EA046455B1 - SELECTIVE H3-HISTAMINE RECEPTOR ANTAGONISTS FOR THE TREATMENT OF AUTISM SPECTRUM DISORDER - Google Patents

Description

Technical field

The present invention relates to a selective H3histamine receptor antagonist/inverse agonist, 1-[4-(4-{3-[(2R)-2-methylpyrrolidin-1 -yl]propoxy}phenoxy)piperidin-1 yl]ethan-1-one , its pharmaceutically acceptable salts, derivatives, pharmaceutical compositions, active metabolites and combinations for use in the treatment of symptoms of autism spectrum disorder (PAC (ASD, from autism spectrum disorder)).

Prior Art

Patent Application WO 2014/136075A1 discloses phenoxypiperazine derivatives, their method of preparation and therapeutic applications for the treatment of conditions requiring modulation of histamine H3 receptors. According to patent document WO 2014/136075A1, 1-[4-(4-{3-[(2R)-2methylpyrrolidin-1-yl]propoxy}phenoxy)piperidin-1-yl]ethan-1-one corresponding to formula 1

Formula 1 is a high affinity and highly selective ligand of the histamine H3 receptor. This compound can be obtained by evaporation of the dichloromethane solution of the final product synthesized in Example 11 of patent document WO 2014/136075, or by releasing the base after isolation as a hydrochloride salt - which is obviously known to those skilled in the art.

In vitro, the compound functionally behaves as a receptor antagonist/inverse agonist and also exhibits antagonism of histamine III receptors in vivo in rats.

PAC is a complex, demanding, and widespread disorder of the nervous system, affecting approximately 1% of children and adults (Brugha et al., Arch. Gen. Psychiatry. 2011, 68:459-465; Murphy et al., Neuropsychiatr. Dis Treat 2016, 12:1669-1686). The disease is characterized by two main symptoms:

1) socio-communicative dysfunctions (chronic deficits in social communication and social interaction in various contexts), as well as

2) limited (repetitive, stereotypical) behavior and thinking (limited, repetitive patterns of behavior, interests and activities) (Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition, pp. 50-59 (Diagnostic and Statistical Manual of Mental Disorders, 5 1st edition, pp. 50-59).

Social impairments include an abnormal social approach, failure to engage in normal two-way communication, and an inability to initiate and maintain interpersonal interactions. Communication deficits may include poorly integrated verbal and nonverbal communication, impaired eye contact and use of nonverbal language, impaired understanding of gestures, and lack of facial expressions. In general, there may be deficits in developing, maintaining and understanding relationships, problems adapting to interaction situations with others, problems participating in creative play together, and a lack of interest in peers. In another area of core symptoms, stereotyped or repetitive movements, an insistent need for uniformity and following established routines, strongly fixed interests that are abnormal in intensity or direction, and abnormal sensory reactivity can be identified.

In addition to the main symptoms, PAC is often also accompanied by concomitant or comorbid symptoms, including mental retardation, attention deficit disorder, hyperactivity disorder, mood disorder, seizures, sleep problems, etc. (Lai et al., Lancet 2013, 383(9920):896-910). Another common area of associated symptoms is irritability, including outbursts of anger or irritation, aggression towards others, self-injurious behavior and mood swings. In addition, PAC is associated with significant impairments in adaptive behavior. Symptoms of PAC begin in early childhood and significantly impair daily, social, occupational, and other important areas of functioning.

Histamine H3 receptor antagonists have been widely researched to develop drugs for the treatment of various diseases such as Alzheimer's disease, obesity, schizophrenia, myocardial ischemia, migraine, nasal congestion, etc. (Leurs et al., Nat. Rev. Drug Disc. 2005, 4:107-120; Berlin et al., J. Med. Chem. 2011, 54:26-53). A number of compounds have demonstrated promising preclinical results and have entered the clinical phase for indications such as excessive daytime sleepiness associated with Parkinson's disease, EDS secondary to obstructive sleep apnea, and epilepsy. , schizophrenia, dementia and attention deficit hyperactivity disorder (Kuhne et al., Exp. Opin. Invest. Drugs 2011, 20:1629-1648). Histamine H3 receptor antagonists/inverse agonists have been reviewed in

- 1 046455 as potential pharmacotherapeutic agents for the treatment of sleep disorders (Barbier and Bradbury, CNS Neurol. Disord. Drug Targets 2007, 6:31-43). However, to date only one H3 antagonist, the first of the new class of pitolisant (under the brand name Wakix), has received marketing authorization from the European Medicines Agency for the treatment of narcolepsy with or without cataplexy in adults. (Kollb-Sielecka et al. Sleep Med. 2017, 33:125-129). Notably, there is no drug in clinical development or on the market with a selective H3-histamine receptor antagonistic mechanism of action for the treatment of symptoms of PAC.

