WO2007028770A1

WO2007028770A1 - Monoamine neurotransmitter re-uptake inhibitors for neuroprotection in patients suffering from an advanced stage of a mental disease

Info

Publication number: WO2007028770A1
Application number: PCT/EP2006/065897
Authority: WO
Inventors: Klaus Bornemann; Holger Rosenbrock; Frank Sams-Dodd; Bastian Hengerer; Jens Damsgaard Mikkelsen
Original assignee: Neurosearch A/S
Priority date: 2005-09-05
Filing date: 2006-09-01
Publication date: 2007-03-15

Abstract

The invention relates to the use of a monoamine neurotransmitter re-uptake inhibitor comprising a 2,3-disubstituted tropane moiety for the preparation of a medicament for inducing cerebral progenitor proliferation and synaptic plasticity in patients suffering in an advanced stage form a mental disease associated with the loss of neuronal mass or activity.

Description

MONOAMINE NEUROTRANSMITTER RE-UPTAKE INHIBITORS FOR NEUROPROTECTION IN PATIENTS SUFFERING FROM AN ADVANCED STAGE OF A MENTAL DISEASE

The invention relates to the use of a monoamine neurotransmitter re-uptake inhibitor comprising a 2,3-disubstituted tropane moiety optionally in the form of its physiologically acceptable acid addition salts for the preparation of a medicament for cerebral neuroprotection, in particular for inducing cerebral progenitor proliferation and/or delaying or even stopping the ruin of cerebral neuronal cells and to improve synaptic plasticity. Such medicaments are in particular useful in the treatment of patients suffering from an advanced stage of Parkinson's or Alzheimer's disease (abbreviated AD, PD respectively).

BACKGROUND OF THE INVENTION

Due to the changes in ageing statistics the number of patients suffering from mental diseases due to loss of neurons is increasing, in particular in the Western world. Many of such patients eventually lose self-control and the ability to care for themselves, and will become dependent on part or full care every day. Among the more known diseases are AD and PD. In case of Parkinson's disease a progressive loss of nigral dopaminergic neurons occurs, whereas in AD hippocampal and cortical regions are majorly affected by neuronal apoptosis. Although there are several attempts to stop the disease via medication, they fail to heal the disease. Therefore, there is an essential need for better medication to at least modify the disease or for to protect neurons. One of the proteins that reveals neuroprotective features is the brain- derived neurotrophic factor (BDNF), which belongs to neurotrophins and affects neuronal survival, differentiation and synaptic plasticity. Loss of neurons may be compensated by neuroprogenitor-proliferation. One marker for such proliferation is cyclin D2, a cell cycle gene (protein) that may contribute to progenitor cell proliferation. It is i.e. upregulated in neural stem cells. The initiation of expression of these proteins may contribute to neuroprotection and neuroprogenitor-proliferation.

BRIEF DESCRIPTION OF THE INVENTION

Surprisingly, it has been found, that a monoamine neurotransmitter reuptake inhibitor comprising a 2,3-disubstituted tropane moiety optionally in the form of its physiologically acceptable acid addition salts induces the cerebral production of BDNF and in turn may improve synaptic plasticity. Additionally, cerebral progenitor proliferation was observed. Both effects, although different and independent in nature are promising starting points for an improved treatment of diseases in that the loss of neurons is a significant feature. Accordingly, one embodiment of the current invention relates to the use of a monoamine neurotransmitter re-uptake inhibitor comprising a 2,3-disubstituted tropane moiety optionally in the form of its physiologically acceptable acid addition salts for the preparation of a medicament to reverse the loss of neurons or neuronal activity by either inducing the synthesis of BDNF in the brain, with the option to enhance synaptic plasticity and/or by inducing cerebral progenitor proliferation. Thus the invention is of interest in the treatment of a disease or condition associated with the degradation of cerebral progenitors, the loss of neuronal activity in the brain, the loss of synaptic activity in the brain, the degeneration of cerebral cells in the brain. The invention is of particular interest in the treatment of patients that suffer from an advanced stage of such diseases.

DETAILED DESCRIPTION OF THE INVENTION

As a rule the monoamine neurotransmitter re-uptake inhibitor comprising a

2,3-disubstituted tropane moiety are those which are disclosed by International patent applications WO 93/09814 and WO 97/30997.

Preferably the monoamine neurotransmitter re-uptake inhibitor comprising a 2,3-disubstituted tropane moiety are compounds of the general formula (I)

( I ) or a pharmaceutical acceptable addition salt thereof or the N-oxide thereof, wherein R¹ is hydrogen, alkyl, alkenyl, alkynyl, cycloalkyl, cycloalkylalkyl or 2-hydroxyethyl; R⁶ is CH₂-X-R³, wherein X is O, S, or NR'; wherein

