Field of the invention

The invention refers to the use of a compound of formula

I

X Y R

Aryl-C=N-0-CH ₂ -CH-CH ₂ -N

Ri wherein

Aryl represents a phenyl, naphthyl or pyridyl group,

X stands for a halo atom and then Y represents a hydroxy group or

X is a nitrogen atom and then Y represents a valence bond between this nitrogen atom and the carbon atom adjacent to Y, thus, forming a six-membered oxadiazine ring,

R and Ri form together with the adjacent nitrogen atom a 5-7- membered saturated heterocyclic group,

or an N-oxide of the compound of formula I or a pharmaceutically suitable acid addition salt thereof for the preparation of a pharmaceutical composition for the prevention and/or treatment of muscle atrophy.

Background of the invention

For lack of regular stimulation by the motorial nerves, the skeletal muscle has losses in tone and mass. The muscle becomes flaccid while containing smaller and weaker muscle fibres. This reduction of muscle size, tone and power is called muscle atrophy.

The muscle mass and muscular strength are diminished, gradually, due to ageing [Karakelides, H. and Nair, K. S. (2005) Curr. Top Dev. Biol., 68, 123-148]. The role of several mechanisms has been pointed out in muscle atrophy connected with ageing [Doherty, T. J. et al., (1993) J. Appl. Physiol. 74, 868-874; Delbono, O. (2003) Aging Cell 2, 21-29]. The most important causal mechanism can be the loss of motoneurons or the reduction of neural connections [Brown, W. F.: A method for estimating the number of motor units in thenar muscles and the changes in motor unit count with ageing. (1972) J. Neurol. Neurosurg. Psychiatry 35, 845-852; Brown, W. F. and Chan, K. M.: Quantitative methods for estimating the number of motor units in human muscles. (1997) Muscle Nerve, 5, (suppl.) S70- S73]. The muscle mass is determined by the ratio of synthesis and decomposition of muscle protein. In various conditions causing muscle atrophy, in addition to ageing, an activation of a complex biochemical and transcription system can be observed leading to the expression of an atrogenic set of genes [Glass, DJ. Molecular mechanisms modulating muscle mass. (2003) Trends Mol Med, 9(8):344-50]; Cao PR, Kim HJ, Lecker SH Ubiquitin-protein ligases in muscle wasting. (2005) Int J Biochem Cell Biol. 37(10):2088-97]. A part of the atrogenic genes belongs to the ubiquitin-proteasome system allowing the selective degradation of regulating and structural proteins [Lecker SH, Goldberg AL, Mitch WE.: Protein degradation by the ubiquitin-proteasome pathway in normal and disease states. (2006) J Am Soc Nephrol.;17(7):1807-19]. The expression of two E3 ubiquitin ligases: the„muscle RING-finger" 1 (MuRF1) and the „muscle atrophy F-box" (MAFbx; also named as Atrogin-1) is highly increased in various forms of muscle atrophy both in man and rodent [Bodine, S.C. et al., Identification of ubiquitin ligases required for skeletal muscle atrophy. (2001) Science., 294 (5547): 1704-8]. The important catabolic role of the two enzymes is supported by the fact that several types of muscle atrophy is interrupted by their inactivation. [Bodine, S.C. et al., cited reference; Glass DJ.: Signaling pathways perturbing muscle mass. (2010) Curr Opin Clin Nutr Metab Care, 13(3):225-9].

