FR3110394A1 - Pharmaceutical or veterinary composition for use in the treatment and / or prevention of a parasitic disease - Google Patents

Abstract

Pharmaceutical or veterinary composition for its use in the treatment and / or prevention of a parasitic disease The invention relates to a pharmaceutical or veterinary composition for its use in the treatment and / or prevention of a parasitic disease caused by a blood-sucking nematode in a mammal. The invention is characterized in that it comprises as active principle at least one benzoylurea chosen from diflubenzuron, chlorfluazuron, flufenoxuron, hexaflumuron, triflumuron or lufenuron, their salts or their derivatives.

Description

Pharmaceutical or veterinary composition for use in the treatment and/or prevention of a parasitic disease

The subject of the invention is a pharmaceutical composition for human or veterinary use for the treatment and/or prevention of a parasitic disease caused by an endoparasite.

It more particularly relates to such a composition comprising a benzoylurea for the treatment and/or prevention of a disease caused by a nematode.

Nematodes are roundworms and are the most abundant animals on Earth. About 80% of all multicellular animals are nematodes. More than 40,000 species live free while other species parasitize plants, fungi, animals and even humans.

In humans and animals, a large number of nematodes are endoparasites responsible for various pathologies.

In humans, filariasis is a very common parasitic disease, caused by the presence in the body of nematodes belonging to the Filaridae family. Only some filariae are pathogenic. Depending on their location in humans, four filariases are very different from each other: lymphatic filariasis, loiasis, onchocerciasis and dracunculiasis.

In pigs, Ascaris ( Ascaris suum ) can be responsible for liver damage, pneumonia, gastrointestinal disorders, changes in the blood formula and a drop in the body's defences. Ascaris suum infestation is the best-known parasitosis in pigs. Other roundworms are caused by nodular worms ( Oesophagostomum spp. ), red stomach worm ( Hyostrongylus rubidus ), and whipworms ( Trichuris ).

In cattle, abomasum ( Ostertagia ostertagi ) and lungworms ( Dictyocaulus viviparus ) are the main endoparasitic nematodes.

In sheep, the gastrointestinal nematode ( Haemonchus contortus ) is the main parasitic nematode. This hematophagous parasite causes severe inflammation and hemorrhage in the abomasal wall.

• le ver intestinal Ascaris tel queToxocara canis,Toxocara cati,Toxascaris leonina;
• le ver de l’estomacOllulanus tricuspis le;
• le ver du cœurDirofilaria immitis;
• le ver des poumonsAelurostrongylus abstrusus;
• le ver sous-cutanéDirofilaria repens; ou
• le ver des yeuxThelazia callipaeda .

Dogs and cats can also be infected by a large number of different nematodes such as for example:

• the intestinal worm Ascaris such as Toxocara canis , Toxocara cati , Toxascaris leonina ;
• the stomach worm Ollulanus tricuspis the ;
• the heartworm Dirofilaria immitis ;
• the lungworm Aelurostrongylus abstrusus ;
• the subcutaneous worm Dirofilaria repens ; Or
• the eye worm Thelazia callipaeda .

The dog is the normal host of five species of heartworm disease: Dirofilaria immitis, Dirofilaria repens, Acanthocheilonema reconditum, Acanthocheilonema dracunculoides and Acanthocheilonema grassii . Only Dirofilaria immitis has strong pathogenicity.

In Europe, cases of canine dirofilariasis have been reported in Italy, Spain, Portugal, Romania and France. Heartworm can occur throughout France.

Cardiopulmonary filariasis caused by Dirofilaria immitis is the most medically important canine dirofilariasis. This parasitosis can also affect humans, for whom the dog is a reservoir of parasites. It is a fairly specific parasitosis, affecting mainly dogs but also Canids in a broad way, and sometimes Felidae, Ursids, Mustelids and even humans. The infestation of cats by Dirofilaria immitis is detected more and more frequently, especially in regions of high canine endemia, but with a lower incidence than in dogs.

The Dirofilaria immitis cycle is an obligate heteroxenous cycle. There is no passage in the external medium, since the cycle calls upon a vector.

The definitive host of Dirofilaria immitis is essentially the dog.

The vector of Dirofilaria immitis is a mosquito belonging mainly to the genera Culex, Aedes, Psorophora or Mansonia .