R' is hydrogen or alkyl; and

R³ is alkyl, alkenyl, alkynyl, cycloalkyl, cycloalkylalkyl, or-CO-alkyl; heteroaryl which may be substituted one or more times with alkyl, cycloalkyl, or cycloalkylalkyl; phenyl which may be substituted one or more times with substituents selected from the group consisting of halogen, CF₃, CN, alkoxy, alkyl, alkenyl, alkynyl, amino, nitro, and heteroaryl; phenylphenyl; pyridyl which may be substituted one or more times with substituents selected from the group consisting of halogen, CF₃, CN, alkoxy, alkyl, alkenyl, alkynyl, amino, nitro, and heteroaryl; thienyl which may be substituted one or more times with substituents selected from the group consisting of halogen, CF₃, CN, alkoxy, alkyl, alkenyl, alkynyl, amino, nitro, and heteroaryl ; or benzyl which may be substituted one or more times with substituents selected from the group consisting of halogen, CF₃, CN, alkoxy, alkyl, alkenyl, alkynyl, amino, nitro, and heteroaryl; or (CH₂)_nCO₂R⁷, COR⁷, or CH₂R⁸, wherein R⁷ is alkyl, cycloalkyl, or cycloalkylalkyl; phenyl which may be substituted one or more times with substituents selected from the group consisting of halogen, CF₃, CN, alkoxy, alkyl, alkenyl, alkynyl, amino, nitro, and heteroaryl ; phenylphenyl ; pyridyl which may be substituted one or more times with substituents selected from the group consisting of halogen, CF₃, CN, alkoxy, alkyl, alkenyl, alkynyl, amino, nitro, and heteroaryl; or thienyl which may be substituted one or more times with substituents selected from the group consisting of halogen, CF₃, CN, alkoxy, alkyl, alkenyl, alkynyl, amino, nitro, and heteroaryl; or benzyl; n is 0 or 1 ; and R⁸ is O-phenyl which may be substituted one or more times with substituents selected from the group consisting of halogen, CF₃, CN, alkoxy, alkyl, alkenyl, alkynyl, amino, nitro, and heteroaryl; or O-CO-phenyl which may be substituted one or more times with substituents selected from the group consisting of halogen, CF₃, CN, alkoxy, alkyl, alkenyl, alkynyl, amino, nitro, and heteroaryl; or

CH=NOR³ ; wherein R³ is hydrogen; alkyl, cycloalkyl, cycloalkylalkyl, alkenyl, alkynyl or aryl; all of which may be substituted with -COOH; -COO-alkyl; -COO-cycloalkyl; or phenyl which may be substituted one or more times with substituents selected from the group consisting of halogen, CF₃, CN, alkyl, cycloalkyl, alkoxy, cycloalkoxy, alkenyl, alkynyl, amino, and nitro;

R⁴ is phenyl, 3,4-methylenedioxyphenyl, benzyl, naphthyl, or heteroaryl all of which may be substituted one or more times with substituents selected from the group consisting of halogen, CF₃, CN, alkoxy, cycloalkoxy, alkyl, cycloalkyl, alkenyl, alkynyl, amino, nitro, and heteroaryl.

In a special embodiment of the compound of general formula I, R⁶ is 1 ,2,4- oxadiazol-3-yl which may be substituted in the 5 position with alkyl, cycloalkyl, or cycloalkylalkyl; phenyl which may be substituted one or more times with substituents selected from the group consisting of halogen, CF₃, CN, alkoxy, alkyl, alkenyl, alkynyl, amino, nitro, and heteroaryl; phenylphenyl; or benzyl which may be substituted one or more times with substituents selected from the group consisting of halogen, CF₃, CN, alkoxy, alkyl, alkenyl, alkynyl, amino, nitro, and heteroaryl; or 1 ,2,4-oxadiazol-5-yl which may by substituted in the 3 position with alkyl, cycloalkyl, or cycloalkylalkyl; phenyl which may be substituted one or more times with substituents selected from the group consisting of halogen, CF₃, CN, alkoxy, alkyl, alkenyl, alkynyl, amino, nitro, and heteroaryl; phenylphenyl; benzyl which may be substituted one or more times with substituents selected from the group consisting of halogen, CF₃, CN, alkoxy, alkyl, alkenyl, alkynyl, amino, nitro, and heteroaryl; pyridyl which may be substituted one or more times with substituents selected from the group consisting of halogen, CF₃, CN, alkoxy, alkyl, alkenyl, alkynyl, amino, nitro and heteroaryl; or thienyl which may be substituted one or more times with substituents selected from the group consisting of halogen, CF₃, CN, alkoxy, alkyl, alkenyl, alkynyl, amino, nitro and heteroaryl.

In a further special embodiment of the compound of general formula (I), R⁶ is CH₂-X-R³, wherein X is O, S, or NR'; wherein R' is hydrogen or alkyl; and R³ is alkyl, alkenyl, alkynyl, cycloalkyl, cycloalkylalkyl, or-CO-alkyl.