Baronio and co-workers reported that the H3-histamine receptor antagonist ciproxifan, administered intraperitoneally at a dose of 3 mg/kg, improved social deficits and excessive repetitive behavior in a mouse model of PAC induced by prenatal valproate exposure (Baronio et al., PLOS One 2015, 10:1). In the same model, ciproxifan did not affect preference for social novelty, a cognitive function impaired in mice prenatally exposed to VPA. Ciproxifan is a non-selective H3-histamine receptor antagonist. In addition to histamine H3 receptor antagonism, ciproxifan also inhibits human and rat monoamine oxidase A and B in the micromolar concentration range, with a slight preference for monoamine oxidase B (Hagenow et al., Sci. Rep. 2017 7:40541). Ciproxifan administered intraperitoneally at a dose of 3 mg/kg produces plasma concentrations in the micromolar range (Ligneau et al., J. Pharm. Exp. Ther. 1998, 287:658-666). Thus, the effects on behavior reported by Baronio et al. (2015), is due to either inhibition of monoamine oxidase or a combination of monoamine oxidase and histamine H3 receptor antagonism.

Prenatal exposure of rodents to valproate (valproic acid, VPA) is an established preclinical model of autism spectrum disorder. Prenatal exposure to valproate is known to increase the risk of developing PAC in humans (Christensen et al, JAMA 2013, 309), and the presence of VPA during fetal life in rodents is known to result in an autistic-like phenotype in the offspring (Roullet et al, Neurotox. Teratol. 2013, 36, 45-56). Typically, VPA is administered to rodents around embryonic day 12, when the neural tube closes and the cranial nerve nuclei and cerebellum form. The inhibitory effect of VPA on histone deacetylase interferes with the above developmental stages and, as a consequence, causes the appearance of an autism-like phenotype in the offspring (Kataoka et al., Int. J. Neuropsychopharm. 2011 16:91-103). The autistic-like phenotype includes, among other things, impaired communication in infant rats, impaired social play behavior in young rats, and impaired sociability in the 3-chamber analysis in adult rats. Because the physiological origin and symptoms of the prenatal VPA exposure model are highly consistent with the human condition, it is an established rodent model of PAC with high translational value.

The unmet medical need for PAC is high because there is currently no available pharmacological treatment for the core symptoms of PAC. Given the lack of a clinically approved drug for the treatment of core symptoms (social-communication dysfunction and restricted and repetitive behavior), only two of the many available drugs in this class of antipsychotics - risperidone and aripiprazole - have been approved by the FDA. Food and Drug Administration (FDA) for the treatment of irritability associated with PAC in children aged 5 to 16 years (risperidone) or 6 to 17 years (aripiprazole). The use of aripiprazole for this purpose has also been approved in Japan. Although significant efforts have been invested in clinical research, no effective pharmacological treatment has yet been found to relieve the core symptoms of PAC.

Brief description of the invention

The present invention relates to a compound of formula 1, its pharmacologically acceptable salts, derivatives, pharmaceutical compositions, metabolites and combinations for use in the treatment of symptoms of autism spectrum disorder.

Brief description of graphic materials

Fig. 1. Repeated (once a day for 8 days) oral administration of 1-[4-(4-{3[(2R)-2-methylpyrrolidin-1 -yl]propoxy}phenoxy)piperidin-1 -yl]ethane dicitrate 1 -ona (CMPD) reversed social play deficits induced by prenatal valproate exposure by postnatal day 30.

Fig. 2. Repeated (once a day for 8 days) oral administration of 1-[4-(4-{3[(2R)-2-methylpyrrolidin-1 -yl]propoxy}phenoxy)piperidin-1 -yl]ethane dicitrate 1-she reversed the social preference deficits induced by prenatal valproate exposure by postnatal day 59.

Fig. 3. Repeated (once a day for 9 days) oral administration of 1-[4-(4-{3[(2R)-2-methylpyrrolidin-1 -yl]propoxy}phenoxy)piperidin-1 -yl]ethane dicitrate 1-she reversed social recognition deficits induced by prenatal valproate exposure at postnatal day 60

- 2046455 of the new period.

Detailed Description of the Invention

In order to evaluate the potential of the compound of formula 1, it was studied in a model of PAC caused by prenatal exposure to valproate. Surprisingly, the compound of formula 1 was found to have significant benefits in this animal model reproducing the symptoms of PAC. As described in the Examples, the compound is capable of reversing behavioral deficits in rats exposed to valproate during their fetal life. The results obtained indicate that the compound of Formula 1 and its derivatives may be used therapeutically for the treatment of symptoms of PAC in human patients.

Accordingly, the present invention relates to a compound of formula 1 and/or derivatives thereof and/or metabolites thereof and/or pharmaceutically acceptable salts thereof for use in the treatment of symptoms of PAC.

According to another preferred embodiment, the present invention is directed to a compound of formula 1 or pharmaceutically acceptable salts thereof for use in the treatment of symptoms of PAC.

According to another preferred embodiment, the present invention is directed to a compound of Formula 1 and/or derivatives thereof and/or metabolites thereof and/or pharmaceutically acceptable salts thereof for use in the treatment of sociocommunicative dysfunction as a core symptom of PAC.

According to another preferred embodiment, the present invention is directed to a compound of formula 1 and/or derivatives thereof and/or metabolites thereof and/or pharmaceutically acceptable salts thereof for use in the treatment of restricted and repetitive behavior as a core symptom of PAC.

According to another preferred embodiment, the present invention is directed to a compound of formula 1 and/or derivatives thereof and/or metabolites thereof and/or pharmaceutically acceptable salts thereof for use in the treatment of irritability associated with PAC.

