CN117858708A - Discovery of F-ATP synthase inhibitors for treatment of mycobacterial abscess diseases - Google Patents

Abstract

Disclosed herein is the use of a compound of formula I, or a salt or solvate thereof, for the treatment of a bacterial infection caused by mycobacterium abscessus, wherein the compound of formula I has the formula: i is as follows: r is R ₁ 、R _a 、R ₂ 、R ₃ X, Y, Z and R ₄ As defined herein. Also disclosed herein are compounds and uses of formula ICombination therapy comprising pharmaceutical formulations of said compounds.

Description

Discovery of F-ATP synthase inhibitors for the treatment of Mycobacterium abscessus disease

Technical Field

The present invention relates to the use of compounds for treating diseases associated with Mycobacterium abscessus infection.

Background technique

The listing or discussion of a previously published document in this specification should not necessarily be taken as an admission that the document is part of the prior art or is common general knowledge.

Mycobacterium abscessus (Mycobacterium abscessus, Mab) complex is a group of fast-growing nontuberculous mycobacteria (NTM), which can cause serious human diseases, including respiratory system, skin and soft tissue diseases, especially in cystic fibrosis and elderly patients. The global prevalence, morbidity and mortality of NTM infection are increasing, and often exceed the global incidence of TB infection in developed countries. Mab is the main NTM pathogen in Singapore, and accounts for about 80% of all lung infections caused by fast-growing NTM. Mab has been classified into three subspecies, Mycobacterium abscessus subspecies (Mycobacteriumabscessus subsp.abscessus, narrow sense), Mycobacterium abscessus subspecies (Mycobacterium abscessussubsp.massiliense) and Mycobacterium abscessus subspecies (Mycobacterium abscessussubsp.bolletii). They have different sensitivities to antimicrobial agents, and Mycobacterium abscessus subspecies is the most common and most resistant, and is called "nightmare" bacteria. Mab therapy is largely empirical, including a regimen of amikacin, cefocetin, clarithromycin, and imipenem for the initial phase, and a regimen of oral antimicrobials for the continuation phase, with a total duration of 18 to 24 months. Even with such complex regimens and long duration, the outcome of Mab disease remains poor (40-50%), with severe drug-related toxicity and side effects. In addition, most drugs are not bactericidal.

Mabs are well known to be resistant to standard anti-TB agents and most antimicrobials. The pathogen is also resistant to disinfectants and can therefore cause postsurgical and postprocedural infections. Treatment of diseases caused by NTM, including the fast-growing bacterium Mycobacterium abscessus, is problematic due to low permeability of the cell wall, biofilm formation, insufficient drug-activated enzymes, numerous enzymes that neutralize the drug or modify its specific target, naturally occurring polymorphisms, and induction of drug efflux pumps. Such pumps use energy forms driven by adenosine triphosphate (ATP) or proton motive force generated by the electron transport chain (ETC), which generates the proton motive force used to condense _adenosine diphosphate (ADP) plus Pi to form ATP during oxidative phosphorylation of the _F1F0 -ATP synthase. Oxidative phosphorylation is the major process for ATP synthesis in pathogens, making enzymes of the ETC and the _{F1F0 -} ATP synthase attractive as drug targets, as shown by clofazimine (CFZ), which affects the NADH dehydrogenase (NDH-2) of the ETC, or the repurposing of the anti-tuberculosis (TB) drug bedaquiline (BDQ) and its derivative TBAJ876, which targets the _F1F0 ATP synthase of _M. abscessus. However, although these compounds are potent growth inhibitors, their effects on M. abscessus are mainly bacteriostatic.

Therefore, there is a need to discover new F-ATP synthase inhibitors for the treatment of M. abscessus disease.

Summary of the invention

It has unexpectedly been discovered that a number of compounds can treat Mycobacterium abscessus disease. Various aspects and embodiments of the present invention will now be discussed with reference to the following numbered items.

1. Use of a compound of formula I in the preparation of a medicament for treating bacterial infection caused by Mycobacterium abscessus:

in:

R ₁ and _Ra each independently represent H, halogen, C ₁ -C ₄ alkyl, C ₁ -C ₄ alkoxy or OH;

_R2 represents H, unsubstituted or substituted _C1 - _C4 alkyl, or

_{-CH2CO2Et ;}

R ₃ represents H or C ₁ -C ₄ alkyl;

X, Y and Z each independently represent CR ₄ or N;

Each R ₄ independently represents H, halogen, C ₁ -C ₄ alkyl or C ₁ -C ₄ alkoxy, or a salt or solvate thereof.

2. A compound of formula I or a salt or solvate thereof as described in item 1 for use in treating bacterial infection caused by Mycobacterium abscessus.

3. A method for treating a bacterial infection caused by Mycobacterium abscessus, comprising the step of providing a subject in need thereof with a pharmaceutically effective amount of a compound of formula I as described in item 1 or a salt or solvate thereof.

4. The use according to item 1, the compound for use according to item 2 or the method according to item 3, wherein the compound of formula I is a compound in which R ₂ represents H, unsubstituted or substituted C ₁ -C ₄ alkyl.

5. The use according to item 1 or item 4, the compound for the use according to item 2 or item 4, or the method according to item 3 or item 4, wherein R ₃ represents H, CH ₃ or CH ₂ CH ₃ .

6. The use according to item 1 or items 4 to 5, the compound for the use according to item 2 or items 4 to 5, or the method according to items 3 to 5, wherein _Ra is H and _R1 is Br.

7. The use according to item 1 or items 4 to 6, the compound for the use according to item 2 or items 4 to 6, or the method according to items 3 to 6, wherein X is N.

8. The use according to item 1 or items 4 to 7, the compound for the use according to item 2 or items 4 to 7 or the method according to items 3 to 7, wherein Z is N.

9. The use according to item 1 or items 4 to 8, the compound for the use according to item 2 or items 4 to 8, or the method according to items 3 to 8, wherein Y is C-CH ₃ .

10. The use according to item 1 or items 4 to 9, the compound according to item 2 or items 4 to 9, or the method according to items 3 to 9, wherein the compound of formula I or a salt or solvate thereof is selected from the following list:

Optionally, the compound of formula I or its salt or solvate is selected from the following list:

11. The use according to item 1 or items 4 to 10, the compound for use according to item 2 or items 4 to 10, or the method according to items 3 to 10, wherein the bacterial infection presents in the form of one or more respiratory, skin or soft tissue disorders (e.g. one or more selected from the group consisting of lung infection, amyotrophic lateral sclerosis and bronchiectasis).

12. Use of a compound of formula I or a salt or solvate thereof as defined in any one of items 1 and 4 to 10 and another therapeutic agent or a salt or solvate thereof in the preparation of a medicament for treating a bacterial infection caused by Mycobacterium abscessus, wherein the compound of formula I and the other therapeutic agent are administered sequentially, simultaneously or in combination.