In a still further embodiment of the compound of general formula (I), R⁶ is CH=NOR³; wherein R³ is hydrogen; alkyl, cycloalkyl, cycloalkylalkyl, alkenyl, alkynyl or aryl; all of which may be substituted with -COOH; -COO-alkyl; -COO-cycloalkyl; or phenyl which may be substituted one or more times with substituents selected from the group consisting of halogen, CF₃, CN, alkyl, cycloalkyl, alkoxy, cycloalkoxy, alkenyl, alkynyl, amino, and nitro. In a further special embodiment of the compound of general formula (I), R⁴ is phenyl, which is substituted once or twice with substituents selected from the group consisting of halogen, CF₃, CN, alkoxy, cycloalkoxy, alkyl, cycloalkyl, alkenyl, alkynyl, amino, nitro, and heteroaryl.

In a more special embodiment, R⁴ is phenyl substituted once or twice with chlorine.

In a further special embodiment, the tropane derivative having dopamine reuptake inhibitor activity is a (1 R, 2R, 3S) -2, 3-disubstituted tropane derivative of formula I. In a still further embodiment, the tropane derivative having dopamine reuptake inhibitory activity is a compound of general formula I wherein R⁶ Js-CH₂-X-R³, wherein X is O or S, and R³ is methyl, ethyl, propyl, or cyclopropylmethyl; -CH=NOR³; wherein R³ is hydrogen or alkyl, or 1 ,2,4-oxadiazol-5-yl which may by substituted in the 3 position with alkyl.

In a still further embodiment, the tropane derivative having dopamine reuptake inhibitory activity is a compound of general formula I wherein R¹ is hydrogen, methyl, ethyl or propyl.

In a still further embodiment, the tropane derivative having dopamine reuptake inhibitory activity is a compound of general formula I wherein R⁴ is 3,4- dichlorophenyl.

More preferably those monoamine neurotransmitter re-uptake inhibitor comprising a 2,3-disubstituted tropane moiety are compounds of formula (II)

wherein

R¹ represents a hydrogen atom or a C-i-6 alkyl group, preferably a hydrogen atom, a methyl or an ethyl group;

R² each independently represents a halogen atom or a CF₃ or cyano group, preferably a fluorine, chlorine or bromine atom;

R³ represents a hydrogen atom or a C-i-6 alkyl or Cs-β-cycloalkyl-d-s-alkyl group, preferably a methyl, ethyl or n-propyl group; and m is 0 or an integer from 1 to 3, preferably 1 or 2; or a tautomer, a pharmaceutically acceptable salt, solvate, or physiologically functional derivative thereof.

As used herein, the expression "alkyl" in particular refers to "Cι-6 alkyl" both of which include methyl and ethyl groups, and straight-chained and branched propyl, butyl, pentyl and hexyl groups. Particular alkyl groups are methyl, ethyl, n-propyl, isopropyl and t-butyl.

The expression "cycloalkyl" as used herein in particular refers to "C3-6 cycloalkyl" both of which include cyclic propyl, butyl, pentyl and hexyl groups such as cyclopropyl and cyclohexyl.

As used herein, the expression "alkenyl" in particular refers to "C_2-6 alkenyl". As used herein, the expression "alkynyl" in particular refers to "C2-6 alkynyl" The term "halogen" as used herein includes fluorine, chlorine, bromine and iodine, of which fluorine and chlorine are preferred.

As used herein, the expression "heteroaryl" in particular refers to C_5-7 membered ring systems with 1 , 2 or 3 heteroatoms selected from the group of N, O, S, such as pyridinyl, pyrrolyl, thienyl, furyl and the like.

The term "physiologically functional derivative" as used herein includes derivatives obtained from the compound of formula (I) under physiological conditions, these are for example N-oxides, which are formed under oxidative conditions. The term "pharmaceutically acceptable acid addition salt" as used herein includes those salts which are selected from among the acid addition salts formed with hydrochloric acid, hydrobromic acid, sulphuric acid, phosphoric acid, methanesulphonic acid, acetic acid, fumaric acid, succinic acid, lactic acid, citric acid, tartaric acid and maleic acid, the salts obtained from hydrochloric acid, hydrobromic acid, sulphuric acid, phosphoric acid and acetic acid being particularly preferred. The salts of citric acid are of particular significance.

In a special embodiment, the tropane derivative having dopamine reuptake inhibitor activity is a compound of the general formula (I) selected from:

(1 R,2R,3S)-2-(3-Cyclopropyl-1 2, 4-oxadiazol-5-yl)-3- (4-fluorophenyl) tropane; (1 R,2R,3S)-2-(3-Phenyl-1 ,2,4-oxadiazol-5-yl)-3-(4-fluorophenyi) tropane;

(1 R,2R,3S)-2-(3-Phenyl-1 ,2,4-oxadiazol-5-yl)-3-(4-methylphenyl)-tropane;

(1 R,2R,3S)-2-(3-Benyl-1 ,2, 4-oxadiazol-5-yl)-3-(4-fluorophenyl) tropane;

(1 R,2R,3S)-2- (3-(4-Phenyl-phenyl)-1 ,2, 4-oxadiazol-5-yl)-3-(4-fluorophenyl) tropane;

(1 R,2R,3S)-2-(3-Phenyl-1 ,2, 4-oxadiazol-5-yl)-3-(2-naphthyl) tropane; (1 R,2R,3S)-3-(3,4-Dichlorophenyl) tropane-2-aldoxime;

