WO1994021274A1

WO1994021274A1 - Synergistic combination of ethambutol and a glycopeptide antibiotic

Info

Publication number: WO1994021274A1
Application number: PCT/EP1994/000732
Authority: WO
Inventors: Beth P. Goldstein; Taraq Mahmood Arain
Original assignee: Gruppo Lepetit S.P.A.
Priority date: 1993-03-24
Filing date: 1994-03-09
Publication date: 1994-09-29
Also published as: AU6375994A; ZA942036B; IL109022A0; HUT69730A

Abstract

The present invention is directed to a synergistic combination of ethambutol and an antibiotic selected from teicoplanin, a teicoplanin amide derivative, an aglycon or pseudoaglycon thereof, antibiotic A40926 complex, a factor, a derivative, aglycon or pseudoaglycon thereof. The synergistic combinations of the invention are particularly effective in the treatment of infections caused or sustained by mycobacteria, particularly M. tuberculosis, including multi-drug resistant strains of M. tuberculosis.

Description

SYNERGISTIC COMBINATION OF ETHAMBUTOL AND A GLYCOPEPTIDE ANTIBIOTIC

The present invention is directed to a synergistic combination of ethambutol and an antibiotic selected from teicoplanin, a teicoplanin amide

derivative, an aglycon or pseudoaglycon thereof, antibiotic A40926 complex, a factor, a derivative, aglycon or pseudoaglycon thereof.

The synergistic combinations of the invention are particularly effective in the treatment of

infections caused or sustained by mycobacteria,

particularly M. tuberculosis, including multi-drug resistant strains of M. tuberculosis.

Recently there has been an increase in the incidence of new cases of tuberculosis. The problem is exacerbated by the AIDS epidemic and the emergence of drug resistance. New agents which can substitute or supplement the existing treatments are therefore needed.

Ethambutol is a known drug that is widely used in the treatment of tuberculosis.

Teicoplanin is an antibiotic drug approved for treatment of Gram-positive infections in several

countries. It has been previously reported to have no significant in vitro activity against M. tuberculosis (F. Parenti et al, J. Antibiotics, 1978, 31, 276-283).

Teicoplanin and its derivatives that can be employed in the present invention can be represented by the following formula I

wherein

Y' represents hydroxy or [mono- or

di-(C₁-C₄)alkyl]amino[(CH₂)_n]amino, wherein n represent an integer from 2 to 4,

A' represents hydrogen or N[(C₉-C₁₂)aliphatic

acyl]-β-2-amino-2-deoxy-glucopyranosyl, G' represents hydrogen or N-acetyl-β-2-amino-2- deoxy-glucopyranosyl,

M' represents hydrogen or α-D-mannopyranosyl, or an acid addition salt thereof.

Teicoplanin is described in US patents 4,239,751 and 4542018.

More particularly it is an antibiotic substance produced by a strain of Actinoplanes teichomyceticus

ATCC 31121, that essentially consist of a main

component, named TA2-2, that is accompanied by other components named TA2-1, TA2-3, TA2-4, TA2-5 and TA3-1. Depending on the specific production or isolation conditions, one or more of these compounds may be present in only very low or negligible amounts. TA2-2 is the compound of formula I wherein A', G' and M'

represent the sugar moieties defined above, Y'

represents hydroxy and (C₉-C₁₂)aliphatic acyl represents 8-methylnonanoyl, TA2-1 is the compound of formula I wherein A', G' and M' represent the sugar moieties defined above, Y' represents hydroxy and (C₉- C₁₂)aliphatic acyl represents 4Z-decenoyl, TA2-3 is the compound of formula I wherein A', G' and M' represent the sugar moieties defined above, Y' represents hydroxy and (C₉-C₁₂)aliphatic acyl represents decanoyl, TA2-4 is the compound of formula I wherein A^,, G' and M'

represent the sugar moieties defined above, Y'

represents hydroxy and (C₉-C₁₂)aliphatic acyl represents 8-methyldecanoyl, TA2-5 is the compound of formula I wherein A', G' and M' represent the sugar moieties defined above, Y' represents hydroxy and (C₉- C₁₂)aliphatic acyl represents 9-methyldecanoyl, TA3-1 is the compound of formula I wherein A' represents hydrogen, and G' and M' represent the sugar moieties defined above.

Teicoplanin aglycone and pseudoaglycones are described in DS patents 4650855, 4645827, and 4629781.

Teicoplanin amide derivatives are described in European Patent No.218099, corresponding to US

application 08/079970.