It became obvious that also the lisosome autophagy system played an essential role in muscle atrophy [Sandri, M.: Autophagy in skeletal muscle. (2010) FEBS Lett, 584(7):1411- 6]. In addition, the coordinated function of the two systems (i.e. proteosome and autophagy) is more and more clear in various atrophy conditions [Mammucari, C. et al., Fox03 controls autophagy in skeletal muscle in vivo. (2007) Cell Metab. 6(6):458-71; Zhao, J. et al., Fox03 coordinately activates protein degradation by the autophagic/lysosomal and proteasomal pathways in atrophying muscle cells. (2007) Cell Metab. 6(6):472-83; Doyle, A. et al., Toll-like receptor 4 mediates lipopolysaccharide-induced muscle catabolism via coordinate activation of ubiquitin-proteasome and autophagy- lysosome pathways. (2011) FASEB J. 25(1):99-110]. A significant part of the genes induced during muscle atrophy is controlled by the Fox03 transcription factor that is activated in the atrophic muscle [Sandri, M. et al., (2004) Cell 117,399-412; Stitt, T. et al., (2004) Mol. Cell 14, 395-403]. Fox03 alone can also stimulate both the ubiquitin-proteosome and autophagy systems [Zhao, J. et al., (2007) Cell Metab. 6, 458-471] and induce the atrophy of the muscle fibre. The muscle specific ubiquitin ligases induced by Fox03 (i.e. Atroginl/MAFBx and MuRF1) are remarkably important in the proteolysis of muscle proteins [Bodine, S. C. et al., 2001, Science 294, 1704-1708] and, in the absence thereof, muscle atrophy caused by denervation is significantly inhibited. The role of NF-κΒ was proved by several observations in different forms of muscle atrophy. Physical activity protects from the muscle atrophy caused by inactivity and some systemic diseases. Also PGC-1 (peroxisome proliferator-activated receptor gamma coactivator) transcription factors stimulated by the physical activity protect against muscle atrophy and they are effective mainly through the inhibition of Fox03 and NF-κΒ [Jeffrey J. Brault et al., (2010) J. Biol. Chem. 285:19460-19471].

In addition to the reduction of life expectancy, also the functional state and life quality is deteriorated by muscle atrophy. The most frequent causes of muscle atrophy comprise ageing, denervation, neuronal impairment, immobilization, starvation, chronic diseases (diabetes, renal diseases, tumours). The patients of intensive care units, especially the ones treated by respirator machines often experience serious muscle loss. Recent studies have proved that muscle atrophy and muscle weakness have been a grave complication of survivors of the intensive treatment, wherein the complication lasts for years [van Mook, W. N., Hulsewe-Evers, R. P.: Critical illness polyneuropathy. (2002) Curr Opin Crit Care. 8(4):302-10; Herridge, M. S. et al., One-year outcomes in survivors of the acute respiratory distress syndrome. (2003) N Engl J Med. 348(8) :683-93; Cheung, A. M. et al., Two-year outcomes, health care use, and costs of survivors of acute respiratory distress syndrome. (2006) Am J Respir Crit Care Med. 174(5): 538-44]. A prolonged treatment with a respirator machine, steroid or neuromuscular inhibitor may lead to acute quadriplegic myopathy [Larsson L, (2008) Adv Exp Med Biol., 642:92-8] in which nearly all the skeletal muscles are influenced by the muscle atrophy, consequently, the movement of the patients is not possible anymore.

The treatment and prevention of serious muscle atrophy have been unsolved up to now. The rehabilitation of the patients is very slow, the therapies employed for improving the movement are expensive and of low effectivity. There is no allowed pharmaceutical treatment for the prevention or curing of muscle atrophy.

The aim of the invention is the provision of a pharmaceutical composition for the prevention and/or treatment of muscle atrophy. The compounds of formula I are known compounds.

US 5,147,879 discloses compounds of formula I, wherein X represents a halo atom and Y stands for a hydroxy group, as well as acid addition salts and the manufacture thereof. The known compounds have selective beta-blocking action and can be used for the treatment of diabetic angiopathy.

The effect of the compounds of formula I on the increase of the activity of the molecular chaperon is discussed in EP 801 649. This effect results in many medical uses such as the treatment of cardiovascular, vascular, cerebral, allergic, immune and autoimmune diseases as well as the skin and mucus diseases.