(1 R,2R,3S)-3- (3,4-Dichlorophenyl)-tropane-2-O-methyl-aldoxime;

(1 R,2R,3S)-3-(3,4-Dichlorophenyl)tropane-2-O-benzyl-aldoxime;

(1 R,2R,3S)-3-(3,4-Dichlorophenyl) tropane-2-O-ethoxycarbonylmethyl-aldoxime;

(1 R,2R,3S)-3-(3,4-Dichlorophenyl) tropane-2-O-methoxycarbonylmethyl-aldoxime; (1 R,2R,3S)-3-(3,4-Dichlorophenyl)tropane-2-O-(1 -ethoxycarbonyl-1 , 1 -dimethyl- methyl)-aldoxime;

(I R^R^SJ-S-β^-DichlorophenyO tropane^-O-carboxymethyl^-aldoxime;

(1 R,2R,3S)-N-Normethyl-3-(3,4-dichlorophenyl) tropane-2-O-methyl-aldoxime;

(1 R,2R,3S)-N-Normethyl-3-(3,4-dichlorophenyl) tropane-2-O-benzyl-aldoxime; (1 R,2R,3S)-3-(4-Methylphenyl) tropane-2-O-methyl-aldoxime;

(1 R,2R,3S)-3-(3,4-Dichlorophenyl)tropane-2-O-(1 , 1 -dimethylethyl)-aldoxime;

(1 R,2R,3S)-3-(4-Chlorophenyl) tropane-2-O-aldoxime;

(1 R,2R,3S)-3-(4-Chlorophenyl) tropane-2-O-methylaldoxime hydrochloride; (1 R,2R,3S)-3-(4-Chlorophenyl)tropane-2-O-methoxycarbonylmethyl-aldoxime;

(1 R,2R,3S)-3-(3,4-Dichlorophenyl) tropane-2-O- (2-propynyl)-aldoxime;

(1 R,2R,3S)-3-(3,4-Dichlorophenyl)tropane-2-O-(2-methylpropyl)-aldoxime;

(1 R,2R,3S)-3-(3,4-Dichlorophenyl)tropane-2-O-cyclopropylmethyl-aldoxime; (1 R,2R,3S)-3-(3,4-Dichlorophenyl) tropane-2-O-ethyl-aldoxime;

(1 R,2R,3S)-2-Methoxymethyl-3-(3,4-dichlorophenyl)-tropane;

(1 R,2R,3S)-2-lsopropoxymethyl-3-(3,4-dichlorophenyl)-tropane;

(1 R,2R,3S)-2-Ethoxymethyl-3-(3,4-dichlorophenyl)-tropane;

(1 R,2R,3S)-2-Ethoxymethyl-3-(3,4-dichlorophenyl)-nortropane; (1 R,2R,3S)-2-Cyclopropylmethyloxymethyl-3-(3,4-dichlorophenyl)-tropane;

(1 R,2R,3S)-2-Methoxymethyl-3-(4-chlorophenyl)-tropane;

(1 R,2R,3S)-N-Normethyl-2-methoxymethyl-3-(4-chlorophenyl)-tropane;

(1 R,2R,3S)-2-Ethoxymethyl-3-(4-chlorophenyl)-tropane;

(1 R,2R,3S)-N-Normethyl-2-methoxymethyl-3-(3,4-dichlorophenyl)-tropane; (1 R,2R,3S)-N-Normethyl-2-ethoxymethyl-3-(3,4-dichlorophenyl)-tropane;

(1 R,2R,3S)-N-Normethyl-2-ethoxymethyl-3-(4-chlorophenyl)-tropane;

(1 R,2R,3S)-N-Normethyl-2-cyclopropylmethyloxymethyl-3-(4-chlorophenyl)-tropane;

(1 R,2R,3S)-2-Cyclopropylmethyloxymethyl-3-(4-chlorophenyl)-tropane;

(1 R,2R,3S)-2-Ethylthiomethyl-3-(3,4-dichlorophenyl)-tropane; (1 R,2R,3S)-2-Hydroxymethyl-3-(4-fluorophenyl) tropane;

(1 R,2R,3S)-2-Hydroxymethyl-3-(3,4-dichlorophenyl) tropane;

(1 R,2R,3S)-N-Normethyl-N-(tert-butoxycarbonyl)-2-hydroxymethyl-3-(3,4- dichlorophenyl) tropane;

(1 R,2R,3S)-2-Hydroxymethyl-3-(4-chlorophenyl) tropane; (1 R,2R,3S)-2- (3- (2-Furanyl)-1 ,2,4-oxadiazol-5-yl)-3-(3,4-dichlorophenyl)-tropane;

(1 R,2R,3S)-2-(3-(3-Pyridyl)-1 ,2,4-oxadiazol-5-yl)-3-(3,4-dichlorophenyl)-tropane;

(I R^R.SSJ-N-Normethyl-N-allyl^-CS^-pyridyO-i ^^-oxadiazol-δ-yO-S-CS^- dichlorophenyl)-tropane;

