and survivors. In humans, CICI is characterized by subtle to moderate cognitive deficits that include decreases in processing speed, memory, executive functioning, and attention, as assessed by neuropsychological tests. CICI patients report cognitive impairment that affects their daily function, in particular in regards to attention, concentration, memory, word-finding, multi tasking, and organization. Many CICI patients report accompanying anxiety, depression, fatigue, and overall health-related decline. CICI includes impairments in visual and semantic memory, attention and motor coordination. These effects can impair a chemotherapy patient's ability to understand and make decisions regarding treatment, perform in school or employment, and can reduce quality of life. Patients often report difficulty multitasking, comprehending what they have just read, following the thread of a conversation, and retrieving words. Thus, CICI patients have a distressing, often disabling, and sometimes chronic impairment of cognitive abilities that has a major impact on their quality of life.

[0011] Advanced neuroimaging techniques have revealed that chemotherapy causes structural alterations in the white and gray matter of cancer patients along with decreased level of activation of the fronto-parietal attend onal network. Therefore, chemotherapy causes substantial decrements in short and long-term learning and memory function that persists well after exposure.

[0012] The success of various chemotherapy regimens has led to a dramatic increase in cancer survivorship, and this has been accompanied by an increased burden of CXCI. CICI is a common effect of treatment with commonly used cytotoxic agents including but not limited to paelitaxel, docetaxel, carbopiatin, eisplatim oxa!iplatin, doxorubicin, and bortezomib. For example, between 18% and 78% of breast cancer patients report impairment soon after initiating chemotherapy treatment. The symptoms have been reported to persist for months to years in ~35% of patients in disease-free remission. In some patients CICI may last for 5—10 years after treatment

[0013] In the CNS, the purine nucleoside adenosine is an important neuromodulator that regulates neuronal and glial function. The estimated baseline extracellular concentration of adenosine is 30-200 nM and this can increase substantially in inflammatory conditions. This triggers compensatory homeostatic and neuromoduiatory actions that protect against neuronal damage through a myriad of local neuronal and glial responses. Therefore, adenosine regulates global brain function under normal physiological settings and provides neuroprotection under pathophysiological conditions. However, as the pathological insult progresses, the levels of beneficial adenosine decrease in response to alterations in the extracellular enzymes that make it (ectonucleotidases) and the intracellular enzyme that removes it (adenosine kinase, ADK).

[0014] Despite the increase in cancer survivorship, no FDA-approved preventive or curative interventions tor CICI have been developed. Treatment options include the use of antioxidants, cognitive behavior therapy, erythropoietin and stimulant daigs such as

rnethyiphemdate and modafmil . None of these treatments has been shown to be effective in double-blind, placebo-controlled clinical trials. Accordingly, there exists a need to understand the underlying causes of this serious adverse drug reaction and identify novel therapeutic approaches for treating CICI.

SUMMARY

[QQ15] The present disclosure is directed to the use of drugs that are a highly- selective agonist for the human adenosine A·_.? receptor (A₃AR) subtype in the prevention and treatment of patients having cognitive impairment due to various causes including traumatic brain injury and chemotherapy.

[0016] In one aspect, the present disclosure is directed to a method for

prophylactic-ally treating neurological sequelae of traumatic brain injury in a patient via administration of a selective A3 human receptor subtype agonist as soon as is medically practicable following traumatic brain injury.

[0017] In one aspect, the present disclosure is directed to a method for

prophylactically treating traumatic brain injury-induced cognitive impairment in a patient by administering a selective adenosine A·_.? human receptor subtype agonist to a patient following traumatic brain injur _{' .}

[0018] In one aspect, the present disclosure is directed to a method for treating established neurological sequelae of traumatic brain injury in a patient by administering a selective adenosine A¾ human receptor subtype agonist to the patient.

[0019] in one aspect, the present disclosure is directed to a method for treating established traumatic brain injury-induced cognitive impairment in a patient by administering a selective adenosine A₃ human receptor subtype agonist to the patient.

[0Q20] In certain aspects, there is provided a method for prophylactically treating chemotherapy-induced cognitive impairment by administering a selective adenosine A₃ human receptor subtype agonist to a patient undergoing or about to undergo cancer chemotherapy treatment.

[0021] In certain aspects, the present disclosure is directed to a method for treating chemotherapy-induced cognitive impairment by administering a selective adenosine A_?, human receptor subtype agonist to a patient who has completed cancer chemotherapy treatment.

BRIEF DESCRIPTON OF THE DRAWINGS

[0022] The disclosure will be beter understood, and features, aspects and advantages other than those set forth above will become apparent when consideration is given to the following detailed description thereof. Such detailed description make reference to the following drawings, where! n :

[0023] FIG. 1 is a Western blot depicting A₃AR expression in the prefrontal cortex (PFC) and hippocampus (HC) following completion of cispiatin treatment in the mouse.

[0024] FIG. 2 depicts the assessment of male mice in the puzzle box test 1 week after completion of a course of chemotherapy with cispiatin. All data are expressed as rnean±SD for (n) mice/group; ANOVA with Bonferroni’s correction; *p<0.05 vs vehicle (Veh).

[0025] FIGS. 3A-3D depict CDS 9 ectonucleotidase (FIG. 3 A) and CD71

ectonudeotidase (FIG 3B) expression in prefrontal cortex in 2 s and ADK (FIG. 3C) and .43 AR (FIG. 3D) expression in the hippocampus · n 3 } of male mice following completion

chemotherapy treatment with cispiatin. Images were cropped from the same blot. All Western blots were performed at least twice. All data are expressed as mea.n-t-SD. [0026] FIG. 4 depicts results of mice treated with vehicle, eisplatin alone, or concomitantly with eisplatin and a higlily-selective A₃AR agonist (MRS5980) and tested several days later. Data are means ± SEM for n^::::3/group. ANOVA *p<0.05 MS. Saline, °p<0.05 MS.

Cispiatin.

[0027] FIG. 5 depicts cispiatin-induced decrease in spare respiratory capacity of mitochondria due to manganese superoxide dismutase nitration in the hippocampus. Data are means ± SEM for n^::::5/group. Student's t-test, *p<0.05 vs. vehicle (Veh).

[0028] FIG. 6 depicts that chemotherapy treatment was sufficient to induce NLRP3 expression in the mouse brain. Data are means ± SEM for n^::::2 mice/group.

[0029] FIGS. 7 A and 7B depict blocking the development of neuropathic pain by inhibiting MnSOD nitration and mitochondrial dysfunction (loss of ATP production) in peripheral sensory afferents by A AR agonists following chemotherapy treatment with oxaiiplatin. Data are means ± SD for n=6/group. ANOVA; *p<0.05 vs. vehicle (Veh);†p<0.05 vs. Oxaiiplatin (Ox) or Oxalipiatin t IB-MBCA (Ox+IB~MECA).

[0030] FIGS. 8A-8D depict Western blots analysis for activation of inflammasome NLR.P3 (FIG. 8A) and caspase-l (FIG. 8B) at 24 hours post-TBI and assessment of cognitive function using the Novel Object Recognition test (FIG. 8C) and the T- aze learning test (FIG. 8D) 4 weeks after TBI. Means ± SEM for n=5 (FIGS. 8A-8B) and n=7 (FIGS. 8C-8D). * P<

0.05 vx. sham,† P<0.05 vx. lift alone.

DETAILED DESCRIPTION

[0031] Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which the disclosure belongs.