Preferred amide derivatives are those wherein Y' represents a 3,3-dimethylaminopropylamine group. Most preferred are those amides wherein A', G', and M' represent the sugar moieties defined above.

Antibiotic A 40926 and its derivatives can be represented by the following formula II

wherein : R² represents (C₉-C₁₂)alkyl;

M represents hydrogen, α-D-mannopyranosyl or

6-O-acetyl-α-D-mannopyranosyl;

Y represents carboxy, (C₁-C₄)alkoxycarbonyl,

aminocarbonyl, (C₁-C₄)alkylaminocarbonyl, di(C₁-C₄)alkylaminocarbonyl wherein the alkyl moiety may bear a substituent selected from hydroxy, amino, (C₁-C₄)alkylamino and

di(C₁-C₄)alkylamino or hydroxymethyl;

X represents hydroxy or an amino group of formula -NR³-alk₁-(NR⁴-alk²)_p -(NR⁵-alk³)_q-W

wherein:

R³ represents hydrogen or (C₁-C₄)alkyl; alk¹,alk²

and alk³ each independently represent a linear or branched alkylene of 2 to 10 carbon atoms;

p and g are integers which independently

represent zero or 1;

R⁴ and R⁵ each independently represent hydrogen,

(C₁-C₄)alkyl or

R³ and R⁴ taken together represent a

(C₂-C₄)alkylene moiety connecting the two nitrogen atoms with the proviso that p is 1; or

R⁴ and R⁵ taken together represent a

(C₂-C₄)alkylene moiety connecting the two nitrogen atoms with the proviso that both p and g are 1;

W represents hydrogen, (C₁-C₄)alkyl,

amino, (C₁-C₄)alkylamino, di(C₁-C₄)alkylamino, amino substituted with one or two amino-(C₂-C₄)alkyl moieties or with one or two

(C₁-C₄)alkylamino-(C₂-C₄)alkyl moieties or with one or two di(C₁-C₄)alkylamino-

(C₂-C₄)alkyl moieties, or, when both p and q are zero, taken together with the moiety -NR³-alk¹- it may also represent piperazino or 4-methylpiperazino, with the proviso that when X represents hydroxy Y represents hydroxymethyl,

Z represents hydrogen or a group

wherein A^Θ represents a mineral or organic acid anion or, when a carboxyacid function is present in the remaining portion of the antibiotic, it may also represent the internal anion deriving from said carboxyacid function; or an addition salt thereof .

Antibiotic A 40926 and its factors, i.e. the compounds of formula II wherein X is OH, are described in US Patent 4,935,238.

More particularly, antibiotic A 40926 factor A is a compound of the above Formula (II) wherein X represents hydroxy, Y represents carboxy, R₂ represents n-decyl and M represents α-D-mannopyranosyl.

Antibiotic A 40926 factor B₀, which is the main component of A 40926 factor B, corresponds to the compound of the above formula (II) wherein X represents hydroxy, Y represents carboxy, R₂ represents

9-methyldecyl and M represents α-D-mannopyranosyl.

Antibiotic A 40926 factor B₁ differs from factor B₀ only in that R² represents n-undecyl (E. Riva et al, Chromatografia, Vol. 24, 295, 1987).

Antibiotic A 40926 factor PA and factor PB differ from the corresponding factor A and B in that the mannose unit is replaced by a 6-O-acetyl-α-D-mannopyranose unit.

Antibiotic A 40926 mannosyl aglycon, i.e. the compound of formula II wherein X represents OH and the sugar in position 56 is replaced by a OH group, is described in DS patent 4782042. Antibiotic A 40926 pseudoaglycons and aglycon, i.e. the compound of formula II wherein X represents OH and M represents hydrogen and the compound of formula II wherein X represents OH, the sugar in position 56 is replaced by a OH group, and M represents hydrogen, is described in DS patent 4868171. The compounds reported above wherein X is different from OH are reported in PCT/EP92/01594, designating inter alia the USA, which was published as WO 93/03060. Other derivatives, that are also useful for preparing them, are reported in PCT/EP92/00374, designating inter alia the USA, which was published as WO 92/17495.

A group of preferred compounds of Formula II includes those compounds wherein X represents a mono- or di- (alkyl)amino alkyl group, most preferably 3,3- dimethylaminopropyl. Another group of preferred

compounds of Formula II includes those compounds wherein R² represents 9-methyldecyl. The most preferred

compounds of Formula II are those wherein X represents 3,3-dimethylaminopropyl and Y represents hydroxymethyl. The methods for preparing these compounds are known from the above references, which are hereby incorporated by reference, and are also known by analogy in the art.