(1 R,2R,3S)-N-Normethyl-N-ethyl-2-(3-(4-pyridyl)-1 ,2,4-oxadiazol-5-yl)-3-(3,4- dichlorophenyl)-tropane;

(1 R,2R,3S)-N-Normethyl-N-(2-hydroxyethyl)-2-(3-(4-pyridyl)-1 ,2,4-oxadiazol-5-yl)-3-

(3,4-dichlorophenyl)-tropane;

(1 R,2R,3S)-N-Normethyl-2-(3-(4-pyridyl)-1 ,2,4-oxadiazol-5-yl)-3-(3,4-dichlorophenyl)- tropane; (1 R,2R,3S)-N-Normethyl-N-allyl-2-(3-(3-pyridyl)-1 ,2,4-oxadiazol-5-yl)-3-(3,4- dichlorophenyl)-tropane;

(I R^R.SSJ-N-Normethyl-N-allyl^-CS^-pyridyO-i ^^-oxadiazol-δ-yO-S-CS^- dichlorophenyl)-tropane; (1 R,2R,3S) 2-(3-(2-Thienyl)-1 ,2,4-oxadiazol-5-yl)-3-(4-chlorophenyl)-tropane; (1 R,2R,3S) 2-(3-(2-Thienyl)-1 ,2,4-oxadiazol-5-yl)-3-(3,4-dichlorophenyl)-tropane; (1 R,2R,3S) 2-(3-(4-Pyridyl)-1 ,2,4-oxadiazol-5-yl)-3-(3,4-dichlorophenyl)-tropane; (1 R,2R,3S) 2-(3-(2-Pyridyl)-1 ,2,4-oxadiazol-5-yl)-3-(3,4-dichlorophenyl)-tropane; (1 R,2R,3S) 2-(3-(4-Pyridyl)-1 ,2,4-oxadiazol-5-yl)-3-(4-chlorophenyl)-tropane; (1 R,2R,3S) 2-(3-(3-Pyridyl)-1 ,2,4-oxadiazol-5-yl)-3-(4-chlorophenyl)-tropane; (1 R,2R,3S) -2-(3-2-Pyridyl)-1 ,2,4-oxadiazol-5-yl)-3-(4-chlorophenyl)-tropane; (1 R,2R,3S) 2-(3-Phenyl-1 ,2,4-oxadiazol-5-yl)-3-(4-fluorophenyl)-tropane; (1 R,2R,3S) -2-(3-Phenyl-1 ,2,4-oxadiazol-5-yl)-3- (4-methylphenyl)-tropane; (1 R,2R,3S) -2-(3-Benzyl-1 ,2, 4-oxadiazol-5-yl)-3-(4-fluorophenyl)-tropane; (1 R,2R,3S) -2-(3-(4-Phenylphenyl)-1 ,2,4-oxadiazol-5-yl)-3-(4-fluorophenyl)-tropane; (1 R,2R,3S) -2-(3-Phenyl-1 ,2,4-oxadiazol-5-yl)-3-(2-naphthyl)-tropane; (1 R,2R,3S) -2-(4-Chlorophenoxy-methyl)-3-(4-fluorophenyl)-tropane; (1 R,2R,3S) -2-(4-Chlorophenoxy-methyl)-3-(4-fluorophenyl)-tropane; (1 R,2R,3S) -2-(4-Chlorophenoxy-methyl)-3-(3,4-dichlorophenyl)-tropane; (1 R,2R,3S) -2-(4-Chlorophenoxy-methyl)-3-(4-methylphenyl)-tropane; (1 R,2R,3S) -2-(4-Benzoyloxy-methyl)-3-(4-fluorophenyl)-tropane; (1 R,2R,3S) -2-Carbomethoxy-3-(2-naphthyl)-tropane; (1 R,2R,3S) -2-Carbomethoxy-3-(3,4-dichlorophenyl)-tropane; (1 R,2R,3S) -2-Carbomethoxy-3-benzyl-tropane; (1 R,2R,3S) -2-Carbomethoxy-3-(4-chlorophenyl)-tropane; (1 R,2R,3S) -2-Carbomethoxy-3-(4-methylphenyl)-tropane; (1 R,2R,3S) -2-Carbomethoxy-3-(1-naphthyl)-tropane; (1 R,2R,3S) -2-Carbomethoxy-3-(4-phenylphenyl)-tropane; (1 R,2R,3S) -2-Carbomethoxy-3-(4-t-butyl-phenyl)-tropane; (1 R,2R,3S) -2-(4-Fluoro-benzoyl)-3-(4-fluorophenyl)-tropane; or a pharmaceutically acceptable addition salt thereof.

Most preferred are the compounds of formulae (III) and (IV)

or pharmaceutically acceptable salts thereof, in particular the citrates thereof. Accordingly, one embodiment of the current invention relates to the use of a monoamine neurotransmitter re-uptake inhibitor comprising a 2,3-disubstituted tropane moiety optionally in the form of its physiologically acceptable acid addition salts for the preparation of a medicament for the treatment of a disease mentioned at the beginning.

