IE922229A1 - Novel therapeutic use of pyridylpyrrolothiazolecarboxamide - Google Patents

Abstract

Use of 3-(3-pyridyl)-1H,3H-pyrrolo[1,2-c]thiazole-7-carboxamide of formula: in its stereoisomeric forms or mixtures thereof, as well as its salts, for obtaining a medicament intended for prophylaxis and/or therapeutic treatment of retroviral infections.

Description

NOVEL THERAPEUTIC USE OF PYRIDYLPYRROLOTHIAZOLECARBOXAMIDE The present invention relates to a novel 5 therapeutic use of 3-(3-pyridyl)-IH,3H-pyrrolo[1,2-c]thiazole-7-carboxamide of formula: and its stereoisomers or a mixture thereof, and its salts.

The product of formula (I) and its preparation have previously been described in European Patent 115,979 15 and US Patent 4,906,757. It is useful in the treatment of allergies, inflammation and inhibition of blood platelet aggregation, and in the treatment of disorders in which the physiological role of PAF-acether is involved.

It has now been found that the pyrrolothiazole20 carboxamide derivative of formula (I), and its salts and its stereo isomers, is useful for the manufacture of a medicament for the prophylaxis and/or therapeutic treatment of retroviral infections, and more particularly of AIDS (acquired immune deficiency syndrome) and associated syndromes [ARC (AIDS-related complex)].

Prophylaxis is the treatment of subjects who have been exposed to HIV viruses (human immune deficiency - 2 viruses), in particular asymptomatic seropositive subjects, who are at risk of developing the disease in the months and years following the primary infection.

The activity of the product of the formula (I) has been demonstrated in the following way: Tumour necrosis factor (TNF) activates the HIV virus, in particular in chronically infected cells.

The effects of (+)-3-(3-pyridyl)-1H,3Hpyrrolo[l,2-c]thiazole-7-carboxamide on the induction of the HIV-1 virus have been studied on chronically infected cell lines.

Ul cell lines obtained after infection of the promonocyte line, U937, by the HIV-1 virus and selected according to the ability to increase the viral production in response to phorbol myristate acetate (PMA), to TNF and to other mediators [Folks et al., Science, 238. 800 (1987)] are used. The reverse transcriptase activity is used as an indicator of the viral production. The effect of increasing concentrations of the product to be studied on the stimulated cell lines is thus analysed.

Experimental study The cell cultures are withdrawn in the exponential growth phase and recultured to a final concentration of 2 χ 105 cells/ml, in the presence of various concentrations of the product to be studied. minutes later, TNFa or GM-CSF (granulocyte macrophage - 3 “ colony stimulating factor) plus IL-6 (interleukin-6) are added to the cultures as a whole. Each experiment is carried out in duplicate, except for the controls, which are carried out in quadruplicate. Each day thereafter a fraction of supernatant is taken from the cultures and frozen with a view to measuring the reverse transcriptase. The cells are nourished if necessary, with fresh medium containing neither the product to be studied nor activator.

The reverse transcriptase activity is measured 10 using known techniques, in duplicate [Strebel et al., Nature, 328, 728 (1987)]. (+) -3-(3-Pyridyl)-IH,3H-pyrrolo[l,2-c]thiazole-7carboxamide is studied in concentrations of 100, 10, 1 and 0.1 μΜ.

TNFa is added in an amount of 100, 10 or 1 units/ml. GM-CSF + IL-6 is added in an amount of 100 U/ml. Some controls do not receive activator. Other controls do not receive the product to be studied. Others receive neither the product nor the activator.

Results: The reduction in the viral production by (+)-3(3-pyridyl)-IH,3H-pyrrolo[l,2-c]thiazole-7-carboxamide is significant and dosage-dependent in the case of Ul cells treated with TNFa. On day 3 a reduction of 50 % is observed in the reverse transcriptase activity for the Ul cells treated with 100 units/ml of TNFa and to which a - 4 concentration of 10'5 M of the above product is added, and a reduction of 84 % is observed in the case of a concentration of 104 M. The reduction in the viral production increases until it becomes obvious on day 7.

The inhibitory effect of HIV-1 in the Ul cells, stimulated by GM-CSF + IL-6, is also significant.

Moreover, ( + )-3-(3-pyridyl)-IH,3H-pyrrolo[1,2-c] thiazole-7-carboxamide has no effect on the viability of the cells whatever the concentration used.