[0032] The term“salt” or“pharmaceutically acceptable salt” refers to salts derived from a variety of organic and inorganic counter ions vcel! known in the art. Pharmaceutically acceptable acid addition salts can be formed with inorganic acids and organic acids. Inorganic acids from which salts can be derived include, for example, hydrochloric acid, hydrobromic acid, sulfuric add, nitric acid, phosphoric acid, and the like. Organic acids from which salts can be derived include, for example, acetic acid, propionic acid, glycolic acid, pyruvic acid, oxalic acid, maleic acid, malonic add, succinic add, fumaric acid, tartaric add, citric acid, benzoic acid, cinnamic acid, mandeiic acid, methanesul tonic acid, eihanesultbnic acid, /wtoSuenesidfomc acid, salicylic acid, and the like. Pharmaceutically acceptable base addition salts can be formed with inorganic and organic bases. Inorganic bases from which salts can be derived include, for example, sodium, potassium, lithium, ammonium, calcium, magnesium, iron, zinc, copper, manganese, aluminum, and the like. Organic bases from which salts can he derived include, for example, primary, secondary, and tertiary amines, substituted amines including naturally occurring substituted amines, cyclic amines, basic ion exchange resins, and the li ke, specifically such as isopropylamine, trimethylamine, diethylamine, triethylamine, tripropylamine, and ethanolamine. In some embodiments, the pharmaceutically acceptable base addition salt is chosen from ammonium, potassium, sodium, calcium, and magnesium salts.

[0033] The phrase '‘pharmaceutically acceptable’^' is employed herein to refer to those compounds, materials, compositions, and/or dosage forms which are, within the scope of sound medical judgment, suitable for use in contact with the tissues of human beings and animals without excessive toxicity, irritation, allergic response, or other problem or complication, commensurate with a reasonable benefit/risk ratio.

[0034] In certain embodiments, the term '‘prevent” or“preventing” as related to a disease or disorder may refer to a compound that, in a statistical sample, reduces the occurrence of the disorder or condition in the treated sample relative to an untreated control sample, or delays the onset or reduces the severity of one or more symptoms of the di order or condition relative to the untreated control sample.

[0035] The terms“treat,”“treating” or“treatment,” as used herein, may include alleviating, abating or ameliorating a disease or condition symptoms, preventing additional symptoms, ameliorating or preventing the underlying causes of symptoms, inhibiting the disease or condition, e.g., arresting the development of the disease or condition, relieving the disease or condition, causing regression of the disease or condition, relieving a condition caused by the disease or condition, or stopping the symptoms of the disease or condition either prophylactica!iy an d/or therapeuti cal 1 y .

Traumatic Brain Injury

[0036] In certain aspects, the present disclosure is directed to the use of drugs that are a highly-selective agonist for the human adenosine A3 receptor (A3AR) subtype in the prevention of cognitive impairment or sequelae of traumatic brain injury and treatment of patients having a traumatic brain injury . There are known to be four G-protein-coupled receptor subtypes for adenosine: AiAR, A₂AAR, A₂BAR, and A3AR. Drug-like molecules are known that have selectivity for binding to each of the four subtypes. In particular, highly-selective (greater than 10,000-foid relative to each of the other three subtypes) agonists for the A₃AR are available. Drugs that selectively activate the A3AR are advantageous because they avoid the

cardiovascular, renal and immunological side-effects that are produced by activation of the other three receptor subtypes. [0037] In one aspect, the present disclosure is directed to a method for prophylactically treating neurological sequelae of traumatic brain injury in a patient via administration of a selective A₃ human receptor subtype agonist as soon as is medically practicable following injury. The method includes administering a selective adenosine A_?, human receptor subtype agonist to a patient as soon as is medically practicable following a traumatic brain injury. Sequelae of traumatic brain injury include headache and dizziness, anxiety, apathy, depression, aggression, cognitive impairments, personality changes, mania, psychosis.

[0038] In one aspect, the present disclosure is directed to a method for

prophylactically treating traumatic brain injury-induced cognitive impairment in a patient by administering a selective adenosine A₃ human receptor subtype agonist to a patient fol lowing traumatic brain injury.

[0039] In one aspect, the present disclosure is directed to a method for treating established neurological sequelae of traumatic brain injury in a patient by administering a selective adenosine A¾ human receptor subtype agonist to the patient.

[0040] In one aspect, the present disclosure is directed to a method for treating established traumatic brain injury-induced cognitive impairment in a patient by administering a selective adenosine A₃ human receptor subtype agonist to the patient.

Chernotherapy-Induced Cognitive Impairment

[0041] In another aspect, the present disclosure is directed to a method for treating chemotherapy-induced cognitive impairment The method includes administering a selective adenosine A₃ human receptor subtype agonist to a patient who has completed cancer treatment with one or more chemotherapeutic agents. In certain embodiments, the selective adenosine As human receptor subtype agonist is administered to a patient prior to and/or during cancer treatment with one or more chemotherapeutic agents.

Such chemotherapeutic agents include those that are currently known to be associated with CIO when given singly or in combination with another chemotherapeutic: these include hut are not limited to taxane agents (e.g., paclitaxel and docetaxel), platinum-complex agents (e.g., carboplatin, cisp!atin, and oxaliplatin), vinca alkaloids {e.g., vincristine and vinblastine), proteasome inhibitors (e.g., bortezomib), 5-fluorouracil, methotrexate, and doxorubicin

L . LE agoni ts

[0042] A compound can be identified as a selective A₃AR. agonist using known methods, including competitive radioimmunoassays and assays of forskoiin-stimuiated cyclic adenosine monophosphate (cAMP) production in human A3AR transfected CHO cells or HEK cells. As used herein, the ter “selective” refers to a binding affinity (or cAMP production) for the human A₃ receptor subtype that is at least 50-fold greater, at least 60-fold greater, at least 70- fold greater, or at least 80-fold greater than the binding affinity (or cAMP production) for any of the other three types of human receptor subtypes (A.AR, A?_AAR, A₂BAR).

[0043] Suitable A₃AR gonists include N^-benzydadenosine-S -N-methyluronaniides such as N°-(3-iodobenzyl)-adenosine-5'-N-methy!uronamide (also known as IB-MECA), and 2- Chloro-N⁶ (3-iodobenzyl)-adenosine-5'-N-methyluronamide (also known as 2-CI-IB-MECA); (N)-methanocarba nucleosides such as ( 1 ,2R, 3 S,4R)-4-(2-chl oro-6-((3 -chlorobenzyl)arai no)- 9H-purin-9-yl)-2,3 -di -hydroxy ~N- ethylbicyclo[3.1. G]hexane- 1 -carboxami de (al so known as CF502. Can-File Biopharma, MA); (2S,3S,4R,5R)-3-amiiio-5-[6-(2,5- dichiorchenzyiainino)purin-9-yi]-4-hydroxy-tetrahydrofuran-2-carboxyiicacid methylamide (also known as CP-532,903); (l'S,2'R,3'S,_' ⁱrR,5'S)-4-(2-chloro-6-(3-clilorobenz\'lamino)-9H- purin-9-yl)-2,3-dihydroxy-N-methylbicyclo[3.1.0]hexane-l -carboxami de (also known as MRS- 3558); (rR,2^,R,3^,S,4ⁱR,5ⁱS)-4-{2-cliloro~6-[(3-iodophenylmethyl)amino]purin-9 yl } l- (rnelhylarninocarbonyi)-bicyelo[3 1 0]hexane-2,3-diol (also known as MRS 1898); and 2- Dialkynyl derivatives of (N)-methanocarba nucleosides, 2-(arylethynyl)adenine and N(6)-methyl or N(6)-(3-substituted-benzyl), N(6)-raethyl 2~(balophenylethynyl) analogues, polyaromatic 2- ethynyl N(6)-3-ehlorohenzyl analogues, such as 2-p-biphenyiethynyl (MRS5679) and fluorescent 1 -pyrene adduct (MRS 5704), as well as MRS5678.