In particular the invention is for the use of a compound of formula I, preferably Il and more preferably III and/or IV, for the preparation of a medicament for the treatment of a disease associated with cerebral neuronal degradation, cerebral atrophic process and/or for treating a mammal that profits from cerebral neuroprotection due to significant loss of cerebral neurons. There are no treatment options currently to treat the disease progression in patients suffering from such a disease in an advanced stage. In such patients imaging techniques often show signs of cerebral lesions. Among the relevant diseases are Parkinson's disease as well as Alzheimer's disease. In an advanced stage of the disease there is are typical signs of dementia with progression and if there are no systemic or brain diseases which may be responsible of the deficits.

A systematic approach to define the state of Alzheimer's disease is the Minimum Mental State Examination (MMSE) according to Folstein. (Folstein, "Mini- Mental Sate", a practical method for grading the cognitive state of patients for the clinician. J. Psychiatr. Res 1975;12:189-98.) The severity of the disease is measured in a scale. Values of equal or less than 10 may be considered to be advanced or even severe in context of the present invention.

Advanced stage in Parkinson's disease is accompanied by motor dysfunction as Parkinson's disease is considered to be a motor system disorder. The most frequent symptoms of PD are tremor, rigidity/akinesia, loss of dexterity, handwriting disturbances, gait disturbances, bradykinesia, postural instability, difficulty in swallowing and chewing, difficulties in speaking, urinary problems, constipation and/or other. Motor fluctuations may develop with the progression of the disease. Such changes are often referred to as late (motor)-complications of PD. Such late motor fluctuations and dyskinesia complications may have idiopathic origin as well as they may be caused by long-term dopaminergic treatment, eg with L-DOPA. In the progression of treatment with dopaminergic drugs side effects typically may increase over time, and the disease often manifests an "on-off" syndrome in advanced patients in which the drug simply doesn't work for unpredictable durations. In such stage periods with rapid fluctuations between uncontrolled movements and normal movement may occur, usually occurring after long-term use of L-DOPA. Advanced patients often have an "off" -time of more than 2 hours, more often more than 3 or even more than 4 hours a day.

The present invention is also applicable for the treatment of patients suffering from Parkinson's disease with dementia. In some instances of such patients, Magnetic Resonance Imaging (MIR), T1 -weighted images or Computed Tomography (CT) Imaging reveal lesions in the cerebral white matter.

A more systematic approach to define the stage of the Parkinson's disease is the modified Hoehn and Yahr scale or the Unified Parkinson Disease Rating Scale (UPDRS). It may be considered that patients with a stage of at least 2 to 3, preferably

3 or more according the modified Hoehn and Yahr system are in an advanced stage of Parkinson's disease in the sense of the present invention. In this five stage disability scale stage one means least severe and stage five means most severe.

Stage One symptoms are signs and symptoms on one side only, symptoms mild, symptoms inconvenient but not disabling, usually presents with tremor of one limb, friends have noticed changes in posture, locomotion and facial expression. Stage Two symptoms are symptoms are bilateral, minimal disability, posture and gait affected.

Stage Three symptoms are significant slowing of body movements, early impairment of equilibrium on walking or standing, generalized dysfunction that is moderately severe.

Stage Four symptoms are severe symptoms, can still walk to a limited extent, rigidity and bradykinesia, no longer able to live alone, tremor may be less than earlier stages. Stage Five symptoms are cachectic stage, invalidism complete, cannot stand or walk, requires constant nursing care.

The Unified Parkinson Disease Rating Scale is a rating tool to follow the longitudinal course of Parkinson's Disease. It is made up of the following sections: 1 ) mentation, behavior, and mood, 2) activities of daily living and 3) motor. Among the diseases mentioned above the one that shall be treated with preference are diseases that respond to the induction of cerebral progenitor proliferation and/or amelioration of the cerebral synaptic plasticity and/or counteraction to the loss of neuronal activity and/or counteraction to the loss of synaptic activity.

Among interesting diseases is advanced dementia of the Alzheimer type (DAT).

Among the even more interesting diseases is advanced Parkinson as defined above. BRIEF DESCRIPTION OF THE DRAWINGS

The present invention is further illustrated by reference to the accompanying drawing, in which: Fig. 1 shows the regulation of BDNF (upper row) and Arc (lower row) transcripts in the hippocampus following short (5 days) and long-term (14 days) treatment with tesofensine. Rats were administered for 5 or 14 days and levels of transcripts were determined by in situ hybridization. Representative images of scanned autoradiograms from animals sub-chronically (5 days) and chronically (14 days) treated with either tesofensine or vehicle are shown.

