Compounds and compositions for the treatment of nervous system disorders

Abstract

New 3-phenoxy-3-phenylpropanamine derivatives, compositions thereof and their use as a medicament in the treatment of nervous system disorders associated with cognitive deficits and behavioural dysfunctions, in particular fragile X syndrome and Rett syndrome.

Description

[0001] COMPOUNDS AND COMPOSITIONS FOR THE TREATMENT OF NERVOUS SYSTEM DISORDERS

[0002] FIELD OF THE INVENTION

[0003] New 3-phenoxy-3-phenylpropanamine derivatives, compositions thereof and their use as a medicament in the treatment of nervous system disorders associated with cognitive deficits and behavioural dysfunctions, in particular in the treatment of fragile X syndrome and Rett syndrome.

[0004] BACKGROUND OF THE INVENTION

[0005] Cognitive deficit is an inclusive term used to describe the impairment of different domains of cognition, wherein cognition is the mental action or process of acquiring knowledge and understanding through thought, experience, and the senses. Cognition encompasses various aspects of high-level intellectual functions and processes such as memory, knowledge, decision making, planning, reasoning, judgment, perception, attention, comprehension, language, and visuospatial function, among others. [Dhakal A, Bobrin BD. Cognitive Deficits. [Updated 2023 Feb 14]. In: StatPearls [Internet], Treasure Island (FL): StatPearls Publishing; 2024 Jan-. Available from: https: / / www.ncbi.nlm.nih.gOv / books / NBK559052 / 1.

[0006] Behavioural dysfunctions, also known as behavioural abnormalities, comprise alterations in emotionality, social interaction and spatial memory, as well as hyperactivity, aggressiveness, stereotypy, and the like, which impact a person's ability to effectively recognize, interpret, control, and express fundamental emotions.

[0007] Cognitive deficit and behavioural dysfunctions are not limited to any particular disease or condition but a manifestation of an underlying condition.

[0008] Cognitive deficits and behavioural dysfunctions have been observed in a large variety of nervous system disorders. For the purpose of the present invention, nervous system disorders associated with cognitive deficits and behavioural dysfunctions consist of developmental anomalies, such as fragile X syndrome, Rett syndrome, Down syndrome, DiGeorge syndrome (22q11.2 deletion syndrome), Prader-Willi syndrome, and Angelman syndrome; mental, behavioural and neurodevelopmental disorders such as autism spectrum disorder, Asperger syndrome, attention deficit hyperactivity disorder, anxiety, bipolar disorder, depression, Pheland-McDermid syndrome, Pitt-Hopkins syndrome, and schizophrenia; and diseases of the nervous system, such as Alzheimer’s disease, Huntington’s disease, and Parkinson’s disease; as defined by the World Health Organization in the International Classification of Diseases 11th Revision (ICD-11 , https: / / icd.who.int / ).

[0009] Fragile X syndrome (FXS) is the most commonly inherited form of single-gene mutation that causes a range of nervous system manifestations with an estimated frequency of 1 :4,000-5,000 worldwide. FXS is typically characterized by mild to severe cognitive deficits with associated mood, social and behavioural dysfunctions including autism spectrum disorder, attention-deficit hyperactivity disorder and aggression [Dionne O, Corbin F. (2021) An “omic” overview of fragile X syndrome. Biology (Basel), 10(5):433], FXS is caused by a mutation of the fragile X messenger ribonucleoprotein 1 (FMR1) gene, which arises from the hypermethylation of a cytosine-guanine-guanine trinucleotide repeat expansion [Protic DD, Aishworiya R, Salcedo-Arellano MJ, et al. Fragile X syndrome: From molecular aspect to clinical treatment. (2022). Int J Mol Sci, 23(4): 1935], A full mutation consists of >200 repeats, resulting in epigenetic silencing of FMR1 leading to loss of expression [Dionne O, Corbin F. An “omic” overview of fragile X syndrome. (2021). Biology (Basel).10(5):433], Fragile X messenger ribonucleoprotein (FMRP), the product of the FMR1 gene, is an RNA-binding protein critical to neuronal development, synaptic plasticity, and dendritic spine architecture [Bagni C, Zukin RS. (2019). A Synaptic Perspective of Fragile X Syndrome and Autism Spectrum Disorders. Neuron, Mar 20; 101 (6): 1070-1088],

[0010] Rett syndrome (RS) is a severe neurological disorder predominantly affecting females, caused by mutations in the MECP2 gene. This gene encodes for the MeCP2 protein, a critical transcriptional regulator involved in gene expression, chromatin remodelling, and RNA processing [Lopes, A. G., Loganathan, S. K., & Caliaperumal, J. (2024). Rett Syndrome and the Role of MECP2: Signaling to Clinical Trials. Brain Sciences, 14(2), 120; and Gomes, A. R., Fernandes, T. G., Cabral, J. M., & Diogo, M. M. (2021). Modeling Rett syndrome with human pluripotent stem cells: Mechanistic outcomes and future clinical perspectives. International journal of molecular sciences, 22(7), 3751], The dysfunction of MeCP2 results in a variety of symptoms including microcephaly, seizures, and intellectual disabilities. Down syndrome (DS) is a genetic disorder caused by the trisomy of chromosome 21 [Dierssen M. (2012). Down syndrome: the brain in trisomic mode. Nat Rev Neurosci, Dec;13(12):844-58], DS is the most common genetic form of intellectual disability. It is usually associated with developmental delays, distinct facial features and congenital heart defects [Bull, M. J. (2020). Down syndrome. New England Journal of Medicine, 382(24), 2344-2352],

[0011] DiGeorge syndrome, also known as 22q11.2 deletion syndrome (22q11.2DS), is a genetic disorder that arises from a hemizygous deletion on the long arm of chromosome 22q11.2. 22q11.2DS presents a varied combination of anatomical, behavioral, and cognitive dysfunctions, such as cardiac defects, palatal deformities, and facial abnormalities, an increased risk for an array of psychiatric disorders, most notably schizophrenia, though autism spectrum disorder, attention deficit hyperactivity disorder, and anxiety disorders [Smerconish S, Schmitt JE. (2024). Neuroanatomical Correlates of Cognitive Dysfunction in 22q11.2 Deletion Syndrome. Genes (Basel), 15(4):440],

[0012] Prader-Willi syndrome (PWS) is a multisystemic complex genetic disorder caused by lack of expression of genes on the paternally inherited chromosome 15q11.2-q13 region. Clinical manifestations evolve along ages, including hypothalamic dysfunction and developmental delay, cognitive disability and behavioral issues [Angulo MA, Butler MG, Cataletto ME. (2015). Prader-Willi syndrome: a review of clinical, genetic, and endocrine findings. J Endocrinol Invest, Dec;38(12): 1249-63],

[0013] Angelman syndrome (AS) is a genetic disorder caused by loss of the maternal copy of the UBE3A gene on the 15q11-q13 chromosomal region [Maranga C, Fernandes TG, Bekman E, da Rocha ST. (2020). Angelman syndrome: a journey through the brain. FEBS J. 287(11):2154-2175], AS is characterized by severe cognitive disability, motor dysfunction, speech impairment, hyperactivity, frequent seizures, and sleep disturbances [Margolis SS, Sell GL, Zbinden MA, Bird LM. (2015). Angelman Syndrome. Neurotherapeutics, 12(3):641 -50],

[0014] Autism spectrum disorder (ASD) is a neurodevelopmental disorder that includes impairments in social communication and interaction, sensory anomalies, repetitive behaviours and varying levels of intellectual disability. ASD has a particularly large genetic contribution, and is among the most heritable common medical conditions [Lord C, Brugha TS, Charman T, Cusack J, Dumas G, Frazier T, Jones EJH, Jones RM, Pickles A, State MW, Taylor JL, Veenstra-VanderWeele J. (2020). Autism spectrum disorder. Nat Rev Dis Primers, 16;6(1):5],

[0015] Asperger syndrome (AS) is a neurodevelopmental disorder characterized by impaired social communication and interaction, average or superior intelligence, and no significant language delay. AS etiology has been linked to a variety of genetic, neurological, and environmental variables. Genomic sequencing data suggests that hundreds of genes are associated with the disorder, which are engaged in a wide range of biological processes that affect the maturation and functioning of the brain [Hosseini SA, Molla M. Asperger Syndrome. (2024) Feb 12. In: StatPearls [Internet], Treasure Island (FL): StatPearls Publishing; 2024 Jan. Available from: https: / / www.ncbi.nlm.nih.gov / books / NBK557548 / ].

[0016] Attention deficit hyperactivity disorder (ADHD) is a nervous system condition that show patterns of developmentally inappropriate levels of inattentiveness, hyperactivity, or impulsivity. ADHD is associated with cognitive and functional deficits that relate to diffuse abnormalities in the brain [Magnus W, Nazir S, Anilkumar AC, et al. Attention Deficit Hyperactivity Disorder. [Updated 2023 Aug 8], In: StatPearls [Internet], Treasure Island (FL): StatPearls Publishing; 2024 Jan-. Available from: https: / / www.ncbi.nlm.nih.gov / books / NBK441838 / ].

[0017] Anxiety is mental health disorder characterized by a complex cognitive, affective, physiological, and behavioral response system associated with preparation for the anticipated events or circumstances perceived as threatening [Chand SP, Marwaha R. Anxiety. [Updated 2023 Apr 24], In: StatPearls [Internet], Treasure Island (FL): StatPearls Publishing; 2024 Jan-. Available from: https: / / www.ncbi.nlm.nih.gov / books / NBK470361 / ].

[0018] Bipolar disorder (BD) is a common, chronic, and recurring medical disorder characterized by episodes of mania - extremely elevated mood, energy, unusual thought patterns, and sometimes psychosis - and depression, usually interspersed with periods of relatively normal mood, related to dysfunctions in neurotransmitter systems [Martinowich, K., et al (2009). Bipolar disorder: from genes to behavior pathways. The Journal of clinical investigation, 119(4), 726-736]; [Bertollo, A. G., et al (2025). Neurobiological Relationships Between Neurodevelopmental Disorders and Mood Disorders. Brain Sciences, 15(3), 307], Depression is a mental health disorder that causes a persistent feeling of sadness and loss of interest [Chand SP, Arif H. Depression. [Updated 2023 Jul 17]. In: StatPearls [Internet], Treasure Island (FL): StatPearls Publishing; 2024 Jan-. Available from: https: / / www.ncbi.nlm.nih.goV / books / NBK430847 / 1.

[0019] Pheland-McDermid syndrome (PM DS) is a neurodevelopmental rare genetic disorder commonly due to a deletion of chromosome 22q13.3 and affecting the SHANK3 gene. It is characterized by a large variety of clinical features with considerable heterogeneity in disease severity, including neonatal hypotonia, severely delayed absenting speech, developmental delay, and minor dysmorphic facial features. Cognitive development is generally delayed, and adaptive skills are at a low level of functioning [European Reference Network ITHACA. Special issue. European Journal of Medical Genetics. [Updated 2023 Feb 12], In: https: / / www.sciencedirect.com / special-issue / 103SFTL92SC1

[0020] Pitt-Hopkins syndrome (PTHS) is a rare neurodevelopmental disorder due to a mutation in the Transcription Factor 4 (TCF4) gene that regulates brain development and neuronal function [Rannals, M. D., & Maher, B. J. (2017). Molecular Mechanisms of Transcription Factor 4 in Pitt Hopkins Syndrome. Current genetic medicine reports, 5(1), 1-7], It is characterized by moderate to severe intellectual disability, global developmental delay, dysmorphic facial features, and episodic hyperventilation followed by periods of apnea [Dennys, C. N., et al (2024). MeCP2 gene therapy ameliorates disease phenotype in mouse model for Pitt Hopkins syndrome. NeuroTherapeutics, 21(5), e00376].

[0021] Schizophrenia is a severe mental health disorder with multifactorial causes and multiple symptoms, including delusions, hallucinations, disorganized speech or behavior, and impaired cognition. [Patel KR, Cherian J, Gohil K, Atkinson D. (2014). Schizophrenia: overview and treatment options. Pharmacy and Therapeutics, 39(9):638-45], Increased gray matter loss and aberrant network organization apparent at illness onset are associated with cognitive deficits [McCutcheon RA, Reis Marques T, Howes OD. (2020). Schizophrenia — An Overview. JAMA Psychiatry, 77(2):201-210],

[0022] Alzheimer's disease (AD) is considered the most harmful form of dementia in the elderly population, characterized by the presence of amyloid plaques in the brain, and a progressive loss of cognitive functions [Breijyeh Z, Karaman R. (2020) Comprehensive Review on Alzheimer's Disease: Causes and Treatment. Molecules. Dec 8;25(24):5789], Huntington disease (HD) is a neurodegenerative genetic disorder originated by the elongation of cytosine, adenine, and guanine (CAG) trinucleotide repeats on the short arm of chromosome 4p16.3 in the Huntingtin (HTT) gene. This mutation leads to an abnormally long expansion of the polyglutamine in the HTT protein, which leads to neurodegeneration. The expansion also causes the HTT protein to be more prone to aggregation and accumulation that mitigates protein folding. HD is characterized by involuntary motor, cognitive and behavioral disturbances. These symptoms then progress with more cognitive deficits leading to dementia [Ajitkumar A, De Jesus O. Huntington Disease. [Updated 2023 Aug 23], In: StatPearls [Internet], Treasure Island (FL): StatPearls Publishing; 2024 Jan-. Available from: https: / / www.ncbi.nlm.nih.gov / books / NBK559166 / ].

[0023] Parkinson’s disease (PD) is characterized by death of dopaminergic neurons in the substantia nigra. PD causes motor symptoms (tremor, stiffness, slowness, and imbalance), psychological or cognitive problems (cognitive decline, depression, anxiety), as well as nonmotor symptoms affecting many organ systems, such as gastrointestinal and genitourinary systems [Armstrong MJ, Okun MS. (2020). Diagnosis and Treatment of Parkinson Disease: A Review. JAMA, 323(6):548-560],

[0024] WO 2014 / 096377 A1 discloses hydroxyl aliphatic substituted phenyl aminoalkyl ether derivatives which are useful for the treatment of nervous system diseases, and developmental, behavioral and mental disorders associated with cognitive deficits by inhibiting serotonin and / or norephinephrine (monoamine) reuptake, and promoting Akt and ERK phosphorylation, ending in CREB phosphorylation through a mechanism not specific for a brain derived neurotrophic factor (BDNF)-dependent TrkB receptor agonistic activation.

[0025] The scientific challenge to alleviate human suffering in nervous system diseases is enormous.

[0026] Thus, there is a need for new treatments of nervous system disorders associated with cognitive deficits and behavioural dysfunctions, in particular for fragile X syndrome and Rett syndrome. SUMMARY OF THE INVENTION

[0027] The inventors have obtained new 3-phenoxy-3-phenylpropanamine derivatives which are useful for the treatment of nervous system disorders associated with cognitive deficits and behavioural dysfunctions, in particular, fragile X syndrome and Rett syndrome. The new 3-phenoxy-3-phenylpropanamine derivatives promote neurogenesis, neuritogenesis and synaptogenesis (elongation of the neurite network, increase of neuritic roots and number of branching points) in primary hippocampal neurons and promote morphological changes in pyramidal cells from Fmr1 KO2 (Fragile X syndrome knockout) model prefrontal cortex in vivo (total dendritic lengths, total spine counts, overall spine density, and the like) to a comparable level of the wild type non treated counterparts.

[0028] Surprisingly, and different from the prior art, this pharmacological activity is primarily obtained through the selective allosteric modulation of the TrkB (tropomyosin receptor kinase B) receptor pathway mediated by BDNF (brain derived neurotrophic factor). Advantageously and compared to compounds described in US 2015 / 0344408 A1 , the compounds of the present invention do not present significant inhibition for the re-uptake of serotonin, norepinephrine nor dopamine, pharmacological activities that may induce a variety of side effects and drug-drug interactions which can result in poor patient adherence. The selectivity of the compounds of the present invention on the TrkB receptor modulation is an advantage, since it allows their administration, or its coadministration with other active compounds in the field, for the treatment of nervous system disorders.