13. Use of a compound of formula I or a salt or solvate thereof as defined in any one of items 1 and 4 to 10 for treating a bacterial infection caused by Mycobacterium abscessus, wherein the compound of formula I is administered sequentially, simultaneously or in combination with the other therapeutic agent or a salt or solvate thereof.

14. A method for treating a bacterial infection caused by Mycobacterium abscessus, which method comprises administering to a patient in need of such treatment a pharmaceutically effective amount of a compound of formula I as defined in any one of items 1 and 4 to 10, or a salt or solvate thereof, and another therapeutic agent, or a salt or solvate thereof.

15. The use according to item 12, the compound for use according to item 13 or the method according to item 14, wherein the other therapeutic agent is selected from one or more of the group consisting of oral antimicrobials, amikacin, cefocetin, clarithromycin, clofazimine and imipenem, optionally wherein the other therapeutic agent is clofazimine.

16. A pharmaceutical composition comprising a compound of formula I as defined in any one of items 1 and 4 to 10, or a salt or solvate thereof, and another therapeutic agent, or a salt or solvate thereof, wherein the other therapeutic agent is selected from one or more of the group consisting of oral antimicrobials, amikacin, cefocetin, clarithromycin, clofazimine and imipenem, optionally wherein the other therapeutic agent is clofazimine.

BRIEF DESCRIPTION OF THE DRAWINGS

Figure 1 depicts GaMF1 sensitivity testing. (A) The structure of GaMF1; (B) The effect of GaMF1 on the growth of Mycobacterium abscessus subspecies ATCC19977 (Mycobacterium abscessus) when grown on cation-regulated Mueller-Hinton (CAMH) medium. The experiment was repeated three times; (C) The effect of GaMF1 on the clinical isolate Mycobacterium abscessus Bamboo in CAMH broth. The experiment was repeated three times. P<0.0001. The experiments in panels B to D were statistically analyzed using a single sample t and Wilcoxon test (Motulsky, H. & Christopoulos, A., 2003. Fitting Models to Biological Data Using Linear and Nonlinear Regression: A Practical Guide to Curve Fitting. GraphPad Software Inc., San Diego CA); and (D) The six-day killing kinetics of GaMF1 against Mycobacterium abscessus. Bacteria were grown in liquid culture (CAMH medium) in the presence of a specified concentration of GaMF1. The experiment was repeated twice and the characteristics were similar. P < 0.001. The experiment was statistically analyzed using ordinary one-way analysis of variance (ANOVA) combined with Bartlett's test.

Figure 2 depicts GaMF1 susceptibility testing in 7H9 medium. (A) Effect of GaMF1 on the growth of three Mab subspecies (M. abscessus subspecies, M. abscessus subspecies, and M. abscessus subspecies) when grown in Middlebrook 7H9 broth. The experiment has been repeated three times; (B) Comparison with clinical isolate M. abscessus Bamboo on 7H9 medium. ***: P < 0.0001, statistical analysis of experiments A-B using single sample t- and Wilcoxon tests (Motulsky, H. & Christopoulos, A., 2003. Fitting Models to Biological Data Using Linear and Nonlinear Regression: A Practical Guide to Curve Fitting. GraphPad Software Inc., San Diego CA); (C) Initial three-day killing kinetics of GaMF1 on the growth of M. abscessus subspecies. Bacteria were grown in liquid culture (7H9) in the presence of the specified concentrations of GaMF1. The experiment was repeated twice and the characteristics were similar. ****: P < 0.0001, statistical analysis was performed using ordinary one-way ANOVA Bartlett’s test.

FIG3 depicts GaMF1 inhibiting oxidative phosphorylation. (A) Inhibition of intracellular ATP synthesis of Mycobacterium abscessus cells by GaMF1. The ATP content of the cells was measured by adding BacTiter-Glo (Promega) to the cells. The total ATP content is proportional to the number of relative luminescent units (RLU). The experiment was repeated three times; and (B) ATP synthesis using electron donor nicotinamide adenine dinucleotide (NADH) in Mycobacterium abscessus inner-outer membrane vesicles (IMV) was inhibited by GaMF1. After adding CellTiter-Glo (Promega), ATP synthesis by Mycobacterium abscessus IMV was measured as luminescence. The experiment was repeated three times. P<0.0001. Statistical analysis of the two experiments in panels A and B was performed using single sample t and Wilcoxon tests (Motulsky, H. & Christopoulos, A., 2003. Fitting Models to Biological Data Using Linear and Nonlinear Regression: A Practical Guide to Curve Fitting. GraphPad Software Inc., San Diego CA).

Figure 4 depicts the increased potency of GaMF1 in combination with the antibiotics CFZ, rifabutin, and amikacin in 7H9 medium. (A) GaMF1 (circles) inhibited the growth of Mycobacterium abscessus in combination with 3.4 mM (inverted triangles), 6.8 mM (open squares), or 27.2 μM (open circles) CFZ; (B) GaMF1 (circles) in combination with 1 μM (squares) or 4.2 μM (triangles) rifabutin sensitivity to Mycobacterium abscessus; and (C) Amikacin (5 μM [squares]) increased the potency of GaMF1 growth inhibition of Mycobacterium abscessus subsp. abscessus. P < 0.0001. Statistical analysis was performed for all experiments presented using two-way ANOVA.

FIG5 depicts the killing efficacy of GaMF1 and rifabutin. Initial six-day killing kinetics of GaMF1 and GaMF1 plus rifabutin on the growth of Mycobacterium abscessus subsp. abscessus. Bacteria were grown in liquid culture (7H9) in the presence of the indicated concentrations of GaMF1 and rifabutin. The experiment was repeated twice and the characteristics were similar. P<0.0001. The experiments were statistically analyzed using ordinary one-way ANOVA with Bartlett's test.

FIG6 depicts that the _F1FO ATP synthase is a molecular engine composed of _{the F0 motor} (a: _c9 ), the _F1 -engine ( _α3 : _β3 :γ:δ:ε) and the peripheral stalk (b-δ:b').

Detailed ways

As noted above, the present invention relates to the discovery of a group of compounds that can treat infections caused by M. abscessus.

Therefore, in a first aspect of the present invention, there is provided the use of a compound of formula I in the preparation of a medicament for treating a bacterial infection caused by Mycobacterium abscessus:

in:

R ₁ and _Ra each independently represent H, halogen, C ₁ -C ₄ alkyl, C ₁ -C ₄ alkoxy or OH;

R ₂ represents H, C ₁ -C ₄ alkyl which is unsubstituted or substituted by a hydroxyl group, or -CH ₂ CO ₂ Et;

R ₃ represents H or C ₁ -C ₄ alkyl;

X, Y and Z each independently represent CR ₄ or N;

Each R ₄ independently represents H, halogen, C ₁ -C ₄ alkyl or C ₁ -C ₄ alkoxy, or a salt or solvate thereof.