[0044] in certain embodiments, compounds of the methods described herein, are represented by Formula (I):

or a pharmaceutically acceptable salt thereof, wherein:

X is selected from NHR¹, CH₃, and CH=C(R^a)(R^b) wherein R^aand R^b are independently selected from hydrogen, hydroxyl, Ci-Cs alkyl, and Cg-Cir and:

Y is N or CH;

R^l is selected from O.-Cf, alkyl, Ci-Ce aikoxy, hydroxyl, C₃-Cs cycloalkyl, C CM aryl C3 Cg cydoalkyl, Cs-Cgcycloaikyl Ci-Ce. alkyl, C₃-Cg dicycloalkyl Ci-Ce alkyl,€7-

C] 2 bicycioalkyl, C 7-C12 bicycloalkyl Ci-Ce al yi, C?-C utricy cloalkyi Ci-Cs al kyl, C₆- C14 and, C6-C14 aryl Ci-Cealkyl, Ce-Cu diary! Ci-Ce alkyl, Ce-Cw aryl Ci-Ce aikoxy, heterocyclyl CVCA alkyl, heterocyclyl, 4-[[[4-[[[(2~amino CuCY alkyl) arninoj-carbonyl]- Ci-Ce a!kyljaniiino] carbonyl] Ci-Ce alkyl] C0-C14 aryl, and CS-CM aryl C₃-Cgcycloalkyl, wherein the aryl or heterocyelyl portion of R^fis optionally substituted with one or more substituents selected from halo, amino, hydroxyl, carboxy, aikoxyearbonyl,

aminocarbonyi, aikyiaminocarbonyl, diaikyiaminocarbonyl, Ci-C alkyl, C_2~C alkenyl, C₂-Ce.alkynyl_s€·-€ό alkoxy, Ce-Cn_? aryloxy, hydroxy Ci-Cs alkyl, hydroxy C2-C6 alkenyl, hydroxy ik-Ck aikynyl, carboxy ik-Ck alkyl, carboxy (k~Ck alkenyl, carboxy ik- Ck alkynyi, aminocarbonyi C -Cs alkyl, aminoearbonyl Ck-C alkenyl, aminocarbonyi Ck- Ck alkynyi, and any combination thereof, and the alkyl or cydoalkyl portion of R¹ is optionally substituted with one or more substituents selected from halo, hydroxy, amino, alkyl, alkoxy, aryloxy, bydroxyalkyl, hydroxyalkenyl, bydroxyalkynyl,

ami nocarbonylaikoxy , and arylalkoxy, and any combination thereof,

R²is selected from C6-C12 aryl, C₃-Cg cydoalkyl, heteroaryl, and metailocenyl, wherein the aryl group is optionally substituted with one or more substituents selected from halo, trifluoromethyl, bydroxyalkyl, alkoxy, sulfonyioxy, carboxyalkyl, sulfonyloxyalkyl,

arylcarbonyl, and any combination thereof, wherein the heteroaryl group is optionally substituted with one or more substituents selected from halo, trifluoromethyl, amino, alkyl, hydroxyaikyi, aryl, benzo, alkoxy, hydroxyl, carboxyl, sulfonyioxy, carboxyalkyl, sulfonyloxyalkyl, alkyl carbonyl, arylcarbonyl, and any combination thereof,

R^J and R⁴ are independently selected from hydrogen, hydroxyl, amino, mercapto, ureido, ik-Ck alkyl carbonylamino, hydroxy Ci-ik alkyl, and hydrazinyl,

R⁵ is selected from hydrogen, C1-C3 alkyl aminocarbonyi, di(Ci-C₃ alkyl) aminocarbonyi, Ck-Ck alkylthio Ci-Chalk !, halo C -Ck alkyl, hydrazinyl, amino C₁-C₃ alkyl, hydroxy Cj~C₃ alkyl, Ck-Ck cydoalkyl amino, hydroxyl ami no, and C₂-C₃ alkenyl; and

R° is selected from hydrogen, Ci-Ck alkyl, Ck-Ck alkenyl, Ck-Ck alkynyi, heteroaryl, and Ci-Ck ami noalkyl.

[QQ45] In certain embodiments, a compound of formula (I) is racemic or one or more of the stereocenters has the opposite configurat on relative to the structure as depicted.

[QQ46] In certain embodiments, for a compound or salt of Formula (I), when R¹ is methyl, R" and Rf are both hydroxyl, R⁶ is hydrogen, and ~ is methyl aminocarbonyi, R'ks not 2-pyridyl or phenyl.

[QQ47] In certain embodiments, for a compound or salt of Formula (I), R⁶ is hydrogen.

[0048] in certain embodiments, for a compound or salt of Formula (I), Y is N.

[0049] In certain embodiments, for a compound or salt of Formula (I), R’ and R⁴ are each hydroxyl. |00S0] In certain embodiments, for a compound or salt of Formula (I), Rf is selected from C1-C3 alkyl aminocarbonyl or diCCi-Cu alkyl) aminocarbonyi. In certain embodiments, R⁵

is represented by:

10051 \ In certain embodiments, for a compound or salt of Formula (I), X is NHR.¹. In certain embodiments, R^l is selected from Ci-Ce. alkyl. In certain embodiments, R¹ is selected from -Cl -h, -CH2CH3, and -CH2CH2CH3.

|00S2] In certain embodiments, for a compound or salt of Formula (I), R² is Ce.-Cic· aryl, wherein the aryl group is optionally substituted with one or more substituents selected from halo, trifluorom ethyl, hydroxyalky!, alkoxy, and any combination thereof.

In certain embodiments, for a compound or salt of Formula (T), R² is heteroaryl, and the heteroaryl group is optionally substituted with one or more substituents selected from halo, hydroxy, and alkyl. In certain embodiments, for a compound or salt of Formula (I), R^* is heteroaryl selected from furanyl, thiopbeneyl, pyrrolyl, pyrazolyl, imidazolyl, oxazolyl, pyrimidinyl, pyrazinyl, pyridazinyl, and benzofuranyl, and the heteroaryl group is optionally substituted with one or more substituents selected from halo, hydroxy, and alkyl. In certain embodiments, for a compound or salt of Formula (I), R^“ is furanyl optionally substituted with one or more substituents selected from halo, hydroxy, and alkyl.

[QQ54] In certain embodiments, the compound of Formula (I) is selected from:

, pharmaceutically acceptable salt of any one thereof.

[0055] In certain embodiments, for a compound or salt of Formula (I), Y is CH.

[00S6| In certain embodiments, the compound of Formula (I) is selected from:

pharmaceutically acceptable salt thereof. |0057] In certain embodiments, the compound of Formula (I) is:

pbarmaceutically acceptable salt thereof.

In certain embodiments, the compound of Formula (I) is:

pharmaceutically acceptable salt thereof.

In certain embodiments, the compound of Formula (I) is:

pharmaceutically acceptable salt thereof.

|0060J In certain embodiments, the compound of Formula (I) is:

pharmaceutical ly acceptable salt thereof.

[QQ61] In certain embodiments, the compound of Formula (I) is

, . In certain embodiments, the compounds of the disclosure are represented by

Formula (II):

wherein X is selected from NHR¹⁰¹, CH₃, and CH=C(R^a)(R^b) wherein R^a and R^b are independently selected from hydrogen, hydroxyl, Ci-C₆ alkyl, and C₆-Ci₄ aryl,

Y is N or CH,

R¹⁰¹ is selected from Ci-C₆ alkyl, Ci-C₆ alkoxy, hydroxyl, C3-C8 cycloalkyl, C₆-Ci4 aryl C3-C8 cycloalkyl, C3-C8 cycloalkyl Ci-C₆ alkyl, C3-C8 dicycloalkyl Ci-C₆ alkyl, C7-C12 bicycloalkyl, C₇-C₁₂ bicycloalkyl Ci-C₆ alkyl, C₇-C₁₄ tricycloalkyl Ci-C₆ alkyl, C₆-Ci₄ aryl, C₆- C14 aryl Ci-C₆ alkyl, C₆-Ci4 diaryl Ci-C₆ alkyl, C₆-Ci4 aryl Ci-C₆ alkoxy, heterocyclyl Ci-C₆ alkyl, heterocyclyl, 4-[[[4-[[[(2-amino Ci-C₆ alkyl) amino]-carbonyl]- Ci-C₆ alkyl] anilino] carbonyl] Ci-C₆ alkyl] C₆-Ci₄ aryl, and C₆-Ci4 aryl C₃-C₈ cycloalkyl, wherein the aryl or heterocyclyl portion of R¹ is optionally substituted with one or more substituents selected from halo, amino, hydroxyl, carboxy, alkoxycarbonyl, aminocarbonyl, alkylaminocarbonyl, dialkylaminocarbonyl, Ci-C₆ alkyl, C2-C6 alkenyl, C2-C6 alkynyl, Ci-C₆ alkoxy, C₆-Ci4 aryloxy, hydroxy Ci-C₆ alkyl, hydroxy C₂-C₆ alkenyl, hydroxy C₂-C₆ alkynyl, carboxy Ci-C₆ alkyl, carboxy C₂-C₆ alkenyl, carboxy C₂-C₆ alkynyl, aminocarbonyl Ci-C₆ alkyl, aminocarbonyl C₂-C₆ alkenyl, aminocarbonyl C₂-C₆ alkynyl, and any combination thereof; and the alkyl or cycloalkyl portion of R¹⁰¹ is optionally substituted with one or more substituents selected from halo, amino, alkyl, alkoxy, aryloxy, hydroxyalkyl, hydroxyalkenyl, hydroxyalkynyl, aminocarbonylalkoxy, and arylalkoxy, and any combination thereof,