[0029] Thus, in the first aspect the invention relates to a compound having formula (I) wherein, • R1is selected from the group consisting of -OR and -NR’R”, wherein R is selected from the group consisting of hydrogen, glycosyl, acyl, acetyl, and Ci-Ce alkyl, and R’ and R” are independently selected from the group consisting of hydrogen and Ci-Ce alkyl,

[0030] • R2is selected from the group consisting of H and OH,

[0031] • R3is selected from the group consisting of H and OH,

[0032] • R4is selected from the group consisting of H, -CH3 and OH,

[0033] • R5is selected from the group consisting of H and -CH3,

[0034] • G1is a divalent linker comprising two carbon atoms and at least one oxygen atom selected from the group consisting of -CH2-CH(OH)-, -CH2-C(=O)-, -CH=C(OH)-, -CH(OH)-CH(OH)-, -CH(OH)-C(=O)-, and -C(=O)-C(=O)-, and

[0035] • G2is selected from the group consisting of -CH2- and -C(=O)-, or a pharmaceutically acceptable salt, hydrate or stereoisomer thereof.

[0036] In the second aspect, the invention relates to a pharmaceutical composition comprising a compound as defined in the first aspect and one or more pharmaceutically acceptable carriers.

[0037] In the third aspect, the invention relates to a compound as defined in the first aspect for use as a medicament.

[0038] In the fourth aspect, the invention relates to compound as defined in the first aspect for use in the treatment of nervous system disorders associated with cognitive deficits and behavioural dysfunctions.

[0039] In the fifth aspect, the invention relates to a combination comprising a compound as defined in the first aspect and another drug selected from the group consisting of drugs for the treatment of nervous system disorders or their clinical manifestations anxiolytics and antidepressants, such as sertraline, fluoxetine, citalopram, escitalopram, trazodone, bupropion, cannabidiol, paroxetine, duloxetine, buspirone, venlafaxine, desvenlafaxine, olanzapine, mirtazapine, psilocybin and atomoxetine; antipsychotics, such as aripiprazole, risperidone, quetiapine and olanzapine; tranquilizers, such as clonazepam and lorazepam; hypnotics, such as zolpidem and melatonin; stimulants, such as methylphenidate, amphetamine, amphetamine salts and L-acetylcarnitine; nonstimulants such as clonidine and guanfacine; cognition enhancers, such as donepezil, zatolmilast, trofinetide and metformin; antiepileptics and anticonvulsants, such as levetiracetam, oxcarbazepine, valproic acid, valproate, carbamazepine, lamotrigine and topiramate; and 2-[4-[3-(methylamino)-1-phenylpropoxy]phenyl]ethanol or a pharmaceutically acceptable salt, hydrate or stereoisomer thereof.

[0040] In a sixth aspect, the invention relates to the use of a compound as defined in the first aspect or a combination as defined in the fifth aspect for the manufacture of a medicament.

[0041] In a seventh aspect, the invention relates to the use of a compound as defined in the first aspect or a combination as defined in the fifth aspect for the manufacture of a medicament for the treatment of nervous system disorders associated with cognitive deficits and behavioural dysfunctions, preferably a nervous system disorder associated with cognitive deficits and behavioural dysfunctions which is selected from the group consisting of fragile X syndrome, Rett syndrome, Down syndrome, DiGeorge syndrome (22q11.2 deletion syndrome), Prader-Willi syndrome, Angelman syndrome, autism spectrum disorder, Asperger syndrome, attention deficit hyperactivity disorder, bipolar disorder, anxiety, depression, Pheland-McDermid syndrome, Pitt-Hopkins syndrome, schizophrenia, Alzheimer’s disease, Huntington’s disease, Parkinson’s disease.

[0042] In an eight aspect, the invention relates to a method for the treatment of nervous system disorders associated with cognitive deficits and behavioural dysfunctions by administering to a subject in need thereof a compound as defined in the first aspect or a combination as defined in the fifth aspect, preferably wherein the nervous system disorder associated with cognitive deficits and behavioural dysfunctions is selected from the group consisting of fragile X syndrome, Rett syndrome, Down syndrome, DiGeorge syndrome (22q11.2 deletion syndrome), Prader-Willi syndrome, Angelman syndrome, autism spectrum disorder, Asperger syndrome, attention deficit hyperactivity disorder, bipolar disorder, anxiety, depression, Pheland-McDermid syndrome, Pitt-Hopkins syndrome, schizophrenia, Alzheimer’s disease, Huntington’s disease, Parkinson’s disease.

[0043] BRIEF DESCRIPTION OF THE FIGURES

[0044] Figure 1 shows the impact of Compound 1 on the number of neurons in a primary culture of hippocampal neurons. Figure 2 shows the impact of Compound 1 on the neurite network in a primary culture of hippocampal neurons.

[0045] Figure 3 shows the impact of Compound 1 on branching points in a primary culture of hippocampal neurons.

[0046] Figure 4 shows the impact of Compound 1 on neurite extremities in a primary culture of hippocampal neurons.

[0047] Figure 5 shows the results on the co-incubation with inhibitors of TrkB pathway alone (TrkB, PI3K, PLCy and RAS), with Compound 1 alone and with combinations of Compound 1 and inhibitors of TrkB pathway on the number of neurons in a primary culture of hippocampal neurons (day 3).

[0048] Figure 6 shows the results on the co-incubation with inhibitors of TrkB pathway alone (TrkB, PI3K, PLCy and RAS), with Compound 1 alone and with combinations of compound 1 and inhibitors of TrkB pathway on the neurite network in a primary culture of hippocampal neurons (day 3).

[0049] Figure 7 shows the results on the co-incubation with inhibitors of TrkB pathway alone (TrkB, PI3K, PLCy and RAS), with Compound 1 alone and with combinations of compound 1 and inhibitors of TrkB pathway on branching points in a primary culture of hippocampal neurons (day 3).

[0050] Figure 8 shows the results on the co-incubation with inhibitors of TrkB pathway alone (TrkB, PI3K, PLCy and RAS), with Compound 1 alone and with combinations of Compound 1 and inhibitors of TrkB pathway on neurite extremities points in a primary culture of hippocampal neurons (day 3).

[0051] Figure 9 shows the results of the open field test (distance travelled) in a mouse model of FXS using saline or Compound 1 .

[0052] Figure 10 shows the results of the open field test (time moving) in a mouse model of FXS using saline or Compound 1.

[0053] Figure 11 shows the results of the open field test (latency to center) in a mouse model of FXS using saline or Compound 1 . Figure 12 shows the results of the three-chamber partition test (time spent with the novel mouse) in a mouse model of FXS using saline or Compound 1 .

[0054] Figure 13 shows the results of the novel object recognition test (time spent with the novel object) in a mouse model of FXS using saline or Compound 1.

[0055] Figure 14 shows the results of the novel object recognition test (discrimination index) in a mouse model of FXS using saline or Compound 1 .

[0056] Figure 15 shows the results of the hyponeophagia test (latency) in a mouse model of FXS using saline or Compound 1 .

[0057] Figure 16 shows the results of the open field test (total distance) in a mouse model of FXS using saline or Compound 1 .

[0058] Figure 17 shows the results of the open field test (time moving) in a mouse model of FXS using saline or Compound 1.

[0059] Figure 18 shows the results of the open field test (latency to center) in a mouse model of FXS using saline or Compound 1 .

[0060] Figure 19 shows the results of the self-grooming test in a mouse model of FXS using saline or Compound 1 .

[0061] Figure 20 shows the results of the nesting test in a mouse model of FXS using saline or Compound 1.

[0062] Figure 21 shows the results of the marble burying test in a mouse model of FXS using saline or Compound 1 .

[0063] Figure 22 shows the results of the partition test (time spent with the novel mouse) in a mouse model of FXS using saline or Compound 1.

[0064] Figure 23 shows the results of the hyponeophagia test (latency) in a mouse model of FXS using saline or Compound 1 .

[0065] Figure 24 shows the results of the aggression test (number of mounts) in a mouse model of FXS using saline or Compound 1 . Figure 25 shows the results of the novel object recognition test (time spent with the novel object) in a mouse model of FXS using saline or Compound 1.

[0066] Figure 26 shows the results of the novel object recognition test (discrimination index) in a mouse model of FXS using saline or Compound 1 .

[0067] Figure 27 shows the representative images of a dendritic segment of pyramidal cells between groups using saline or Compound 1.

[0068] Figure 28 shows the total spine counts of pyramidal cells between groups using saline or Compound 1.

[0069] Figure 29 shows the overall spine density of pyramidal cells between groups using saline or Compound 1.

[0070] Figure 30 shows the results of novel object recognition (discrimination index) test in a mouse model of Rett Syndrome using saline or Compound 1.

[0071] Figure 31 shows the results of the social recognition test in a mouse model of Rett Syndrome using saline or Compound 1 .

[0072] DESCRIPTION OF THE INVENTION

[0073] In the first aspect the invention relates to a compound having formula (I) wherein,

[0074] • R1is selected from the group consisting of -OR and -NR’R”, wherein R is selected from the group consisting of hydrogen, glycosyl, acyl, acetyl and Ci-Ce alkyl, and R’ and R” are independently selected from the group consisting of hydrogen and Ci-Ce alkyl, • R2is selected from the group consisting of H and OH,

[0075] • R3is selected from the group consisting of H and OH,

[0076] • R4is selected from the group consisting of H, -CH3 and OH,

[0077] • R5is selected from the group consisting of H and -CH3,

[0078] • G1is a divalent linker comprising two carbon atoms and at least one oxygen atom selected from the group consisting of -CH2-CH(OH)-, -CH2-C(=O)-, -CH=C(OH)-, -CH(OH)-CH(OH)-, -CH(OH)-C(=O)-, and -C(=O)-C(=O)-, and

[0079] • G2is selected from the group consisting of -CH2- and -C(=O)-, or a pharmaceutically acceptable salt, hydrate or stereoisomer thereof.

[0080] The term “alkyl” as employed herein alone or as part of another group designates both straight- and branched-chain saturated hydrocarbons containing the indicated number of carbon atoms, such as 1 to 6 carbon atoms, preferably 1 to 4 carbon atoms, more preferably 1 to 3 carbon atoms. Examples of alkyl groups are methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, sec-butyl, pentyl, hexyl, isohexyl, and the various branched-chain isomers thereof.

[0081] The term “acyl” or “alkanoyl” as indistinctively used herein alone or as part of another group refers to an alkyl group attached to a carbonyl group. In the context of the present invention, the terms “acyl” and “alkanoyl” have the same meaning. Thus, a Ci-Ce acyl or alkanoyl groups is a Cn-i alkyl group attached to a carbonyl group. Examples of alkanoyl or acyl groups are acetyl, propionyl and butyroyl.

[0082] The term “glycosyl” as employed herein refers to a radical derived from galactose, glucose and trehalose wherein one of the hydroxyl groups, in particular the hydroxyl groups of the anomeric carbon, has been removed (to form the ether bond with the oxygen atom in the OR group). Preferably, glycosyl refers to 1-O-p-D-galactopyranosyl (galactose), 1-O-p-D-glucopyranosyl (glucose) and 1-O-a-D-glucopyranosyl-a-D- glucopyranosyl (trehalose).

[0083] Where the compounds of formula (I) contain acid groups (such as carboxylic acid) or basic groups (such as amines), they may form pharmaceutically acceptable salts.

[0084] As used herein, the term “pharmaceutically acceptable salt” embraces salts with a pharmaceutically acceptable acid or base. Pharmaceutically acceptable acids include both inorganic acids, for example hydrochloric, sulfuric, phosphoric, diphosphoric, hydrobromic, hydroiodic and nitric acid and organic acids, for example citric, fumaric, maleic, malic, mandelic, ascorbic, oxalic, succinic, tartaric, benzoic, acetic, methanesulfonic, ethanesulfonic, benzenesulfonic, ferulic, caffeic, valproic, lipoic or p- toluenesulfonic acid. Pharmaceutical acceptable bases include alkali metal (e.g., sodium or potassium) and alkali earth metal (e. g. calcium or magnesium) hydroxides and organic bases, such as alkyl amines, arylalkyl amines and heterocyclic amines. Preferably, the pharmaceutically acceptable salt is the hydrochloride salt.

[0085] The compounds of formula (I) may also form hydrates, which are solvates of the compound of formula (I) with a water molecule via non-covalent bonding. The number of molecules compound of formula (I) with respect to the number water molecules may vary. In an embodiment the compounds of formula (I) may be obtained in the form of hemihydrates, i.e. containing two molecules of the compound of formula (I) per one molecule of water.

[0086] All stereoisomers of the compounds of this invention are contemplated either alone or as mixtures thereof. The process of preparation can utilize racemates, enantiomers, or diastereomers as starting materials. When diastereomeric or enantiomeric products are prepared, they can be separated by conventional methods, for example chromatographic or functional crystallization.

[0087] The term “stereoisomer” as used herein makes reference to compounds made up of the same atoms bonded by the same sequence of bonds but having different three- dimensional structures which are not interchangeable, for example, due to the presence of chiral centers. The present invention encompasses all such variations, in particular enantiomers, diastereoisomers and mixtures thereof. Enantiomers refer to a pair of stereoisomers that differ in all stereocenters and are therefore mirror images of one another. Diastereoisomers refer to compounds that have different configurations at one or more (but not all) of the stereocenters and are not mirror images of each other.

[0088] The compounds of the present invention represented by the above-described formula (I) have at least one chiral carbon atom shown below with an asterisk *

[0089] Moreover, when G1is -CH2-*CH(OH)- it has a chiral carbon atom (marked with an asterisk), when G1is -*CH(OH)-C(=O)- it has a chiral carbon atom (marked with an asterisk), and when G1is -*CH(OH)-*CH(OH)- it has two chiral carbon atoms (marked with an asterisk).

[0090] The present invention encompasses all stereoisomers of the compounds of formula (I), either as a single stereoisomer or mixtures of one or more stereoisomers.

[0091] G1is a divalent linker comprising two carbon atoms and at least one oxygen atom selected from the group consisting of -CH2-CH(OH)-, -CH2-C(=O)-, -CH=C(OH)-, -CH(OH)-CH(OH)-, -CH(OH)-C(=O)-, and -C(=O)-C(=O)-. When G1is not symmetrical, the carbon atom depicted on the left part of the mentioned G1groups may be bonded to the benzene ring or to the R1residue; the carbon atom depicted on the right side of said G1groups may be bonded to the R1residue or the benzene ring. For example, -CH2-CH(OH)- is the same as -CH(OH)-CH2-.

[0092] Preferably, in the compounds of formula (I) according to the invention, G1is selected from the group consisting of -CH2-C(=O)-, -CH(OH)-C(=O)- and -C(=O)-C(=O)-; more preferably G1is selected form the group consisting of -CH2-C(=O)-, -CH(OH)-C(=O)- and -C(=O)-C(=O)-, wherein the carbon atom depicted on the left part of said G1groups is bonded to the benzene ring and the carbon atom depicted on the right side of said G1groups is bonded to the R1residue; more preferably G1is -CH2-C(=O)- or-C(=O)-C(=O)-; still more preferably G1is -CH2-C(=O)- or -C(=O)-C(=O)-, wherein the carbon atom depicted on the left part of said G1groups is bonded to the benzene ring and the carbon atom depicted on the right side of said G1groups is bonded to the R1residue; even more preferably G1is -CH2-C(=O)-; the most preferred, G1is -CH2-C(=O)- wherein the carbon atom depicted on the left part of said G1groups is bonded to the benzene ring and the carbon atom depicted on the right side of said G1groups is bonded to the R1residue. Preferably, in the compounds of formula (I) according to the invention, at least one of R2and R3is H.

[0093] Preferably, in the compounds of formula (I) according to the invention, R2is H.

[0094] Preferably, in the compounds of formula (I) according to the invention, R3is H.

[0095] Preferably, in the compounds of formula (I) according to the invention, both R2and R3are H.

[0096] Preferably, in the compounds of formula (I) according to the invention, R4is H or -CH3, more preferably H.

[0097] Preferably, in the compounds of formula (I) according to the invention, R5is -CH3.