In a second aspect of the present invention, there is provided a compound of formula I as described above or a salt or solvate thereof for use in treating bacterial infection caused by Mycobacterium abscessus.

In the third aspect of the present invention, there is provided a method for treating bacterial infection caused by Mycobacterium abscessus, comprising the step of providing a pharmaceutically effective amount of a compound of formula I as described above or a salt or solvate thereof to a subject in need thereof.

In the embodiments herein, the word "comprising" may be interpreted as requiring the features mentioned, but not limiting the presence of other features. Alternatively, the word "comprising" may also refer to situations in which only the listed components/features are intended to be present (e.g., the word "comprising" may be replaced by the phrase "consisting of" or "consisting essentially of". It is expressly contemplated that both the broad and narrow interpretations may apply to all aspects and embodiments of the present invention. In other words, the word "comprising" and its synonyms may be replaced by the phrase "consisting of" or the phrase "consisting essentially of" or their synonyms, and vice versa.

Reference herein (in any aspect or embodiment of the invention) to a compound of Formula I includes reference to such compound per se, tautomers of such compound, and pharmaceutically acceptable salts or solvates of such compound.

Pharmaceutically acceptable salts that may be mentioned include acid addition salts and base addition salts. Such salts may be formed by conventional methods, for example by reaction of a free acid or free base form of a compound of formula I with one or more equivalents of a suitable acid or base, optionally in a solvent or in a medium in which the salt is insoluble, then removing the solvent or medium using standard techniques (e.g., in a vacuum, by freeze drying or by filtering). Salts may also be prepared by exchanging the counter ion of a compound of formula I in salt form with another counter ion, for example, using a suitable ion exchange resin.

Examples of pharmaceutically acceptable salts include acid addition salts derived from mineral and organic acids, and salts derived from metals such as sodium, magnesium or, preferably, potassium and calcium.

Examples of acid addition salts include acid addition salts formed with acetic acid, 2,2-dichloroacetic acid, adipic acid, alginic acid, arylsulfonic acids (e.g., benzenesulfonic acid, naphthalene-2-sulfonic acid, naphthalene-1,5-disulfonic acid, and p-toluenesulfonic acid), ascorbic acid (e.g., L-ascorbic acid), L-aspartic acid, benzoic acid, 4-acetamidobenzoic acid, butyric acid, (+) camphoric acid, camphor-sulfonic acid, (+)-(1S)-camphor-10-sulfonic acid, decanoic acid, hexanoic acid, caprylic acid, cinnamic acid, citric acid, cyclamic acid, dodecylsulfuric acid, ethane-1,2-disulfonic acid, ethanesulfonic acid, 2-hydroxyethanesulfonic acid, formic acid, fumaric acid, galactaric acid, gentisic acid, glucoheptonic acid, gluconic acid (e.g., D-gluconic acid), glucuronic acid ( [0013] Examples of the invention include, but are not limited to, D-glucuronic acid), glutamic acid (e.g., L-glutamic acid), α-oxoglutaric acid, glycolic acid, hippuric acid, hydrobromic acid, hydrochloric acid, hydroiodic acid, isethionic acid, lactic acid (e.g., (+)-L-lactic acid and (±)-DL-lactic acid), lactobionic acid, maleic acid, malic acid (e.g., (-)-L-malic acid), malonic acid, (±)-DL-mandelic acid, metaphosphoric acid, methanesulfonic acid, 1-hydroxy-2-naphthoic acid, nicotinic acid, nitric acid, oleic acid, orotic acid, oxalic acid, palmitic acid, pamoic acid, phosphoric acid, propionic acid, L-pyroglutamic acid, salicylic acid, 4-aminosalicylic acid, sebacic acid, stearic acid, succinic acid, sulfuric acid, tannic acid, tartaric acid (e.g., (+)-L-tartaric acid), thiocyanic acid, undecylenic acid, and valeric acid.

Specific examples of salts are those derived from mineral acids such as hydrochloric acid, hydrobromic acid, phosphoric acid, metaphosphoric acid, nitric acid and sulfuric acid; organic acids such as tartaric acid, acetic acid, citric acid, malic acid, lactic acid, fumaric acid, benzoic acid, glycolic acid, gluconic acid, succinic acid, arylsulfonic acids; and metals such as sodium, magnesium, or, preferably, potassium and calcium.

As mentioned above, also encompassed by formula I are any solvates of the compound and their salts. Preferred solvates are solvates formed by incorporating molecules of a non-toxic pharmaceutically acceptable solvent (hereinafter referred to as a solvating solvent) into a solid state structure (e.g., a crystalline structure) of the compounds of the invention. Examples of such solvents include water, alcohols (such as ethanol, isopropanol, and butanol) and dimethyl sulfoxide. Solvates can be prepared by recrystallizing the compounds of the invention with a solvent or solvent mixture comprising a solvating solvent. Whether a solvate has been formed in any given case can be determined by analyzing the crystals of the compound using known standard techniques such as thermogravimetric analysis (TGE), differential scanning calorimetry (DSC), and X-ray crystallography.

The solvate may be a stoichiometric or non-stoichiometric solvate. A particularly preferred solvate is a hydrate, and examples of hydrates include hemihydrates, monohydrates, and dihydrates.

For a more detailed discussion of solvates and methods for preparing and characterizing them, see Bryn et al., Solid-State Chemistry of Drugs, 2nd edition, published by SSCI, Inc of West Lafayette, IN, USA, 1999, ISBN 0-967-06710-3.

For simplicity, compounds of Formula I and pharmaceutically acceptable salts and solvates of such compounds are hereinafter collectively referred to as "compounds of Formula I".

The compounds of Formula I may contain double bonds and may therefore exist as E (entgegen) and Z (zusammen) geometric isomers about each individual double bond. All such isomers and mixtures thereof are included within the scope of the present invention.

The compounds of formula I may exist as positional isomers and may also exhibit tautomerism. All tautomeric forms and mixtures thereof are included within the scope of the present invention.

The compound of formula I may contain one or more asymmetric carbon atoms, and therefore may exhibit optical and/or diastereoisomerism. Diastereomers can be separated using conventional techniques, such as chromatography or fractional crystallization. Various stereoisomers can be separated by using conventional techniques, such as fractional crystallization or HPLC to separate the racemic or other mixtures of the compound. Alternatively, the desired optical isomer can be made by: by reaction of suitable optically active starting materials under conditions that do not cause racemization or epimerization (i.e., "chiral pool" method); by reaction of suitable starting materials with "chiral auxiliary agents" that can be removed at a suitable stage; by derivatization (i.e., splitting, including dynamic splitting), for example, with homochiral acids, and then by conventional means such as chromatography to separate diastereomeric derivatives, or by reacting with suitable chiral reagents or chiral catalysts, all of which are carried out under conditions known to the technician. All stereoisomers and mixtures thereof are included within the scope of the present invention.

For the avoidance of doubt, in the context of the present invention, the term "treatment" includes therapeutic or palliative treatment of a patient in need of such treatment, as well as prophylactic treatment and/or diagnosis of a patient susceptible to the relevant disease state.