Z is halo, azido, or a group of the formula: ^N N wherein R¹⁰² is selected from

C₆-C₁₂ aryl, C₆-Ci₂ aryl-Ci-C₆ alkyl, C₃-C₈ cycloalkyl, heteroaryl, and metallocenyl, wherein the aryl group is optionally substituted with one or more substituents selected from trifluoromethyl, hydroxyalkyl, alkoxy, sulfonyloxy, carboxyalkyl, sulfonyloxyalkyl, arylcarbonyl, and any combination thereof, wherein the heteroaryl group is optionally substituted with one or more substituents selected from halo, trifluoromethyl, amino, alkyl, hydroxyalkyl, aryl, alkoxy, hydroxyl, carboxyl, sulfonyloxy, carboxyalkyl, sulfonyloxyalkyl, alkylcarbonyl, arylcarbonyl, and any combination thereof;

R¹⁰³ and R¹⁰⁴ are independently selected from hydrogen, hydroxyl, amino, mercapto, ureido, Ci-C₆ alkyl carbonylamino, hydroxy Ci-C₆ alkyl, and hydrazinyl;

R¹⁰⁵ is selected from hydrogen, C₁-C₃ alkyl aminocarbonyl, di(Ci-C₃ alkyl)

aminocarbonyl, C₁-C₃ alkylthio C₁-C₃ alkyl, halo C₁-C₃ alkyl, hydrazinyl, amino C₁-C₃ alkyl, hydroxy C₁-C₃ alkyl, C₃-C₆ cycloalkylamino, hydroxylamino, and C₂-C₃ alkenyl; and

R¹⁰⁶ is selected from hydrogen, Ci-C₆ alkyl, C₂-C₆ alkenyl, C₂-C₆ alkynyl, heteroaryl, and Ci-C₆ aminoalkyl;

or a pharmaceutically acceptable salt thereof.

[0064] In certain embodiments, a compound of formula (II) is racemic or one or more of the stereocenters has the opposite configuration relative to the structure as depicted.

[0Q65] In certain embodiments, for a compound or salt of Formula (II), when R¹" and R¹⁰⁴ are both hydroxyl, K¹'¹ is methylaminoearbonyl, R^i0i> is hydrogen, X is NHMe, and Y is CH, then Z is not iodo.

[QQ66] In certain embodiments, for a compound or salt of Formula (II), Rⁱ⁰° is hydrogen.

[QQ67] In certain embodiments, for a compound or salt of Formula (II), Ύ is N.

[0068] In certain embodiments, for a compound or salt of Formula (II), R^:°⁵ is selected from C₁-C₃ alkyl aminocarbonyl or di(Ci-C₃ alkyl) aminocarbonyl.

[0069] In certain embodiments, for a compound or salt of Formula (II), R ^: and R^:0’ are both hydroxyl.

[0070] In certain embodiments, for a compound or salt of Formula (II), X is NHR¹⁰f In certain embodiments, for a compound or salt of Formula (II), R^kU is Ci-Cs alkyl or tfo-Cs cycloalkyl.

In certain embodiments, for a compound or salt of Formula (II), Z is

[0072] In certain embodiments, for a compound or salt of Formula (II), R¹"² is Cs-C io aryl, wherein the aryl group is substituted with one or more substituents selected from

trifluorom ethyl, hydroxyalkyl, alkoxy, and any combination thereof.

[0073] In certain embodiments, for a compound or salt of Formula (II), R^!02 is heteroaryl, and the heteroaryl group is optionally substituted with one or more substituents selected from halo, hydroxy, and alkyl.

[0074] In certain embodiments, a compound of Formula (II) is selected from:

pharmaceutically acceptable salt thereof. |0075] In certain embodiments, for a compound or salt of Formula (H i. the compound is:

pharmaceutically acceptable salt thereof.

In certain embodiments a compound of Formula (II) is selected from:

pharmaceutically acceptable salt thereof, wherein:

R¹⁰² is C₆-Cio aryl, wherein the aryl group is substituted with one or more substituents selected from trifluoromethyl, hydroxyalkyl, alkoxy, and any combination thereof; or

R¹⁰² is heteroaryl, and the heteroaryl group is optionally substituted with one or more substituents selected from halo, hydroxy, and alkyl.

[0077] In certain embodiments, a compound of Formula (II) is selected from:

[0078] In certain embodiments, a compound of the methods described herein s selected from Tables 1 to 4.

[0079] Highly-selective (<10,000-fold) A3AR agonist are preferred and include, adeonosine methanocarba derivatives, such as the adenosine methanocarba derivatives described in Tosh et al. (2014; 2015a, 2015b, 2015c, and 2016) and also described in US Patent

9, 963, 450, B2, and US Patent Application 15/949,701, including those designated MRS5980, MRS7144, MRS7154, MRS7334, MRS7137, MRS7555, MRS7556, and MRS7557. The compounds and chemical genuses in US Patent No. 9,963,450, and US Patent Application No.15/949,701 are incorporated herein by reference.

[0080] Chemical entities having carbon-carbon double bonds or carbon -nitrogen double bonds may exist in Z- or E- form (or cis- or tram- form). Furthermore, some chemical entities may exist in various tautomeric forms. Unless otherwise specified, compounds described herein are intended to include all Z-, E- and tautomeric forms as well.

[0081] A "tautomer" refers to a molecule wherein a proton shift from one atom of a molecule to another atom of the same molecule is possible. The compounds presented herein, in certain embodiments, exist as tautomers. In circumstances where tautomerization is possible, a chemical equilibrium of the tautomers will exist. The exact ratio of the tautomers depends on several factors, including physical state, temperature, solvent, and pH. Some examples of tautomeric equilibrium include:

[0082] The compounds disclosed herein, in some embodiments, are used in different enriched isotopic forms, e.g., enriched in the content of ¾ Ή, ⁿC, ⁱ³C and/or ^l4C. In one particular embodiment, the compound is deuterated in at least one position. Such deuterated forms can be made by the procedure described in U.S. Patent Nos. 5,846,514 and 6,334,997. As described in U.S. Patent Nos. 5,846,514 and 6,334,997, deuteration can improve the metabolic stability and or efficacy, thus increasing the duration of action of drugs.

[0083] Unless otherwise stated, compounds described herein are intended to include compounds which differ only in the presence of one or more isotopically enriched atoms. For example, compounds having the present structures except for the replacement of a hydrogen by a deuterium or tritium, or the replacement of a carbon by ^tC~ or ^l4C~enriched carbon are within the scope of the present disclosure.

[0084] The compounds of the present disclosure optional iy contain unnatural proportions of atomic isotopes at one or more atoms that constitute such compounds. For example, the compounds may be labeled with isotopes, such as for example, deuterium (²H), tritium (¾), iodine-125 (¹²⁵I) or carbon-14 (¹⁴C). Isotopic substitution with ²H, ^UC, ¹³C, ¹⁴C, ¹⁵C, ¹²N, ¹³N, ¹⁵N, ¹⁶N, ¹⁶0, ¹⁷0, ¹⁴F, ¹⁵F, ¹⁶F, ¹⁷F, ¹⁸F, ³³S, ³⁴S, ³⁵S, ³⁶S, ³⁵C1, ³⁷C1, ⁷⁹Br, ⁸¹Br, and ¹²⁵I are all contemplated. All isotopic variations of the compounds of the present invention, whether radioactive or not, are encompassed within the scope of the present invention.