According to the present invention, any of the above compounds of Formula I or II can be used in the combinations and methods of the invention either each individually or as a mixture thereof in any proportion. For conciseness, a compound of the above

Formula I will be referred to in this application as "teicoplanin or a derivative thereof", and a compound of Formula II will be referred to in this application as "antibiotic A40926 or a derivative thereof".

Teicoplanin or a derivative thereof and antibiotic A40926 or a derivative thereof, represent one of the components of the synergistic combination of the invention. It will be indicated below as the

"glycopeptide component" of the synergistic combination of the invention. The other component of this

combination is ethambutol, that will be referred to also as the "ethambutol component" of this synergistic combination.

The term "treatment" as used in this

application, is intended to encompass the aspects of prophylaxis, therapy and cure and also refers to each of them individually.

The term "conjunctive treatment" refers to the simultaneous or sequential administration of the

components of the combination of the invention to a patient in need of this treatment. Thus meaning that the effects of the first component to be administered are still present in the patient when the second one is administered.

One object of this invention is therefore a combination for the conjunctive treatment of

tuberculosis which comprises a synergistically effective dosage of the glycopeptide component and the ethambutol component. The synergistically effective dosage of each component in each combination of the invention can be ascertained by a person of ordinary skill in the art on the basis of the general and detailed description, test methods and results thereof that are reported in this application, or by applying conventional procedures that can be deduced from those described herein on the basis of the common knowledge in this art.

For use in the combination of the invention, it is not required that the above components are formulated in a single formulation but, on the contrary, it is preferred that the glycopeptide component and the ethambutol component are administered each individually according to their preferred formulation and route of administration.

Conventional formulations of the glycopeptide component or the ethambutol component are in general those derivable from the common knowledge in the art, by reference also to some textbooks, such as Remington's Pharmaceutical Sciences, Alfonso R. Gennaro Editor, 17th Edition, Mack Publishing Co., Easton, Pennsylvania, Particularly preferred formulations are, of course, those already approved by the Health Authorities and currently available on the market. More particularly, for use in the combination of the invention, the glycopeptide component is preferably formulated as a dosage form for parenteral

administration, preferably by intramuscular (i.m.) or intravenous (i.v.) route. Its preferred dosage range is from 1 to 15 mg/kg of patient body weight per day and most preferably from 3 to 6 mg/kg of patient body weight per day.

Preferred for use in the combination of the invention is a dosage form of the glycopeptide component for

intramuscular administration containing from 100 to 600mg , and preferably from 200 to 400 mg, of this active ingredient.

For use in the combination of the invention, the ethambutol component is preferably formulated as an oral dosage form, such as a tablet or a capsule.

Its preferred dosage range is from 5 to 25 mg/kg of patient body weight per day, and preferably from 10 to 20 mg/kg of patient body weight per day.

Preferred for use in the combination of the invention is a dosage form of the ethambutol component for oral administration containing from 50 to 500 mg, and

preferably from 100 to 400 mg of this active ingredient.

The combination of the invention has the advantage of being particularly active in the treatment of M. tuberculosis infections, including multi-drug resistant M. tuberculosis infections, at dosages of the ethambutol component that are in general significantly lower than the currently used dosages or the dosages expected to be necessary to cure the infection employing ethambutol alone. Also the teicoplanin component is employed in the combination of the invention at an effective dosage that is in the lower range of doses so far used for the treatment of Gram-positive infections, and are considerably lower than any expected effective dosages of teicoplanin alone against M. tuberculosis. The administration of the combination of the invention to a patient in need thereof contemplates administering the glycopeptide component and the

ethambutol component, each by its preferred or suggested route of administration, either simultaneously or sequentially, according to the conjunctive treatment of this invention.

Preferably, the glycopeptide component is administered first, by its preferred administration route, that is i.m., and then the ethambutol component is administered at a time when the blood levels of the glycopeptide component are still high.

More preferably, the ethambutol component is administered, per os, within 1 to 3 hours of the

administration, i.m., of the glycopeptide component.

When the glycopeptide component is teicoplanin or another member of this group having a similarly prolonged half-life, the glycopeptide component of the invention can be administered only two or three times per week, while the ethambutol component continues to be administered once a day. This schedule of administration is particularly convenient in the conventional treatment of tuberculosis possibly sustained by multi-drug resistant strains, where a multi-drug treatment is required, and the combination of the invention can be added to the

conventional treatments with rifampicin, isoniazid and/or pyrazinamide and/or streptomycin.