The terms "patient" and "patients" include references to mammalian (e.g., human) patients. As used herein, the terms "subject" or "patient" are recognized in the art and are used interchangeably herein to refer to mammals, including dogs, cats, rats, mice, monkeys, cows, horses, goats, sheep, pigs, camels, and most preferably humans. In some embodiments, the subject is a subject in need of treatment or a subject with a disease or illness. However, in other embodiments, the subject can be a normal subject. The term does not indicate a specific age or gender. Therefore, it is intended to cover adult and neonatal subjects, whether male or female.

The term "effective amount" refers to the amount of a compound that has a therapeutic effect on a treated patient (e.g., sufficient to treat or prevent a disease). The effect can be objective (i.e., measurable by some test or marker) or subjective (i.e., the subject gives an indication of the effect or feels the effect).

As used herein, the term "halogen" includes reference to fluorine, chlorine, bromine and iodine.

Unless otherwise indicated, the term "alkyl" refers to a non-branched or branched, non-cyclic or cyclic, saturated or unsaturated (e.g., forming an alkenyl or alkynyl) hydrocarbon group, which may be substituted or unsubstituted (e.g., having one or more halogen atoms). When the term "alkyl" refers to an acyclic group, it is preferably a C _1-4 alkyl group (such as ethyl, propyl (e.g., n-propyl or isopropyl), butyl (e.g., branched or non-branched butyl), or more preferably methyl). When the term "alkyl" is a cyclic group (which may be the case with the designated group "cycloalkyl"), it is preferably a C _3-4 cycloalkyl group.

Further embodiments of the invention that may be mentioned include those in which the compounds of formula I are isotopically labeled. However, other specific embodiments of the invention that may be mentioned include those in which the compounds of formula I are not isotopically labeled.

When the term "isotopically labeled" is used herein, it includes reference to compounds of Formula I, wherein non-natural isotopes (or non-natural distributions of isotopes) are present at one or more positions in the compound. Those skilled in the art will understand that reference to "one or more positions in a compound" herein refers to one or more atoms of a compound of Formula I. Thus, the term "isotopically labeled" includes reference to compounds of Formula I that are isotopically enriched at one or more positions in the compound.

Isotopic labeling or enrichment of the compounds of formula I may be with a radioactive or non-radioactive isotope of any one of hydrogen, carbon, nitrogen, oxygen, sulfur, fluorine, chlorine, bromine and/or iodine. Specific isotopes that may be mentioned in this regard include ² H, ³ H, ¹¹ C, ¹³ C, ¹⁴ C, ¹³ N, ^{15 N, 15} O, ¹⁷ O, ¹⁸ O, ³⁵ S, ¹⁸ F, ³⁷ CI, ⁷⁷ Br, ⁸² Br and ^{125 I} ).

When the compound of formula I is labeled or enriched with a radioactive or non-radioactive isotope, the compounds of formula I that may be mentioned include those compounds wherein at least one atom in the compound exhibits an isotopic distribution, wherein the radioactive or non-radioactive isotope of the atom is present at a level that is at least 10% (e.g. 10% to 5000%, in particular 50% to 1000%, and more particularly 100% to 500%) higher than the natural level of the radioactive or non-radioactive isotope.

The following embodiments also relate to the use according to the first aspect of the invention, the compounds for use according to the second aspect of the invention and the method of treatment according to the third aspect of the invention and can be combined with said aspects in any technically reasonable manner.

Therefore, in an embodiment of the present invention, the compound of formula I or a salt or solvate thereof may be one in which:

(a) R ₂ represents H, unsubstituted or substituted C ₁ -C ₄ alkyl;

(b) R ₃ may represent H, CH ₃ or CH ₂ CH ₃ ;

(c) _Ra may be H and _R1 may be Br;

(d) X may be N;

(e) Z may be N;

(f) Y may be C—CH ₃ .

In other embodiments of the present invention that may be mentioned herein, the compound of formula I or its salt or solvate may be selected from the following table:

In more particular embodiments that may be mentioned herein, the compound of formula I or its salt or solvate may be selected from the following table:

In aspects and embodiments disclosed herein, the bacterial infection may present in the form of one or more of respiratory, skin or soft tissue disorders. For example, the bacterial infection may be one or more selected from the group consisting of lung infection, amyotrophic lateral sclerosis and bronchiectasis.

The compound of formula I as defined above or its salt or solvate can be used in combination with other therapeutic agents or their salts or solvates to provide a synergistic effect. Therefore, the fourth to sixth aspects of the present invention respectively relate to:

(A) Use of a compound of formula I as defined above, or a salt or solvate thereof, and another therapeutic agent, or a salt or solvate thereof, in the preparation of a medicament for treating a bacterial infection caused by Mycobacterium abscessus, wherein the compound of formula I and the other therapeutic agent are administered sequentially, simultaneously or in combination;

(B) use of a compound of formula I as defined above, or a salt or solvate thereof, for treating a bacterial infection caused by Mycobacterium abscessus, wherein the compound of formula I is administered sequentially, simultaneously or in combination with other therapeutic agents or salts or solvates thereof; and

(C) A method for treating a bacterial infection caused by Mycobacterium abscessus, which method comprises administering to a patient in need of such treatment a pharmaceutically effective amount of a compound of formula I as defined above, or a salt or solvate thereof, and another therapeutic agent, or a salt or solvate thereof.

As used herein, the term "other therapeutic agent" includes reference to one or more (eg, one) therapeutic agents (eg, one therapeutic agent) known to be useful (eg, known to be effective) in treating bacterial infections caused by M. abscessus.

As used herein, the term "sequential, simultaneous or combined administration" includes reference to the following:

administering separate pharmaceutical formulations (one comprising a compound of Formula I, and one or more others comprising one or more other therapeutic agents); and

A single pharmaceutical formulation comprising a compound of Formula I and the additional therapeutic agent(s) is administered.

In said aspect of the invention, the other therapeutic agent may be selected from one or more of the group consisting of oral antimicrobial agents, amikacin, cefocetin, clarithromycin, clofazimine and imipenem. For example, the other therapeutic agent may be clofazimine.

As will be appreciated, a compound of formula I as described above, or a salt or solvate thereof, will be provided for use as a pharmaceutical composition. Thus, in a seventh aspect of the invention, a pharmaceutical composition is provided comprising a compound of formula I as defined above, or a salt or solvate thereof, in combination with one or more pharmaceutically acceptable adjuvants, diluents or carriers.

The compounds of formula I can be administered by any suitable route, but in particular can be administered orally, intravenously, intramuscularly, cutaneously, subcutaneously, transmucosally (e.g. sublingually or buccally), rectally, transdermally, nasally, pulmonary (e.g. tracheally or bronchially), topically, by any other parenteral route, in the form of a pharmaceutical preparation comprising the compound in a pharmaceutically acceptable dosage form. Specific modes of administration that may be mentioned include oral, intravenous, cutaneous, subcutaneous, nasal, intramuscular or intraperitoneal administration.