The present invention also relates to a pharmaceutical composition containing a compound of formula 1 and/or derivatives thereof and/or metabolites thereof and/or pharmaceutically acceptable salts and pharmaceutically acceptable excipients thereof, for use in the treatment of symptoms of PAC.

The present invention also relates to a pharmaceutical composition containing a compound of formula 1 and/or derivatives thereof and/or metabolites thereof and/or pharmaceutically acceptable salts and pharmaceutically acceptable excipients thereof, for use in the treatment of the core symptoms of PAC.

According to another preferred embodiment, the invention relates to a pharmaceutical composition for use as defined above, wherein the main symptom of PAC is social-communication dysfunction.

According to another preferred embodiment, the invention relates to a pharmaceutical composition for use as defined above, where the main symptom of PAC is restricted and repetitive behavior.

According to another preferred embodiment, the invention relates to a pharmaceutical composition for use as defined above, wherein the condition to be treated is irritability associated with PAC.

The present invention also provides a method of treating PAC comprising administering to a subject in need thereof a therapeutically effective amount of a compound of formula 1 and/or derivatives thereof and/or metabolites thereof and/or pharmaceutically acceptable salts thereof.

The present invention also provides a method of treating the symptoms of PAC, comprising administering to a subject in need thereof a therapeutically effective amount of a compound of formula 1 and/or derivatives thereof and/or metabolites thereof and/or pharmaceutically acceptable salts thereof.

According to another preferred embodiment, the invention relates to a method of treating social-communicative dysfunction as a primary symptom of PAC, comprising administering to a subject in need thereof a therapeutically effective amount of a compound of formula 1 and/or derivatives thereof and/or metabolites thereof and/or pharmaceutically acceptable salts.

According to another preferred embodiment, the invention relates to a method of treating restricted and repetitive behavior as the main symptom of PAC, comprising administering to a subject in need thereof a therapeutically effective amount of a compound of formula 1 and/or derivatives thereof and/or metabolites thereof and/or pharmaceutically acceptable salts.

According to another preferred embodiment, the invention relates to a method of treating irritability associated with PAC, comprising administering to a subject in need thereof a therapeutically effective amount of a compound of formula 1 and/or derivatives thereof and/or metabolites thereof and/or pharmaceutically acceptable salts thereof.

The present invention also relates to a method of treating symptoms of PAC, comprising administering to a subject in need thereof a pharmaceutical composition containing a therapeutically effective

- 3 046455 effective amount of a compound of formula 1 and/or its derivatives and/or its metabolites and/or pharmaceutically acceptable salts thereof.

The compositions in accordance with the present invention can be administered by oral, transdermal, parenteral, intranasal and rectal routes. In particular, the compositions can be administered orally in an appropriate formulation. Dosages of a compound of Formula 1 or its pharmaceutically acceptable salts, derivatives or metabolites in the compositions of the invention may be adjusted to obtain the amount of active substance that produces the desired therapeutic response. Thus, the dosage level depends on the desired therapeutic response, route of administration, expected duration of treatment, and other factors such as the age, sex, or weight of the patient. Dosages range from 0.01 to 40 mg/day and can be titrated to effect. Dosages are preferably from 0.01 to 20 mg/day, more preferably from 0.01 to 10 mg/day.

The compound of formula 1 can also be used in combination with at least one other active ingredient for the treatment of comorbid symptoms of PAC (for example, in combination with psychostimulants, antipsychotics, compounds acting on the oxytocin/vasopressin receptor system, antidepressants, anxiolytics, antihypertensives , antiepileptic drugs, narcotics, antispasmodics or other agents).

The present invention provides pharmaceutical compositions containing a combination of a compound of formula 1, as defined above, with one or more other active ingredients. The pharmaceutical composition may contain at least one compound of the invention together with one or more other active ingredients in a single dosage form or separately. The combination composition can be administered simultaneously, separately or sequentially.

The present invention also relates to pharmaceutical compositions for use in pediatrics, such as, but not limited to, solutions, syrups, elixirs, suspensions, powders for suspension, dispersible or effervescent tablets, chewable tablets, lozenges, tablets or film-coated tablets, foaming powders or granules for oral use, capsules.

Psychostimulants include, but are not limited to, centrally acting sympathomimetic agents (amphetamine, methylphenidate, modafinil, atomoxetine), nootropics (vinpocetine, donepezil, memantine) or other psychostimulants.

Antipsychotic drugs include, but are not limited to, typical and atypical antipsychotic drugs such as haloperidol, pimozide, clozapine, olanzapine, quetiapine, sertindole, ziprasidone, lurasidone, risperidone, aripiprazole, cariprazine, brexpiprazole, iloperidone, paliperidone, lithium.

Compounds that target the oxytocin/vasopressin receptor system include, but are not limited to, oxytocin, carbetocin, arginine vasopressin, balovaptan, relkovaptan, conivaptan, selepressin, nelivaptan, tolvaptan, atosiban.

Antidepressants include, but are not limited to, non-selective monoamine reuptake inhibitors (desipramine, imipramine, clomipramine, amitriptyline, nortriptyline), serotonin modulators and stimulants (vilazodone, vortioxetine), selective serotonin reuptake inhibitors (fluoxetine, paroxetine, sertraline, fluvoxamine, citalopram, escitalopram), non-hydrazide monoamine oxidase inhibitor (moclobemide), or other agents (mianserin, trazodone, nefazodone, mirtazapine, tianeptine, venlafaxine, milnacipran, reboxetine, duloxetine, agomelatine, bupropion, gepirone).