[0085] in certain embodiments, the compounds disclosed herein have some or all of the ¾ atoms replaced with ²H atoms. The methods of synthesis for deuterium-containing compounds are known in the art and include, by way of non-limiting example only, the following synthetic methods.

[0086] Deuterium substituted compounds are synthesized using various methods such as described in: Dean, Dennis C.; Editor. Recent Advances in the Synthesis and Applications of Radiolabeled Compounds for Drug Discovery and Development. [In: Cun:., Pharm. Des., 2000;

6(10)] 2000, 1 10 pp; George W., Varma, Rajender S. The Synthesis of Radiolabeled Compounds via Organometallic Intermediates, Tetrahedron, 1989, 45(21), 6601-21; and Evans, E. Anthony. Synthesis of radiolabeled compounds, i . Radioanal. Chem ., 1981, 64(1 -2), 9-32.

[0087] Deuterated starting materials are readily available and are subjected to the synthetic methods described herein to provide for the synthesis of deuterium -containing compounds. Large numbers of deuterium-containing reagents and building blocks are available commercially from chemical vendors, such as Aldrich Chemical Co.

[0088] Compounds of the present invention also include crystalline and amorphous forms of those compounds, pharmaceutically acceptable salts, and active metabolites of these compounds having the same type of activity, including, for example, polymorphs. pseudopolymorphs, solvates, hydrates, unsolvated polymorphs (including anhydrates), conformational polymorphs, and amorphous forms of the compounds, as well as mixtures thereof.

100891 Compounds of the present disclosure may be administered as prodrugs. As used herein, a“prodrug” refers to a pharmacologically less active derivative of a parent drug molecule that requires biotransformation, either spontaneous or enzymatic, within the organism to release the more active parent drug. Prodrugs are variations or derivatives of the parent drugs which have groups cieavable under metabolic conditions. Prodrugs become the parent drugs which are pharmaceutically active in vivo , when they undergo solvolysis under physiological conditions or u dergo enzymatic degradation. Prodrugs may be called single, double, triple, etc., depending on the number of biotransformation steps required to release the active parent drug within the organism, and indicating the number of functionalities present in a precursor-type form. Prodrugs commonly known in the art include acid derivatives well known to practitioners of the art, such as, for example, esters prepared by reaction of the parent acids with a suitable alcohol, or amides prepared by reaction of the parent acid compound with an amine, or basic groups reacted to form an acylated base derivative. See, Bundgard, Design of Prodrugs, pp. 7-9, 21-24, Elsevier, Amsterdam 1985; Silverman, The Organic Chemistry of Drug Design and Drug Action, pp. 352-401, Academic Press, San Diego, Calif, 1992; and Burger’s Medicinal

Chemistry and Drug Chemistry, Fifth Ed., Vol. 1, pp. 172-178, 949-982 (1995).

Pharmaceutical Formulation and Administration Thereof

[0090] The A₃AR agonist may be formulated according to any generally known pharmaceutical method (Remington & Gennaro, 2015) that is appropriate for the intended route of administration, including any generally known and appropriate vehicle, salt, hydrate, carrier or in any appropriate molecular precursor form (he., pro-drug). A particularly suitable formulation includes a formulation in which the A₃AR agonist is formulated in a manner intended to promote transfer across the blood-brain-barrier via any method known to one skilled in the art.

[0091] Suitable dosage includes about 0.1 mg to about 1.0 gram per day per patient (nominally weighing 60 kilograms) or equivalent amounts calculated on the basis of milligrams per kilogram of body weight, or on the basis of milligram per meter-squared of body surface area.

[0092] Suitable routes of administration include any standard drug administration method, including injections via the intravenous, intramuscular, subcutaneous, and Intrathecal routes; Inhalation (nasal or oral); per os; per rectum; and transcutaneous methods (patches, ointments, salves, etc). Drug may be administered via bolus one to four times a day, or via any slow release method that yields a plasma drug level above the therapeutic threshold.

[0093J With regard to traumatic brain injury, in certain embodiments, treatment may begin at any time post TBI provided that the physician determines that the patient’s condition is stable. In certain embodiments, the treatment is administered immediately after the injury occurs, such as within 12 hours of the injury_' or within a day or two of the injury or within a week of the injury. In certain embodiments, the treatment is administered to a subject at risk of developing traumatic brain injury, e.g., a high impact-sport athlete, to prevent the development or advancement of traumatic brain injury

[0094] With regard to chemotherapy -i duced cognitive impairment, according to one embodiment, the A_?,A agonist may be given according to a prophylactic protocol wherein the drug (i.e., A₃AR agonist) is given prior to the chemotherapeutic, simultaneously with the chemotherapeutic, and/or soon after the chemotherapeutic. When given prior to the

chemotherapeutic, the interval between A₃AR agonist and chemotherapeutic may vary' from one minute to 7 days. When given after the chemotherapeutic, the interval between L . LE agonist and chemotherapeutic may vary from one minute to 7 days, e g., within 12 hour of

chemotherapy, within 24 hours of chemotherapy. When the course of chemotherapy involves dosing on one day followed by one to 14 days before the next dose of chemotherapeutic, the A- AR agonist may he given only on those days when chemotherapeutic is also given, or the AsAR agonist may be given on one or more of the days when the chemotherapeutic is not given. According to another embodiment, A₃AR adm nistration may continue for up to six months after the last administration of the chemotherapeutic.

[0095] According to another embodiment, the AiAR agonist may be given according to a treatment protocol wherein the drug is given to a patient who already has chemotherapy- induced cognitive impairment (CIO). In this protocol, the A₃AR agonist may be given one-to- four times a day.

[0096] The disclosure will be more fully understood upon consideration of the fol lowing non-limiting Examples.

EXAMPLES

EXAMPLE 1

[0097] In this Example, the temporal expression and cellular distribution of ectonucleotidases, ADK and A_?AR in the prefrontal cortex (PFC) and hippocampus (HC) in response to cisplatin or doxorubicin treatment protocols that cause CIO was determined. Whether chemotherapy causes the dysregulation of ectonucleotidase and ADK activity and, in parallel, purine nucleoside concentrations (targeted metabolomic assays) was then determined. Using selective ADK inhibitors to restore adenosine levels in the presence and absence of adenosine receptor (AR) antagonists, the functional contribution of dysreguiated adenosine metabolism to AR signaling was examined. Using A₃AR knockout mice, the effects of deficient A₃AR signaling in CICI was determined. The pharmacology of molecu!arly diverse A₃AR agonists administered preventively and therapeutically was determined on the development of CICI in normal and tumor-hearing animal , using time course and dose responses in a variety of behavioral assays. The receptor specificity of the agonists was confirmed via an A_?AR antagonist and A₃AR knockout mice. Finally, the impact of A-_.?AR agonists was assessed on the development of structural correlates of cognitive impairment at the level of white and grey matter abnormalities and loss of neuronal precursors in dentate gyrus of the hippocampus and subventricular zone.

[0098] As depicted in FIG. L A¾AR were found throughout the CNS in neurons and glial cells and found in centers of cognitive function (PFC and H€). These data provide strong support for the robust efficacy of an A¾AR agonist in mitigating CICI.