The mosquito usually absorbs larvae called Dirofilaria immitis microfilariae by taking a solenophage-like blood meal from an infected animal. The microfilariae ingested by the mosquito first develop in the Malpighian tube of the insect from the L1 larval stage to the L3 larval stage. Then the L3 larva perforates the wall of the Malpighian tube on the ninth day and finds itself in the general cavity, then in the thorax, the proboscis, and finally in the cavity of the labium of the mosquito.

Mosquitoes carrying infective L3 larvae transmit these during their blood meal. They don't inoculate them. The larvae actively exit the insect's proboscis through the puncture site of the mosquito's proboscis or through hair follicles.

Besides mosquitoes, other insects are capable of carrying Dirofilaria immitis , such as certain fleas and lice.

In dogs, the infesting L3 larvae travel through the connective tissue to give the L4 stage a few days after infestation. Then, the L4 larvae spread into the muscles and blood vessels. The L4 larvae progress to the immature adult stage between the ^60th and ^80th day after infestation.

The immature adult stage passes through the venous circulation and arrives in the right heart. The larvae then enter the pulmonary artery and persist there for 50-60 days, reaching a length of 8-11 cm. From the ^110th day after infestation, these larvae perform a retrograde migration in the right ventricle. There they become adults. Females are 15 to 30 cm long and 1 to 1.3 mm in diameter. The males, smaller and thinner, are 12 to 18 cm long and 0.6 to 0.8 mm in diameter. Once mature, heartworms can live for 5 to 7 years in dogs and up to 2 or 3 years in cats.

The cycle lasts about five to six months in dogs. When at least one female and one male have developed, they can produce offspring called microfilariae which are released into the host's bloodstream. These microfilariae can, in turn, be ingested by a mosquito that feeds on the infected hosts.

Each mosquito season can thus lead to an increasing number of worms in an infected animal.

Heartworms are found primarily in the pulmonary artery in dogs with a low parasite load (less than 50 worms). In infestations with a high parasitic load (greater than 50 worms), they can reach the right ventricle, the right atrium and sometimes the vena cava. The initial response includes swelling of the small pulmonary arteries and blood clotting. The physical presence of heartworm in the pulmonary artery and right ventricle of the canine heart, and the resulting tissue destruction, cause respiratory and circulatory problems that can be fatal under conditions of stress or vigorous exercise. It usually takes a large number of heartworms to obstruct blood flow. This accumulation is possible because heartworms can be present inside the heart for two to three years before causing clinical signs. If left untreated, heartworm disease can cause death in dogs and other animals (e.g. cats, cattle, humans, guinea pigs and ferrets).

Currently, the medical treatment of heartworm disease is undertaken after a precise and rigorous definition of the prognosis and an assessment of the risks inherent in the therapy. A distinction is made between the treatment of adult heartworms and the treatment of microfilariae.

The treatment of adults or macrofilaricidal treatment aims to first destroy the adult heartworms responsible in particular for pulmonary hypertension. It is generally done by administering arsenic derivatives intravenously. The molecules marketed include in particular thiacetarsamide (CAPARSOLATE®) or even melarsomine (IMMITICIDE®).

Application KR20040014813 thus discloses pharmaceutical compositions for the protection against heartworm disease comprising effective components of arsenic oxide.

Other oral or parenteral treatments include levamisole (LEVAMISOLE®) whose effectiveness varies according to the subjects treated.

Other molecules such as dichlorophenarsine hydrochloride (FILARSEN®), oxyphenarsine hydrochloride (MAPHARSEN ®) or melarsonyl potassium (TRIMELARSAN®) can also be used as macrofilaricidal treatment but their efficacy or toxicity do not make them preferred treatments.

Ivermectin, a semi-synthetic compound of the avermectin class, is also used for the prevention of canine heartworm disease but it is not very active against adult heartworms. On the other hand, ivermectin-based products such as IVOMEC ® and CARDOMEC® are effective for the treatment of microfilariae or microfilaricidal treatment.

Other microfilaricidal treatments include selamectin, a semi-synthetic compound from the avermectin class. The associated veterinary products (STRONGHOLD®, REVOLUTION®) come in the form of spot-on solutions. They are applied locally externally between the shoulder blades.