Anxiolytics include, but are not limited to, benzodiazepines (diazepam, chlordiazepoxide, oxazepam, lorazepam, alprazolam), azaspirodecanediones (buspirone).

Antihypertensives include, but are not limited to, imidazoline receptor agonists (clonidine, guanfacine) and a combination of these compounds with a diuretic.

Antiepileptic drugs include, but are not limited to, barbiturates and their derivatives (phenobarbital), hydantoin derivatives (phenytoin), succinimide derivatives (ethosuximide), benzodiazepine derivatives (clonazepam), carboxamide derivatives (carbamazepine, oxcarbazepine), fatty acid derivatives (valproic acid, valpromide , vigabatrin, tiagabine) and other antiepileptic drugs (lamotrigine, topiramate, gabapentin, levetiracetam, zonisamide, pregabalin).

Narcotics include, but are not limited to, barbiturates (pentobarbital), benzodiazepines (midazolam), cyclopyrrolone and benzodiazepine derivatives (zopiclone, zolpidem), melatonin receptor agonists (melatonin, ramelteon).

Antispasmodics or antispasmodics include, but are not limited to, centrally acting agents (baclofen, arbaclofen, tolperisone) and papaverine.

Other agents include, but are not limited to, medications (probiotics, digestive aids/stimulants, herbal extracts), vitamins (water-soluble and fat-soluble such as, but not limited to, vitamins A, D3, E, K,

- 4 046455

B1, B5, B6, B12, C or their derivatives) and food additives (coenzymes, e.g. Q10, flavonoids, e.g. resveratrol, lecithin, unsaturated fatty acids, including ω3 and ω6 fatty acids).

Accordingly, the present invention also relates to a pharmaceutical composition for use in the treatment of PAC, comprising:

1) a compound of formula 1, and/or its derivatives, and/or its metabolites, and/or pharmaceutically acceptable salts thereof, and

2) at least one other active ingredient selected from the group consisting of psychostimulants/nootropics, antipsychotics, antidepressants, anxiolytics, antihypertensives, antiepileptics, narcotics and antispasmodics, and

3) one or more pharmaceutically acceptable carriers, diluents and excipients.

The present invention also relates to a pharmaceutical composition containing a compound of formula 1 and/or derivatives thereof and/or metabolites thereof and/or pharmaceutically acceptable salts thereof and at least one other active ingredient, for use in the treatment of symptoms of PAC.

According to a preferred embodiment, the present invention relates to a pharmaceutical combination composition for use as defined above, wherein at least one other active ingredient is selected from the group consisting of psychostimulants/nootropics, antipsychotics, antidepressants, anxiolytics, antihypertensives, antiepileptic drugs, narcotic drugs and antispasmodics.

According to another preferred embodiment, the present invention relates to a pharmaceutical combination composition for use as defined above, wherein the psychostimulant/nootropic agent is selected from the group consisting of amphetamine, methylphenidate, modafinil, atomoxetine, vinpocetine, donepezil and memantine.

According to another preferred embodiment, the present invention relates to a pharmaceutical combination composition for use as defined above, wherein the antipsychotic agent is selected from the group consisting of haloperidol, pimozide, clozapine, olanzapine, quetiapine, sertindole, ziprasidone, lurasidone, risperidone, aripiprazole, cariprazine, brexpiprazole, iloperidone, paliperidone and lithium.

According to another preferred embodiment, the present invention relates to a pharmaceutical combination composition for use as defined above, wherein the compound acting on the oxytocin/vasopressin receptor system is selected from the group consisting of oxytocin, carbetocin, arginine vasopressin, balovaptan, relkovaptan, conivaptan, selepressin, nelivaptan, tolvaptan and atosiban.

According to another preferred embodiment, the present invention relates to a pharmaceutical combination composition for use as defined above, wherein the antidepressant is selected from the group consisting of desipramine, imipramine, clomipramine, amitriptyline, nortriptyline, vilazodone, vortioxetine, fluoxetine, paroxetine, sertraline, fluvoxamine, citalopram , escitalopram, moclobemide, mianserin, trazodone, nefazodone, mirtazapine, tianeptine, venlafaxine, milnacipran, reboxetine, duloxetine, agomelatine, bupropion and gepirone.

According to another preferred embodiment, the present invention relates to a pharmaceutical combination composition for use as defined above, wherein the anxiolytic agent is selected from the group consisting of diazepam, chlordiazepoxide, oxazepam, lorazepam, alprazolam and buspirone.

According to another preferred embodiment, the present invention relates to a pharmaceutical combination composition for use as defined above, wherein the antihypertensive agent is selected from clonidine and guanfacine.

According to another preferred embodiment, the present invention relates to a pharmaceutical combination composition for use as defined above, wherein the antiepileptic agent is selected from the group consisting of phenobarbital, phenytoin, ethosuximide, clonazepam, carbamazepine, oxcarbazepine, valproic acid, valpromide, vigabatrin, tiagabine, lamotrigine , topiramate, gabapentin, levetiracetam, zonisamide and pregabalin.