[0099] The Puzzle Box consists of a start box and a goal box. The start box is brightly lit while the goal box is darkened by opaque walls and ceiling. The two boxes are connected by a tunnel beneath the wall that separates them. The brightly lit box is inherently aversive to mice, while the mice have a strong inherent preference for the darkened box. At start of each trial, the mouse was placed In the start box, its task was to discover the tunnel and enter the goal (dark) box. Mice underwent a total of 9 trials over 3 days. Day 1 : the tunnel was opened (Trial (T) 1 -4); day 2: the tunnel was covered by saw dust (T5-7); and day 3: the tunnel was plugged with saw dust (T 8-9). Time until entrance of the goal box was recorded with a maximum of 240 seconds. This sequence allowed assessment of short term memory (for the location of the tunnel) and problem-solving ability (uncovering and unplugging the tunnel). The time to complete these tasks in the puzzle box were increased in mice treated with cisplatin (red lines) relative to those treated with vehicle (the control group, blue lines) several days previously, indicating the development of impaired cognitive functioning following cisplatin chemotherapy. Mice underwent a total 9 trials over 3 days where the underpass was: open (Trial (T) 1-4), blocked by saw dust (T5-7) or plugged (T8-9). This sequence allowed assessment of shor term memory (T3,T6.T9), long term memory (T4, T7) and problem solving ability (T5. T8). The times to complete these tasks in the puzzle box were increased in mice treated with cisplatin (FIG. 2) or doxorubicin, indicating the development of impairment of their executive functioning. [0100] CIO was associated with reduced ectonueleotidases (CD39 and CD72) and increased ADK expression in the mouse brain following cisplatin (FIG. 3A-3C), suggestive of dysregulated adenosine signaling increased expression of A₃AR was observed in CNS in mice with CICI compared to those treated with vehicle (FIG. 3D).

[0101] Mice were treated with vehicle, cisplatin alone, or concomitantly with cisplatin and a highly-selective A₃AR agonist (MRS5980) and tested several days later in the Puzzle Box. As depicted in FIG. 4, MRS5980 attenuated cisplatin-induced deficits in executive cognitive function. Trial 8 shows acquisition of the solution to the plugged tunnel problem and Trial 9 shows the short-term memory' for that learning. Cisplatin produced a decrease in cognitive function and this was completely prevented by co-ad inistration of the A₃AR agonist.

[0102] The results of this Example link chemotherapy-induced changes in cognition and CNS functionalities to alterations in purine metabolism and signaling at the A₃AR while providing the first demonstration of the utility of selective A₃AR agonists for blocking and reversing chemotherapy-induced neuronal deficits and cognitive dysfunction.

EXAMPLE 2

[0103] In Example 2, pharmacological and genetic approaches were used to determine whether the beneficial effects of A AR agonists are exerted through protective effects on mitochondrial dysfunction (reduced respiration and adenosine triphosphate (ATP) production and increased production of reactive oxygen species and reactive nitrogen species (ROS/RNS)) and/or inflammasome-driven neuroinflammation through the endogenous signaling pathway- driven by the potent anti -mil ammatory/neuroproteetive cytokine, IL10. Inflammasorne formation was assayed as levels of Nod-like receptor protein 3 (NLRP3).

[0104] Peroxynitrite can nitrate mitochondrial manganese superoxide dismutase (MnSOD; a key enzyme that regulates the levels of superoxide and therefore of peroxynitrite) at Tyr-34 via a Mn-catalyzed process. PN-driven nitration Inactivates MnSOD by >80% and favors a“feed-forward” mechanism that sustains elevated levels of ROS/RNS in mitochondria. This process has been linked to mitochondria! dysfunction in several pathological conditions. As depicted in FIG. 5, decrease in spare respiratory capacity of mitochondria was linked to the presence of MnSOD nitration in the hippocampus following cisplatin treatment.

[0105] Chemotherapy treatment was sufficient to induce NLRP3 expression in the mouse brain (FIG. 6), suggesting the potential contribution of NLRP3 to the observed Increases in IL Ip.

[0106] As depicted in FIGS. 7A and 7B, an A₃AR agonit, IB-MECA, attenuated

ROS/RNS stress and mitochondrial dysfunction in the periphery in rats treated with oxaliplatin. Mice were treated with oxalipiatin. On day 25, the saphenous nerves were harvested for western blot analysis with MnSOD in the nitrotyrosine immunoprecipitate (FIG. 7A). ATP production was determined in saphenous nerve mitochondria harvested from paditaxei- and oxalipiatin- treated rats on day 25.

[0107] These results provide the first data linking chemotherapy to the dysregulation of adenosine metabolism and deficient A₃AR signaling in the development of CIO and the first to identify A_?AR agonists as a novel approach for the treatment of CIO. Use of A AR agonists will provide a distinct advantage/opportimity in this therapeutic area because A₃AR agonists are not expected to interfere with antitumor effects and may actually enhance their antitumor effects while minimizing this major chemotherapy-induced neurotoxicity.

[0108] Data suggested that alterations in adenosine signaling contributes to the development of CIO, and that supplementing adenosine signaling with selective A₃AR agonists blocks the development of CIO. Results were obtained using a cispiatin treatment protocol that was previously shown to cause CIO.

EXAMPLE 3

10109] In this Example, activation of inflammasome NLRP3 (FIG. 8A) and caspase-1 (FIG. 8B) at 24 hours post-TBI and assessment of cognitive function using the Novel Object Recognition test (FIG. 8C) and the T-maze learning test (FIG. 80) 4 weeks after TBI.

[0110] TBI was created in mice with the closed-head concussive method.

Inflammasome NI.RP3 activation was assessed via Western blots (FIG. 8A) and caspase-1 (FIG. SB) at 24 hr post-TBI. Cognitive function was assessed with the Novel Object Recognition test (FIG. 8C) and the T-maze learning test (FIG. 8D) 4 weeks after TBI MRS598G, a highly- selective A₃AR agonist given at 1 mg/kg IP, blocked inflammasome activation and caspase-1 levels, and blocked TBI-induced impaired cognitive function. GAPDH was used as a control as a housekeeping gene whose levels do not change in response to FBI and to normalize the amount of protein extract loaded onto each lane.

[0111] The results presented herein demonstrate that TBI is associated with the long term (days-months) dysregulation of endogenous adenosine signaling in the brain including increased expression of adenosine kinase, which wi ll reduce extracellular adenosine levels and reduce adenosine signaling at the four known types of adenosine G-protein coupled receptor subtypes (designated A AR, AJAAR, A₂BAR ami A₃AR) In the brain. The dysregulation of endogenous adenosine signaling is associated with activation of the NLRP3 inflammasome and caspase-1 , and increased formation of pro-inflam atory cytokines like interleukin 1 -beta (II.,- I p). Administering a selective A₃AR agonist 1 hour to 3 hours post-TBI attenuates the increases In adenosine kinase and IL-Ib, reduces inflammasome activation, protects the brain against infarction and disrupted tissue architecture, and prevents TBI-indueed cognitive impairment. Treatment with a selective A₃AR agonist is also effective when given 4 weeks after TBL These data demonstrate that treatment with a selective A₃AR agonist is an effective treatment for TBi and post-TBI neurological sequelae, including cognitive impairment.

Claims

CLAIMS What is claimed is:

1. A method for treating or preventing symptoms associated with traumatic brain injury in a subject in need thereof, comprising administering a selective adenosine A₃ human receptor subtype agonist to the subject.

2. The method of claim 1, wherein the method comprises treating one or more symptoms associated with traumatic brain injury.

3. The method of claim 2, wherein the symptom is cognitive impairment.

4. The method of claim 3, wherein the cognitive impairment comprises memory loss, disrupted insight, judgement, and thought, reduced processing speed, distractibility and/or deficits in executive functions such as abstract reasoning, planning, problem-solving, and multi- tasking.

5. The method of any one of claims 1 to 4, wherein the selective adenosine A₃ human receptor subtype agonist is administered within 48 hours of a traumatic brain injury.

6. The method of claim 5, wherein the selective adenosine A₃ human receptor subtype agonist is administered within 24 hours of a traumatic brain injury.

7. The method of any one of claims 1 to 4, wherein the selective adenosine A₃ human receptor subtype agonist is first administered 1 or more years following a traumatic brain injury.

8. The method of claim 7, wherein the selective adenosine A₃ human receptor subtype agonist is first administered 3 or more years following a traumatic brain injury.

9. The method of any of claims 1 to 8, wherein the selective adenosine A₃ human receptor subtype agonist is administered in multiple doses.