WO 00/50403 discloses the compound N-[2-hydroxy-3- (1-piperidinyl)propoxy]pyridine-1-oxide-3-carboximidoyl chloride (arimoclomol), stereoisomers thereof and use of the compound for treating insulin resistance and pathologic states connected with insulin resistance. An industrially applicable preparation of the latter compound and stereoisomers thereof is discussed in WO 01/79174.

HU-P 226 206 and HU-P 226 617 describe the (+)- and (-)-enantiomer, respectively, of the 5-(piperidin-1-ylmethyl)-3- pyridyl-5,6-dihydro-2H-1 ,2,4-oxadiazine known from EP 801 649. The enantiomers are suitable for the treatment of vascular diseases.

Summary of the invention

It was found that the above aim was achieved by a pharmaceutical composition comprising a compound of formula I or an N-oxide of the compound of formula I or a pharmaceutically suitable acid addition salt thereof.

Thus, the invention provides the use of a compound of formula I or an N-oxide of the compound of formula I or a pharmaceutically suitable acid addition salt thereof for the preparation of a pharmaceutical composition for the prevention and/or treatment of muscle atrophy.

Furthermore, the invention provides a method for the prevention and/or treatment of muscle atrophy which comprises administering to a patient exposed to or suffering from muscle atrophy an effective non-toxic dose of a compound of formula I or an N-oxide of the compound of formula I or a pharmaceutically suitable acid addition salt thereof.

Description of preferred embodiments

Under the N-oxide of a compound of formula I, the N- oxide of the nitrogen atom being in the pyridyl group and/or in the 5-7-membered heterocyclic group is meant.

The 5-7-membered heterocyclic group formed by R, Ri and the adjacent nitrogen atom is preferably a pyrrolidinyl or piperidinyl group.

When X represents a nitrogen atom and Y is a valence bond between this nitrogen atom and the carbon atom being adjacent to Y, then a 6-membered 1 ,2,4-oxadiazine ring is formed having a double bond between the carbon atom in position 3 and one of the nitrogen atoms (either in position 2 or in position 4).

A halo atom is a fluoro, chloro, bromo or iodo atom, preferably a chloro atom. A pharmaceutically suitable acid addition salt is an acid addition salt formed with a pharmaceutically acceptable inorganic or organic acid such as a hydrochloride, acetate, fumarate, maleate, lactate, tartrate etc.

A preferred compound of formula I is N-[2-hydroxy-3-(1- piperidinyl)propoxy]pyridine-3-carboximidoyl chloride (bimoclomol) of formula II

or a pharmaceutically suitable acid addition salt thereof or an N- oxide thereof i.e. N-[(2R)-2-hydroxy-3-(1-piperidinyl)propoxy]- pyridine-1-oxide-3-carboximidoyl chloride of formula III

or a pharmaceutically suitable acid addition salt thereof or 5- (piperidin-1-ylmethyl)-3-pyridyl-5,6-dihydro-2H-1 ,2,4-oxadiazine (iroxanadine) of formula IV

and the optically active enantiomers thereof as well as a ^' pharmaceutically suitable acid addition salt thereof.

In the description and claims under the term „muscle atrophy" a muscle atrophy of any origin, especially the following ones are meant:

- muscle atrophy caused by ageing,

- muscle atrophy developed due to inactivity or immobilization e.g. fracture of limbs, treatment with a respirator machine, treatment in an intensive care unit, a physical state requiring keeping to bed for a long time etc.,

- muscle atrophy of neuronal origin (damage of neurons, degeneration, muscle atrophy caused by neuromuscular synapsis inhibitors),

- muscle atrophy developed as a side effect of a steroid treatment,

- muscle atrophy caused by myopathies,

- muscle atrophy due to systemic diseases (diabetes, renal diseases, tumors, treatment of AIDS etc.).

Under a ..pharmaceutical composition" any composition for human or veterinary use is meant, wherein the composition comprises, in addition to the active ingredient i.e. a compound of formula I or an N-oxide of the compound of formula I or a pharmaceutically suitable acid addition salt thereof, one or more carrier(s) conventionally employed in such compositions.