According to another preferred embodiment, the present invention relates to a pharmaceutical combination composition for use as defined above, wherein the drug is selected from the group consisting of pentobarbital, midazolam, zopiclone, zolpidem, melatonin and ramelteon.

According to another preferred embodiment, the present invention relates to a pharmaceutical combination composition for use as defined above, wherein the antispasmodic agent is selected from the group consisting of baclofen, arbaclofen, tolperisone and papaverine.

Manufacturing of pharmaceutical compositions

The following formulation examples illustrate typical pharmaceutical compositions

- 5 046455 according to this invention. However, the present invention is not limited to the following pharmaceutical compositions.

A) Solid dosage forms for oral administration Tablets.

Active substance(s) 0.005 - 90% Filler Binder 1 - 99.9% 0 - 20% Baking powder 0 - 20% Lubricant 0-10% Other specific excipient(s) 0 - 50%

B) Dosage forms for parenteral use Intravenous injections.

Active substance(s) 0.001 - 50% Solvent 10-99.9% Co-solvent 0 - 99.9% Osmotic agent 0 - 50%

Buffer agent q.s. (in sufficient quantities)

C) Other dosage forms Suppositories.

Active substance(s) 0.0003 - 50% Suppository base 1 - 99.9% Surfactants 0 - 20% Lubricant 0 - 20% Preservatives q.s. (in sufficient quantity)

Definitions

The term active ingredient means a compound of formula 1, its pharmacologically acceptable salts, active metabolites and derivatives.

The term active metabolite refers to metabolites produced by various biotransformation routes whose biological activity is similar to that of the parent compound.

The term affinity refers to the affinity of a drug with a biological target; is a chemical term used to quantify the strength of a drug-target interaction.

The term antagonist means a compound that binds to a receptor and does not cause a response or prevents the response caused by an agonist of the same receptor.

The term derivative means compounds formed by chemical transformation of a compound of the invention resulting in other than prodrugs, deuterated compounds, etc.

The term excipient defines a chemical compound that facilitates the introduction of the compound into cells or tissues. The excipients used in the formulation may be selected from the following categories such as, but not limited to, tablet and capsule fillers, tablet and capsule binders, modified drug release agents, disintegrating agents, glidants, lubricants, sweeteners , substances that correct the taste and odor of a medicinal product, flavoring additives, coating materials, surfactants, stabilizers, preservatives or antioxidants, buffering agents, complexing agents, wetting or emulsifying agents, salts for regulating osmotic pressure, lyophilization auxiliaries, microencapsulating agents , ointment materials, penetration enhancers, dissolution improvers, solvents, suppository materials, suspending agents. Acceptable pharmaceutical excipients may be, for example: starch, microcrystalline cellulose, talc, glucose, lactose, gelatin, silicon dioxide, talc, magnesium stearate, sodium stearate, glycerol monostearate, cellulose derivatives, sodium chloride, glycerin, propylene glycol, water, ethanol, etc. similar.

The term inverse agonist means an agent that binds to constitutively active receptors and reduces their activity, thereby causing a pharmacological response opposite to the agonist.

- 6 046455

The term patient refers to a patient who is diagnosed with PAC.

The term pharmaceutically acceptable describes an ingredient that is useful in the manufacture of a pharmaceutical composition and is generally safe, non-toxic and not biologically or otherwise objectionable, and includes ingredients suitable for human pharmaceutical use.

The term pharmaceutical composition refers to a mixture of a compound of the invention with other chemical components, such as pharmaceutically acceptable excipients, for example, diluents or carriers. The pharmaceutical composition facilitates administration of the compound to a subject.

The term pharmaceutically acceptable salt refers to a conventional acid addition salt retaining the biological effectiveness and properties of the compounds of Formula (I) and formed with suitable non-toxic organic or inorganic acids. Examples of acid addition salts include salts derived from inorganic acids such as, but not limited to, (mono- or di-) hydrochloric acid, (mono- or di-) hydrobromic acid, hydroiodic acid, sulfuric acid, sulfamic acid, phosphoric acid , nitric acid and perchloric acid, and salts derived from various organic acids such as, but not limited to, acetic acid, propionic acid, benzoic acid, glycolic acid, phenylacetic acid, salicylic acid, malonic acid, maleic acid, oleic acid, pamic acid, palmitic acid, benzenesulfonic acid, toluenesulfonic acid, methanesulfonic acid, oxalic acid, tartaric acid, succinic acid, (mono- or di-)citric acid, malic acid, lactic acid, glutamic acid, fumaric acid, etc. Such salts often have more favorable solubility than the compounds used to prepare them and are therefore better suited for use in the manufacture of various pharmaceutical compositions.

The term selective means that the ligand binds more preferentially to one molecular target than to other targets, which may ultimately result in different pharmacological activities.

When used in this context, the term treatment refers to alleviating a particular pathological condition, eliminating or reducing one or more symptoms of the condition, slowing or eliminating the progression of the disease state, and preventing or delaying the recurrence of the pathological condition in a patient or subject who already suffers from or has been diagnosed with a disease. .