10. The method of any one of claims 1 to 9, comprising administering the selective adenosine A₃ human receptor subtype agonist in a dosage of from about 0.1 mg to about 1.0 gram per day per patient (nominally weighting 60 kilograms) or equivalent amounts calculated on the basis of milligrams per kilogram of body weight, or on the basis of milligram per meter-squared of body surface area.

11. A method for treating or preventing chemotherapy-induced cognitive impairment, comprising administering a selective adenosine A₃ human receptor subtype agonist to a patient undergoing or about to undergo cancer chemotherapy treatment.

12. The method of claim 11, comprising administering the selective adenosine A₃ human receptor subtype agonist prior to the cancer chemotherapy treatment.

13. The method of claim 12, comprising administering the selective adenosine A₃ human receptor subtype agonist from about one minute to about 7 days prior to the cancer chemotherapy treatment.

14. The method of any one of claims 11 to 13, comprising administering the selective adenosine A₃ human receptor subtype agonist simultaneously with the cancer chemotherapy treatment.

15. The method of claim 14, comprising administering the selective adenosine A₃ human receptor subtype agonist only on days when the cancer chemotherapy treatment is administered.

16. The method of claim 14, comprising administering the selective adenosine A3 human receptor subtype agonist on days when the cancer chemotherapy treatment is administered and on one or more of those days intervening between successive doses of the chemotherapeutic.

17. The method of any one of claims 11 to 16, comprising administering the selective adenosine A₃ human receptor subtype agonist after the cancer chemotherapy treatment.

18. The method of claim 17, comprising administering the selective adenosine A₃ human receptor subtype agonist from about one minute to about 7 days after the cancer chemotherapy treatment.

19. The method of claim 18, comprising administering the selected adenosine A₃ human receptor subtype agonist for up to six months after the last administration of the cancer chemotherapy treatment.

20. The method of any one of claims 11 to 19, wherein the cancer chemotherapy treatment is selected from the group consisting of taxane agents, platinum-complex agents, vinca alkaloids, proteasome inhibitors, 5-fluorouracil, methotrexate, doxorubicin, and combinations thereof.

21. The method of any one of claims 1 to 20, wherein the selective adenosine A₃ human receptor subtype agonist is selected from the group consisting of N⁶-benzyladenosine-5'-N- methyluronamides, (N)-methanocarba adenosine derivatives, 2-Dialkynyl derivatives of (N)- methanocarba nucleosides, 2-(arylethynyl)adenine, N(6)-methyl, N(6)-(3-substituted-benzyl), N(6)-methyl 2-(halophenylethynyl) analogues, and polyaromatic 2-ethynyl N(6)-3-chlorobenzyl analogues.

22. The method of any one of claims 1 to 20, wherein the selective adenosine A₃ human receptor subtype agonist is selected from the group consisting of N -(3-iodobenzyl)- adenosine-5'-N-methyluronamide; 2-Chloro-N -(3-iodobenzyl)-adenosine-5'-N- methyluronamide; (1R, 2R, 3 S,4R)-4-(2-chloro-6-((3-chlorobenzyl)amino)-9H-purin-9-yl)-2, 3-di- hydroxy -N-methylbicyclo[3. l.0]hexane-l -carboxamide; (2S,3S,4R,5R)-3-amino-5-[6-(2,5- dichlorobenzylamino)purin-9-yl]-4-hydroxy-tetrahydrofuran-2-carboxylicacid methylamide; (rS,2'R,3'S,4'R,5'S)-4-(2-chloro-6-(3-chlorobenzylamino)-9H-purin-9-yl)-2,3-dihydroxy-N- methylbicyclo[3.l.0]hexane-l -carboxamide; (TR,2'R,3'S,4'R,5'S)-4-{2-chloro-6-[(3- iodophenylmethyl)amino]purin-9-yl-}-l-(methylaminocarbonyl)-bicyclo[3.1 0]hexane-2,3-diol; 2-p-biphenylethynyl (MRS5679); fluorescent l-pyrene adduct (MRS5704); and MRS5678.

23. The method of any one of claims 1 to 20, wherein the selective adenosine A₃ human receptor subtype agonist is selected from the group consisting of MRS5980, MRS7144, MRS7154, MRS7334, MRS7137, MRS7555, MRS7556, and MRS7557.

24. The method of any one of claims 1 to 20, wherein the selective adenosine A₃ human receptor subtype agonist is a compound of formula (I):

wherein X is selected from NHR¹, CH₃, and CH=C(R^a)(R^b) wherein R^a and R^b are independently selected from hydrogen, hydroxyl, Ci-C₆ alkyl, and C₆-Ci₄ aryl,

Y is N or CH, R¹ is selected from Ci-C₆ alkyl, Ci-C₆ alkoxy, hydroxyl, C₃-C₈ cycloalkyl, C₆-Ci₄ aryl C₃-C₈ cycloalkyl, C₃-C₈ cycloalkyl Ci-C₆ alkyl, C₃-C₈ di cycloalkyl Ci-C₆ alkyl, C₇- Ci₂ bicycloalkyl, C₇-Ci₂ bicycloalkyl Ci-C₆ alkyl, C₇-C₁₄ tricycloalkyl Ci-C₆ alkyl, C₆-Ci₄ aryl, C₆-Ci4 aryl Ci-C₆ alkyl, C₆-Ci4 diaryl Ci-C₆ alkyl, C₆-Ci4 aryl Ci-C₆ alkoxy, heterocyclyl Ci-C₆ alkyl, heterocyclyl, 4-[[[4-[[[(2-amino Ci-C₆ alkyl) amino]-carbonyl]- Ci-C₆ alkyl] anilino] carbonyl] Ci-C₆ alkyl] C₆-Ci₄ aryl, and C₆-Ci₄ aryl C₃-C₈ cycloalkyl, wherein the aryl or heterocyclyl portion of R¹ is optionally substituted with one or more substituents selected from halo, amino, hydroxyl, carboxy, alkoxycarbonyl, aminocarbonyl, alkylaminocarbonyl, dialkylaminocarbonyl, Ci-C₆ alkyl, C₂-C₆ alkenyl, C₂-C₆ alkynyl, Ci-C₆ alkoxy, C₆-Ci4 aryloxy, hydroxy Ci-C₆ alkyl, hydroxy C₂-C₆ alkenyl, hydroxy C₂-C₆ alkynyl, carboxy Ci-C₆ alkyl, carboxy C₂-C₆ alkenyl, carboxy C₂-C₆ alkynyl, aminocarbonyl Ci-C₆ alkyl, aminocarbonyl C₂-C₆ alkenyl, aminocarbonyl C₂-C₆ alkynyl, and any combination thereof; and the alkyl or cycloalkyl portion of R¹ is optionally substituted with one or more substituents selected from halo, hydroxy, amino, alkyl, alkoxy, aryloxy, hydroxyalkyl, hydroxyalkenyl, hydroxyalkynyl, aminocarbonylalkoxy, and arylalkoxy, and any combination thereof,

R² is selected from C₆-Ci₂ aryl, C₃-C₈ cycloalkyl, heteroaryl, and metallocenyl, wherein the aryl group is optionally substituted with one or more substituents selected from halo, trifluoromethyl, hydroxyalkyl, alkoxy, sulfonyloxy, carboxyalkyl, sulfonyloxyalkyl, arylcarbonyl, and any combination thereof, wherein the heteroaryl group is optionally substituted with one or more substituents selected from halo, trifluoromethyl, amino, alkyl, hydroxyalkyl, aryl, benzo, alkoxy, hydroxyl, carboxyl, sulfonyloxy, carboxyalkyl, sulfonyloxyalkyl, alkylcarbonyl, arylcarbonyl, and any combination thereof,

R³ and R⁴ are independently selected from hydrogen, hydroxyl, amino, mercapto, ureido, Ci-C₆ alkyl carbonylamino, hydroxy Ci-C₆ alkyl, and hydrazinyl;

R⁵ is selected from hydrogen, C₁-C₃ alkyl aminocarbonyl, di(Ci-C₃ alkyl) aminocarbonyl, C₁-C₃ alkylthio C₁-C₃ alkyl, halo C₁-C₃ alkyl, hydrazinyl, amino C₁-C₃ alkyl, hydroxy C₁-C₃ alkyl, C₃-C₆ cycloalkylamino, hydroxylamino, and C₂-C₃ alkenyl; and

R⁶ is selected from hydrogen, Ci-C₆ alkyl, C₂-C₆ alkenyl, C₂-C₆ alkynyl, heteroaryl, and Ci-C₆ aminoalkyl; or a pharmaceutically acceptable salt thereof.