In a second series of experiments, the duration of the action of (+)-3-(3-pyridyl)-IH,3H-pyrrolo[l,2-c]thiazole-7-carboxamide was tested. It was thereby demonstrated that pretreatments for periods ranging from 30 minutes to 24 hours before stimulation by TNF, PMA or GM15 CSF + IL-6 do not affect the inhibitory effect of the replication of HIV-1.

The results are shown in Tables I, II and III and are illustrated by Figures 1, 2 and 3. -5 Table I Reverse transcriptase production Counts per minute (cpm) Culture conditions Contact time with t before stimulation 0.5 2 he product (hours) 7 10 Control (Ul cells) <100 <100 <100 <100 Ul cells + product (ΙΟΟμΜ) <100 <100 <100 <100 Ul cells + TNFa (100U) 1500 1000 800 1200 Ul cells + product (ΙΟΟμΜ) + TNF a(100U) 300 200 180 approx. 100 Table II Culture conditions Reverse transcriptase production Counts per minute (cpm) Contact time with the product 10 before s 0.5 timulation (hours) 2 7 Control (Ul cells) approx. 100 approx. 100 <100 <100 Ul cells + product (ΙΟΟμΜ) approx. 100 approx. 100 approx. 100 <100 Ul cells + PMA (10'7M) 6700 6000 7800 6700 Ul cells + product (ΙΟΟμΜ) + PMA (10-7) 4700 1900 1900 900 -6Table III Culture conditions Reverse transcriptase production Counts per minute (cpm) Contact time with the product before stimulation (hours) 10 0.5 2 7 Control (Ul cells) 160 180 150 160 Ul cells + product (ΙΟΟμΜ) 180 150 180 160 Ul cells + GM-CSF(IOOU) + + IL6(100U) 1200 650 500 1000 Ul cells + product (ΙΟΟμΜ) + GM-CSF (100U) + IL6 (100U) 200 180 170 180 The present invention also provides a process for the preparation of a pharmaceutical composition for the prophylaxis or therapeutic treatment of retroviral infections by mixing a pyrrolothiazolecarboxamide derivative of formula (I), which may be in the form of a stereoisomer or mixture, and optionally in the form of a salt, with one or more compatible and pharmaceutically acceptable diluents or adjuvants. The compositions may also comprise the active ingredient in the pure state.

The pharmaceutical compositions according to the invention are capable of inhibiting the replication of retroviruses and therefore of reducing the progression towards the disease or of reducing its severity in infected -7subjects.

In particular in the case of HIV infections, by inhibiting the replication of this virus, the compositions are capable of reducing the progression towards AIDS or of reducing its severity in infected subjects.

The pharmaceutical compositions according to the invention are capable of preventing or slowing down the progression of the disease to a more advanced stage in subjects infected with the retrovirus.

They may be used either preventively or curatively.

Preventively means in order to prevent development in subjects having an immune deficiency and/or who are infected by retrovirus.

Of course, the formulation of these compositions will be adapted to the particular state of the digestive tract of the immunosuppressed patients.

The compositions may be used orally, parenterally or rectally.

The sterile compositions for parenteral administration may preferably be aqueous or non-aqueous solutions or suspensions or emulsions. Solvents or vehicles which can be used are water, propylene glycol, a polyethylene glycol, vegetable oils, in particular olive oil, injectable organic esters, for example ethyl oleate, or other suitable organic solvents. These compositions may also contain adjuvants, in particular wetting agents, agents which render the composition isotonic, emulsifiers, - 8 dispersants and stabilisers. Sterilisation may be carried out in several ways, for example by aseptic filtration, by incorporating sterilising agents in the composition, by irradiation or by heating. They may also be prepared in the form of sterile solid compositions which may be dissolved at the time of use in an injectable sterile medium.

Solid compositions for oral administration which can be used are tablets, pills, powders or granules. In these compositions, the active compound according to the invention (optionally in combination with another pharmaceutically compatible product) is mixed with one or more inert diluents or adjuvants, such as sucrose, lactose or starch. These compositions may also contain substances other than diluents, for example a lubricant, such as magnesium stearate.

Liguid compositions for oral administration which can be used are pharmaceutically acceptable emulsions, solutions, suspensions, syrups and elixirs containing inert diluents such as water or paraffin oil. These compositions may also contain substances other than diluents, for example wetting agents, sweeteners or flavourings.