Model of prenatal valproate exposure

As previously described, the prenatal valproate exposure (VPA) model has good construct and face validity and is therefore an established model of PAC disease. Because there is no medically approved drug on the market to treat the core symptoms of PAC, the predictive validity of the model can only be assessed based on compounds that have shown signals of efficacy in humans. Compounds that produce efficacy signals in subjects with PAC include, for example, oxytocin (Andari et al., PNAS 2010, 107:4389-4394). Oxytocin has been found to improve behavioral disturbances in a model of prenatal VPA exposure (Hara et al., Horm. Behav. 2017, 96:130-137), suggesting that this model would be predictive of use in the treatment of core PAC symptoms in patients .

In this method, simultaneously fertilized female Wistar rats are administered a single dose of VPA (600 mg/kg, i.p., intraperitoneally) on day 12.5 of gestation. Offspring are housed under standard laboratory conditions until behavioral testing. Animals are housed in groups of 4 in regular cages and kept at 22°C to 24°C on a standard 12-hour light/dark cycle, with food and water available ad libitum. After treatment with study drugs, the behavior of the offspring is studied using tests suitable for assessing autistic behavior. Such tests include social games, social preferences, and social recognition memory. These tests are suitable for assessing behavioral elements representing the core symptoms of PAC in experimental animals. The efficacy of the investigational compound (i.e., improvement in behavioral deficits caused by prenatal VPA exposure) may indicate its potential for use in the pharmacotherapy of core symptoms of PAC. Study drug doses were adjusted for the salt, dicitrate, with a correction factor of 2.07 and expressed as free base. Reference is made herein to a parallel patent application filed by the applicant entitled Selective histamine H3 receptor antagonist acid addition salts and process for the preparation thereof', which describes the salts in detail , including dicitrate.

Maternal deprivation-induced ultrasonic vocalizations in rat pups are an indicator of social-communicative function that is impaired in offspring following prenatal VPA exposure (Gandal et al., Biol. Psychiatry 2010, 68, 1100-1106). To cause ultrasonic sig

- 7 046455 naly, rat pups, prenatally treated with VPA, are placed in a cage one at a time, where sound signals are recorded using acoustic sensors for bats. Audio signals are digitized using an audio filter, and ultrasonic vocalizations are recorded and quantified using SonoTrack software (Metris bv. The Netherlands). Initial vocalization is measured on days 11-12 of the postnatal period for 10 minutes. Animals are divided into homogeneous groups based on initial vocalizations. On postnatal day 13, animals were administered orally appropriate doses of drug or vehicle 60 min before measurement and then returned to their nests until recording. The number of ultrasonic signals is recorded for 10 minutes. Statistical analysis is performed based on the calculation of ultrasonic signals using the nonparametric Kruskal-Wallis test and the Dunnett a posteriori test.

Social play is a type of social interaction characteristic of young mammals, including rodents, as well as humans (Vanderschuren and Trezza, Curr. Topics Behav. Neurosci. 2014, 16:189-212). Social play behavior is an indicator of healthy social functioning in adulthood and is impaired by prenatal VPA exposure in offspring (Schneider and Przewlocki Neuropsychopharmacology 2005, 30:80-89). At postnatal day 30 after 8 days of treatment with the test compound, rats prenatally treated with VPA were assessed for juvenile play behavior. The test is performed in a test arena unfamiliar to the rats for pairs of animals from the same experimental group for a 15-minute trial. Animals are assessed for the duration of social play behavior. Statistical analysis was performed using one-way analysis of variance ANOVA and parametric Student's t test.

Analyzes of social preference and recognition memory in a 3-chamber device provide another indication of intact social behavior in rats. Preference for conspecific animals over inanimate objects and the ability to discriminate between familiar and novel conspecifics are essential for normal social functioning and are impaired in a rat model of prenatal VPA exposure (Bambini-Junior et al., Brain Res. 2011, 1408:8-16). Social preferences and social recognition memory are examined in a 3-chamber device. On postnatal day 59, rats prenatally treated with VPA were assessed for their social preference following oral administration of a test compound for 8 days. At postnatal day 60, the same rats are assessed for their social recognition memory after oral administration of a test compound for 9 days. Statistical analysis was performed using two-way ANOVA and parametric Student's t-test.

Detailed description of graphic materials

Fig. 1. Repeated (once a day for 8 days) oral administration of 1-[4-(4-{3[(2R)-2-methylpyrrolidin-1 -yl]propoxy}phenoxy)piperidin-1 -yl]ethane dicitrate 1 -one (CMPD) reversed social play deficits induced by prenatal valproate exposure at postnatal day 30 (*P < 0.05, Student's t test versus prenatal VPA + vehicle treatment (VPA + VEH) group). The effect of 1-[4-(4-{3-[(2R)-2-methylpyrrolidin-1yl]propoxy}phenoxy)piperidin-1-yl]ethan-1-one dicitrate was statistically significant at doses of 0.1 and 1 mg /kg (+ p<0.05, post hoc Bonferroni test compared with the VPA + VEH group). VEH + VEH means prenatal vehicle treatment combined with vehicle treatment before behavioral testing. Animals in the VPA + VEH group received prenatal VPA in combination with vehicle treatment before behavioral testing. VPA + CMPD/0.01, CMPD/0.1, and CMPD/1 groups received prenatal VPA followed by 0.01, 0.1, and 1 mg/kg 1-[4-(4-{3-[( 2R)2-methylpyrrolidin-1 -yl] propoxy}phenoxy)piperidin-1 -yl] ethan-1 -one, respectively.