In these treatments, the combination of the invention is preferably intended to be a substitute for streptomycin whose toxicity is known.

The combination of the invention can also be employed, alone or with isoniazid, in the

chemoprophylaxis of tuberculosis of populations at risk, such as the hospital personnel, families or coworkers of patients.

While it is usually preferred to administer the ethambutol component by its own preferred route, i.e. orally, the ethambutol and the glycopeptide components of the combination of the invention can be conveniently co-formulated in a single formulation for intramuscular administration, particularly when oral administration is not feasible.

According to the present invention, the term patient is intended to refer to an individual in need of the treatment with the combination of the invention, and includes a warm blooded animal such as avian, e.g.

poultry, mammals e.g. rodents, ovine, canid, feline, bovine, primates, and humans in particular.

The indications pertaining to effective dosages, preferred dosage ranges, formulations, administration modes and routes of the combination of the invention. while are considered accurate, are intended to be indicative only, since the conditions of use of the combination of the invention are ultimately decided by the attending physician on the basis of the conditions of the patient, including age, general health

conditions, associated pathologies and specific drug resistance or hypersensitivity.

Minimum inhibitory concentrations (MICs) and "checkerboard" titrations for determination of

synergistic activity were performed in 2.0 ml final volumes using Middlebrook 7H9 broth (Difco) containing 0.2% (v/v) glycerol and 10% (v/v) ADC enrichment (Difco) as the basal medium. The inoculum was derived from a 21-day Lowenstein-Jensen culture (Sclavo) suspended to an optical density (OD) of 0.8 at 540 nm. This was incubated at 37°C for 48 hours and a further suspension prepared in glycerol/ADC-supplemented 7H9 broth (see above) to an OD of 0.12 and used as a 2% (v/v) final inoculum. Inhibition was determined as lack of visible growth in any given tube after 21 days incubation at 37°C.

An interaction coefficient termed the Fractional Inhibitory Concentration Index (FIC Index) was

calculated from the results to determine whether the combined effect of the two drugs was synergistic (FIC Index ≤0.5), additive (FIC Index = 1.0) or antagonistic (FIC Index ≥4.0) according to the method originally described by M.C.Berenbaum, J. Infectious Diseases, 1978, 137, 122-130 and reviewed in details by G.M.

Eliopoulos and R.C. Moellering, Antibiotics in

Laboratory Medicine, V. Lorian et al Ed, Baltimore, 1991, 432-492, i.e. : ^MICEthambutol combination ^MICTeicoplanin combinat ion

FIC Index= _____________________________ + _________________________

^MICEthambutolalone ^MICTe icoplaninalone

The results of these experiments are reported below in Table I :

On the basis of these results, teicoplanin and ethambutol were found to act synergistically in 8 out of 9 of the tested strains. The result with the discrepant strain is described as "autonomy" according to the above cited review by G.M. Eliopoulos and R.C. Moellering.

These findings were also confirmed on strains of Mycobacterium tubercolosis resistant to different antibiotics. No synergy was observed with an

ethambutol-resistant strain (L 1966, ATCC 35837).

These experiments were conducted according to methodologies known in the art using BACTEC 12B vials (Becton & Dickinson) that were inoculated with

approximately 105 viable cells of a strain of

M. tubercolosis. Different amounts of antibacterial agents, singly or in combination, were added to the different vials. Concentrations of teicoplanin

represented serial two-fold dilutions from 128 to

0.25 mg/l. Ethambutol was tested at concentrations ranging from 0.06 to 4 mg/l. Control vials for each strain were inoculated with a 1:100 dilution of the inoculum used in the vials containing antibacterial agents. The vials were incubated at 37°C and the growth index (GI) measured each day using a BACTEC 460

instrument (Becton & Dickinson). ΔGI was calculated when the GI of the control culture reached a value of 30 or more. For each culture, ΔGI is obtained by subtracting the GI value of the penultimate day from that of the final day. A concentration of an antibacterial agent was considered to be inhibitory for a given bacterial strain when its ΔGI value was less than or egual to that of the untreated control.

Having established the lowest inhibitory concentration for each single agent and for various combinations, the criteria for synergy were exactly as described for MIC determinations (see above).