Application KR20060005472 also contemplates oral compositions in the form of pastes for the treatment and/or prevention of heartworm disease.

However, the use of avermectins to combat ectoparasites and endoparasites has been controversial for some years. In particular, avermectins can accumulate and persist in animal waste for long periods (up to two months) and have lethal and sublethal effects on a range of non-target invertebrates, such as Diptera, Beetles and benthic organisms. This effect on the environment is harmful. Avermectins can enter freshwater ecosystems through four pathways: runoff; groundwater infiltration; direct deposit ; and soil erosion.

This problem related to avermectins as well as the progression of resistance to macrocyclic lactones which generates treatment failures encourage researchers to limit their use or even to find alternative solutions with other active ingredients.

An object of the present invention is therefore to develop a pharmaceutical composition for human or veterinary use making it possible to effectively combat parasitic diseases caused by hematophagous nematodes which has fewer disadvantages than existing solutions, is more effective and more respectful of the 'environment.

Surprisingly, the Applicant was able to demonstrate that administration of at least one benzoylurea allowed the treatment and/or prevention of a parasitic disease caused by a hematophagous nematode in a mammal but also to limit or prevent the propagation of said nematode such as Dirofilaria immitis.

Thus, an object of the present invention is to provide a pharmaceutical composition for human or veterinary use for the treatment and/or prevention of a parasitic disease caused by an endoparasite.

More particularly, the invention relates to the field of compositions comprising a benzoylurea for the treatment and/or prevention of a disease caused by a hematophagous nematode.

Considering the foregoing, a problem which the present invention proposes to solve consists in developing stable, effective, well-tolerated compositions which possibly make it possible to include high concentrations of active principles compared to pharmaceutical products for human or veterinary use currently marketed and comprising active ingredients of the benzoylurea type.

• directement sur l’hôte infecté ou susceptible d’être infecté en agissant sur les nématodes (microfilaires et filaires adultes) aux différents stades du cycle de leur vie ; mais également
• indirectement au niveau du vecteur de la maladie, par exemple en limitant la digestion du repas de sang, sa reproduction, l’infection ou la surinfection future des hôtes donc en limitant sa capacité à propager le pathogène;
• préventivement en administrant le traitement aux hôtes sains.

Moreover, an additional problem which the present invention proposes to solve is that said composition makes it possible to control and/or limit the spread of infestations of worms, particularly of heartworm, and thus makes it possible to overcome the problems set out above. This by acting preferentially at different levels:

• directly on the host infected or likely to be infected by acting on the nematodes (microfilariae and adult filariae) at the different stages of their life cycle; but also
• indirectly at the level of the disease vector, for example by limiting the digestion of the blood meal, its reproduction, the infection or the future superinfection of the hosts therefore by limiting its capacity to spread the pathogen;
• preventively by administering the treatment to healthy hosts.

The solution to this problem has as its first object a pharmaceutical composition for human or veterinary use, comprising as active principle a benzoylurea chosen from diflubenzuron, chlorfluazuron, flufenoxuron, hexaflumuron, triflumuron or lufenuron, their salts or their derivatives, taken alone or in combination. More particularly, the solution to the problem posed relates to a pharmaceutical composition for human or veterinary use, for its use in the treatment and/or prevention of a parasitic disease caused by a hematophagous nematode in a mammal, comprising as a principle active agent a benzoylurea chosen from diflubenzuron, chlorfluazuron, flufenoxuron, hexaflumuron, triflumuron or lufenuron, their salts or their derivatives, taken alone or in combination.

Its second subject is a pharmaceutical composition for human or veterinary use, for its use in the prevention of re-infestations and over-infestations of a parasitic disease caused by a hematophagous nematode in a mammal, comprising as active principle a benzoylurea chosen from diflubenzuron, chlorfluazuron, flufenoxuron, hexaflumuron, triflumuron or lufenuron, their salts or their derivatives, taken alone or in combination.