Fig. 2. Repeated (once a day for 8 days) oral administration of 1-[4-(4-{3[(2R)-2-methylpyrrolidin-1 -yl]propoxy}phenoxy)piperidin-1 -yl]ethane dicitrate 1 -ona reversed the social preference deficits induced by prenatal valproate exposure at postnatal day 59 (*P < 0.05, Student's t test versus prenatal VPA + vehicle treatment (VPA + VEH) group). The effect of 1-[4-(4-{3-[(2R)-2-methylpyrrolidin-1yl]propoxy}phenoxy)piperidin-1-yl]ethan-1-one dicitrate was statistically significant at doses of 0.1 and 1 mg /kg (+ p<0.05, Bonferroni post hoc test compared with the VPA + VEH group). VEH + VEH means prenatal vehicle treatment combined with vehicle treatment before behavioral testing. Animals in the VPA + VEH group received prenatal VPA in combination with vehicle treatment before behavioral testing. VPA + CMPD/0.01, CMPD/0.1, and CMPD/1 groups received prenatal VPA followed by 0.01, 0.1, and 1 mg/kg 1-[4-(4-{3-[( 2R)-2methylpyrrolidin-1-yl]propoxy}phenoxy)piperidin-1-yl]ethan-1-one, respectively.

Fig. 3. Repeated (once a day for 9 days) oral administration of 1-[4-(4-{3[(2R)-2-methylpyrrolidin-1 -yl]propoxy}phenoxy)piperidin-1 -yl]ethane dicitrate 1-she reversed social recognition deficits induced by prenatal valproate exposure at postnatal day 60

- 8 046455 new period (*P<0.05, Student's t-test; new versus familiar). Familiar means time spent studying a conspecific already known to the experimental animal, new means time spent studying a conspecific not yet known to the experimental animal. The effect of 1-[4-(4-{3-[(2R)-2-methylpyrrolidin-1-yl]propoxy}phenoxy)piperidin-1-yl]ethan-1-one dicitrate was statistically significant at a dose of 1 mg/kg (+ p < 0.05, Bonferroni post hoc test versus prenatal VPA treatment + vehicle treatment group (VPA + VEH), familiar). VEH + VEH means prenatal vehicle treatment combined with vehicle treatment before behavioral testing. Animals in the VPA + VEH group received prenatal VPA in combination with vehicle treatment before behavioral testing. VPA + CMPD/0.01, CMPD/0.1, and CMPD/1 groups received prenatal VPA followed by 0.01, 0.1, and 1 mg/kg 1-[4-(4-{3-[( 2R)-2methylpyrrolidin-1 -yl] propoxy}phenoxy)piperidin-1 -yl] ethan-1 -one, respectively.

The following examples illustrate the invention without limiting its scope.

Description of embodiments of the invention

Example 1.

1-[4-(4-{3-[(2R)-2-methylpyrrolidin-1-yl]propoxy}phenoxy)-piperidin-1-yl]ethan-1-one dicitrate was tested using a social play assay in rats. who received valproate in the prenatal period (Fig. 1). Effect of subacute (once daily for 8 days) administration of 1-[4-(4-{3-[(2R)-2methylpyrrolidin-1-yl]propoxy}phenoxy)piperidin-1-yl]ethane-1-dicitrate it on the social play behavior of rats is shown in Fig. 1. The data presented are the mean value ± SEM (standard error of the mean) for 4 pairs of young (on the 30th day of the postnatal period) male rats of each group. Orally administered 1-[4-(4-{3-[(2R)-2-methylpyrrolidin-1yl]propoxy}phenoxy)piperidin-1-yl]ethan-1-one dicitrate partially reversed social play deficits in offspring. treated with valproate, reaching significance at a dose of 0.1 mg/kg. Thus, the compound of the invention was able to reduce the social deficits caused by prenatal exposure to valproate.

Example 2.

1-[4-(4-{3-[(2R)-2-methylpyrrolidin-1-yl]propoxy}phenoxy)-piperidin-1-yl]ethan-1-one dicitrate was tested for social preferences in a 3-chamber device in rats receiving valproate in the prenatal period (Fig. 2). Effect of subacute (once daily for 8 days) oral administration of 1-[4-(4-{3-[(2R)-2-methylpyrrolidin-1-yl]propoxy}phenoxy)piperidin-1-yl]ethane dicitrate -1 on social preferences is shown in Fig. 2. Data shown are the mean ± SEM of 8 male rats in each group (at postnatal day 59). 1-[4(4-{3-[(2R)-2-methylpyrrolidin-1 -yl]propoxy}phenoxy)piperidin-1-yl]ethan-1-one dicitrate, administered orally, completely reversed social preference deficits in offspring receiving valproate at a dose of 1 mg/kg. Thus, the compound of the invention was able to reduce the social deficits caused by prenatal exposure to valproate.

Example 3.