The compound of formula I will generally be administered as a pharmaceutical preparation mixed with a pharmaceutically acceptable adjuvant, diluent or carrier, which can be selected with due consideration of the intended route of administration and standard pharmaceutical practice. Such a pharmaceutically acceptable carrier can be chemically inert to the active compound and can have no harmful side effects or toxicity under the conditions of use. Suitable pharmaceutical preparations can be found in, for example, Remington The Science and Practice of Pharmacy, 19th ed., Mack Printing Company, Easton, Pennsylvania (1995). For parenteral administration, parenteral acceptable aqueous solutions can be used, which are pyrogen-free and have the necessary pH, isotonicity and stability. Suitable solutions will be well known to those skilled in the art, and many methods are described in the literature. A brief review of drug delivery methods can also be found in, for example, Langer, Science (1990) 249, 1527.

Otherwise, the preparation of suitable formulations may be routinely accomplished by the skilled artisan using conventional techniques and/or in accordance with standard and/or accepted pharmaceutical practice.

The amount of the compound of formula I in any pharmaceutical formulation used according to the present invention will depend on various factors, such as the severity of the condition to be treated, the specific patient to be treated, and the compound(s) used. In any case, the amount of the compound of formula I in the formulation can be routinely determined by a skilled person.

For example, a solid oral composition such as a tablet or capsule may contain 1 to 99% (w/w) of active ingredient; 0 to 99% (w/w) of diluent or filler; 0 to 20% (w/w) of disintegrant; 0 to 5% (w/w) of lubricant; 0 to 5% (w/w) of glidant; 0 to 50% (w/w) of granulating agent or binder; 0 to 5% (w/w) of antioxidant; and 0 to 5% (w/w) of pigment. A controlled release tablet may additionally contain 0 to 90% (w/w) of a controlled release polymer.

Parenteral formulations (such as solutions or suspensions for injection or solutions for infusion) may contain 1 to 50% (w/w) of active ingredient; and 50% (w/w) to 99% (w/w) of a liquid or semisolid carrier or vehicle (e.g., a solvent such as water); and 0-20% (w/w) of one or more other excipients, such as buffers, antioxidants, suspension stabilizers, tonicity regulators and preservatives.

Depending on the condition and patient to be treated and the route of administration, the compounds of formula I can be administered to a patient in need thereof at varying therapeutically effective doses.

However, the dose administered to a mammal, particularly a human, in the context of the present invention should be sufficient to produce a therapeutic response in the mammal within a reasonable time frame. Those skilled in the art will recognize that the selection of the exact dose and composition and the most appropriate delivery regimen will also be influenced by, inter alia, the pharmacological properties of the formulation, the nature and severity of the condition being treated and the physical condition and mental acuity of the recipient, as well as the potency of the specific compound, the age, condition, weight, sex and response of the patient being treated, and the stage/severity of the disease.

Administration can be continuous or intermittent (e.g., by bolus injection). Dosage can also be determined by the timing and frequency of administration. In the case of oral or parenteral administration, the dosage of the compound of Formula I can vary between about 0.01 mg to about 1000 mg per day.

In any case, a practicing physician or other technician will be able to routinely determine the actual dosage that is most suitable for an individual patient. The dosages mentioned above are examples of average cases; of course, there are individual cases where a higher or lower dosage range is required, and such is within the scope of the present invention.

As described above, the compound of formula I or its salt or solvate can be combined with a further therapeutic agent. Therefore, in an eighth aspect of the present invention, a pharmaceutical composition is provided, which comprises a compound of formula I as defined above or its salt or solvate, and other therapeutic agents or their salts or solvates, wherein the other therapeutic agent is selected from one or more of the group consisting of oral antimicrobial agents, amikacin, cefocetin, clarithromycin, clofazimine and imipenem, optionally wherein the other therapeutic agent is clofazimine.

The above-mentioned combination products provide for the combined administration of component (A) and component (B), and therefore, can be presented as separate preparations, wherein at least one of these preparations includes component (A) and at least one includes component (B), or can be presented (i.e. formulated) as a combined preparation (i.e. presented as a single preparation including component (A) and component (B)).

Therefore, it is further provided that:

(I) a pharmaceutical preparation comprising a compound of formula I as defined above and another therapeutic agent, mixed with a pharmaceutically acceptable adjuvant, diluent or carrier (such preparation is hereinafter referred to as a "combination preparation"); and

(II) a kit of parts comprising the following components:

(i) a pharmaceutical formulation comprising a compound of formula I as defined above in admixture with a pharmaceutically acceptable adjuvant, diluent or carrier; and

(ii) pharmaceutical preparations comprising other therapeutic agents in admixture with a pharmaceutically acceptable adjuvant, diluent or carrier,

The components (i) and (ii) are each provided in a form suitable for administration in combination with the other components.

Thus, component (i) of the kit of parts is component (A) mixed with a pharmaceutically acceptable adjuvant, diluent or carrier. Similarly, component (ii) is component (B) mixed with a pharmaceutically acceptable adjuvant, diluent or carrier.

It will be appreciated that the combination products discussed above may be formulated as discussed above with respect to the seventh aspect of the invention.

The various aspects of the invention described herein (e.g., the above-described compounds, combinations, methods and uses) may have the advantage that they may be more convenient for physicians and/or patients in the treatment of the conditions described herein, more effective, less toxic, more selective, have a broader spectrum of activity, be more potent, produce fewer side effects, or may have other useful pharmacological properties than similar compounds, combinations, methods (treatments) or uses known in the prior art for the treatment of these conditions or others.

Further aspects and embodiments of the invention will now be discussed with reference to the following non-limiting examples.

Example

Material

DNase I and MgCl ₂ were purchased from Thermo Fischer, USA. Middlebrook 7H9 medium, CAMH broth and Middlebrook albumin-dextrose-catalase (ADC) were purchased from BD Difco. Glycerol was purchased from Fisher Scientific. Tween 80 was purchased from Sigma-Aldrich. EDTA-free protease inhibitor cocktail was purchased from Roche-USA. CellTiter-glow and Bac titer glo were purchased from promega. 3-(N-morpholino)propane sulfonic acid (MOPS), ADP, NADH, lysozyme, KH ₂ PO ₄ , clofazimine and amikacin were purchased from Sigma-Aldrich. BCA kit was purchased from Pierce.

Mycobacterium abscessus subsp. abscessus ATCC 19977, Mycobacterium abscessus subsp. boleyi, Mycobacterium abscessus subsp. massei strains and a clinical isolate of Mycobacterium abscessus Bamboo from a patient with amyotrophic lateral sclerosis and bronchiectasis were used. The latter belongs to Mycobacterium abscessus subsp. abscessus and carries the inactive clarithromycin-sensitive erm(41)C28sequevar (GenBank accession number MVDX00000000) (Yee, M. et al., Genome Announc. 2017, 5, e00388-17).