[0098] Preferably, in the compounds of formula (I) according to the invention, G2is -CH2-.

[0099] Preferably, in the compounds of formula (I) according to the invention, R1is -OR; preferably -OH.

[0100] Preferably, in the compounds of formula (I) according to the invention, R1is -NR’R”; R’ and R” are independently selected from the group consisting of hydrogen and Ci-Ce alkyl; preferably hydrogen.

[0101] Preferably, in the compounds of formula (I) according to the invention, G1is selected from the group consisting of -CH2-C(=O)- and-C(=O)-C(=O)-, R1is -OR, R2, R3and R4are H, R5is -CH3 and G2is -CH2-. More preferably, in the compounds of formula (I) according to the invention, G1is selected from the group consisting of -CH2-C(=O)- and -C(=O)-C(=O)-, wherein the carbon atom depicted on the left part of said G1groups is bonded to the benzene ring and the carbon atom depicted on the right side of said G1groups is bonded to the R1residue, R1is -OR, R2, R3and R4are H, R5is -CH3 and G2is -CH2-.

[0102] Preferably, in the compounds of formula (I) according to the invention, G1is selected from the group consisting of -CH2-C(=O)- and -C(=O)-C(=O)-, R1is -OH, R2, R3and R4are H, R5is -CH3 and G2is -CH2-. More preferably, in the compounds of formula (I) according to the invention, G1is selected from the group consisting of -CH2-C(=O)- and -C(=O)-C(=O)-, wherein the carbon atom depicted on the left part of said G1groups is bonded to the benzene ring and the carbon atom depicted on the right side of said G1 groups is bonded to the R1residue, R1is -OH , R2, R3and R4are H, R5is -CH3 and G2is -CH2-.

[0103] Preferably, in the compounds of formula (I) according to the invention, G1is -CH2-C(=O)-, R1is -OH, R2, R3and R4are H, R5is -CH3 and G2is -CH2-. More preferably, in the compounds of formula (I) according to the invention, G1is -CH2-C(=O)-, wherein the carbon atom depicted on the left part of said G1groups is bonded to the benzene ring and the carbon atom depicted on the right side of said G1groups is bonded to the R1residue, R1is -OH, R2, R3and R4are H, R5is -CH3 and G2is -CH2-.

[0104] Preferably, the compound of formula (I) according to the invention is selected from group consisting of:

[0105] • 2-(4-(3-(methylamino)-1-phenylpropoxy)phenyl)acetic acid

[0106] • methyl 2-(4-(3-(methylamino)-1-phenylpropoxy)phenyl)acetate

[0107] • 2-(4-(3-(methylamino)-1-phenylpropoxy)phenyl)acetamide

[0108] • 2-(4-(3-(methylamino)-1-phenylpropoxy)phenyl)ethane-1 ,1-diol

[0109] • 2-(4-(3-(methylamino)-1-phenylpropoxy)phenyl)ethene-1 ,1-diol

[0110] • 2-hydroxy-2-(4-(3-(methylamino)-1-phenylpropoxy)phenyl)acetic acid

[0111] • 2-(2-hydroxy-4-(3-(methylamino)-1-phenylpropoxy)phenyl)acetic acid

[0112] • 2-(3-hydroxy-4-(3-(methylamino)-1-phenylpropoxy)phenyl)acetic acid

[0113] • 2-(4-(3-(methylamino)-1-phenylpropoxy)phenyl)-2-oxoacetic acid

[0114] • 2-(4-(3-amino-1-phenylpropoxy)phenyl)ethane-1 ,1-diol

[0115] • 2-(4-(3-amino-1-phenylpropoxy)phenyl)acetic acid

[0116] • 2-hydroxy-1-(4-(3-(methylamino)-1-phenylpropoxy)phenyl)ethan-1-one or a pharmaceutically acceptable salt, hydrate or stereoisomer thereof.

[0117] Preferably, the compound of formula (I) according to the invention is selected from the group consisting of 2-(4-(3-(methylamino)-1-phenylpropoxy)phenyl)acetic acid, methyl 2-(4-(3-(methylamino)-1-phenylpropoxy)phenyl)acetate and 2-(4-(3-(methylamino)-1- phenylpropoxy)phenyl)acetamide or pharmaceutically acceptable salts, hydrates or stereoisomers thereof; more preferably, the compound of formula (I) according to the invention is selected from group consisting of 2-(4-(3-(methylamino)-1- phenylpropoxy)phenyl)acetic acid or a pharmaceutically acceptable salt, hydrate or stereoisomer thereof, more preferably selected from the group consisting of (R)-2-(4-(3- (methylamino)-1-phenylpropoxy)phenyl)acetic acid, (S)-2-(4-(3-(methylamino)-1- phenylpropoxy)phenyl)acetic acid, and mixtures thereof, preferably the racemate thereof, or a pharmaceutically acceptable salt or hydrate thereof. More preferably, the compound of formula (I) according to the invention is 2-(4-(3- (methylamino)-1-phenylpropoxy)phenyl)acetic acid or a pharmaceutically acceptable salt, hydrate or stereoisomer thereof. Still more preferably, the compound of formula (I) according to the invention is 2-(4-(3-(methylamino)-1-phenylpropoxy)phenyl)acetic acid hydrochloride hemihydrate salt.

[0118] The compounds of formula (I) of the present invention can be prepared as shown in the following reaction schemes 1 and 2 and the description thereof. All the stereoisomers, hydrates and salts of the compounds depicted in these schemes, unless otherwise specified, are also encompassed within the scope of this invention. Protection and deprotection steps, when needed, may be carried out by general procedures (see, for example, Greene, T.W. and Wuts, P.G.M. Protecting Groups in Organic Synthesis (Third Edition), J. Wiley & Sons, 1999).

[0119] Scheme 1

[0120] (II) (IV) (i)

[0121] The compounds of formula (I) may be synthesized by reaction of a compound of formula (II), wherein R2, R3and G1are as defined for the compounds of formula (I), and LGi is a leaving group selected from halogen, alkoxy, methylsufonyl, p-toluenesulfonyl, trifluoromethylsulfonyl, and the like, with a compound of formula (III), wherein G2, R4and R5are as defined for the compound of formula (I), under suitable conditions such as those of Mitsunobu reaction, to give a compound of formula (IV) wherein R2-R5, G1, G2and LGi are as previously defined. The compound of formula (IV) may be then reacted with R1-X, wherein R1is as defined for the compounds of formula (I) and X is selected from the group consisting of H and a counterion selected from the alkali and alkaline- earth metals, such as but not limited to Li+, Na+, K+, Cs+, Mg2+, Ca2+, and the like, under suitable acid or basic conditions, to give the compounds of formula (I). Scheme 2

[0122] The compounds of formula (I) may also be synthesized by reaction of a compound of formula (II), wherein R2, R3and G1are as defined for the compounds of formula (I), and LGi is a leaving group selected from halogen, alkoxy, methylsufonyl, p-toluenesulfonyl, trifluoromethylsulfonyl, and the like, with R1-X, wherein R1is as defined for the compounds of formula (I) and X is selected from the group consisting of H and a counterion selected from the alkali and alkaline-earth metals, such as but not limited to Li+, Na+, K+, Cs+, Mg2+, Ca2+, and the like, under suitable acid or basic conditions, to give a compound of formula (V) wherein R1-R3and G1are as defined for the compounds of formula (I). The compound of formula (V) may be then reacted with a compound of formula (III), wherein G2, R4and R5are as defined for the compound of formula (I), under suitable conditions such as those of Mitsunobu reaction, to give the compounds of formula (I).

[0123] Compounds of formula (II), compounds of formula (III), and R1-X are either commercially available of may be prepared by conventional procedures known in the art.

[0124] The term “halogen” as used herein alone or as part of another group refers to chlorine, bromine, fluorine and iodine.

[0125] The term “alkoxy” as employed herein alone or as part of another group designates an alkyl group containing 1 to 20 carbons, preferably 1 to 10 carbons, more preferably 1 to 8 carbons, more preferably 1 to 6 carbons, and still more preferably 1 to 3 carbons linked to an oxygen atom. Examples of alkoxy groups are methoxy, ethoxy, n-propoxy, isopropoxy, n-butoxy, isobutoxy, tert-butoxy, pentoxy, hexyloxy, isohexyloxy, heptyloxy, 4,4-dimethylpentoxy, octyloxy, 2,2,4-trimethylpentoxy, nonyloxy, decyloxyl, undecyloxy, dodecyloxy, and the various branched-chain isomers thereof.

[0126] In a second aspect, the invention relates to a pharmaceutical composition comprising a compound as defined in the first aspect and one or more pharmaceutically acceptable carrier.

[0127] The term "pharmaceutically acceptable" refers to molecular entities and compositions that are physiologically tolerable and do not typically produce an allergic or similar untoward reaction, such as gastric upset, dizziness and the like, when administered to a human. Preferably, as used herein, the term "pharmaceutically acceptable" means approved by a regulatory agency of the Federal or a state government, such as the ones from Europe, USA and Japan, or listed in the EU, U.S. or Japan Pharmacopeia or other generally recognized pharmacopeia for use in animals, and more particularly in humans.

[0128] The term "carrier" refers to a diluent, adjuvant, excipient, vehicle or mixture thereof with which the active ingredient is administered. Such pharmaceutical carriers can be sterile liquids, such as water and oils, including those of petroleum, animal, vegetable or synthetic origin, such as peanut oil, soybean oil, mineral oil, sesame oil and the like. Water or aqueous solution saline solutions and aqueous dextrose and glycerol solutions are preferably employed as carriers, particularly for injectable solutions. Suitable pharmaceutical carriers are described in "Remington's Pharmaceutical Sciences" by E.W. Martin.

[0129] Examples of pharmaceutical compositions include any solid (tablets, pills, capsules, granules, etc.) or liquid (solutions, suspensions or emulsions) composition for oral, intranasal, topical or parenteral administration, such as concentrate, dispersion, drops, emulsion, liquid, solution, suspension, spray, syrup, cream, gel, ointment, paste, block, sachet, cachet, capsule, film, granules, gum, lozenge, lyophilizate, pastille, patch, pellets, pessary, plaster, powder, stick, suppository, tablets and mini-tablets. The pharmaceutical composition can be formulated employing carriers according to the desired mode of administration, under conventional, delayed, modified and prolonged release characteristics.

[0130] Preferably, pharmaceutical compositions for parenteral administration may comprise physiologically acceptable sterile aqueous or non-aqueous solutions, emulsions, suspensions (in particular in the case of intramuscular administration or implants) and powders for reconstitution as injectable dosage forms.

[0131] Preferably, pharmaceutical compositions for parenteral administration may also comprise the compounds of the invention of formula (I) in powder form which may be diluted in phosphate buffered saline comprising polysorbate 80, potassium chloride, monobasic phosphate, sodium chloride, dibasic sodium phosphate and water for injection prepared to the desired proportion and volume.

[0132] Preferably, liposome injections for intrathecal use may be prepared in a sterile, injectable dispersion of compounds of formula (I), encapsulated in multi-vesicular lipid-based particles.

[0133] Preferably, pharmaceutical compositions for oral administration may be in the form of tables, capsules or liquid compositions such as aqueous based oral solutions and oral suspensions.

[0134] Tablets may be prepared containing as inactive ingredients lactose, magnesium stearate, hydroxypropylmethylcellulose, polyethylene glycol, povidone, sodium starch glycolate and titanium dioxide.

[0135] Capsules may be prepared containing as inactive ingredients talcum, sodium lauryl sulfate, colloidal silicon dioxide, magnesium stearate, titanium dioxide (E171), hard gelatin or hydroxypropylmethylcellulose capsule, black ink, propylene glycol and shellac.

[0136] Aqueous based oral solutions may be prepared containing as inactive ingredients citric acid, sodium citrate, benzoic acid, fruit flavorings, hydroxyethylcellulose, sorbitol, and water.

[0137] Oral suspensions may be prepared containing as inactive ingredients glycerin, carboxymethylcellulose sodium, hydroxyethylcellulose, citric acid, sodium citrate, benzoic acid, simethicone, polysorbate 80, flavorings, and water.

[0138] As shown in the examples, the compounds of formula (I) are useful for the treatment of nervous system disorder associated with cognitive deficits and behavioural dysfunctions, in particular fragile X syndrome and Rett syndrome.

[0139] Thus, in a third aspect, the invention relates to a compound as defined in the first aspect for use as a medicament. In a fourth aspect, the invention relates to a compound as defined in the first aspect for use in the treatment of, preferably wherein the nervous system disorder associated with cognitive deficits and behavioural dysfunctions is selected from the group consisting of fragile X syndrome, Rett syndrome, Down syndrome, DiGeorge syndrome (22q11.2 deletion syndrome), Prader-Willi syndrome, Angelman syndrome, autism spectrum disorder, Asperger syndrome, attention deficit hyperactivity disorder, anxiety, bipolar disorder, depression, Pheland-McDermid syndrome, Pitt-Hopkins syndrome, schizophrenia, Alzheimer’s disease, Huntington’s disease, Parkinson’s disease; more preferably Rett syndrome; still more preferably fragile X syndrome.

[0140] This aspect may be also formulated as the use of a compound as defined in the first aspect in the manufacture of a medicament for the treatment of, preferably wherein the nervous system disorder associated with cognitive deficits and behavioural dysfunctions is selected from the group consisting of fragile X syndrome, Rett syndrome, Down syndrome, DiGeorge syndrome (22q11.2 deletion syndrome), Prader-Willi syndrome, Angelman syndrome, autism spectrum disorder, Asperger syndrome, attention deficit hyperactivity disorder, anxiety, bipolar disorder, depression, Pheland-McDermid syndrome, Pitt-Hopkins syndrome, schizophrenia, Alzheimer’s disease, Huntington’s disease, Parkinson’s disease; more preferably fragile X syndrome or Rett syndrome; more preferably Rett syndrome; still more preferably fragile X syndrome.

[0141] This aspect may be also formulated as the method of treatment of nervous system disorders associated with cognitive deficits and behavioural dysfunctions, preferably wherein the nervous system disorder associated with cognitive deficits and behavioural dysfunctions is selected from the group consisting of fragile X syndrome, Rett syndrome, Down syndrome, DiGeorge syndrome (22q11.2 deletion syndrome), Prader-Willi syndrome, Angelman syndrome, autism spectrum disorder, Asperger syndrome, attention deficit hyperactivity disorder, anxiety, bipolar disorder, depression, Pheland- McDermid syndrome, Pitt-Hopkins syndrome, schizophrenia, Alzheimer’s disease, Huntington’s disease, Parkinson’s disease; more preferably fragile X syndrome or Rett syndrome, more preferably Rett syndrome, still more preferably fragile X syndrome; wherein the method comprises administering a compound as defined in the first aspect to a subject in need thereof.

[0142] The term treatment is used to designate the administration of a pharmaceutically active compound or a composition thereof to control disease progression before or after the clinical signs have appeared. By control of the disease progression, it is meant to designate beneficial or desired clinical results including, but not limited to, reduction of symptoms, reduction of the length of the disease, stabilization of the pathological state (specifically avoidance of further deterioration), delay in the disease progression, improvement of the pathological state and remission (both partial and total). Control of disease progression can also entail prolonged survival, compared to the expected survival if the treatment is not applied. In a particular embodiment of the invention, the compounds and compositions of the invention may be used to control the disease progression once at least one of the clinical signs of the disease has appeared.

[0143] The expression “nervous system disorder associated with cognitive deficits and behavioural dysfunctions” refers to developmental anomalies, such as fragile X syndrome, Rett syndrome, Down syndrome, DiGeorge syndrome (22q11.2 deletion syndrome), Prader-Willi syndrome, and Angelman syndrome; mental, behavioural and neurodevelopmental disorders such as autism spectrum disorder, Asperger syndrome, attention deficit hyperactivity disorder, anxiety, bipolar disorder, depression, Pheland- McDermid syndrome, Pitt-Hopkins syndrome, and schizophrenia; and diseases of the nervous system, such as Alzheimer’s disease, Huntington’s disease, and Parkinson’s disease; as defined by the World Health Organization in the International Classification of Diseases 11th Revision (ICD-11 , https: / / icd.who.int / ).