Its third object is a pharmaceutical composition for human or veterinary use, for its use in interrupting the transmission of parasitic diseases caused by hematophagous nematodes transmitted by mosquitoes from a first host to a second host, in which the first host is selected from domestic animals, wild animals, birds or human beings, comprising as active principle a benzoylurea chosen from diflubenzuron, chlorfluazuron, flufenoxuron, hexaflumuron, triflumuron or lufenuron, their salts or their derivatives, taken alone or in combination, and wherein said composition is used for the control of mosquitoes which feed on the first host and thereby interrupt the transmission of parasitic disease caused by a blood-sucking nematode induced by the mosquito of the first host to the second host.

It has as its fourth object a method for preventing or interrupting the transmission of a disease caused by a hematophagous nematode, such as dirofilariasis, by application, in a mammal, preferably a dog or a cat, infested with said disease parasitic or likely to be, of an effective dose of a benzoylurea chosen from diflubenzuron, chlorfluazuron, flufenoxuron, hexaflumuron, triflumuron or lufenuron, their salts or their derivatives, taken alone or in combination.

Its fifth subject is a method for controlling the spread of a parasitic disease caused by hematophagous nematodes, such as dirofilariasis, by application, in a mammal, preferably a dog or a cat, infested by said parasitic disease or susceptible being, of an effective dose of a benzoylurea chosen from diflubenzuron, chlorfluazuron, flufenoxuron, hexaflumuron, triflumuron or lufenuron, their salts or their derivatives, taken alone or in combination.

Its sixth object is a kit suitable for implementing a method for controlling a parasitic disease caused by hematophagous nematodes as described above. Said kit advantageously comprises one or more packaging units composed of at least one composition comprising as active principle a benzoylurea chosen from diflubenzuron, chlorfluazuron, flufenoxuron, hexaflumuron, triflumuron or lufenuron, their salts or derivatives thereof, taken alone or in combination, and preferably instructions for use for the administration of said composition to a mammal, preferably a dog or a cat, infested by said parasitic disease or likely to be so.

The invention also relates to a pharmaceutical product for human or veterinary use comprising:
- as the first active principle, a benzoylurea chosen from diflubenzuron, chlorfluazuron, flufenoxuron, hexaflumuron, triflumuron or lufenuron, their salts or their derivatives, taken alone or in combination, and
- as second active ingredient a compound preferably chosen from moxidectin or melarsomine, as a combination product for simultaneous, separate or spread out use over time for its use in the treatment and/or prevention of a parasitic disease caused by a hematophagous nematode in a mammal.

The Applicant has in particular been able to develop a pharmaceutical composition for human or veterinary use which is particularly effective for its use in the treatment and/or prevention of a parasitic disease caused by a hematophagous nematode in a mammal.

More particularly, the Applicant was able to demonstrate that the chemical compounds benzoylureas, known for their use as insecticides, could be effective against parasitic diseases caused by a hematophagous nematode such as in particular the genus Dirofilaria .

The invention and the advantages resulting therefrom will be better understood on reading the description and the non-limiting embodiments which follow, illustrated with regard to the appended drawings in which:

Fig.1

illustrates the plasma profile of lufenuron at different concentrations as detailed in Example 3.

Fig.2

illustrates an extrapolation of the concentration of lufenuron in adipose tissue in dogs dosed at 10, 50 and 100 mg/kg) as detailed in Example 3.

In this description, unless otherwise specified, it is understood that when an interval is given, it includes the upper and lower limits of said interval. Likewise, when referring to a compound, it includes any pharmaceutically acceptable form and in particular isomers, salts, solvates and polymorphs. In particular if a compound exhibits optical activity, the referenced compound will include the racemic mixture of the different isomers. The subject of the invention is a pharmaceutical composition for human or veterinary use, for its use in the treatment and/or prevention of a parasitic disease caused by a hematophagous nematode.

• Anguillulose ;
• Anisakiose ;
• Ankylostomoses ;
• Ascaridiose ;
• Filariose ;
• Larva migrans viscérale (toxocarose) ;
• Larva migrans cutanée (larbish) ;
• Oxyurose ;
• Trichinellose ; et
• Trichocéphalose.

According to the invention, by hematophagous nematode is meant endoparasitic roundworms of cylindrical shape inducing diseases called parasitoses in mammals. More particularly, the term haematophagous nematode preferentially designates the nematodes responsible for the following diseases:

• Anguillulosis;
• Anisakiosis;
• Hookworms;
• Ascariasis;
• Filariasis;
• Visceral larva migrans (toxocariasis);
• Cutaneous larva migrans (larbish);
• Pinworm;
• Trichinellosis; And
• Trichocephalosis.