Figs. 2A-B and 2C-D show the influence of sub-chronic (5 days) and chronic (14 days) of treatment with tesofensine relative to vehicle (n = 8) on the levels of BDNF mRNA expression (Fig. 2A and 2B) and Arc mRNA expression (Fig. 2C and 2D). Sections were subjected to in situ hybridization and quantification of the levels of the two transcripts was performed using densitometric analysis. BDNF mRNA levels in the CA3 region (Fig. 2A) and the granular cell layer of the dentate gyrus (Fig. 2B) revealed a significant increase in the CA3, but not in the granular cell layer. Arc mRNA expression in the CA1 region of the hippocampus (Fig. 2C) and in the parietal cortex (Fig. 2D) significantly increased after tesofensine for 14 days. Data are presented as relative increase in the tissue compared to control as mean ± SEM (n = 8). ^*P<0.05 (student's t-test).

Figs. 3A-D and 3E-F show NeuroD-positive cells that are non-mature neurons. Dual-labeling for NeuroD- and either NeuN (3A), GFAP (3B), Ki-67 (3C), or Cd11 b (3D) revealed no co-localization of NeuroD and any of the other markers. Figs. 3E and 3F are representative images of dual labeling of Ki-67 (arrows marked with a star) and NeuroD (white arrows) immunoreactivity in the dentate gyrus of a rat treated for 14 days with vehicle and tesofensine.

Fig. 4 shows quantification of Ki-67-immunopositive cells (4A), Ki-67 immunopositive cell clusters (4B), and NeuroD-immunopositive cells (4C) in the dentate gyrus of the rat hippocampus after 5 days or 14 days of treatment with vehicle or tesofensine. Data are presented as mean ± SEM (n = 8) of the number of cell or cell clusters per section. ^* P < 0.05, Student's t-test.

EXAMPLES

The invention is further illustrated with reference to the following examples, which are not intended to be in any way limiting to the scope of the invention as claimed. Example 1

Experimental 5 To examine the effect of 2,3-disubstituted tropanes in view of neuroprotection of neuroprogenitor proliferation, mice have been treated for 2 weeks with 3 mg/kg of the compound. One gene that codes for a protein with neuroprotective features is BDNF, belonging to neurotrophins and affecting neuronal survival, - differentiation and synaptic plasticity. As a marker for neuroproliferation, cyclin D2 was 10 selected, a cell cycle gene (protein) that may contribute to progenitor cell proliferation.

Results

After 2 weeks of treatment the mRNA levels in the entorhinal cortex were increased by 83% (p=0.084) and 63% (p=0.061) for BDNF and cyclin D2. These 15 results provided evidence that 2,3-disubstituted tropanes may modulate cerebral gene expression, thereby, leading to neuroprotection and induction of progenitor cell proliferation.

Example 2

20

Experimental

In another set of experiments adult male Wistar rats (n = 8 per group) were treated with daily oral administration of the compound of formula III (tesofensine) at a dose of 3 mg/kg for either 5 or 14 days. The dose of tesofensine (as citrate salt) was 3 25 mg/kg p.o., since this dose has been shown to be active in other in-vivo models

(Thatte, Current Opinion in Investigational Drugs 2001 2 1592-1594). Twenty-four hours after the last treatment, animals were anaesthetized and perfused with ringer solution and the brains were removed. Each brain was divided into two hemispheres.

One hemisphere was immediately frozen in crushed dry-ice and kept at -80 ⁰C for in 30 situ hybridisation. The other hemisphere was were native frozen under cryoprotection with TissueTek in methylbutane (pre-cooled in liquid nitrogen) and then stored at -70⁰C until cryosectioning for Ki-67/NeuroD immunohistochemistry.

Twelve-μm serial coronal sections of the hippocampal formation were hybridized for Arc (targeting bases 789-839; NM 019361 ). BDNF (targeting bases 35 585-630; NM 012513). and synaptophysin (targeting bases 143-187; NM 012664) genes were used (DNA Technology, Aarhus, Denmark) (Mikkelsen et al., MoI. Brain

Res. 1994 23 317-322). For analyzing the proteins of interest in the hippocampus, consecutive parasagittal sections from 0.9 mm lateral were rehydrated in PBS 3 x 5 min at room temperature. Unspecific protein binding sites were blocked with PBS containing 3 % (w/v) BSA, 0.1 % (w/v) NaN₃ for 1 h and directly incubated with primary antisera overnight at 4°C according to earlier protocols (Rosenbrock et al, Brain Res. (2005) 1040, 55-63).

For quantification of Ki-67 and NeuroD immunopositve cells in the hippocampus, 6 sections per animal with 24 μm space in between were used for immunohistochemistry. After digitizing the images, immunopositive NeuroD cells as well as Ki-67 immunopositive cells and cell clusters were automatically calculated in the region of interest using Halcon imaging software. The region of interest consisted of the subgranular zone and the hilus of the dentate gyrus. The mean of the 6 values derived from 6 slices per animal was used for further statistical analysis regarding group comparisons. Quantitative data are presented as mean ± SEM calculated from 8 animals per group. The quantitative data from in-situ hybridization and immunofluorescence stainings, comparisons between control and compound-treated groups were performed by Student's t-test.