[0144] The compounds of the first aspect may also be administered in combination with other drugs that are also useful for the treatment of nervous system disorders associated with cognitive deficits and behavioural dysfunctions.

[0145] Thus, in the fifth aspect, the invention relates to a combination comprising a compound as defined in the first aspect and another drug selected from the group consisting of drugs for the treatment of nervous system disorders or their clinical manifestations: anxiolytics and antidepressants, such as sertraline, fluoxetine, citalopram, escitalopram, trazodone, bupropion, cannabidiol, paroxetine, duloxetine, buspirone, venlafaxine, desvenlafaxine, olanzapine, mirtazapine, psilocybin and atomoxetine; antipsychotics, such as aripiprazole, risperidone, quetiapine and olanzapine; tranquilizers, such as clonazepam and lorazepam; hypnotics, such as zolpidem and melatonin; stimulants, such as methylphenidate, amphetamine, amphetamine salts and L-acetylcarnitine; nonstimulants, such as clonidine and guanfacine; cognition enhancers, such as donepezil, zatolmilast, trofinetide and metformin; antiepileptics and anticonvulsants, such as levetiracetam, oxcarbazepine, valproic acid, valproate, carbamazepine, lamotrigine and topiramate; and 2-[4-[3-(methylamino)-1-phenylpropoxy]phenyl]ethanol or a pharmaceutically acceptable salt, hydrate or stereoisomer thereof.

[0146] The term “combination” refers to a one or more compositions wherein the above- mentioned products are distributed among the one or more compositions, for example one or two compositions, in particular wherein one composition comprises the compound of formula (I) as defined in the first aspect and another composition comprises the other drug, or one composition comprising both the compounds of formula (I) and the other drug.

[0147] In a particular embodiment, the combination does not comprise 2-[4-[3-(methylamino)- 1-phenylpropoxy]phenyl]ethanol or a pharmaceutically acceptable salt, hydrate or stereoisomer thereof.

[0148] In a particular embodiment, the combination comprises 2-[4-[3-(methylamino)-1- phenylpropoxy]phenyl]ethanol or a pharmaceutically acceptable salt or stereoisomer thereof and 2-(4-(3-(methylamino)-1-phenylpropoxy)phenyl)acetic acid or a pharmaceutically acceptable salt, hydrate or stereoisomer thereof.

[0149] Preferably, the 2-[4-[3-(methylamino)-1-phenylpropoxy]phenyl]ethanol or pharmaceutically acceptable salt or stereoisomer thereof is in the form of the hydrochloride salt. In one embodiment, the 2-[4-[3-(methylamino)-1- phenylpropoxy]phenyl]ethanol or pharmaceutically acceptable salt or stereoisomer thereof is in the form of the (S)-2-[4-[3-(methylamino)-1-phenylpropoxy]phenyl]ethanol enantiomer or pharmaceutically acceptable salt or stereoisomer thereof, in the form of the (R)-2-[4-[3-(methylamino)-1-phenylpropoxy]phenyl]ethanol enantiomer or pharmaceutically acceptable salt or stereoisomer thereof, or mixtures thereof. More preferably, the (S)-2-[4-[3-(methylamino)-1 -phenylpropoxy] phenyl]ethanol or a pharmaceutically acceptable salt or stereoisomer thereof is in the form of (S)-2-[4-[3- (methylamino)-1-phenylpropoxy]phenyl]ethanol hydrochloride, the (R)-2-[4-[3- (methylamino)-1-phenylpropoxy]phenyl]ethanol enantiomer is in the form of (R)-2-[4-[3- (methylamino)-l -phenylpropoxy]phenyl]ethanol hydrochloride, or mixtures thereof.

[0150] Drugs of the present invention may be administered as a liquid, semi-solid or solid state of matter. Any dosage form commonly used for drugs, such as concentrate, dispersion, drops, emulsion, liquid, solution, suspension, spray, syrup, cream, gel, ointment, paste, block, sachet, cachet, capsule, film, granules, gum, lozenge, lyophilizate, pastille, patch, pellets, pessary, plaster, powder, stick, suppository, and tablets, may be used. The pharmaceutical composition can be formulated employing conventional carriers according to the desired mode of administration, under conventional, delayed, modified and prolonged release characteristics. The intended site may be buccal, endocervical, gastric, gastroenteral, intestinal, intraarticular, intraperitoneal, intrathecal, intrauterine, intravesical, nasal, oral, parenteral, pulmonary, rectal, sublingual, subcutaneous, topical, transdermal, urethral or vaginal by swallowing, chewing, sucking application, bioadhesion, insertion, orodispersion, infusion, inhalation, and injection administration methods. Preferably, the compositions of the invention are administered orally (solids or liquids), transdermally, subcutaneously, parenterally, locally (ointments, creams, gels, plasters, powders), as drops or as a nasal or buccal compositions.

[0151] When the combination as defined above comprises more than one composition, for example two compositions as defined above, said compositions may be administered simultaneously or separately.

[0152] Simultaneous administration refers to the administration of the compositions at the same time point, for example within a time span of no more than 5 minutes. Simultaneous administration is feasible for combinations as defined above in the form of one or more compositions, such as one or two compositions.

[0153] Separate administration refers to the administration of one composition at one time point and another composition at another time point independently of each other at different time points, for example wherein the time points are separated by more than 5 minutes, such as more than 15 minutes, more than 1 hour, more than 2 hours, more than 3 hours or more than 6 hours. Separate administration is only feasible when the combination as defined above is in the form of more than one composition, such as two compositions.

[0154] EXAMPLES

[0155] The following examples represent specific embodiments of the present invention. Method A:

[0156] Triphenylphosphine (1.25 eq.), methyl 2-(4-hydroxy-phenyl)acetate (1.0 eq.) and tertbutyl 3-hydroxy-3-phenylpropyl(methyl)carbamate (1 .27 eq.) were dissolved in toluene under nitrogen and cooled to 0 °C. A solution of DEAD (-40% in toluene, 1.25 eq.) was added drop wise at 0°C. The mixture was allowed to warm to rt during 1h and heated at 80 °C for 21 h. Then, it was cooled to room temperature, diluted with ethyl acetate and washed with 5% HCI (3x), dried over anhydrous MgSO4 and concentrated under vacuum. The resulting crude was purified by flash chromatography to afford the expected product in 74% yield as a colorless oil.

[0157] Method B:

[0158] Methyl 2-(4-hydroxy-phenyl)acetate (1.0 eq.), tert-butyl 3-hydroxy-3- phenylpropyl(methyl)carbamate (1.1 eq.) and Triphenylphosphine (1.2 eq.) was dissolved Toluene and cooled to 0-10°C. A 40% DEAD solution in toluene (1.2 eq.) was successively added at 0-10°C and the mixture was stirred at 0-10 °C for 1 h and allowed the reaction mass temperature to reach 25-35°C. Progress of the reaction was monitored by HPLC / TLC. After completion of the reaction, add n-Heptane at 25-35 °C. Allow the reaction mass to reach 0-10 °C and stir the reaction mixture at 0-5°C for 1-2 h. Filter the reaction mass and wash the wet cake with 25% toluene in heptane mixture. Filtered liquid was washed with water and brine. The organic layer was dried over anhydrous Na2SC>4 and concentrated the solvent up to 2.5-3 vol. and co-distilled with n-hexanes. The crude obtained was purified by silica gel column chromatography to afford the expected product in 50% yield.

[0159] 2-(4-3-((tert-butoxycarbonyl)(methyl)amino)-1-phenylpropoxy)phenyl)acetic acid

[0160] To a stirred solution of methyl 2-(4-3-((tert-butoxycarbonyl)(methyl)amino)-1- phenylpropoxy)phenyl) acetate (1.0 eq.) in THF (10 vol.) and water (2.0 vol.) at room temperature, LiOH H2O (2.5 eq.) was added and the mixture was stirred for 2h at room temperature. Reaction progress was monitored by TLC. After completion of reaction, reaction mass was distilled to remove the THF solvent. Water (10 vol.) was added to the reaction mass and pH adjusted to 2-3 with 6N HCI at 10-15 °C. Reaction mass was extracted with Ethyl acetate at room temperature. Distilled off the Ethyl acetate solvent up to 4.0-5.0 vol. remains in the reaction mass. Filtered the reaction mass at room temperature and dried the material at 50-55 °C. Ethyl acetate was added to the dried material and heated the mass at 50-55 °C and stirred for 20 min. Cooled the reaction mass to 10-15 °C and 4N HCI in Ethyl acetate was added to the reaction mass and stirred for 2 h at 10-15 °C. Reaction progress was monitored by TLC. After completion of reaction, reaction mass was filtered, washed and the material was dried at 50-55 °C. 2-(4-3-(methylamino)-1-phenylpropoxy)phenyl)acetic acid hydrochloride hemihydrate To a stirred solution of methyl 2-(4-3-((tert-butoxycarbonyl)(methyl)amino)-1- phenylpropoxy)phenyl) acetate (1.0 eq.) in THF and water at room temperature, LiOH H2O was added and stirred for 3h at room temperature. Reaction progress was monitored by TLC. After completion of reaction, reaction mass was distilled to remove the THF solvent. Water was added to the reaction mass and pH adjusted to 2-3 with 6N HCI at 10-15 °C. Reaction mass was extracted with ethyl acetate at room temperature. The aqueous and organic layers were separated and the organic layer was worked-up in brine, filtered and the solvent distilled to dryness. Ethyl acetate was added to the dried material and heated the mass at 50-55 °C and stirred for 20 min. Cooled the reaction mass to 10-15 °C and 4N HCI in ethyl acetate was added to the reaction mass and stirred for 2 h at 10-15 °C. After completion of reaction, crude was filtered, washed with ethyl acetate and dried to afford 2-(4-(3-(methylamino)-1-phenylpropoxy)phenyl)acetic acid hydrochloride hemihydrate in 67% yield.

[0161] 1H NMR (400 MHz, DMSO-cfe), 6: 9.42 (br, 1 H), 7.42 (d, J = 6.8, 2H), 7.35 (t, J = 7.2, 2H), 7.26 (t, J = 7.2 Hz, 1 H), 7.08 (d, J = 8.8 Hz, 2H), 6.86 (d, J = 8.4 Hz, 2H), 5.58-5.55 (m, 1 H), 3.44 (s, 2H), 3.04 - 2.98 (m, 2H), 2.52 (s, 3H), 2.32 - 2.19 (m, 2H) ppm.

[0162] 13C NMR (100 MHz, DMSO-cfe), 6: 172.93, 156.04, 140.84, 130.32, 128.71 , 127.88, 127.46, 126.04, 115.74, 76.14, 45.28, 40.12, 34.24, 32.37 ppm.

[0163] Elemental analysis: Found: C, 63.12%; H, 6.77%; N, 4.09%; O, 16.19%; S, 0.00%. Cl content (by potentiometric analysis): 10.54%; H2O content (by Karl-Fisher): 2.2% Molecular formula: Ci8H2iNO3 HCI-1 / 2H2O; Molecular weight: 344.82 g / mol MS-ESI (+): (m / z): [M+H]+= 300.15

[0164] Title compound was prepared in 21 % yield, 98% purity and 99% enantiomeric purity, following the same procedure described in Example 1 , using methyl (R)-3- (methylamino)-l -phenylpropanol as starting material.

[0165] 1H NMR (400 MHz, DMSO-cfe), 6: 12.22 (br, 1 H), 9.15 (br, 2H), 7.40 (tt, i = 7.2 Hz, J2= 1.2 Hz, 2H), 7.36 (tt, i = 7.2 Hz, J2= 1.2 Hz, 2H), 7.29 (tt, i = 7.2 Hz, J2= 1.2 Hz, 1 H), 7.07 (d, J = 8.8 Hz, 2H), 6.84 (d, J = 8.8 Hz, 2H), 5.52 (m, 1 H), 3.42 (s, 2H), 3.05 - 2.95 (m, 2H), 2.53 (s, 3H), 2.31 - 2.12 (m, 2H) ppm.13C NMR (100 MHz, DMSO-cfe), 6: 172.81 , 155.94, 140.75, 130.24, 128.65, 127.80, 127.37, 125.95, 115.63, 76.05, 45.18, 40.12, 34.15, 32.32 ppm.

[0166] Melting point: 136-145°C

[0167] Elemental analysis: Found: C, 61.59%; H, 6.73%; N, 3.82%; O, 14.94%; S, 0.00%.

[0168] Cl content (by potentiometric analysis): 10.92%; Molecular formula: C18H21NO3 HCI Molecular weight: 335.83 g / mol; MS-ESI (+): (m / z): [M+H]+= 300.16

[0169] Title compound was prepared in 16% yield, 99% purity and 100% enantiomeric purity, following the same procedure described in Example 1 , using methyl (S)-3- (methylamino)-l -phenylpropanol as starting material.

[0170] 1H NMR (400 MHz, DMSO-cfe), 6: 12.22 (br, 1 H), 9.19 (br, 2H), 7.40 (tt, i = 7.2 Hz, J2= 1.2 Hz, 2H), 7.36 (t, J = 7.2 Hz, 2H), 7.28 (tt, i = 7.2 Hz, J2= 1.2 Hz, 1 H), 7.07 (d, J = 8.8 Hz, 2H), 6.84 (d, J = 8.8 Hz, 2H), 5.52 (m, 1 H), 3.42 (s, 2H), 3.02 - 2.97 (m, 2H), 2.53 (s, 3H), 2.29 - 2.15 (m, 2H) ppm.

[0171] 13C NMR (100 MHz, DMSO-cfe), 6: 172.82, 155.95, 140.76, 130.24, 128.65, 127.81 , 127.38, 125.96, 115.64, 76.05, 45.18, 40.12, 34.16, 32.31 ppm.

[0172] Melting point: 145-150°C

[0173] Elemental analysis: Found: C, 62.43%; H, 6.56%; N, 3.79%; O, 15.39%; S, 0.00%.

[0174] Cl content (by potentiometric analysis): 10.68%

[0175] Molecular formula: C18H21NO3 HCI; Molecular weight: 335.83 g / mol; MS-ESI (+): (m / z): [M+H]+= 300.16 4-(3-(methylamino)-1 -

[0176] Title compound was prepared in 26% yield and 99% purity following a procedure adapted from Example 1 , using methyl 3-(methylamino)-1-phenylpropanol as starting material.

[0177] 1H NMR (400 MHz, DMSO-cfe), 6: 9.31 (br, 2H), 7.41 (dd, i = 7.2 Hz, J2= 1.2 Hz, 2H), 7.36 (t, J = 7.2 Hz, 2H), 7.28 (tt, i = 7.2 Hz, J2= 1 .2 Hz, 1 H), 7.08 (d, J = 8.8 Hz, 2H), 6.86 (d, J = 8.4 Hz, 2H), 5.56 (m, 1 H), 3.56 (s, 3H), 3.53 (s, 2H), 3.02 - 2.97 (m, 2H), 2.52 (s, 3H), 2.30 - 2.16 (m, 2H) ppm.

[0178] 13C NMR (100 MHz, DMSO-cfe), 6: 171.76, 156.13, 140.75, 130.23, 128.64, 127.80, 126.64, 125.97, 115.75, 76.04, 51.58, 45.16, 40.12, 34.16, 32.26 ppm.

[0179] Melting point: 103-106 °C

[0180] Elemental analysis: Found: C, 64.55%; H, 6.81 %; N, 3.77%; O, 14.85%; S, 0.00%. Cl content (by potentiometric analysis): 10.43%; Molecular formula: C19H23NO3 HCI

[0181] Molecular weight: 349.86 g / mol; MS-ESI (+): (m / z): [M+H]+= 314.17 methylamino)-1-

[0182] Title compound was prepared in 17% yield and 99% purity following a procedure adapted from Example 1 , using methyl 3-(methylamino)-1 -phenylpropanol as starting material. 1H NMR (400 MHz, DMSO-cfe), 6: 9.17 (br, 2H), 7.41 (tt, i = 7.2 Hz, J2= 1.6 Hz, 2H), 7.37 (t, J = 7.2 Hz, 2H), 7.29 (tt, i = 7.2 Hz, J2= 1.6 Hz, 1 H), 7.07 (d, J = 8.8 Hz, 2H), 6.81 (dd, i = 8.8 Hz, J2= 1.6 Hz, 2H), 6.80 (br, 2H), 5.51 (m, 1 H), 3.23 (s, 2H), 3.01 - 2.96 (m, 2H), 2.50 (s, 3H), 2.27 - 2.14 (m, 2H) ppm.