General procedure for culturing Mab strains

All Mab strains were maintained in Middlebrook 7H9 medium supplemented with 0.2% (vol/vol) glycerol, 0.05% (vol/vol) Tween 80, and 10% (vol/vol) Middlebrook ADC. CAMH broth was used to grow the Mab strains and was prepared according to the manufacturer's instructions.

Example 1. Recycling method of GaMF1 anti-TB compound

_{Mycobacterial F1F0} -ATP synthase consists of its proton translocation _F0 region (a: _c9 ), which is connected to the catalytic _α3 : _β3 region via a central rotation γ.ε and a peripheral stalk subunit b:b′:δ, where ATP is formed (Kamariah, N. et al., J. Struct. Biol. 2019, 207, 199-208; Kamariah, N, et al., Prog. Biophys. Mol. Biol. 2020, 152, 64-73; and Guo, H. et al., Nature 2021, 589, 143-147). Compared to non- _{mycobacterial F1F0} -ATP synthase, mycobacterial F-ATP synthase subunits α, δ, and γ contain a C-terminal extension (Ragunathan, P. et al., J. Biol. Chem. 2017, 292, 11262-11279), an insertion domain (Kamariah, N. et al., J. Struct. Biol. 2019, 207, 199-208), or an additional loop of 12 to 14 amino acids (Hotra, A. et al., FEBS J. 2016, 283, 1947-1961), respectively. These appendages are important for regulation (Kamariah, N, et al., Prog. Biophys. Mol. Biol. 2020, 152, 64-73; Guo, H. et al., Nature 2021, 589, 143-147; Ragunathan, P. et al., J. Biol. Chem. 2017, 292, 11262-11279; and Wong, C.-F. & Grüber, G., Antimicrob. Agents Chemother. 2020, 64, e01568-20) or ATP synthesis (Ragunathan, P. et al., J. Biol. Chem. 2017, 292, 11262-11279; Hotra, A. et al., FEBS J. 2016, 283, 1947-1961; and Harikishore, A. et al., Nature 2016, 589, 143-147). al., Antibiotics 2021, 10, 1456). For example, the mycobacterial extra loop of subunit γ provides a failsafe device (Montgomerya, M. Get al., Proc. Natl. Acad. Sci. USA 2021, 118, e2111899118), by which one of its aspartate residues forms a salt bridge with an arginine residue of the peripheral handle subunit b' during rotation when subunit g approaches subunit b' (Montgomerya, M. Get al., Proc. Natl. Acad. Sci. USA 2021, 118, e2111899118). These new mycobacterial features of subunits α and γ are targets for specificity and new inhibitors (Harikishore, A. et al., Antibiotics 2021, 10, 1456; and Hotra, A. et al., Angew. Chem. Int. Ed. Engl. 2020, 59, 13295-13304). GaMF1 is a bactericidal anti-TB compound that targets an extra ring of the γ subunit of Mycobacterium tuberculosis (M. tuberculosis), representing this new type of mycobacterial F-ATP synthase inhibitor, which has a clogP of 4.37 and good metabolic stability in mouse liver microsomes, and does not inhibit the growth of Gram-positive and Gram-negative bacteria such as Staphylococcus aureus and Escherichia coli (Hotra, A. et al., Angew. Chem. Int. Ed. Engl. 2020, 59, 13295-13304).

The reuse method was used for GaMF1 anti-TB compound (Figure 1A), and the sensitivity of Mab (Mycobacterium abscessus subsp. abscessus) to the compound in complete Middlebrook 7H9 broth was studied using the model strain Mycobacterium abscessus subsp. abscessus ATCC 19977 as the test bacteria, as well as the sensitivity of Mycobacterium abscessus to the compound in cation-adjusted Mueller-Hinton (CAMH) medium (Pang, H. et al., Int. J. Clin. Exp. Med. 2015, 8, 15423-15431; and Low, J. L. et al., Front. Microbiol. 2017, 8, 1539) and in complete Middlebrook 7H9 broth (Broda, A. et al., J. Clin. Microbiol. 2013, 51, 217-223). GaMF1 was synthesized according to the literature (Hotra, A. et al., Angew. Chem. Int. Ed. Engl. 2020, 59, 13295-13304).

Determination of minimum inhibitory concentration (MIC)

Growth inhibition dose-effect assays were performed using broth microdilution as described previously (Moreira, W., Aziz, DB & Dick, T., Front. Microbiol. 2016, 7, 199). The reported MIC ₅₀ represents the concentration that inhibits 50% growth compared to untreated cultures.

Results and discussion

GaMF1 showed the following efficacy, with the MIC required to inhibit 50% growth of Mycobacterium abscessus (MIC ₅₀ ) being 13±2.1 μM (Figure 1B) and 33±4.7 μM (Figure 2A), which is even better than the MIC _{50 values of first-line drugs cefocetin (43 μM), amikacin (44 μM) and amikacin (360 μM) (Sarathy, JP et al., Antimicrob. Agents Chemother. 2020, 64, e02404). GaMF1 also inhibited 50} % growth of two other subspecies, Mycobacterium abscessus subspecies Bole (at 36.2 μM) and Mycobacterium abscessus subspecies Massimo (at 35.8 μM) (Figure 2A). These values are also comparable to those determined for GaMF1 in Mycobacterium tuberculosis (33 μM) and Mycobacterium bovis (M. Bovis) Calmette-Guérin (BCG, 17 μM, Hotra, A. et al., Angew. Chem. Int. Ed. Engl. 2020, 59, 13295-13304), and to the clinically used anti-Mycobacterium abscessus drugs cefoxitin (38 μM, Ferro, BE et al., Antimicrob. Agents Chemother. 2016, 60, 6374-6376), amikacin (55 μM, Ferro, BE et al., Antimicrob. Agents Chemother. 2016, 60, 6374-6376), and imipenem (14 μM, Brown-Elliott, BA et al., Antimicrob. Agents Chemother. 2016, 60, 6374-6376). al., J. Clin. Microbiol. 2016, 54, 1586-1592). Although the F-ATP synthase inhibitors bedaquiline (BDQ) and TBAJ876 showed 100× higher potency against Mycobacterium tuberculosis than against Mycobacterium abscessus (Sarathy, JP et al., Antimicrob. Agents Chemother. 2020, 64, e02404-19), GaMF1 maintained similar potency in cell growth inhibition and killing of a broad spectrum of mycobacteria.

Example 2. GaMF1 sensitivity

We determined whether GaMF1 sensitivity was retained against the clinical isolate Mycobacterium abscessus subsp. Bamboo (Yee, M. et al., Genome Announc. 2017, 5, e00388-17). MIC ₅₀ was determined according to the protocol in Example 1.