Preferably, the blood-sucking nematodes targeted are invasive tissue nematodes carried by vectors responsible for filariasis. Such nematodes are also called filariae and are mainly responsible for six subtypes of filariasis:
1) lymphatic filariasis (LF);
2) onchocerciasis;
3) loiasis;
4) mansonellosis;
5) heartworm disease; And
6) dracunculiasis.

These pathologies are notably caused respectively by:
1) Wuchereria bancrofti and filarioidea of the genus Brugia ;
2) Onchocerca volvulus ;
3) Loa loa ;
4) filarioidea of the genus Mansonella ;
5) Heartworm ; And
6) Dracunculus medinensis .

Even more preferentially, the hematophagous nematode targeted by the present invention is responsible for dirofilariasis. These are essentially nematodes of the species Dirofilaria immitis, Dirofilaria repens, Acanthocheilonema reconditum, Acanthocheilonema dracunculoides and Acanthocheilonema grassii . More particularly it is the species Dirofilaria immitis which has a high pathogenicity. The development of the different stages of Dirofilaria immitis is particularly detailed in the article by T. Kotani et Al., Developmental stages of Dirofilaria immitis in the dog , American Journal of Veterinary Research, vol 43, n°12, December 1982.

As emerges from the examples, the composition which is the subject of the invention is generally effective, for its use in the treatment and/or prevention of a parasitic disease caused by a hematophagous nematode in a mammal, preferentially heartworm disease, more preferentially again cardiopulmonary filariasis caused by Dirofilaria immitis.

This effectiveness is made possible by the use of at least one active principle belonging to the chemical family of benzoylureas.

Benzoylureas are known for their use as insecticides, in particular by inhibiting the biosynthesis of chitin.

Benzoylureas are also used in aquaculture to control sea lice. The article by Macken et Al., Benzoylurea pesticides used as veterinary medicines in aquaculture: Risks and developmental effects on nontarget crustaceans, Environmental Toxicology and Chemistry, February 7, 2015, describes in particular the effectiveness of flubenzurons on copepods.

Surprisingly, the Applicant was able to demonstrate that benzoylureas, to date not used in the treatment and/or prevention of a parasitic disease caused by a hematophagous nematode, were particularly effective in the treatment and/or prevention of a parasitic disease caused by a blood-sucking nematode.

A subject of the invention is therefore also a pharmaceutical composition for human or veterinary use, comprising as active principle a benzoylurea chosen from diflubenzuron, chlorfluazuron, flufenoxuron, hexaflumuron, triflumuron or lufenuron, their salts or their derivatives, taken alone or in combination.

According to the invention, the benzoylureas that can be used are chosen from chlorfluazuron, diflubenzuron, flufenoxuron, hexaflumuron, lufenuron, novaluron, noviflumuron, teflubenzuron and triflumuron, their salts or their derivatives, taken alone or in combination .

Preferably, the benzoylureas which can be used in the compositions for their uses according to the invention are chosen from diflubenzuron, chlorfluazuron, flufenoxuron, hexaflumuron, triflumuron or lufenuron, their salts or their derivatives, taken alone or in combination.

More preferably still, the benzoylurea that can be used is lufenuron.

Lufenuron also called lufenurone in French or 1-[2,5-Dichloro-4-(1,1,2,3,3,3-hexafluoropropoxy)phenyl]-3-(2,6-difluorobenzoyl)urea is a compound corresponding to the following formula:

Lufenuron is a benzoylurea insecticide, dichlorobenzene, N-acylurea, aromatic ether and organofluorine compound. It is used in particular as a veterinary medicinal product, in particular for the control of fleas.

Thus, it is known in particular that lufenuron at a concentration of 10 mg/kg administered to dogs is rapidly absorbed and then stored in adipose tissue (subcutaneous in particular). It is then slowly but steadily released into the bloodstream to provide systemic protection against parasites such as fleas for a period of approximately one month. According to the publication by Hotz et Al., Determination of Lufenuron in canine skin layers by radiumluminography , Schweizer Archiv für Tierheilkunde, Band 142, Heft 4 April 2000,173-176, the concentrations in the cutaneous adipose tissue would reach 6 to 12 µg/ g, 21 days after treatment.