[0183] 13C NMR (100 MHz, DMSO-cfe), 6: 171.76, 156.13, 140.75, 130.23, 128.64, 127.80, 126.64, 125.97, 115.75, 76.04, 51.58, 45.16, 40.12, 34.16, 32.26 ppm.

[0184] Melting point: 128-133 °C

[0185] Elemental analysis: Found: C, 57.38%; H, 6.56%; N, 7.33%; O, 12.01 %; S, 0.00%.

[0186] Cl content (by potentiometric analysis): 18.21 %

[0187] Molecular formula: C18H22N2O2 2HCI; Molecular weight: 371.30 g / mol; MS-ESI (+): (m / z): [M+H]+= 299.17 of 2-hydroxy-2-(4-(3-(methylamino)-1 - drochloride (Compound 6)

[0188] Title compound was prepared in moderate to low yield following the same procedure described in Example 1 , using methyl 2-hydroxy-2-(4-hydroxyphenyl)acetate as starting material.

[0189] MS-ESI (+): (m / z): [M+H]+= 316.15

[0190] Title compound was prepared in moderate to low yield following the same procedure described in Example 1 , using methyl 2,4-dihydroxyphenylacetate as starting material.

[0191] MS-ESI (+): (m / z): [M+H]+= 316.15 Title compound was prepared in moderate to low yield following the same procedure described in Example 1 , using methyl 3,4-dihydroxyphenylacetic acid as starting material.

[0192] MS-ESI (+): (m / z): [M+H]+= 316.15

[0193] 9.1. Materials and methods

[0194] 9.1.1. Binding assays

[0195] The in vitro binding activity to the norepinephrine transporter was tested following the experimental protocol disclosed in Pacholczyk, T. [Nature, (1991), 350: 350-354] on human recombinant CHO cells using [3H]nisoxetine as the ligand at 1 nM concentration (Kd 2.9 nM), the non-specific binding was determined using desipramine (1 pM), the incubation time was 120 min at 4°C and the detection method was by scintillation counting.

[0196] The in vitro binding activity to the dopamine transporter was tested following the experimental protocol disclosed in Pristupa, Z.B. et al. [Mol. Pharmacol., (1994), 45: 125- 135] on human recombinant CHO cells using [3H]BTCP as the ligand at 4 nM concentration (Kd 4.5 nM), the non-specific binding was determined using BTCP (10 pM), the incubation time was 120 min at 4°C and the detection method was by scintillation counting.

[0197] The in vitro binding activity to the 5-HT transporter was tested following the experimental protocol disclosed in Tatsumi, M. et al. [Eur. J. Pharmacol., (1999), 368: 277-283] on human recombinant CHO cells using [3H]imipramine as the ligand at 2 nM concentration (Kd 1.7 nM), the non-specific binding was determined using imipramine (10 pM), the incubation time was 60 min at room temperature and the detection method was by scintillation counting.

[0198] Compounds were tested at 1.0E-05 M. Compound binding was calculated as a % inhibition of the binding of a ligand specific for each target.

[0199] Comparative example 2 is 3-[4-[3-(Methylamino)-1-phenylpropoxy]phenyl]propan-1-ol hydrochloride described as example 16 in US 2015 / 0344408 A1 and Comparative example 3 is 2-[4-[3-(methylamino)-1-phenylpropoxy]phenyl]ethanol hydrochloride described as example 2 in US 2015 / 0344408 A1.

[0200] 9.1.2. Enzyme and uptake assays The in vitro uptake by the norepinephrine transporter was tested following the experimental protocol disclosed in Perovic, S. and Muller, W.E.G. [Arzneim-Forsch. Drug Res., (1995), 45:1145-1148] on human recombinant cells using norepinephrine hydrochloride, DL-[7-3H(N)] (500 nM) as the substrate, the incubation time was 180 min at room temperature, measuring [3H]NE incorporation into cells by scintillation counting. The in vitro uptake by the dopamine transporter was tested following the experimental protocol disclosed in Verrico C. et al. [Psychopharmacology (Berl), (2005), in press] on human recombinant cells using 3H DA (300 nM) I DA (300 nM) as the substrate, the incubation time was 90 min at room temperature, measuring [3H]DA incorporation into cells by scintillation counting.

[0201] The in vitro uptake by the serotonin transporter was tested following the experimental protocol disclosed in Verrico C. et al. [Psychopharmacology (Berl), (2005), in press] on human recombinant cells using 5HT (150 nM) 1 3H 5HT as the substrate, the incubation time was 120 min at room temperature, measuring [3H]5HT incorporation into cells by scintillation counting.

[0202] 9.2. Results

[0203] The results are expressed as a percent of control specific binding: measured specific binding - * 100 control specific binding and as a percent inhibition of control specific binding:

[0204] / measured specific binding \

[0205] 100 - - ; — * 100

[0206] \ control specific binding / obtained in the presence of the test compound.

[0207] Results showing an inhibition higher than 50% are considered to represent significant effects of the test compounds. Results showing an inhibition (or stimulation) between 25% and 50% are indicative of weak to moderate effects (they should be confirmed by further testing as they are within a range where more inter-experimental variability can occur). Results showing an inhibition lower than 25% are not considered significant and mostly attributable to variability of the signal around the control level.

[0208] The IC50 values (concentration causing a half-maximal inhibition of control specific binding) and Hill coefficients (nH) were determined by non-linear regression analysis of the competition curves generated with mean replicate values using Hill equation curve fitting where Y = specific binding, A = left asymptote of the curve, D = right asymptote of the curve, C = compound concentration, C50 = IC50, and nH = slope factor. This analysis was performed using software developed at Cerep (Hill software) and validated by comparison with data generated by the commercial software SigmaPlot® 4.0 for

[0209] Windows® (© 1997 by SPSS Inc.). The inhibition constants (Ki) were calculated using the Cheng Prusoff equation where L = concentration of ligand in the assay, and KD = affinity of the ligand for the receptor.

[0210] The reference compound parameters for each assay are provided in the tables below:

[0211] Table 1

[0212] Table 2

[0213] 9.2.1. Binding assay The results of the binding assays of Compound 1 are gathered in the table below: Table 3

[0214] Results showing an inhibition lower than 25% are not considered significant and mostly attributable to variability of the signal around the control level. Results showing an inhibition (or stimulation) between 25% and 50% are indicative of weak to moderate effects (they should be confirmed by further testing as they are within a range where more inter-experimental variability can occur). Particularly, further testing of serotonin transporter uptake to confirm the above findings is disclosed in the next section.

[0215] 9.2.2. Enzyme and uptake assays

[0216] The results of the IC50 determination for serotonin, norepinephrine and dopamine transporter of Compound 1 is gathered in the table below:

[0217] Table 4

[0218] IC50 value above the highest test concentration. Concentration-response curves show less than 50 % effect at the highest validated testing concentration. Therefore, there was no significant effect of Compound 1 in any of the assays, either binding and enzyme and uptake assays, in the selected targets. In conclusion, compounds of the present invention do not present significant inhibition for the re-uptake of serotonin, norepinephrine nor dopamine, thus preventing potential adverse events and drug-drug interactions associated to this pharmacological activity.

[0219] Example 10. Effects on TrkB / BDNF pathway in a rat primary culture of hippocampal neurons. A mechanistic study.

[0220] 10.1. Methodology

[0221] 10.1.1. Materials and methods

[0222] Rat hippocampal neurons were cultured as described earlier [Callizot, N. et al., (2021). Huperzia serrata Extract 'NSP01' With Neuroprotective Effects-Potential Synergies of Huperzine A and Polyphenols. Front Pharmacol.12:681532], Briefly, pregnant female rats of 17 days gestation (Rats Wistar; Janvier Labs France) were killed using a deep anesthesia with CO2 chamber and a cervical dislocation. Then, fetuses were removed from the uterus and immediately placed in ice-cold L15 Leibovitz medium with a 2% penicillin (10,000 U / mL) and streptomycin (10 mg / mL) solution (PS) and 1 % bovine serum albumin (BSA). Hippocampi were treated for 20 minutes at 37°C with a trypsin- EDTA solution at a final concentration of 0.05% trypsin and 0.02% EDTA. The dissociation was stopped by the addition of Dulbecco’s modified Eagle medium (DM EM) with 4.5 g / L of glucose, containing DNAse I grade II (final concentration 0.5 mg / mL) and 10% fetal bovine serum. Cells were mechanically dissociated by three forced passages through the tip of a 10-mL pipette. Cells were then centrifuged at 515 x g for 10 min. at 4°C. The supernatant was discarded, and the pellet was resuspended in a defined culture medium consisting of Neurobasal medium with a 2% solution of B27 supplement, 2 mM of L-glutamine, 2% PS solution, and 10 ng / mL of brain-derived neurotrophic factor (BDNF). Viable cells were counted using the LUNA-FL (logosbio) cell counter. Cells were seeded at a density of 20,000 (96-well plate) precoated with poly-L-lysine and were cultured at 37°C in an air (95%) - CO2 (5%) incubator. The medium was changed every 2 days. To avoid any edge effect, the first and last columns as well as first and last lines of the plate were not used in the study. Empty wells were filled with water.

[0223] 10.1 .2. Application of test compounds (according to the present invention) Vehicle: Culture medium (vehicle: water).

[0224] Treatment: On day 1 of culture, the test compound was dissolved first in water (1000- fold concentrated stock solution) and then diluted in the culture medium. Next, the compound was incubated with primary hippocampal neurons for 72 hours. The antagonists / inhibitors (ANA-12, BEZ235, U-73122 or FTS) were added (at the appropriate concentration) 1 hour before the addition of the test compound (500 nM). All compounds (test compound + / - inhibitors) were then incubated for 72 hours.

[0225] The antagonists / inhibitors used were the following:

[0226] ANA-12 (N-[2-[(2-oxoazepan-3-yl)carbamoyl]phenyl]-1-benzothiophene-2-carboxami- de) is a selective, small-molecule non-competitive antagonist of the TrkB receptor.

[0227] BEZ235 (2-methyl-2-(4-(3-methyl-2-oxo-8-(quinolin-3-yl)-2,3-dihydro-1 / 7-imidazo[4,5-c] quinolin-1-yl)phenyl)propanenitrile) is an active PI3K and mTOR Kinase inhibitor.

[0228] U-73122 (1-(6-(((8R,9S,13S,14S,17S)-3-methoxy-13-methyl-6,7,8,9,11,12, 14,15,16, 17-decahydro-6H-cyclopenta[a]phenanthren-17-yl)amino)hexyl)-1 / - / -pyrrole-2, 5-dione) is a selective and cell-permeable phospholipase C (PLCy) inhibitor.

[0229] FTS (Farnesyl thiosalicylic acid or 2-(((2E,6E)-3,7,11-trimethyl2,6,10- dodecatrien-1- yl)thio)benzoic acid) is a RAS inhibitor.

[0230] 10.1 .3. Immunostaininq: MAP2 (ICC analysis)

[0231] After the 72 hours of test compound’s treatment (on day 3), hippocampal neurons were fixed by a solution of PFA 4% at room temperature (RT) for 20 minutes (plate 1) or cold acetic acid 5% for 5 minutes at -20°C (plate 2). The cells were washed twice in PBS azide, and then permeabilized. Non-specific sites were blocked with a solution of PBS containing 0.1% saponin and 1 % FBS for 15 minutes at RT. The cultures were incubated with a chicken polyclonal anti Microtubule-associated protein 2 (MAP2, a neuronal marker) antibody at a dilution of 1 / 1000 in PBS containing 1 % FBS and 0.1 % saponin, for 2 hours at RT. This antibody was revealed with a goat anti-chicken CF647 or A488 secondary antibody, at a dilution of 1 / 400 in PBS containing 1 % FCS, 0.1% saponin, for 1 hour at RT. Cell nuclei were counterstained with Hoechst solution (Sigma, 1 / 1000).

[0232] 10.1 .4. Automated image analysis

[0233] For each condition, 30 pictures (representative of the whole well area) per well were automatically taken using Operetta CLS™ (Revvity) with 20 x magnification. All images were generated using the same acquisition parameters. From images, analyses were directly and automatically performed by Harmony™ (Revvity).

[0234] The following readouts were investigated:

[0235] - Number of neurons (number of MAP2 positive neurons).

[0236] - Total neurite network (length of MAP2 positive neurite, in pm).

[0237] - Analysis of branch points (number of neurite branches or roots) and extremities.

[0238] 10.1.5. Statistics All values are expressed as mean ± SEM (standard error of the mean). Statistical analysis was performed by one-way ANOVA followed by Fisher’s LSD test, p < 0.05 was considered significant.

[0239] 10.2. Effect on a primary culture of hippocampal neurons: number of neurons, neurite network, branching points and number of neurite extremities (day 3)

[0240] BDNF (a well-known neurotrophic factor displaying neuroprotective properties) was used as positive control. BDNF (50 ng / mL) was able to increase the number of hippocampal neurons (Fig. 1), the length of neurite network (Fig. 2), branching points number (Fig. 3), and number of extremities of the neurite network (Fig. 4), after a 3-day treatment.

[0241] Compound 1 was tested from 1 nM to 100 pM. Compound 1 significantly increased the number of hippocampal neurons (at 500 nM) and promoted the elongation of their neurites (between 25 nM and 100 pM, at similar level to BDNF). Moreover, it enhanced the total number of roots (from 100 nM and 10 pM) and the number of neurite extremities (between 25 nM and 10 pM), following bell-shape curves.

[0242] The ECso for the principal read-out (neurite outgrowth) was calculated as 11.58 nM.

[0243] 10.3. Effect of test compounds in the presence of selective inhibitors / antagonists of TrkB pathway on a primary culture of hippocampal neurons: number of neurons, neurite network, branching points and number of neurite extremities (day 3)

[0244] The inhibitors / antagonists (ANA-12, BEZ235, U-73122 or FTS) were added to the cultures 1 hour before the addition of test compound (500 nM). All compounds (test compound + / - inhibitors) were then incubated for 72 hours.

[0245] As previously described, Compound 1 , applied at 500 nM, significantly increased the number of hippocampal neurons (Fig. 5) and promoted the elongation of their neurites (Fig. 6). Moreover, it enhanced the total number of roots (branching points, Fig. 7) and the number of neurite extremities (Fig. 8). One-way ANOVA followed by Fisher's LSD test *, p<0.05 versus control; n p<0.05 versus Compound 1.

[0246] ANA-12 alone did not significantly modify the number of hippocampal neurons and their neurite network (length, roots, extremities), as compared to control condition. However, ANA-12 pre-treatment abolished the effect of Compound 1 on all readouts assessed, when compared to the control condition.

[0247] BEZ235 (10 nM) applied alone significantly reduced the neurite network, number of branching points and of extremities in a primary culture of hippocampal neurons, as compared to control condition. However, BEZ235 did not significantly impact neuronal survival. Pre-incubation with BEZ235 abolished the positive effects of Compound 1 on the number of hippocampal neurons and their neurites (length, roots and extremities), compared to Compound 1 alone.

[0248] FTS trended to, but did not significantly, increase the number of hippocampal neurons or their neurite roots and extremities, as compared to control condition, although it increased the length of neurites. FTS inhibited the effect of Compound 1 on all parameters assessed except the length of the neurite network.

[0249] U73122 did not significantly modify the number of hippocampal neurons and their neurite network (length, roots, extremities), as compared to control condition. 1173122 pretreatment inhibited the effect of Compound 1 on all readouts assessed.