25. The method of claim 24, when R¹ is methyl, R³ and R⁴ are both hydroxyl, R⁶ is hydrogen, and R⁵ is methylaminocarbonyl, R² is not 2-pyridyl or phenyl.

26. The method of claim 24 or 25, wherein R⁶ is hydrogen.

27. The method of any one of claims 24 to 26, wherein Y is N.

28. The method of any one of claims 24 to 27, wherein R³ and R⁴ are both hydroxyl.

29. The method of any one of claims 24 to 28, wherein R⁵ is selected from C1-C3 alkyl aminocarbonyl or di(Ci-C₃ alkyl) aminocarbonyl.

30. The method of any one of claims 24 to 29, wherein X is NHR¹.

31. The method of claim 30, wherein R¹ is Ci-C₆ alkyl.

32. The method of any one of claims 24 to 31, wherein R² is C₆-Cio aryl, wherein the aryl group is optionally substituted with one or more substituents selected from halo, trifluoromethyl, hydroxyalkyl, alkoxy, and any combination thereof.

33. The method of any one of claims 24 to 28, wherein R² is heteroaryl, and the heteroaryl group is optionally substituted with one or more substituents selected from halo, hydroxy, and alkyl.

34. The method of claim 24, wherein the compound is selected from:

a pharmaceutically acceptable salt of any one thereof.

35. The method of claim 24, wherein the compound is selected from:

or a pharmaceutically acceptable salt of any one thereof.

36. The method of claim 24, wherein the compound is:

pharmaceutically acceptable salt of any one thereof.

37. The method of claim 24, wherein the compound is selected from:

pharmaceutically acceptable salt of any one thereof.

38. The method of claim 24, wherein the compound is:

pharmaceutically acceptable salt thereof.

39. The method of claim 24, wherein the compound is:

pharmaceutically acceptable salt thereof.

40. The method of claim 24, wherein the compound is:

pharmaceutically acceptable salt thereof.

41. The method of claim 24, wherein the compound is:

pharmaceutically acceptable salt thereof.

42. The method of claim 30, wherein R¹ is C₆-Ci₄ aryl C₃-C₈ cycloalkyl, wherein the aryl is optionally substituted with Ci-C₆ alkyl, methyl, F, Cl, and Br.

43. The method of claim 42, wherein the compound is selected from

, or a pharmaceutically acceptable salt thereof.

44. The method of any one of claims 24 to 29, wherein X is CFh.

45. The method of claim 44, wherein the compound is:

pharmaceutically acceptable salt thereof.

46. The method of any one of claims 24 to 29, wherein X is CH^: C(R^a)(R^b).

47. The method of claim 46, wherein the compound is:

pharmaceutically acceptable salt thereof.

48. The method of any one of claims 24 to 26, wherein Y is CH.

49. The method of any one of claims 24 to 33, wherein R³ and R⁴ are each hydroxyl.

50. The method of any one of claims 24 to 33, wherein R⁵ is selected from C₁-C₃ alkyl aminocarbonyl and di(Ci-C₃ alkyl) aminocarbonyl.

51. The method of any one of claims 1 to 20, wherein the selective adenosine A3 human receptor subtype agonist is a compound of the formula (II):

wherein X is selected from NHR¹⁰¹, CH₃, and CH=C(R^a)(R^b) wherein R^a and R^b are independently selected from hydrogen, hydroxyl, Ci-C₆ alkyl, and C₆-Ci₄ aryl,

Y is N or CH,

R¹⁰¹ is selected from Ci-C₆ alkyl, Ci-C₆ alkoxy, hydroxyl, C₃-C₈ cycloalkyl, C₆-Ci₄ aryl C3-C8 cycloalkyl, C3-C8 cycloalkyl Ci-C₆ alkyl, C3-C8 dicycloalkyl Ci-C₆ alkyl, C7-C12 bicycloalkyl, C₇-C₁₂ bicycloalkyl Ci-C₆ alkyl, C₇-Ci₄ tricycloalkyl Ci-C₆ alkyl, C₆-Ci₄ aryl, C₆- Ci₄ aryl Ci-C₆ alkyl, C₆-Ci₄ diaryl Ci-C₆ alkyl, C₆-Ci₄ aryl Ci-C₆ alkoxy, heterocyclyl Ci-C₆ alkyl, heterocyclyl, 4-[[[4-[[[(2-amino Ci-C₆ alkyl) ami no] -carbonyl]- Ci-C₆ alkyl] anilino] carbonyl] Ci-C₆ alkyl] C₆-Ci₄ aryl, and C₆-Ci₄ aryl C₃-C₈ cycloalkyl, wherein the aryl or heterocyclyl portion of R¹ is optionally substituted with one or more substituents selected from halo, amino, hydroxyl, carboxy, alkoxycarbonyl, aminocarbonyl, alkylaminocarbonyl, dialkylaminocarbonyl, Ci-C₆ alkyl, C₂-C₆ alkenyl, C₂-C₆ alkynyl, Ci-C₆ alkoxy, C₆-Ci₄ aryloxy, hydroxy Ci-C₆ alkyl, hydroxy C₂-C₆ alkenyl, hydroxy C₂-C₆ alkynyl, carboxy Ci-C₆ alkyl, carboxy C₂-C₆ alkenyl, carboxy C₂- C₆ alkynyl, aminocarbonyl Ci-C₆ alkyl, aminocarbonyl C₂-C₆ alkenyl, aminocarbonyl C₂-C₆ alkynyl, and any combination thereof; and the alkyl or cycloalkyl portion of R¹⁰¹ is optionally substituted with one or more substituents selected from halo, amino, alkyl, alkoxy, aryloxy, hydroxyalkyl, hydroxyalkenyl, hydroxyalkynyl, aminocarbonylalkoxy, and arylalkoxy, and any combination thereof,

Z is halo, azido, or a group of the formula: ^N=N wherein R¹⁰² is selected from

C₆-Ci₂ aryl, C₆-Ci₂ aryl-Ci-C₆ alkyl, C₃-C₈ cycloalkyl, heteroaryl, and metallocenyl, wherein the aryl group is optionally substituted with one or more substituents selected from trifluoromethyl, hydroxyalkyl, alkoxy, sulfonyloxy, carboxyalkyl, sulfonyloxyalkyl, arylcarbonyl, and any combination thereof, wherein the heteroaryl group is optionally substituted with one or more substituents selected from halo, trifluoromethyl, amino, alkyl, hydroxyalkyl, aryl, alkoxy, hydroxyl, carboxyl, sulfonyloxy, carboxyalkyl, sulfonyloxyalkyl, alkylcarbonyl, arylcarbonyl, and any combination thereof,

R¹⁰³ and R¹⁰⁴ are independently selected from hydrogen, hydroxyl, amino, mercapto, ureido, Ci-C₆ alkyl carbonylamino, hydroxy Ci-C₆ alkyl, and hydrazinyl;

R¹⁰⁵ is selected from hydrogen, C₁-C₃ alkyl aminocarbonyl, di(Ci-C₃ alkyl) aminocarbonyl, Ci-C₃ alkylthio Ci-C₃ alkyl, halo Ci-C₃ alkyl, hydrazinyl, amino Ci-C₃ alkyl, hydroxy Ci-C₃ alkyl, C₃-C₆ cycloalkylamino, hydroxylamino, and C₂-C₃ alkenyl; and

R¹⁰⁶ is selected from hydrogen, Ci-C₆ alkyl, C₂-C₆ alkenyl, C₂-C₆ alkynyl, heteroaryl, and Ci-C₆ aminoalkyl;

or a pharmaceutically acceptable salt thereof.