The compositions for rectal administration are suppositories or rectal capsules, which contain, in addition to the active principle, excipients such as cocoa butter, semi-synthetic glycerides or polyethylene glycols.

In general, the physician will determine the dosage he considers most appropriate, depending on the age, the - 9 weight and factors inherent to the product and to the subject to be treated. In general, for adults the doses are between 25 and 500 mg per day.

The present invention also relates to combinations 5 consisting of the pyrrolo-thiazolecarboxamide derivative of formula (I) in the form of its stereoisomers or their mixtures, and/or, optionally, in the form of a salt, and another active principle known for its antiretroviral activity, optionally in the presence of pharmaceutically acceptable excipients.

The antiretroviral agents capable of being combined are agents which are compatible and inert with respect to the pyrrolo-thiazolecarboxamide derivative of formula (I). By way of non-limiting example, these agents are chosen from reverse transcriptase inhibitors [zidovudine (AZT), didanosine (DDI), dideoxycytidine (DDC), TIBO, nevirapine, PMEA, HEPT etc.], from protease inhibitors [such as, for example, A 77003] or from tat protein inhibitors [such as, for example, RO 24-7429].

The following Example illustrates a composition according to the invention.

Example - (+)-3-(3-Pyridyl)-IH,3H-pyrrolo25 [1,2-c]thiazole-7-carboxamide 5 mg - Magnesium stearate : 1 % 2 mg ACDISOL : 1 % mg - 10 - Colloidal silica : 0.5 % 1 mg - Lactose 190 mg (+)-3-(3-Pyridyl)-1H,3H-pyrrolo[l,2-c]thiazole-75 carboxamide may be obtained in the following way: (+)-3-(3-Pyridyl)-IH,3H-pyrrolo[1,2-c]thiazole-7carboxylic acid (26.11 kg - 110 mol) is suspended, under nitrogen, in 116 litres of dichloromethane and the suspension is then refluxed. A solution of thionyl chloride (19.506 kg - 159 mol) in 23 litres of dichloromethane is added in the course of 2 hours 10 minutes, while keeping the mixture under reflux until 3 hours after the end of the addition.

The mixture is cooled to 20°C and then added, in the course of 1 hour 10 minutes, to 90 litres (1060 mol) of 20 % ammonia, rinsing the above reactor with 20 litres of dichloromethane. The mixture is stirred over night at about 20°C, 46 litres of water and 40 litres of dichloromethane are then added and the mixture is cooled at 3 °C for 2 hours. The precipitate is filtered off, then washed with water and drained. The filtrate is decanted off. After separating the aqueous phase and extracting with twice 40 litres of dichloromethane, the organic phases are combined.

After purification, 19.6 kg of (+)-3-(3-pyridyl)25 IH,3H-pyrrolo[1,2-c]thiazole-7-carboxamide are obtained. - 11 (+)-3-(3-Pyridyl)-IH,3H-pyrrolo[1,2-c]thiazole-7carboxylic acid may be prepared as described in US Patent 4,906,757.

Claims (8)

Claims

1. Use of 3-(3-pyridyl)-lH,3H-pyrrolo[l,2-c]thiazole-7-carboxamide of formula: conh 2 (I) optionally in the form of a stereoisomer or mixture 10 thereof, or a salt thereof, in the manufacture of a medicament for the prophylaxis and/or therapeutic treatment of retroviral infections.

2. Use according to claim 1, in which the medicament is intended for the prophylaxis and/or treatment 15 of AIDS.

3. Process for the preparation of a pharmaceutical composition intended for the prophylaxis and/or therapeutic treatment of retroviral infections, which comprises mixing a product according to claim 1 with one or more compatible 20 and pharmaceutically acceptable diluents or adjuvants.

4. A combination for the treatment of AIDS and other retroviral infections, comprising a pyrrolothiazolecarboxamide derivative according to claim 1, optionally in the form of a stereoisomer or mixtures thereof, or a salt 25 thereof, and another active principle having antiretroviral activity, optionally in combination with one or more pharmaceutically acceptable inert excipients.

5. Use according to claim 1, substantially as hereinbefore described.

6. A process according to claim 3 for the preparation of a pharmaceutical composition, substantially as hereinbefore described and exemplified.

7. A pharmaceutical composition, whenever prepared by a process claimed in claim 3 or 6.

8. A combination according to claim 4, substantially as hereinbefore described.