[0250] 10.4. Conclusions

[0251] The aim of the study was to investigate the efficacy of test compounds in primary hippocampal neurons with a focus on neurite outgrowth and TrkB pathway. Coincubation of Compound 1 (at the most efficient dose selected on step 10.2) and selective inhibitors of TrkB pathway was used to highlight the pathway involvement.

[0252] In line with the results described above, the following conclusions could be made:

[0253] - Compound 1 showed a significant effect on the number of non-mature hippocampal neurons and induced a large elongation of the neurite network. The total number of neuritic roots and the number of extremities was significantly increased in the presence of Compound 1 , in non-mature hippocampal neurons.

[0254] - The ECso of Compound 1 (neurite outgrowth) was 11.58 nM.

[0255] - The effect of Compound 1 on these parameters was reduced in the presence of TrkB receptor antagonist and in the presence of inhibitors of the three main downstream pathways of TrkB (PI3K, PLCy and RAS).

[0256] In conclusion, from a mechanistic perspective, Compound 1 modulates the TrkB pathway, leading to the promotion of neurogenesis, neuritogenesis and synaptogenesis.

[0257] Example 11. Human TrkB receptor pathway activation assay mediated by BDNF

[0258] The aim of this study was to evaluate test compounds for activation activities against human TrkB (MAPK pathway). The reporter cells were treated with an EC50 concentration of BDNF and then treated with test compounds at the target concentration performed in duplicate.

[0259] 11.1. Assay Methods

[0260] ■ Reporter Cells. Reporter Cells used in the TrkB (MAPK pathway) Assay express the native receptor. In addition, these cells express a Gal4-hybrid Elk-1 transcription factor. The reporter gene, firefly luciferase, is functionally linked to tandem Gal4 upstream activation sequences (UAS).

[0261] ■ Compound Handling. The test compounds were stored at room temperature. Compounds were weighed before solubilization in water.

[0262] ■ Setup of Activation Assays.

[0263] Step 1- A suspension of Reporter Cells was prepared in Cell Recovery Medium (CRM) supplemented with a 2x EC50 concentration of BDNF. 100 pl of the Reporter Cell suspension was dispensed into wells of a white 96-well assay plate.

[0264] Step 2: Immediately prior to assay setup, test compound master stock was diluted directly into compound-screening media (CSM) to generate solutions at the selected concentration. 100 pL of each prepared treatment medium was dispensed into duplicate assay wells pre-dispensed with a 100 pL suspension of Reporter Cells (supplemented with 2x EC50 BDNF), thereby achieving the desired final treatment concentrations. Assay plates were incubated for 22 hours in a cell culture incubator (37°C / 5% CC>2 / 70% humidity).

[0265] Step 3: Following the incubation period:

[0266] For Activation assays: Treatment media were discarded and 100 pL / well of Luciferase Detection Reagent was added per well to determine receptor activity in terms of relative luminescence units (RLUs).

[0267] Assay Validation

[0268] Reference compounds were utilized to confirm the performance of the specific lot of Reporter Cells treated with the test compounds. Reference Compound and Test Compound assays were performed at the same time and, hence, were exposed to the same assay reagents and environmental conditions. Reference groups always include a 'Vehicle' control to determine background activity in the assay and to calculate values of 11.2. Activation of receptor activities

[0269] The results of the allosteric modulation of the test compounds on the TrkB receptor pathway mediated by BDNF assay are detailed in Table 5.

[0270] Table 5

[0271] Example 12. Evaluation of the therapeutic activity in a mouse model of Fragile X Syndrome (FXS) under acute administration

[0272] 12.1. Fragile X syndrome (FXS) mouse model

[0273] In this study, we used the FXS mouse model, Fragile X messenger ribonucleoprotein 1 KO2 (Fmr1 KO2) and their corresponding wildtype (WT) littermates.

[0274] Fmr1 KO2 mice were generated by deleting the promoter and first exon of the fmr1 gene according to Mientjes et al. [Mientjes E. J., Nieuwenhuizen I., Kirkpatrick L., Zu T., Hoogeveen-Westerveld M., Severijnen L., et al. (2006). The generation of a conditional Fmr1 knock out mouse model to study Fmrp function in vivo. Neurobiol. Dis., 21 , 549- 555] and then were backcrossed to a C57BL / 6J background for more than eight generations. The Fmr1 KO2 is both, protein and mRNA null, and recapitulate behavioral symptoms observed in human FXS pathology, including hyperactivity, repetitive behavior, and deficits in learning and memory [Gaudissard J, Ginger M, Premoli M, Memo M, Frick A, Pietropaolo S. (2017). Behavioral abnormalities in the Fmr7-KO2 mouse model of fragile X syndrome: The relevance of early life phases. Autism Res., 10(10): 1584- 1596], For dosing, each drug / vehicle was administered on the lower abdominal quadrant via the i.p. route.

[0275] Following pretreatment, all mice continued their dosing regimen, outlined in Table 5, until the completion of all the behavioral phenotyping. On the day of behavioral testing, mice were dosed before the start of the behavioral assay.

[0276] 12.2. Dosing regimen

[0277] Three control groups of 15 mice each were utilized for this study. WT and Fmr1 KO2 control groups (Group 1 and 2) were administered vehicle in an identical manner and volume to that utilized for the treated Fmr1 KO2 group. WT drug control (Group 3) was administered the test compound (Compound 1) in an identical manner and volume to that utilized for the treated Fmr1 KO2 group. One treated Fmr1 KO2 group of 10 mice was utilized for this study (Group 4). Table 6 he administration volume was 0.1 mL / 10 g of body weight.

[0278] 12.3. Cognition and Behavior assays

[0279] Cognition and behavior tests were separated by a minimum of 3 days, during which the mice were dosed with vehicle and compound.

[0280] 1) Behaviour - Hyperactivity: Open field test

[0281] 2) Behaviour - Sociability: Three chamber partition test

[0282] 3) Cognition - Memory and Learning: Novel Object Recognition test

[0283] 4) Behaviour - Anxiety: Hyponeophagia test

[0284] Each cognition and behavior test were performed between 8 a.m. and 4 p.m. Mice were dosed in the housing room (prior to testing, see administration details in each behavioral test in the Methods section) and then brought to the experimental room to acclimate for 20 min before testing. Animals were tested in only one behavioral task on each experimental day, and each additional behavioral test was separated by at least 3 days. Prior to each test, a mouse that was not included in the study was placed in the experimental apparatus for 3 min. Then, this non-study animal was removed, and the apparatus was cleaned with moist and dry tissues before placing a study mouse into the apparatus. The aim was to create a low but constant background mouse odor for all experimental subjects. Experimenters were blinded to mouse genotype and treatment throughout all behavioral tests and data analysis.

[0285] 12.4. Methods

[0286] 12.4.1. Animal housing

[0287] The Fmr1 KO2 mice were housed in four per cage groups of the same genotype in a temperature- and humidity-controlled room with a 12-h light-dark cycle (lights on 7 a.m - 7 p.m.). Mice were housed in commercial plastic cages (40 x 23 x 12 cm) with Aspen bedding and without environmental enrichment on a ventilated rack system. Food and water were available ad libitum, except during test sessions. Testing was conducted during the light phase on male Fmr1 KO2 mice and their WT littermates. 12.4.2. Open-field hyperactivity

[0288] An open-field apparatus [Olmos-Serrano J. L., Corbin J. G., Burns M. P. (2011). The GABAA receptor agonist TH IP ameliorates specific behavioral deficits in the mouse model of fragile X syndrome. Dev. Neurosci., 33, 395-403] was used to test hyperactivity and habituation to a novel environment, in which decreased exploration as a function of repeated exposure to the same environment may be an index of memory. Each mouse was exposed individually to the open field in one session corresponding to 60-min posttest article administration. The open-field assay was performed using an automated system including a Noldus activity monitor chamber with the associated EthoVision software (Noldus Information Technology Inc., Leesburg, VA, USA). A mouse was placed into a corner square facing the wall and horizontal locomotor activity, measured as distance travelled in centimeters (cm) by the number of squares entered with the whole body, was recorded for 30 min.

[0289] 12.4.3. Social recognition

[0290] In the three-chambered social novelty task, a subject mouse was evaluated for its preference to explore a novel versus a familiar social stimulus mouse, defined as the time spent in the chamber with the novel mouse versus the chamber with the familiar mouse. The apparatus was a rectangular three-chambered box, in which each chamber measured 20 cm (length) x 40.5 cm (width) x 22 cm (height) (Spectrum Diversified Designs, Inc., Streetsboro, OH, USA). During the sociability phase, the mouse was allowed to freely explore all three chambers, in which one side chamber contained a mouse and the other side contained a mouse for 10 min. During the social novelty phase, the mouse was allowed to freely explore all three chambers, in which one side chamber still contained a familiar mouse (f) and the other side chamber now contained a novel mouse (n) for 10 min. The novel mouse was enclosed in a wire cage identical to that enclosing the familiar mouse. For each phase of the test, the amount of time spent in each chamber was recorded. An entry was defined as all four paws in one chamber. Test article administration was performed just after the exposure and recognition of the familiar stimuli mice.

[0291] 12.4.4. Novel object recognition

[0292] Recognition memory of a familiar object compared to a novel object was assessed by the novel object recognition (NOR) task. A Plexiglas box (26 cm length x 20 cm width x 16 cm height) and two unique objects (4-6 cm diameter x 2-6 cm height), each in duplicate, were used. Mice were habituated individually to the experimental environment by allowing them to freely explore the box, which was empty, for 20 min per day for two consecutive days before testing. The test involved two consecutive trials, each 5 min in duration. For trial one, two identical objects were placed in the box, and the mouse was allowed to freely explore the objects for 5 min. These objects would be the familiar (f) objects. For trial two, one familiar object (f) is replaced with one novel object (n), and the mouse is allocated 5 min to explore.

[0293] Object exploration was defined as the mouse sniffing or touching the object with its nose, vibrissa, mouth or forepaws. Time spent near or standing on top of the objects without interacting with the object was not counted as exploration. Test article administration was administered 60 minutes prior to the novel object recognition assay.

[0294] 12.4.5. Hyponeophagia or novelty-suppressed feeding

[0295] The novelty-suppressed feeding test, in which a highly palatable but novel liguid food was available for consumption in a novel environment, measured the latency to consume a defined amount of the novel food as an index of anxiety-like behaviour. Mice were food restricted overnight and tested the next morning. Twenty minutes prior to the test, each mouse was individually placed into a temporary holding cage to prevent social transmission of food preferences. Test article administration was performed 60 minutes prior to the exposure to new food type. Testing was conducted in a chamber (30 cm length x 30 cm width x 5 cm height) with three white walls and a fourth wall of transparent plastic to allow observation of the mouse. A food well (1.2 cm diameter, 0.9 cm height) was glued to the white Perspex base of the test chamber. An individual mouse was placed into the chamber facing away from the food well containing sweetened condensed milk diluted 50:50 with water. The latency from placement in the test chamber to the start of a proper drinking bout, defined as drinking continuously was measured.

[0296] 12.4.6. Statistical analysis

[0297] All statistical analysis and graphs were performed using GraphPad Prism software (GraphPad Software) where each point represents data from an individual mouse.

[0298] 12.5. Results

[0299] 12.5.1. Hyperactivity: open field test

[0300] The effects of single administration of vehicle or Compound 1 (30 mg / kg, i.p.) on hyperactivity are presented in Fig. 9 (total distance travelled), Fig. 10 (movement), and Fig. 11 (latency to center).

[0301] • Distance travelled:

[0302] The results are shown in Fig. 9. Vehicle-treated Fmr1 KO2 mice display a hyperactive phenotype by travelling a significantly greater distance in the open field compared to WT mice. Treatment with Compound 1 at 30 mg / kg significantly reduced locomotor activity back to levels observed in the WT vehicle group. Bars indicate mean values (mean ± SEM). Points correspond to values from individual mice. Asterisks represent significant change; ns, not significant; ****P < 0.0001. n = 15.

[0303] • Movement:

[0304] The results are shown in Fig. 10. Only two spatial measures are collected in this test: the total distance travelled (considered as a measure of general activity) and some measure of the animal's tendency to avoid the arena center. Movement time represents the time spent moving. We evaluated the effect of Compound 1 (30 mg / kg) treatment in Fmr1 KO2 mice movement in the open field test. Fmr1 KO2 mice treated with Compound 1 (30 mg / kg) show a significant correction of total movement when compared to WT littermates treated with vehicle (Compound 1 (30 mg / kg), p = 0.1337). Bars indicate mean values (mean ± SEM). Points correspond to values from individual mice. Asterisks represent significant change; ns, not significant; ****P < 0.0001. n = 15.

[0305] • Latency to center:

[0306] The results are shown in Fig. 11 . The Open field is a fast and relatively easy test that provides a variety of behavioral information ranging from general ambulatory ability to data regarding the emotionality of the subject animal. Thigmotaxis refers to a specific behavior of animals (i.e. , to stay close to walls when exploring an open space). Such behavior can be assessed with the open field test, which is a well-established indicator of fear, an anxiety-related emotional behavior. Latency to center measures the animal's tendency to avoid the arena center. The latter measure is considered anxiety related, based on the assumption that the arena center is more threatening for rodents than its periphery. In this study, Fmr1 KO2 mice treated with Compound 1 (at 30 mg / kg) show a significant reversal to WT levels. Bars indicate mean values (mean ± SEM). Points correspond to values from individual mice. Asterisks represent significant change; ns, not significant; ****P < 0.0001. n = 15.

[0307] 12.5.2. Sociability: three chamber partition test

[0308] The partition test is a measure of social recognition (SR) that works on the same principle as novel object recognition (NOR), except in this instance the test animals need to differentiate between a novel and a familiar mouse. The Fmr1 KO2 vehicle-treated mice showed no preference for either the novel or the familiar mouse, as demonstrated by their low score. The 30 mg / kg Compound 1-treated group was able to reverse the SR deficit in Fmr1 KO2 mice back to comparable levels observed for the WT vehicle group indicating improvement in social memory formation. The effects of single administration of vehicle or Compound 1 (30 mg / kg, i.p.) on sociability are presented in Fig. 12. Asterisks represent significant change; ns, not significant; ****p < 0.0001. n = 15.

[0309] 12.5.3. Memory and learning: novel object recognition test

[0310] Cognition was assessed using NOR, which tests an animal’s ability to differentiate between a familiar object and a novel object. If the test animal can differentiate between the two objects, it will naturally show a preference for investigating the novel object. The Fmr1 KO2 vehicle-treated mice cannot recall interacting with the familiar object, and as a result, the time spent investigating both objects are eguivalent resulting in a low score. Compound 1 was able to reverse the cognitive deficit in Fmr1 KO2 mice for the NOR task. The effects of single administration of vehicle or Compound 1 (30 mg / kg, i.p.) on memory and learning are presented in Fig. 13 (NOR, exploration time) and Fig. 14 (NOR, discrimination index). Asterisks represent significant change; ns, not significant; ****p < 0.0001. n = 15.

[0311] 12.5.4. Anxiety: hyponeophagia

[0312] Mice and rats cannot vomit, due to the tightness of the cardiac sphincter of the stomach, so to overcome the problem of potential food toxicity they have evolved a strategy of first ingesting only very small amounts of novel substances. Hyponeophagia was used in this study as a way of measuring anxiety. A highly palatable but novel substance, such as sweetened condensed milk was offered to the mice in a novel situation [Deacon, Rob M J. (2011). Hyponeophagia: a measure of anxiety in the mouse. Journal of visualized experiments: JoVE, 51 : 2613], The latency to consume a defined amount of the new food is then measured.

[0313] The effects of single administration of vehicle or Compound 1 (30 mg / kg, i.p.) on anxiety are presented in Fig. 15 (asterisks represent significant change; ns, not significant; ****P < 0.0001. n = 15). Fmr1 KO2 mice treated with vehicle showed an increased latency to drink the condensed milk (anxious) when compared to WT littermate mice treated with vehicle. Compound 1 at 30 mg / kg significantly improves anxiety in Fmr1 KO2 mice in the latency to drink the condensed milk (ns; p = 0.0753).