Results

Effect of sub-chronic (5 days) and chronic (14 days) treatment with tesofensine on the expression of different markers in the hippocampus was examined. Using in situ hybridization, densitometric analysis on X-ray films was carried out in the granular cell layer and the pyramidal cell layer as well as in the parietal cortex. The influence of tesofensine on the expression of BDNF mRNA and Arc mRNA is shown in the representative autoradiogram in Fig. 1. The quantification of changes observed after sub-chronic and chronic treatment with tesofensine is presented in Fig. 2.

Treatment with tesofensine for 5 days had no effect on BDNF expression in the granular cell layer and the CA3 (Fig. 2A, B). A significant increase in BDNF gene expression in the CA3 region was observed after chronic tesofensine treatment (Fig. 2A, 36 %, p<0.05), but not in the granular cell layer (Fig. 2B). The induction of Arc gene expression was significantly increased in the CA1 region after chronic treatment with tesofensine (Fig. 2C, 66 %, P<0.05). No changes in Arc mRNA levels were observed in the granular cell layer (Fig. 1 ). In the parietal cortex, tesofensine produced a significant reduction of Arc mRNA expression compared to vehicle after 5 days of treatment (38 % reduction, p<0.05) (Fig. 2D), but no change (P < 0.07) after 14 days of treatment (Fig. 2D). Sub-chronic and chronic tesofensine treatment had no significant effect on the expression of synaptophysin mRNA in either the granular cell layer or in the CA1 (not shown).

As illustrated in Fig. 3, the Ki-67- and NeuroD-positive cells were accumulating in the subgranular cell layer. Dual-staining of NeuroD-positive cells with neuronal (NeuN), glial (GFAP), granulocyte (CD11 b), or proliferative (Ki-67) markers revealed no co-localisation indicating that NeuroD is present in non-mature neurons (Figs. 3A-D). In particular, it is noted that NeuroD-positive cells are distinct from those positive for Ki-67 (Fig. 3C).

Treatment of rats with tesofensine for 5 days led only to a slight, but non- significant increase in the subgranular zone of the dentate gyrus, respectively in the number of progenitor cell proliferation (Ki-67 cells: 14%, Ki-67 cell cluster: 16%) and immature neurons (NeuroD cells: 19%), respectively (Fig. 4). However, treatment with tesofensine for 14 days caused a significant increase of the number of Ki-67 cells (37%; Fig. 4A). An increase in number of Ki-67 positive clusters (22%; Fig. 4B) was observed after chronic tesofensine treatment, but these changes did not reach significance. By contrast, the number of NeuroD cells was significantly higher after tesofensine treatment (23%; Fig. 4C).

Claims

1. Use of an effective amount of a monoamine neurotransmitter re-uptake inhibitor comprising a 2,3-disubstituted tropane moiety optionally in the form of its physiologically acceptable acid addition salts for the manufacture of a medicament for slowing down, stopping and/or reversing the loss of neuronal mass or neuronal activity, in particular the loss of neuronal mass, in patients suffering from a mental disease with rapid or advanced loss of neuronal mass or activity, in particular patients suffering from a mental disease in a stage of significant loss of neuronal mass.

2. Use according to claim 1 for a medicament for inducing production of cerebral BDNF in a patient.

3. Use according to claim 1 for a medicament for activating cerebral progenitor proliferation in a patient.

4. Use according to any of claims 1 to 3, wherein the patients are in a stage of a cerebral disease in that they have lost a significant amount of cerebral neurons.

5. Use according to any of claims 1 to 4, wherein the patients are in an advanced stage of Parkinson's disease.

6. Use according to claim 5, wherein the patients have manifested the "on-off syndrome, in particular more than 2 hours a day, more particular more than 3 hours a day and even more particular more than 4 hours a day.

7. Use according to claim 5 or 6, wherein the patients show motor fluctuations, in particular late (motor)-complications.

8. Use according to any of claims 5 to 7, wherein the Parkinson's disease is of the type with dementia.

9. Use according to any of claims 5 to 8, wherein imaging techniques of the patients reveal lesions in the cerebral white matter.

10. Use according to any of claims 1 to 4, wherein the patients are in an advanced stage of Alzheimer's disease.

11. Use according to claim 10, wherein imaging techniques of the patients reveal lesions in the cerebral white matter.

12. Use according to any of the preceding claims, wherein said monoamine 5 neurotransmitter re-uptake inhibitor is is a compound of formula (II)

wherein

R¹ represents a hydrogen atom or a C_h alky! group; 10 R² represents a halogen atom or a CF₃ or cyano group;

R³ represents a hydrogen atom or a d-β alkyl or Cs-β-cycloalkyl-Ci-s-alkyl group; and m is 0 or an integer from 1 to 3.

15 13. Use according to any of the preceding claims, wherein said monoamine neurotransmitter re-uptake inhibitor is the compound of formula (III) or (IV)

20 14. Method of treatment a patient suffering from a mental disease with rapid or advanced loss of neuronal mass or activity, whereby the patients receive a medicament which comprises a compound having a 2,3-disubstituted tropane moiety according to any of claims 1 to 13 to slow down, to stop and/or to reverse the advanced loss of neuronal mass or neuronal activity.