Results and discussion

The MIC ₅₀ determined in CAMH medium and Middlebrook 7H9 broth were 10 ± 1.9 μM ( FIG. 1C ) and 33 ± 3.2 μM ( FIG. 2B ), respectively, which are similar to the values determined for the type strain of M. abscessus, M. abscessus subsp. abscessus ATCC 19977.

Example 3. Bactericidal activity of GaMF1

To determine whether GaMF1 has a bactericidal effect on M. abscessus, we measured the survival of this strain after drug exposure. The _MIC50 was determined according to the protocol in Example 1.

Results and discussion

GaMF1 was bactericidal against M. abscessus at 10 times its _MIC50 in both CAMH medium (Fig. ID) and 7H9 (Fig. 2C).

Example 4. Ability of GaMF1 to inhibit mycobacterial F-ATP synthase

The ability of GaMF1 to inhibit mycobacterial F-ATP synthase was evaluated using an intracellular ATP synthesis assay (Lechartier, B. & Cole, S.T., Antimicrob. Agents Chemother. 2015, 59, 4457-4463) and IMVs of Mycobacterium abscessus (Hotra, A. et al., Angew. Chem. Int. Ed. Engl. 2020, 59, 13295-13304). IMVs of Mycobacterium abscessus were prepared according to Hotra et al. (Hotra, A. et al., Angew. Chem. Int. Ed. Engl. 2020, 59, 13295-13304).

Preparation of Mab reverse membrane vesicles

To purify IMVs of Mabs for ATP synthesis assays, cells were grown overnight at 37°C in 7H9 supplemented with 10% Middlebrook albumin-dextrose-catalase (ADC), 0.5% glycerol and 0.05% Tween 80 until they reached an OD ₆₀₀ value of 0.4. The culture was expanded in 200 ml of supplemented 7H9 and grown in roller bottles (2 rpm) until OD ₆₀₀ = 0.4. This culture was used to inoculate a 5 l culture grown overnight in roller bottles until OD ₆₀₀ = 0.4. Approximately 5 g (wet weight) of Mabs were resuspended in 20 ml of membrane preparation buffer (50 mM MOPS, 2 mM MgCl ₂ , pH 7.5) containing EDTA-free protease inhibitor cocktail (1 tablet in 20 ml buffer) and 1.2 mg/ml lysozyme. The suspension was stirred at room temperature for 45 min, and 300 μl 1M MgCl ₂ and 50 μl DNase I were additionally supplemented, and stirring was continued for another 15 min at room temperature. All subsequent steps were performed on ice. The cells were broken by passing through an ice-precooled M-110L model microfluidizer (M-110L) three times at 18,000 psi. The suspension containing the lysed cells was centrifuged at 4,200 x g for 20 min at 4 ° C. The supernatant containing the membrane fraction was further ultracentrifuged at 45,000 x g for 1 h at 4 ° C. The supernatant was discarded, and the precipitated membrane fraction was resuspended in a membrane preparation buffer containing 15% glycerol, aliquoted, quickly frozen and stored at -80 ° C. The concentration of protein in the vesicle was determined by the BCA method (Smith, PK et al., Anal Biochem. 1985, 150, 76-85).

ATP synthesis assay of IMVs

ATP synthesis was measured in a flat-bottom white microtiter 96-well plate (Corning USA). The reaction mixture was prepared in an assay buffer (50 mM MOPS, pH 7.5, 10 mM MgCl ₂ ) containing 10 μM ADP, 250 μM Pi and 1 mM NADH. The concentration of Pi was adjusted by adding 100 mM KH ₂ PO ₄ salt dissolved in the assay buffer. ATP synthesis was started by adding the reverse vesicles of Mab to a final protein concentration of 5 μg/ml. The reaction mixture was incubated at room temperature for 30 min before adding 50 μl of CellTiter luminescent reagent, and the mixture was incubated at room temperature for another 10 min in the dark. The emitted luminescence was related to the synthesized ATP and was measured by a Tecan microplate reader Infinite 200 Pro (Tecan USA) using the following parameters: luminescence, an integration time of 500 ms and no decay.

Whole-cell ATP measurement

Whole-cell ATP synthesis assays were performed in 96-well plates as previously described (Hotra, A. et al., Angew. Chem. Int. Ed. Engl. 2020, 59, 13295).

Half maximal inhibitory concentration (IC ₅₀ )

100 μl of complete 7H9 medium was placed in each well of a clear 96-well flat-bottom Costar cell culture plate (Corning). GaMF1 was added to the first well in each row to produce twice the desired highest final concentration. Subsequently, a 16-point 2-fold serial dilution was performed starting from the first well in each row. Mycobacterium abscessus subsp. abscessus grown to mid-exponential phase was diluted to an optical density (OD ₆₀₀ ) of 0.1 at 600 nm; 100 μl of the diluted culture was added to each well to produce a final OD ₆₀₀ of 0.05 in all wells. The plate was incubated at 37°C for 6-8h.

At the end of the incubation period, the intracellular ATP content of the sample was measured by adding the BacTiter-Glo microbial cell viability assay (Promega), which was performed according to the manufacturer's instructions as described previously (Wu, M.-L., Gengenbacher, M. & Dick, T., Front Microbiol. 2016, 7, 947). 50 μl of bacterial sample was mixed with 50 μl of BacTiter-Glo reagent in each well of an opaque white 96-well flat-bottom Nunc plate. After the plate was incubated in the dark for 10 min at room temperature, luminescence was measured with a Tecan Infinite Pro 200 microplate reader. The background luminescence reading was subtracted from the luminescence reading of all samples. The amount of ATP content is proportional to the relative luminescence unit. The result graph was prepared using GraphPad Prism 8 software. IC ₅₀ corresponds to a 50% decrease in luminescence value compared to drug-free conditions.

Results and discussion

As shown in Figure 3A, compound GaMF1 depleted intracellular ATP synthesis with an _IC50 of 10 ± 0.9 μM and depleted NADH-driven ATP synthesis of M. abscessus IMV with an _IC50 of 13 ± 2.5 μM (Figure 3B), indicating that the growth inhibition of the pathogen was caused by the inhibition of F-ATP synthase.

Table 1. GaMF1 and its effects on cell growth (MIC ₅₀ ) and ATP synthesis (IC ₅₀ ).

Example 5. Growth inhibitory activity of GaMF1 in combination with CFZ

Since the treatment of M. abscessus infection requires a drug combination, we measured the growth inhibitory activity of GaMF1 in combination with CFZ, which is proposed to compete with the mycobacterium-specific electron acceptor menaquinone for its reduction by the NDH-2 complex (Lechartier, B. & Cole, ST, Antimicrob. Agents Chemother. 2015, 59, 4457-4463). CFZ has recently been shown to be active against M. abscessus and is used clinically as a repurposing drug. The MIC ₅₀ was determined according to the protocol in Example 1.