[0314] 12.6. Conclusions

[0315] Single administration of Compound 1 at 30 mg / kg (i.p) in the Fmr1 KO2 mice model of fragile X syndrome demonstrates a broad range of therapeutic effects. The compound displays broad efficacy across multiple cognition and behaviour measures, including the reduction of anxiety-like behaviour and hyperactivity, the improvement of sociability behaviour, and the attenuation of the dysregulation of recognition memory in the Fmr1 KO2 mice model. The observation of clustering of mice in the open field test among treated Fmr1 K02 mice suggests that there may be a notable response to the treatment. The clustering behavior could suggest that the treatment is having a consistent effect on the treated Fmr1 KO2 mice, leading to a more uniform response across individuals in the group.

[0316] Comparison between treated Fmr1 KO2 and WT mice pointed out to the reversion of the cognition and behaviour pattern of Fmr1 KO2 mouse phenotype to the WT phenotype. Thus, Compound 1 span across the brain as each of these assays target different brain regions and connections.

[0317] As conclusion, Compound 1 improved cognitive deficits and behavioural dysfunctions in a mouse model of FXS, both significantly affected in FXS patients.

[0318] Example 13. Evaluation of the therapeutic activity in a mouse model of Fragile X Syndrome (FXS) under chronic administration

[0319] In this study, we used the FXS mouse model, Fmr1 KO2, and their corresponding wildtype (WT) littermates, already described in Example 12.

[0320] 13.1. Dosing regimen

[0321] Three control groups of 10 mice each were utilized for this study. WT and Fmr1 KO2 control groups (Group 1 and 2) were administered vehicle in an identical manner and volume to that utilized for the treated Fmr1 KO2 group once daily during 28 days. Control Group 3 was administered the test compound (Compound 1) in an identical manner and volume to that utilized for the treated Fmr1 KO2 group (Group 4).

[0322] Table 7

[0323] All the doses are expressed in terms of the corresponding base forms (active moieties).

[0324] 13.2. Cognition and Behavior assays

[0325] Experimenters were blinded to mouse genotype and treatment throughout all behavioural tests and data analysis. Cognition and behavior tests were conducted in the following order with 2 days break between each test:

[0326] 1) Behaviour- Hyperactivity: Open Field test

[0327] 2) Behaviour- Activity of daily living: Nesting test 3) Behaviour- Activity of daily living: Marble burying test

[0328] 4) Behaviour - Sociability: Partition test (Social memory test)

[0329] 5) Behaviour - Anxiety: Hyponeophagia test

[0330] 6) Behaviour - Aggression: Aggression test

[0331] 7) Cognition - Memory and Learning: Novel Object Recognition test

[0332] 8) Behaviour - Stereotypy: Self-grooming test

[0333] Prior to each test, a mouse that was not included in the study was placed in the experimental apparatus for 3 min. Then, this non-study animal was removed, and the apparatus was cleaned with moist and dry tissues before placing a study mouse into the apparatus. The aim was to create a low but constant background mouse odour for all experimental subjects.

[0334] Animal housing, open-field, social recognition, novel object recognition, and Hyponeophagia tests were performed as previously explained. Methodology for the remaining tests are detailed below:

[0335] 13.2.1. Nesting

[0336] Activities of daily living (ADL) are defined as the things we normally do such as feeding ourselves, bathing and dressing. In 2005 it was proposed that the hippocampus is vital for the performance of ADL of mice. Rodents with lesions of the hippocampus typically perform very poorly on ADL. Several tests of ADL in mice have been developed: nesting, marble burying, hoarding and burrowing. For small rodents, nests are important in heat conservation as well as reproduction and shelter. Nesting was measured in the home cages of mice. The mice first shred the tightly packed material, then arranged it into a nest. The protocol used pressed cotton squares and a definitive 5-point nest-rating scale. The test was done overnight. Scores of the quality of the resulting nest were assessed on a 5-point scale.

[0337] Nesting score:

[0338] 1. The nestlet is largely untouched (> 90% intact).

[0339] 2. The nestlet is partially torn up (50-90% remaining intact).

[0340] 3. The nestlet is mostly shredded but often there is no identifiable nest site: < 50% of the nestlet remains intact but < 90% is within a quarter of the cage floor area, i.e. the cotton is not gathered into a nest but spread around the cage.

[0341] 4. An identifiable, but flat nest: > 90% of the nestlet is torn up, the material is gathered into a nest within a quarter of the cage floor area, but the nest is flat, with walls higher than mouse body height (curled up on its side) on less than 50% of its circumference. 5. A (near) perfect nest: > 90% of the nestlet is torn up, the nest is a crater, with walls higher than mouse body height on more than 50% of its circumference.

[0342] 13.2.2. Marble buying

[0343] This test measures a rodent's digging to bury marbles in bedding.

[0344] A standard cage is filled with 5 cm of wood chip bedding. Marbles are added at evenly space 15 marbles across the bedding. The marbles should be flat on one side and rounded on the other. The mouse is in the cage for 30 minutes.

[0345] Count the marbles: the number of marbles that are at least two-thirds covered by bedding are counted.

[0346] 13.2.3. Aggression

[0347] An experimental ‘test’ and wild-type ‘control’ mouse were placed in the testing cage simultaneously. The latency to attack was recorded.

[0348] 13.2.4. Self-grooming

[0349] Self-grooming was evaluated as the time spent grooming was recorded for 3 min in the open field. Self-grooming behavior is an innate stereotyped cephalo-caudal microstructure in rodents that begins with paw licking and progresses to nose / face / head grooming. Mice are placed individually in a standard open field and the cumulative time spent grooming is scored in seconds.

[0350] 13.3. Results

[0351] 13.3.1. Open field test

[0352] The effects of 28 days chronic administration of vehicle or Compound 1 (20 mg / kg / day, p.o.) on hyperactivity are presented in Fig. 16 (total distance travelled), Fig. 17 (movement), and Fig. 18 (latency to center). Bars indicate mean values (mean ± SEM). Points correspond to values from individual mice. Asterisks represent significant change; ns, not significant; ****P < 0.0001. n = 10.

[0353] • Distance travelled:

[0354] The results are shown in Fig. 16. Vehicle-treated Fmr1 KO2 mice display a hyperactive phenotype by travelling a significantly greater distance in the open field compared to WT mice. Compound 1 significantly reduced locomotor activity back to levels observed in the WT vehicle group.

[0355] • Time spent moving:

[0356] The results are shown in Fig. 17. The time moving represents the time the animals spent for moving in the arena during the test in the open field test. Fmr1 KO2 mice treated with Compound 1 showed a significant reduction of the total time spent for moving when compared to Fmr1 KO2 mice treated with vehicle. • Latency to center:

[0357] The results are shown in Fig. 18. The Open field is a fast and relatively easy test that provides a variety of behavioral information ranging from general ambulatory ability to data regarding the emotionality of the subject animal. Thigmotaxis refers to a specific behavior of animals (i.e., to stay close to walls when exploring an open space). Such behavior can be assessed with the open field test, which is a well-established indicator of fear, an anxiety-related emotional behavior. Latency to center measures the animal's tendency to avoid the arena center. The latter measure is considered anxiety related, based on the assumption that the arena center is more threatening for rodents than its periphery. In this study, Fmr1 KO2 mice treated with Compound 1 showed a significant reversal of the latency to enter the center back to the level of the WT littermates.

[0358] 13.3.2. Self-grooming test

[0359] Self-grooming in animals is an innate behavior that is involved in hygiene maintenance and other physiologically important processes, including thermoregulation, social communication, and de-arousal. While vehicle-treated Fmr1 KO2 mice revealed significantly increased self-grooming behavior compared to the WT littermates, treatment with Compound 1 reversed the aberrant self-grooming to the level of vehicle-treated WT animals (Fig. 19).

[0360] 13.3.3. Nesting test

[0361] Nesting behavior is a normal behavior of mice, and mice are highly motivated to build nests. The nest has several functions, including increasing litter survival, regulation of body temperature, protection from predators or aggressive cagemates, shelter from cold or draft, and in laboratory conditions is a form of environmental enrichment. In this study, vehicle treated Fmr1 KO2 mice scored between 1 and 2 in nesting, indicating that this hippocampus-dependent activity of daily living is compromised in this animal model. Chronic treatment either with Compound 1 reversed the nesting guality score of Fmr1 KO2 mice back to the level of the WT littermates (Fig. 20).

[0362] 13.3.4. Marble burying test

[0363] Mice exhibit various species-typical behaviors such as digging and burrowing. They dig in the ground to find food, to hoard food, to create a refuge from predators or cold and to make a safe nursery area for the young. In the laboratory, mice dig vigorously in deep bedding such as wood chips. Digging can be guantified by manual timing. Alternatively, the bedding can be covered with glass marbles and the number buried can be counted after a set time. Treatment with Compound 1 improved this phenotype and importantly, reversed the behavior back to the level of the WT littermates (Fig. 21). 13.3.5. Partition test

[0364] The partition test is a measure of social recognition that works on the same principle as novel object recognition, except in this instance the test animals need to differentiate between a novel and a familiar mouse. The Fmr1 KO2 mice treated with the vehicle showed no preference for either the novel or the familiar mouse, as demonstrated by their low scores, indicating that social memory is compromised in this animal model. Treatment with Compound 1 was able to reverse the social memory deficit in Fmr1 KO2 mice back to the level observed for the WT group indicating improvement in social memory formation (Fig. 22).

[0365] 13.3.6. Hyponeophagia test

[0366] Hyponeophagia was used in this study as a way of measuring anxiety. A highly palatable but novel substance, such as sweetened condensed milk was offered to the mice in a novel situation. The latency to consume the new food was then measured. Fmr1 KO2 mice treated with vehicle showed an increased latency to drink the condensed milk, when compared to the vehicle treated WT littermate mice, which is indicative of increased anxiety in this animal model. Compound 1 reversed the hyponeophagia phenotype in Fmr1 KO2 mice by reducing the latency to consume the novel food back to the level of vehicle treated WT littermates (Fig. 23).

[0367] 13.3.7. Aggression test

[0368] Fmr1 KO2 and wild-type mice were placed in the testing cage simultaneously. Compound 1 reversed the latency to attach to the WT phenotype (Fig. 24).

[0369] 13.3.8. Novel object recognition test

[0370] (A) Exploration time

[0371] Cognition was assessed using NOR, which tests the animal’s ability to differentiate between a familiar object and a novel object. If the test animal can differentiate between the two objects, it will naturally show a preference to investigate the novel object. The Fmr1 KO2 mice treated with vehicle were not able to recall the familiar object they explored before. As a result, the time spent investigating the objects was the same for the familiar and the novel object. Treatment with Compound 1 resulted in increased time spend for the exploration of the novel object, suggesting that it was able to improve the cognitive deficit in Fmr1 KO2 mice in the NOR task (Fig. 25).

[0372] (B) Discrimination Index

[0373] The discrimination index (DI) is calculated as: (Time spent with novel object - Time spent with familiar object) / (Total time spent with both objects). A positive DI indicates a preference for the novel object, suggesting better recognition memory. Compound 1 was able to restore DI back to the WT phenotype (Fig. 26).

[0374] Collectively, these findings provide strong evidence supporting the efficacy of Compound 1 in reversing core cognitive deficits and behavioral dysfunctions in FXS.

[0375] Example 14. Morphological analysis of pyramidal cells in the pyramidal cells of Fmr1 KO2 mice following test compound treatments.

[0376] The current study was conducted to assess morphological properties of pyramidal cells of a mouse model of Fmr1 KO2, which included pyramidal cells in Layer 5 of prefrontal cortex (PFC) between the WT Vehicle and Fmr1 KO2 following 28 days Compound 1 chronic administration (n=10 brains per group).

[0377] 14.1. Methodology

[0378] The brain extraction and initial immersion of the Golgi-Cox staining procedure were conducted following standard procedures [Voronin et al. (2024). Preclinical studies of gene replacement therapy for CDKL5 deficiency disorder. Molecular therapy: the journal of the American Society of Gene Therapy, 32(10),3331-3345] previous to morphological analysis. Each brain sample was composed of 6 to 8 slides that covered the range of the region(s) of interest (ROIs), color-coded with the in-house alphanumerical coding system, randomly assigned to each slide folder, and then distributed to the analysts who were blinded to the original slide IDs. The slides included serial coronal sections that covered the anterior-to-posterior axis of the prefrontal lobe that covered subdivisions, such as the infra-limbic, and another region, such as the primary somatosensory cortex. The sampling of ROIs included the basal and apical dendrites of pyramidal cells in the PFC (prefrontal cortex) of mouse brains. The ROIs were then chosen and analyzed using a stereology-based software, called Neurological (MBF Bioscience, VT), installed on a Dell PC workstation that included a Nikon Eclipse Ni microscope with Hamamatsu CCD camera (C11440, ORCA-Flash4.0) (Full Resolution: 2048 pixels x 2048 pixels), motorized X, Y, and Z-focus for high-resolution image acquisition and digital quantitation for digital dendritic reconstruction, followed by the dendrograms and Sholl analyses. During the analysis, the animal IDs were kept blind to the analysts. Finally, the unblinding was employed for resorting to data and statistical analyses (one-way and two- way ANOVAs).

[0379] Sample selection criteria: The criteria for selecting candidate neurons for analysis were based on i) visualization of a fully filled soma with no overlap of neighboring soma and filled dendrites, ii) the tapering of most distal dendrites; iii) the visualization of the complete 3D profile of dendritic trees using the 3D display of imaging software. Neurons with incomplete impregnation and / or neurons with truncations due to the plane of sectioning were not collected. Moreover, cells with dendrites labeled retrogradely by impregnation in the surrounding neuropil were excluded.

[0380] Spine sampling criteria:

[0381] Only spines orthogonal to the dendritic shaft were readily resolved and included in this analysis, while spines protruding above or beneath the dendritic shaft were not sampled. This principle was performed consistently throughout the analysis.

[0382] Quantitative analysis criteria:

[0383] After tracing and spine counting, the raw data were extrapolated and quantitated using the NeuroExplorer program (MBF Bioscience, VT). In addition, to further investigate the change in spine morphology, Sholl analysis was performed to characterize the spine properties in reference to a series of concentric circles (spheres in 3D) around the soma of the sampled neurons. Within each sphere, various measures were obtained, including 1) Frequency of intersections (or dendritic ramification) and 2) Spine density based on every 30um interval or concentric circle from the soma. Note: Frequency of intersections stands for the intersections or ramifications of dendritic processes interacting with the concentric rings from the soma of pyramidal cells.

[0384] The summary of the quantitative morphology of PFC pyramidal cells between groups is detailed in Table 8.

[0385] Table 8

[0386] 14.2. Results

[0387] 14.2.1. Morphological characterization

[0388] Compared to the WT_Vehicle group (Fig. 27A and 27D), the Fmr1 KO2_Vehicle exhibited elevated dendritic branches and spine quantities (Fig. 27B and 27E). Also, the treatment group showed reduced arborizations (Fig. 27C) and spine counts (Fig. 27F) when compared to the Fmr1 KO2_Vehicle group. The Fmr1 KO2_Compound 1 group did show a comparable level of dendritic morphology to the WT_Vehicle group.

[0389] 14.2.2. Morphological analysis: Total spine counts

[0390] The Fmr1 KO2_Vehicle group showed an increase when compared to both WT_Vehicle and Fmr1 KO2_Compound 1 groups, respectively (p<0.05). Remarkably, the Fmr1 KO2_group treated with Compound 1 did not statistically differ from the WT_Vehicle (p>0.05). (Fig. 28).

[0391] 14.2.3. Morphological analysis: Overall spine density

[0392] Both WT_Vehicle and Fmr1 KO2 treated groups showed a decrease in the overall spine density when compared to the Fmr1 KO2_Vehicle group, respectively (p<0.05). The Fmr1 KO2_Compound 1 treated group had a higher spine density than the WT_Vehicle group (p<0.05). (Fig. 29).

[0393] 14.3. Conclusions

[0394] The current study demonstrates the change in morphological and structural properties of pyramidal cells from prefrontal cortex in the Fmr1 KO2 model following Compound 1 treatment to a level comparable to the WT_Vehicle group. These changes included the total dendritic lengths, total spine counts and, overall spine density between groups.