The results of these experiments are reported below in Table II:

Claims

Claims :

1. A combination for the conjunctive treatment of tuberculosis which comprises : a) a glycopeptide component selected from a compound of Formula I

wherein

Y' represents hydroxy or [mono- or

A' represents hydrogen or N[(C₉-C₁₂)aliphatic

acyl]-β-2-amino-2-deoxy-glucopyranosyl. G' represents hydrogen or N-acetyl-β-2-amino-2- deoxy-glucopyranosyl,

M^, represents hydrogen or α-D-mannopyranosyl, or an acid addition salt thereof,

or a compound of Formula II

wherein

R² represents (C₉-C₁₂)alkyl ; M represents hydrogen, α-D-mannopyranosyl or

6-O-acetyl-α-D-mannopyranosyl;

Y represents carboxy, (C₁-C₄)alkoxycarbonyl,

aminocarbony1, (C₁-C₄)alkylaminocarbonyl,

di(C₁-C₄)alkylaminocarbonyl wherein the alkyl moiety may bear a substituent selected from hydroxy, amino, (C₁-C₄)alkylamino and

di(C₁-C₄)alkylamino or hydroxymethyl;

X represents hydroxy or an amino group of formula -NR³-alk¹-(NR⁴-alk²)_p -(NR⁵-alk³)_q-W

wherein:

R³ represents hydrogen or (C₁-C₄)alkyl;

alk¹,alk²

p and q are integers which independently

represent zero or 1 ;

R⁴ and R⁵ each independently represent hydrogen,

(C₁-C₄)alkyl or

R³ and R⁴ taken together represent a

R⁴ and R⁵ taken together represent a

(C₂-C₄)alkylene moiety connecting the two nitrogen atoms with the proviso that both p and q are 1;

W represents hydrogen, (C₁-C₄)alkyl, amino,

(C₁-C₄)alkylamino, di(C₁-C₄)alkylamino, amino substituted with one or two

amino-(C₂-C₄)alkyl moieties or with one or two (C₁-C₄)alkylamino-(C₂-C₄)alkyl moieties or with one or two di(C₁-C₄)alkylamino-(C₂-C₄)alkyl moieties, or, when both p and g are zero, taken together with the moiety -NR₃-alk₁- it may also represent piperazino or

4-methylpiperazino,

with the proviso that when X represents hydroxy Y represents hydroxymethyl,

Z represents hydrogen or a group

wherein A^Θ represents a mineral or organic acid anion or, when a carboxyacid function is present in the remaining portion of the antibiotic, it may also represent the internal anion deriving from said carboxyacid function. or an addition salt thereof, and b) ethambutol, in a dosage producing a synergistic effect against a Mycobacterium tuberculosis strain.

2. A combination according to claim 1 wherein the glycopeptide component is selected from a compound of formula I wherein Y' represents hydroxy or

3,3-dimethylaminopropyl and G' and M' represent the sugar moieties defined above, and a compound of Formula II wherein X represents 3,3-dimethylaminopropyl, Y represents hydroxymethyl, and M represents

α-D-mannopyranosyl.

3. A combination according to claim 1 or 2 wherein the amount of the glycopeptide component is of from 1 to 15 mg/kg of patient body weight.

4. A combination according to claim 1 or 2 wherein the amount of the glycopeptide component is of from 3 to 6 mg/kg of patient body weight.

5. A combination according to any one of claims 1 to 4 wherein the amount of ethambutol is of from 5 to 25 mg/kg of patient body weight.

6. Method of treatment of tubercular infections which comprises administering an effective amount of a combination of any one of claims 1 to 5 to a patient in need thereof.

7. Method for the prophylaxis of tubercular infections which comprises administering an effective amount of a combination of any one of claims 1 to 5 to a patient in need thereof.

8. Method according to claim 6 or 7 wherein the glycopeptide component is formulated for intramuscular administration and ethambutol is formulated for oral administration.

9. Method according to claim 6 or 7 wherein the glycopeptide component and ethambutol are coformulated for intramuscular administration.

10. Method according to claim 8 wherein the

glycopeptide component is administered from 1 to 3 hours before the administration of ethambutol .

11. Method according to claim 8 wherein the

glycopeptide component is administered first and

ethambutol is administered within one hour from the administration of the glycopeptide component .

12. Method according to claim 8 , 9 , 10 or 11 wherein the glycopeptide component and ethambutol are

administered once a day.

13. Method according to claim 8, 10 or 11 wherein the glycopeptide component is administered two or three times a week and ethambutol is administered once a day.