The pharmaceutical composition may include any dosage form suitable for peroral, parenteral or rectal administration or for local treatment, and can be solid or liquid.

The solid pharmaceutical compositions suitable for peroral administration may be powders, capsules, tablets, film- coated tablets, microcapsules etc., and can comprise binding agents such as gelatine, sorbitol, poly(vinylpyrrolidone) etc.; filling agents such as lactose, glucose, starch, calcium phosphate etc.; auxiliary substances for tabletting such as magnesium stearate, talc, poly(ethylene glycol), silica etc.; wetting agents such as sodium laurylsulfate etc. as the carrier. Capsules may contain the pure active agent without any carrier, other dosage forms contain, in addition to the active agent, one or more carrier(s).

The liquid pharmaceutical compositions suitable for peroral administration may be solutions, suspensions or emulsions and can comprise e.g. suspending agents such as gelatine, carboxymethylcellulose etc.; emulsifiers such as sorbitane monooleate etc.; solvents such as water, oils, glycerol, propylene glycol, ethanol etc.; preservatives such as methyl p-hydroxybenzoate etc. as the carrier.

Pharmaceutical compositions suitable for parenteral administration consist of sterile solutions of the active ingredients, in general. The sterile solution may contain, in addition to the active agent, pH control agents and osmolarity control agents, preservatives, surfactants etc.

For local treatment, for example, ointments, solutions, creames, transdermal patches etc. can be used.

Dosage forms listed above as well as other dosage forms are known per se, see e.g. Remington's Pharmaceutical Sciences, 18th Edition, Mack Publishing Co., Easton, USA (1990).

The pharmaceutical composition contains dosage unit, in general. The daily dose amounting generally to 1-1000 mg of the compound of formula I or an N-oxide of the compound of formula I or a pharmaceutically suitable acid addition salt thereof can be administered in one or more portions. The actual dosage depends on many factors and is determined by the doctor.

The pharmaceutical composition is prepared by admixing the active ingredient to one or more carrier(s), and converting the mixture obtained to a pharmaceutical composition in a manner known per se. Useful methods are known from the literature, e.g. Remington's Pharmaceutical Sciences mentioned above.

The following tests were carried out using the amidoxime derivatives of formula I.

Development of denervation muscle atrophy in rat

Muscle atrophy developed by cutting the nerve in the muscle is a rapid and robust model widely used for the examination of muscle atrophy in vivo. In rodents, the atrophy of the muscle of one of the hind legs is achieved usually by cutting the sciatic nerve (nervus ischiadicus) [Medina, R., Wing SS., Goldberg AL: Increase in levels of polyubiquitin and proteasome mRNA in skeletal muscle during starvation and denervation atrophy. Biochem. J. ,(1995), 308:631-7].

The experiments were carried out in male Wistar rats having a body mass of 150-200 g in narcosis with pentobarbital. The sciatic nerve was exposed by excising the skin of 1 -2 cm growth at about 1 cm from the spinal column and a 5-10 mm section of the nerve was cut out. The wound was sutured. Half of the animals was treated with 20 mg/kg doses of the test compounds 3 hours after the surgical intervention, then once daily for 8 days, orally. The control animals obtained a similar treatment with the same amount of the carrier and tap water/T ween 80. On day 8 of the experiment the animals were overnarcotized with pentobarbital, then the gastrocnemius, soleus and tibial anterior muscles were isolated from both legs, weighed and frozen in liquid nitrogen. The rate of muscle atrophy developed by denervation was characterized by the weight loss in comparison with the weight of the corresponding muscle on the opposite side, in percentage.

The results obtained are shown in Table 1.

Table 1

Statistics: ANOVA, Bonferroni test.

* related to the control p< 0,05

From Table 1 it can be seen that the treatments carried out using bimoclomol, arimoclomol and iroxanadine reduced the muscle loss caused by denervation in a statistically significant manner. The effect is considerable from a biological point of view. Thus, the compounds of the invention are suitable for reducing muscle atrophy.