[0395] Example 15. Evaluation of the therapeutic activity in a mouse model of Rett Syndrome (RS)

[0396] 15.1. Methods and experimental designs

[0397] 15.1.1. Animals

[0398] B6.129P2(C)- / Wecp2tm1 1Bird / J(Mecp2 KO) female mice were purchased from The Jackson Laboratory. These mice have been instrumental in understanding the cellular and molecular mechanisms underlying RS since they exhibit phenotypes similar to human conditions, such as abnormal brain morphology, reduced neuron size and density, and motor coordination issues. Mecp2 KO mice were socially housed in numbers of two to five littermates.

[0399] Mice had access to food and water ad libitum in controlled laboratory conditions with temperature maintained at 22 ± 1°C and humidity at 55 ± 10% on a 12h light / dark cycle (lights off 20:00 h).

[0400] 15.1.2. Cognition - Novel Object Recognition (NOR) test

[0401] The NOR test is a memory test that has been widely used to investigate the neurobiology of memory. The apparatus consisted of a rectangular open field arena (38 cm long x 38 cm wide x 38 cm high) made of black Plexiglas. Animals’ behavior was monitored using System MotorActivity Record and Tracking software (SMART, Panlab H a rva rd A p pa ratu s) .

[0402] On the initial day, the mice underwent a 5 min habituation period in the arena. The following day, they were introduced to two identical objects and allowed a 10 min exploration period. The duration of exploration for each object was recorded, and any subject not engaging in at least 10 seconds of exploration was excluded from further analysis. On the third day, during the test session, one of the familiar objects was replaced with a new one for a 5 min evaluation. The discrimination index was computed by subtracting the time spent exploring the familiar object from the time spent on the novel object, then dividing by the total exploration time. Exploration was only noted when the mouse’s nose was within 2 cm of an object, directed towards it, and was manually quantified by the experimenter. Any behavior such as sitting or resting against the object did not count as exploration. All objects, made of plastic to ensure similar levels of exploration, and the arena were thoroughly cleaned with 70% ethanol between sessions to eliminate olfactory cues. The total exploration time served as an indicator of overall activity within the open field. These behavioral experiments were conducted during the light phase of the light / dark cycle by trained observers under blind conditions. All sessions were recorded for further analysis.

[0403] All mice were individually handled and habituated to the investigator during three days before the experiment.

[0404] Acute intraperitoneal injection of the vehicle or Compound 1 (30 mg / kg) was performed immediately after the familiarization session.

[0405] • Compound administration

[0406] Test compound was diluted in saline and administered intraperitoneally at a dose 30 mg / kg. Fresh solutions were prepared daily.

[0407] 15.1.3. Behaviour - Social behavior assay

[0408] Social behavior test is designed to measure social interaction and preference for social novelty in mice. This test is particularly useful in assessing social behaviors that are indicative of conditions such as autism spectrum disorder in genetic mouse models. The apparatus consisted of an arena (70 cm long x 70 cm wide x 30 cm high made of Plexiglas. Animals’ behavior was monitored using System Motor Activity Record and Tracking software (SMART, Panlab Harvard Apparatus).

[0409] Animals were habituated for 5 min to an arena containing two empty transparent cylinders made of Plexiglas (30 cm diameter x 40 cm high). The cylinders were perforated to allow interaction points and were located on two corners of the open field. After 24h, animals were placed in the same arena containing the two cylinders: one empty and the other one containing a stranger, a juvenile individual of the same genotype of the animal being tested. Exploration towards the stranger individual and empty cylinder was registered for 10 min. On day 3, animals were placed in the arena. In this case, one of the cylinders contained a new strange individual while the other contained the same animal as in day 2 (familiar one). Exploration time of both cylinders were quantified for 10 min. Exploratory behavior was defined as the animal directing its nose towards the cylinder at a distance of < 2 cm. Time spent at the proximal zone to the cylinder was also registered as an index of exploratory behavior. The discrimination index was calculated as time exploring the novel stimulus mouse - time exploring the familiar stimulus mouse I total time of exploration x 100. After every session, both cylinders and arena were cleaned with 70% ethanol to avoid olfactory cues. These behavioral experiments were conducted during the light phase of the light / dark cycle by trained observers under blind conditions. All sessions were recorded for further analysis. All mice were individually handled and habituated to the investigator during three days before the experiment.

[0410] Acute intraperitoneal injection of the vehicle or Compound 1 (30 mg / kg) was performed immediately after the sociability session.

[0411] • Compound administration

[0412] Test compound was diluted in saline and administered intraperitoneally at a dose 30 mg / kg. Fresh solutions were prepared daily.

[0413] 15.2. Results and conclusions

[0414] 15.2.1. Novel Object Recognition (NOR) test

[0415] On day 1 , animals were habituated for 5 min to an open field arena. The following day, they were introduced to two identical objects and allowed a 10 min exploration period. On the third day, during the test session, one of the familiar objects was replaced with a new one for a 5 min evaluation. Acute intraperitoneal injection of the test articles was performed immediately after the sociability session.

[0416] Treated Mecp2 KO mice showed a complete rescue of recognition memory, measured by the discrimination index, compared to Mecp2 KO mice treated with vehicle (Fig. 30). Remarkably, discrimination index in Mecp2 KO mice treated with Compound 1 shown similar values to the WT mice. On the boxplots, the horizontal line indicates the median, the box indicates the first to third quartile of expression and whiskers indicate 1.5 x the interquartile range. Two-way ANOVA, Tukey HSD as post hoc. *P < 0.05.

[0417] 15.2.2. Social behavior assay On day 1 , animals were habituated for 5 min to an arena containing two empty transparent cylinders. After 24h, animals were placed in the same arena containing the two cylinders: one empty and the other one containing a stranger, a juvenile individual of the same genotype of the animal being tested, for 10 minutes. On day 3, animals were placed in the arena. In this case, one of the cylinders contained a new strange individual while the other contained the same animal as in day 2 (familiar one). Exploration time of both cylinders were quantified for 10 min. Acute intraperitoneal injection of test articles was performed immediately after the sociability session.

[0418] Treated Mecp2 KO mice showed a significantly higher social recognition index as compared to Mecp2 KO mice treated with vehicle (Fig. 31). Remarkably, Mecp2 KO mice treated with Compound 1 rescued social recognition to WT values. On the boxplots, the horizontal line indicates the median, the box indicates the first to third quartile of expression and whiskers indicate 1.5 x the interquartile range. Two-way ANOVA, Tukey HSD as post hoc. *P < 0.05, ** P < 0.01 , *** P < 0.001.

[0419] As conclusion, Compound 1 improved cognitive deficits and behavioural dysfunctions in a mouse model of RS, a relevant impaired feature in RS patients.

[0420] Pharmaceutical Compositions

[0421] The present invention also includes pharmaceutically active compositions comprising compounds of formula (I) and a physiological carrier. The active compositions can be administered either orally (solids or liquids), transdermal, subcutaneously, parenterally, locally (ointments, creams, gels, plasters, powders), as drops or as a nasal or buccal compositions.

[0422] The following examples of pharmaceutical compositions are offered with the understanding that they are in no way limiting of the invention.

[0423] Formulation Example 1. Compositions for parenteral administration

[0424] These compositions may comprise physiologically acceptable sterile aqueous or nonaqueous solutions, emulsions, suspensions (in case of intramuscular or implants) and powders for reconstitution as injectable dosage forms.

[0425] The compounds of the invention in powder form may be diluted in phosphate buffered saline comprising polysorbate 80, potassium chloride, monobasic phosphate, sodium chloride, dibasic sodium phosphate and water for injection prepared to the desired proportion and volume.

[0426] Liposome injections for intrathecal use may be prepared in a sterile, injectable dispersion of compounds of formula (I), encapsulated in multi-vesicular lipid-based particles. Formulation Example 2. Tablets and capsules for oral administration

[0427] Tablets may be prepared containing as inactive ingredients lactose, magnesium stearate, hydroxypropylmethylcellulose, polyethylene glycol, povidone, sodium starch glycolate and titanium dioxide. Capsules may be prepared containing as inactive ingredients talcum, sodium lauryl sulfate, colloidal silicon dioxide, magnesium stearate, titanium dioxide (E171), hard gelatin or hydroxypropylmethylcellulose capsule, black ink, propylene glycol and shellac.

[0428] Formulation Example 3. Liquid compositions for oral administration

[0429] Aqueous based oral solutions may be prepared containing as inactive ingredients citric acid, sodium citrate, benzoic acid, fruit flavorings, hydroxyethylcellulose, sorbitol, and water.

[0430] Oral suspensions may be prepared containing as inactive ingredients glycerin, carboxymethylcellulose sodium, hydroxyethylcellulose, citric acid, sodium citrate, benzoic acid, simethicone, polysorbate 80, flavorings, and water.

Claims

CLAIMS1. A compound having formula (I)wherein,• R1is selected from the group consisting of -OR and -NR’R”, wherein R is selected from the group consisting of hydrogen, glycosyl, acyl and Ci-Ce alkyl, and R’ and R” are independently selected from the group consisting of hydrogen and Ci-Ce alkyl,• R2is selected from the group consisting of H and OH,• R3is selected from the group consisting of H and OH,• R4is selected from the group consisting of H, -CH3 and OH,• R5is selected from the group consisting of H and -CH3,• G1is a divalent linker comprising two carbon atoms and at least one oxygen atom selected from the group consisting of -CH2-CH(OH)-, -CH2-C(=O)-, -CH=C(OH)-, -CH(OH)-CH(OH)-, -CH(OH)-C(=O)-, and -C(=O)-C(=O)-, and• G2is selected from the group consisting of -CH2- and -C(=O)-, or a pharmaceutically acceptable salt, hydrate or stereoisomer thereof.

2. A compound according to claim 1 , wherein G1is selected from the group consisting of -CH2-C(=O)-, -CH(OH)-C(=O)- and -C(=O)-C(=O)-, preferably -CH2-C(=O)-.

3. A compound according to any one of claims 1 to 2, wherein at least one of R2and R3is H, preferably both R2and R3are H.

4. A compound according to any one of claims 1 to 3, wherein R4is H.

5. A compound according to any one of claims 1 to 4, wherein R5is -CH3.

6. A compound according to any one of claims 1 to 5, wherein G2is -CH2-.

7. A compound according to any one of claim 1 to 6, wherein R1is -OR, preferably-OH.

8. A compound according to claim 1 , wherein G1is selected from the group consisting of -CH2-C(=O)- and-C(=O)-C(=O)-, R1is -OR, R2, R3and R4are H, R5is -CH3 and G2is -CH2-.

9. A compound of formula (I) according to claim 1 , which is selected from group consisting of:• 2-(4-(3-(methylamino)-1-phenylpropoxy)phenyl)acetic acid• methyl 2-(4-(3-(methylamino)-1-phenylpropoxy)phenyl)acetate• 2-(4-(3-(methylamino)-1-phenylpropoxy)phenyl)acetamide• 2-(4-(3-(methylamino)-1-phenylpropoxy)phenyl)ethane-1 ,1-diol• 2-(4-(3-(methylamino)-1-phenylpropoxy)phenyl)ethene-1 ,1-diol• 2-hydroxy-2-(4-(3-(methylamino)-1-phenylpropoxy)phenyl)acetic acid• 2-(2-hydroxy-4-(3-(methylamino)-1-phenylpropoxy)phenyl)acetic acid• 2-(3-hydroxy-4-(3-(methylamino)-1-phenylpropoxy)phenyl)acetic acid• 2-(4-(3-(methylamino)-1-phenylpropoxy)phenyl)-2-oxoacetic acid• 2-(4-(3-amino-1-phenylpropoxy)phenyl)ethane-1 ,1-diol• 2-(4-(3-amino-1-phenylpropoxy)phenyl)acetic acid• 2-hydroxy-1-(4-(3-(methylamino)-1-phenylpropoxy)phenyl)ethan-1-one or a pharmaceutically acceptable salt, hydrate or stereoisomer thereof.

10. A pharmaceutical composition comprising a compound as defined in any one of claims 1 to 9 and one or more pharmaceutically acceptable carriers.

11. A combination comprising a compound as defined in any one of claims 1 to 9 and another drug selected from the group consisting of drugs for the treatment of nervous system disorders or their clinical manifestations anxiolytics and antidepressants, such as sertraline, fluoxetine, citalopram, escitalopram, trazodone, bupropion, cannabidiol, paroxetine, duloxetine, buspirone, venlafaxine, desvenlafaxine, olanzapine, mirtazapine,psilocybin and atomoxetine; antipsychotics, such as aripiprazole, risperidone, quetiapine and olanzapine; tranquilizers, such as clonazepam and lorazepam; hypnotics, such as zolpidem and melatonin; stimulants, such as methylphenidate, amphetamine, amphetamine salts and L-acetylcarnitine; non-stimulants, such as clonidine and guanfacine; cognition enhancers, such as donepezil, zatolmilast, trofinetide and metformin; antiepileptics and anticonvulsants, such as levetiracetam, oxcarbazepine, valproic acid, valproate, carbamazepine, lamotrigine and topiramate; and 2-[4-[3- (methylamino)-1-phenylpropoxy]phenyl]ethanol or a pharmaceutically acceptable salt, hydrate or stereoisomer thereof.

12. A compound as defined in any one of claims 1 to 9 or a combination as defined in claim 11 for use as a medicament.

13. A compound as defined in any one of claims 1 to 9 or a combination as defined in claim 11 for use in the treatment of nervous system disorders associated with cognitive deficits and behavioural dysfunctions.

14. A compound or a combination for use according to claim 13, wherein the nervous system disorder associated with cognitive deficits and behavioural dysfunctions is selected from the group consisting of fragile X syndrome, Rett syndrome, Down syndrome, DiGeorge syndrome (22q11.2 deletion syndrome), Prader-Willi syndrome, Angelman syndrome, autism spectrum disorder, Asperger syndrome, attention deficit hyperactivity disorder, bipolar disorder, anxiety, depression, Pheland-McDermid syndrome, Pitt-Hopkins syndrome, schizophrenia, Alzheimer’s disease, Huntington’s disease, Parkinson’s disease.

15. A compound or a combination for use according to claim 14, wherein the nervous system disorder associated with cognitive deficits and behavioural dysfunctions is fragile X syndrome or Rett syndrome, preferably fragile X syndrome.

16. Use of a compound as defined in any one of claims 1 to 9 or a combination as defined in claim 11 for the manufacture of a medicament.

17. Use of a compound as defined in any one of claims 1 to 9 or a combination as defined in claim 11 for the manufacture of a medicament for the treatment of nervous system disorders associated with cognitive deficits and behavioural dysfunctions.

18. Use of a compound as defined in any one of claims 1 to 9 or a combination according to claim 11 , wherein the nervous system disorder associated with cognitive deficits and behavioural dysfunctions is selected from the group consisting of fragile X syndrome, Rett syndrome, Down syndrome, DiGeorge syndrome (22q11.2 deletion syndrome), Prader-Willi syndrome, Angelman syndrome, autism spectrum disorder, Asperger syndrome, attention deficit hyperactivity disorder, bipolar disorder, anxiety, depression, Pheland-McDermid syndrome, Pitt-Hopkins syndrome, schizophrenia, Alzheimer’s disease, Huntington’s disease, Parkinson’s disease.

19. A method for the treatment of nervous system disorders associated with cognitive deficits and behavioural dysfunctions by administering to a subject in need thereof a compound as defined in any one of claims 1 to 9 or a combination as defined in claim 11.

20. A method according to claim 19, wherein the nervous system disorder associated with cognitive deficits and behavioural dysfunctions is selected from the group consisting of fragile X syndrome, Rett syndrome, Down syndrome, DiGeorge syndrome (22q11.2 deletion syndrome), Prader-Willi syndrome, Angelman syndrome, autism spectrum disorder, Asperger syndrome, attention deficit hyperactivity disorder, bipolar disorder, anxiety, depression, Pheland-McDermid syndrome, Pitt-Hopkins syndrome, schizophrenia, Alzheimer’s disease, Huntington’s disease, Parkinson’s disease.