However, this subcutaneous tissue where benzoylureas are concentrated is also the site of residence and migration of Dirofilaria larvae. L3 larvae quickly transform into L4 to migrate into the subcutaneous tissue for 30-50 days. According to the article by T. Kotani et Al., Developmental stages of Dirofilaria immitis in the dog , American Journal of Veterinary Research, vol 43, n°12, December 1982, there is never any migration of the larvae to the stages L3 to L5 in the blood.

As emerges from the examples, lufenuron is well tolerated by the animals treated, and this, even at high concentrations.

Thus, the dose of benzoylurea active principle administered contained in the compositions for their uses according to the invention is preferably greater than or equal to 10 mg/kg of mammal to be treated.

The Applicant was able to demonstrate that the dosage of the active principle depended on the final quantity of active principle to reach the target, that is to say preferentially the pharynx of the hematophagous nematode, at the microfilarial stage but also possibly at the macrofilarial stage (stage adult filaria).

• de l’article de Zhang et Al.,The chitin synthase genes chs-1 and chs-2 are essential for C. elegans development and responsible for chitin deposition in the eggshell and pharynx, respectively, Developmental Biology 285 (2005) 330 – 339, cela est vrai pour les nématodes libres peu évolués commeCaenorhabditis elegans;
• de l’article de Fuhrman et Al.,Chitin Synthesis and sheat morphogenesis in Brugia Malayi microfilariae,Molecular and Biochemical Parasitology, 17 (1985) 93-104, cela est vrai pour les vers parasites les plus évolués, les spirurides tels queBrugia malayi ;
• de l’article de Harris et Al.,Structure and expression of chitin synthase in the parasitic nematode Dirofilaria immitis,Molecular & Biochemical Parasitology 122 (2002) 231-234, cela est vrai également pourDirofilaria immitis

The Applicant has also been able to confirm that the active principle of benzoylurea type allows an action on the metabolism of chitin, in particular chitin synthase 1 and 2 (CS1 and CS2). CS1 and CS2 are expressed throughout the life of the worms. As it appears:

• from Zhang et al., The chitin synthase genes chs-1 and chs-2 are essential for C. elegans development and responsible for chitin deposition in the eggshell and pharynx, respectively , Developmental Biology 285 (2005) 330–339 , this is true for low-evolved free-living nematodes like Caenorhabditis elegans ;
• from the article by Fuhrman et al., Chitin Synthesis and sheat morphogenesis in Brugia Malayi microfilariae, Molecular and Biochemical Parasitology, 17 (1985) 93-104, this is true for the most evolved parasitic worms, the spirurids such as Brugia malayi ;
• of the article by Harris et Al., Structure and expression of chitin synthase in the parasitic nematode Dirofilaria immitis, Molecular & Biochemical Parasitology 122 (2002) 231-234, this is also true for Dirofilaria immitis

Chitin is found mainly on the egg membrane (synthesis under the governance of CS1), but especially in the pharynx with regular deposits (under the control of CS2). The pharynx is an essential organ for food intake and therefore the survival of nematodes.

Thus, benzoylureas, at sufficient concentrations, have an action on the chitin of the pharynx in the development of nematodes, ie microfilariae. As for macrocyclic lactones, their main target is the pharyngeal muscle and more particularly the receptors on the GluCl channels.

The effective and sufficient dose of active ingredient depends on parameters such as the galenic form or even the route of administration of the composition according to the invention. The important thing is to target and disrupt the development of the parasite's pharynx.

Preferably, the dose of benzoylurea active principle administered is greater than or equal to 20 mg/kg of mammal to be treated, for example greater than or equal to 30 mg/kg of mammal or greater than or equal to 40 mg/kg of mammal.

Particularly advantageously, the composition for its use according to the invention comprises the active principle benzoylurea and more particularly lufenuron administered at a dose greater than or equal to 50 mg/kg of mammal.