Results and discussion

As shown in Figure 4, the combination of 3.4 μM CFZ or 6.8 μM (MIC ₅₀ of CFZ, Ferro, BE et al., Antimicrob. Agents Chemother. 2016, 60, 1097-1105) with GaMF1 increased the efficacy of inhibition of M. abscessus cells in 7H9 culture medium (Figure 4A). When GaMF1 was combined with rifabutin, an RNA polymerase inhibitor of M. abscessus (MIC of 1 to 4 μM) (Figure 4B) or amikacin, an antibiotic against M. abscessus (5 μM, Figure 4C), a sharp decrease in cell growth was observed.

Example 6. GaMF1 and rifabutin killing efficacy

Study on the killing efficacy of GaMF1 and rifabutin

Abscess mycobacterium culture was grown to exponential phase and diluted to _OD600 of 0.005 and dispensed onto T- ^25mm2 tissue culture flasks. GaMF1 was distributed to each flask along with rifabutin and incubated at 37°C with 180rpm shaking for 5 days. About 10 μl of culture was taken out from each flask and then serially diluted with PBS. 25 μl of the corresponding dilution culture was plated on each quadrant of a 7H10 agar plate. The agar plates were incubated at 37°C for three days. Bacterial viability was determined by counting colony forming units (CFU) on the plate.

Results and discussion

Considering the increased anti-M. abscessus activity in the GaMF1-rifabutin combination and the bactericidal activity of rifabutin (Aziz, D.B. et al., Antimicrob. Agents Chemother. 2017, 61, e00155-17; and Johansen, M.D. et al., Antimicrob. Agents Chemother. 2020, 64, e00363-20), the combined GaMF1-rifabutin effect in M. abscessus killing was shown to be only minimal (Figure 5).

In conclusion, this study demonstrates that GaMF1 is active in cytostasis and cytotoxicity of M. abscessus, similar to the activity of this compound against M. tuberculosis. The identification of GaMF1 as a novel M. abscessus inhibitor expands the scarce pipeline of compounds against this difficult-to-treat opportunistic NTM pathogen. By targeting the F-ATP synthase of M. abscessus, GaMF1 depletes cellular ATP, which is essential for cell wall formation, replication, assimilation, and catabolic processes, as well as ATP-dependent efflux pumps. Inhibition of the latter can hamper drug flux, which has emerged as an important determinant of BDQ and CFZ resistance in M. abscessus. Finally, M. abscessus showed increased sensitivity to GaMF1 in combination with CFZ, rifabutin, or amikacin, a prerequisite for a combination approach to treat M. abscessus infections.

Claims (16)

1. Use of a compound of formula I in the preparation of a medicament for treating bacterial infection caused by Mycobacterium abscessus: in: R ₁ and _Ra each independently represent H, halogen, C ₁ -C ₄ alkyl, C ₁ -C ₄ alkoxy or OH; R ₂ represents H, C ₁ -C ₄ alkyl which is unsubstituted or substituted by a hydroxyl group, or -CH ₂ CO ₂ Et; R ₃ represents H or C ₁ -C ₄ alkyl; X, Y and Z each independently represent CR ₄ or N; Each R ₄ independently represents H, halogen, C ₁ -C ₄ alkyl or C ₁ -C ₄ alkoxy, or a salt or solvate thereof. 2. Use of the compound of formula I or a salt or solvate thereof as claimed in claim 1 for treating bacterial infection caused by Mycobacterium abscessus. 3. A method for treating bacterial infection caused by Mycobacterium abscessus, comprising the step of providing a subject in need thereof with a pharmaceutically effective amount of a compound of formula I as claimed in claim 1 or a salt or solvate thereof. 4. The use according to claim 1, the compound for use according to claim 2 or the method according to claim 3, wherein the compound of formula I is a compound in which _R2 represents H, _C1 - _C4 alkyl which is unsubstituted or substituted by a hydroxyl group. 5. The use according to claim 1 or claim 4, the compound for use according to claim 2 or claim 4, or the method according to claim 3 or claim 4, wherein _R3 represents H, _{CH3 or CH2CH3} . 6. The use according to claim 1 or claims 4 to 5, the compound according to claim 2 or claims 4 to 5 for use, or the method according to claims 3 to 5, wherein _Ra is H and _R1 is Br. 7. The use according to claim 1 or claims 4 to 6, the compound for use according to claim 2 or claims 4 to 6, or the method according to claims 3 to 6, wherein X is N. 8. The use according to claim 1 or claims 4 to 7, the compound for use according to claim 2 or claims 4 to 7, or the method according to claims 3 to 7, wherein Z is N. 9. The use according to claim 1 or claims 4 to 8, the compound according to claim 2 or claims 4 to 8 for use or the method according to claims 3 to 8, wherein Y is C- _CH3 . 10. The use according to claim 1 or claims 4 to 9, the compound for use according to claim 2 or claims 4 to 9, or the method according to claims 3 to 9, wherein the compound of formula I or a salt or solvate thereof is selected from the following list: Optionally, the compound of formula I or its salt or solvate is selected from the following list: 11. The use according to claim 1 or claims 4 to 10, the compound for use according to claim 2 or claims 4 to 10, or the method according to claims 3 to 10, wherein the bacterial infection presents in the form of one or more of respiratory, skin or soft tissue disorders (e.g. one or more selected from the group of lung infection, amyotrophic lateral sclerosis and bronchiectasis). 12. Use of a compound of formula I as defined in any one of claims 1 and 4 to 10, or a salt or solvate thereof, and another therapeutic agent, or a salt or solvate thereof, in the preparation of a medicament for treating a bacterial infection caused by Mycobacterium abscessus, wherein the compound of formula I and the other therapeutic agent are administered sequentially, simultaneously or in combination. 13. Use of a compound of formula I as defined in any one of claims 1 and 4 to 10, or a salt or solvate thereof, for treating a bacterial infection caused by Mycobacterium abscessus, wherein the compound of formula I is administered sequentially, simultaneously or in combination with other therapeutic agents or salts or solvates thereof. 14. A method of treating a bacterial infection caused by Mycobacterium abscessus, said method comprising administering to a patient in need of such treatment a pharmaceutically effective amount of a compound of formula I as defined in any one of claims 1 and 4 to 10, or a salt or solvate thereof, and another therapeutic agent, or a salt or solvate thereof. 15. The use according to claim 12, the compound for use according to claim 13 or the method according to claim 14, wherein the other therapeutic agent is selected from one or more of the group consisting of oral antimicrobials, amikacin, cefocetin, clarithromycin, clofazimine and imipenem, optionally wherein the other therapeutic agent is clofazimine. 16. A pharmaceutical composition comprising a compound of formula I as defined in any one of claims 1 and 4 to 10, or a salt or solvate thereof, and another therapeutic agent, or a salt or solvate thereof, wherein the other therapeutic agent is selected from one or more of the group consisting of oral antimicrobial agents, amikacin, cefocetin, clarithromycin, clofazimine and imipenem, optionally wherein the other therapeutic agent is clofazimine.