1-[4-(4-{3-[(2R)-2-methylpyrrolidin-1-yl]nropoxy}phenoxy)-piperidin-1-yl]ethan-1-one dicitrate was tested for social recognition memory in 3- chamber device in rats receiving valproate in the prenatal period (Fig. 3). Effect of subacute (once daily for 9 days) oral administration of 1-[4-(4-{3-[(2R)-2-methylpyrrolidin-1-yl]nropoxy}phenoxy)piperidin-1yl]ethane-1 dicitrate -on social recognition memory is shown in Fig. 3. Data shown are the mean ± SEM of 8 male rats in each group (at postnatal day 60). 1-[4-(4-{3-[(2R)-2-methylpyrrolidin-1-yl]nropoxy}phenoxy)piperidin-1-yl]ethan-1-one dicitrate, administered orally, completely reversed impairments in social recognition memory in offspring treated with valproate at a dose of 1 mg/kg. Thus, the compound of the invention was able to reduce the social deficits caused by prenatal exposure to valproate.

Example 4.

The effect on behavior of co-administration of 1-[4-(4-{3-[(2R)-2-methyl-pyrrolidin-1yl]propoxy}phenoxy)piperidin-1-yl]ethan-1-one dicitrate and risperidone was studied in pups rats prenatally exposed to valproate (300 mg/kg) by analyzing the emission of ultrasound signals induced by maternal separation. Risperidone was chosen because of its FDA approval for use in the treatment of irritability associated with PAC and its frequent use in routine medical practice for PAC. (McClellan et al., Curr. Treat: Options Psych. 2016 3:161-181). Additionally, the dose of risperidone used in the present study was reported to produce an efficacy signal in a model of prenatal valproate exposure (Kuo and Liu, FASEB J 2017, 31(10):4458-4471). Administration of oral doses of 1-[4-(4-{3-[(2R)-2-methyl-pyrrolidin-1yl]propoxy}phenoxy)piperidin-1-yl]ethan-1-one dicitrate in a dose range of 0.01 up to 1 mg/kg concomitantly with oral risperidone (0.003 mg/kg) dose-proportionally reversed the social-communication impairment caused by prenatal valproate exposure in rat pups.

Claims (25)

1. Use of the compound of formula 1 Formula 1 and its pharmaceutically acceptable salts for the manufacture of a medicament for the treatment of autism spectrum disorder (PAC). 2. Use according to claim 1, wherein treating PAC is treating symptoms of PAC. 3. Use according to claim 2, wherein the PAC symptoms are the main symptoms of the PAC. 4. Use according to claim 3, where the main symptoms of PAC are sociocommunicative dysfunctions. 5. Use according to claim 3, wherein the main symptoms of PAC are restricted and repetitive behavior. 6. Use according to claim 2, wherein the PAC symptom is irritability associated with PAC. 7. Use as claimed in any one of claims 1 to 6, wherein the pharmaceutically acceptable salt is selected from the group consisting of dihydrobromide, sulfate, oxalate, monocitrate and dicitrate. 8. Use according to any one of paragraphs 1 to 7, wherein the therapeutically effective amount of said compound is from 0.01 to 40 mg/day. 9. A method of treating PAC, comprising administering to a patient in need thereof a therapeutically effective amount of a compound of formula 1 and/or pharmaceutically acceptable salts thereof. 10. A method of treating symptoms of PAC, comprising administering to a patient in need thereof a therapeutically effective amount of a compound of Formula 1 and/or pharmaceutically acceptable salts thereof. 11. The method according to claim 10, wherein the symptoms are the main symptoms of PAC. 12. The method according to claim 11, where the main symptoms are socio-communicative dysfunctions. 13. The method of claim 11, wherein the primary symptom is restricted and repetitive behavior. 14. The method of claim 10, wherein the symptom is irritability. 15. The method according to any one of claims 9 to 14, wherein the pharmaceutically acceptable salt is selected from the group consisting of dihydrobromide, sulfate, oxalate, monocitrate and dicitrate. 16. The method according to any one of claims 9 to 15, wherein the therapeutically effective amount of said compound is from 0.01 to 40 mg/day. 17. Use of a pharmaceutical composition containing a compound of formula 1 or pharmaceutically acceptable salts thereof and one or more pharmaceutically acceptable ingredients such as carriers, diluents and excipients for the treatment of PAC. 18. Use according to claim 17, wherein the pharmaceutically acceptable salt is selected from the group consisting of dihydrobromide, sulfate, oxalate, monocitrate and dicitrate. 19. Use according to any one of claims 17, 18, wherein the composition further contains at least one other active ingredient. 20. Use according to any one of claims 17 to 19, wherein the therapeutically effective amount of said compound is from 0.01 to 40 mg/day. 21. The use of any one of claims 17 to 20, wherein treating PAC is treating symptoms of PAC. 22. A pharmaceutical composition for the treatment of PAC comprising a pharmaceutically acceptable dicitrate salt of a compound of Formula 1 and one or more pharmaceutically acceptable ingredients such as carriers, diluents and excipients. 23. The pharmaceutical composition according to claim 22, wherein the composition further contains at least one other active ingredient. 24. Pharmaceutical composition according to any one of claims 22, 23, where the therapeutically effective amount of said salt is from 0.01 to 40 mg/day. 25. The pharmaceutical composition according to any one of claims 22 to 24, wherein the treatment of PAC is the treatment of symptoms of PAC.