Advantageously, the invention also relates to a pharmaceutical composition for human or veterinary use, comprising as active ingredient a benzoylurea chosen from diflubenzuron, chlorfluazuron, flufenoxuron, hexaflumuron, triflumuron or lufenuron, their salts or their derivatives, taken alone or in combination, administered at a dose greater than or equal to 20 mg/kg of mammal to be treated, for example greater than or equal to 30 mg/kg of mammal, greater than or equal to 40 mg/kg of mammal, greater than or equal to 50 mg/kg mammal, greater than or equal to 60 mg/kg mammal, greater than or equal to 70 mg/kg mammal, greater than or equal to 80 mg/kg mammal or greater than or equal to 90 mg/kg mammalian, to disrupt the chitin metabolism of the pharynx of a hematophagous nematode.

Of course, the doses are adapted so as not to exceed doses that can be toxic for the animal.

The Applicant was able to demonstrate that the concentrations of lufenuron in the products currently marketed were not or only slightly effective in treating and/or preventing a parasitic disease caused by a hematophagous nematode. Thus, the person skilled in the art was dissuaded from using a benzoylurea for this type of treatment and would instead turn to treatments with other active agents such as avermectins or combinations of active agents.

Surprisingly, the Applicant was able to demonstrate that the administration of active principles of the benzoylurea family at higher concentrations than the benzoylurea-based products currently on the market were on the one hand well tolerated by the mammals to be treated, preferentially a dog or cat, but also represented a treatment of choice given the efficacy observed. Furthermore, the compositions according to the invention allow an action on different aspects of the transmission and development of the pathology.

It has thus been shown that hematophagous nematodes, such as Dirofilaria immitis for example, are affected by benzoylureas, preferentially lufenuron, at different stages of their cycle, i.e. both at the stages:
- microfilariae;
- larvae L1, L2, L3, L4;
- immature forms; and possibly also, to a lesser extent
- adult.

More particularly, hematophagous nematodes, such as Dirofilaria immitis for example, are affected by benzoylureas, preferentially lufenuron, before the adult stage. The benzoylureas thus act as inhibitors of the development of hematophagous nematodes, in particular as microfilaricides. Indeed, by disrupting the development of the pharynx of hematophagous nematodes, benzoylureas effectively disrupt and prevent the maturation of microfilariae into adult filariae.

The composition according to the invention thus also makes it possible to prevent re-infestations and over-infestations of a parasitic disease caused by a hematophagous nematode in a mammal, comprising as active ingredient a benzoylurea, in which a dose of the benzoylurea compound sufficient to achieve plasma concentrations greater than 330 ng/ml, for example greater than 400 ng/ml, greater than 625 ng/ml, greater than 830 ng/ml or greater than 1250 ng/ml administered systemically to the animal .

Similarly, the composition according to the invention thus also allows the prevention of re-infestations and over-infestations of a parasitic disease caused by a hematophagous nematode in a mammal, comprising as active principle a benzoylurea, in which a dose of the benzoylurea compound sufficient to achieve concentrations in adipose tissue greater than 40 μg/g, for example greater than 50 μg/g, greater than 75 μg/g, greater than 100 μg/g or greater than 150 μg/g is administered .

Of course, the above concentrations are adapted so as not to exceed concentrations which may be toxic for the animal. In particular, it has been observed that benzoylurea compounds, preferentially lufenuron, have an effect on the larvae circulating in the blood and those lodged in the adipose tissue of the host.

It is also preferable to treat healthy mammals preventively in order to prevent the development of larvae from an infected mosquito, but it also appears useful, in order to prevent cases of over-infestation of infested hosts, to treat infested mammals affected by the parasitic disease.

It has also been observed that benzoylurea compounds, preferentially lufenuron, have an effect on mosquitoes responsible for the transmission of the disease from a carrier host to a healthy host of circulating larvae of a hematophagous nematode in the blood. The action on the vector manifests itself in its ability to digest the bolus of blood, to reproduce and to propagate the blood-sucking nematode, but also the action on the blood-sucking nematode itself. The mosquito will ingest microfilariae but also the active ingredient which will reduce and/or block the moulting of the hematophagous nematode which takes place in the mosquito, i.e. L2, L3. It has been observed that the effect of benzoylurea compounds, in particular lufenuron, takes place mainly during larval moults when the parasite must generate chitin in greater quantity to form these new larger organs at each new stage. Lufenuron has also been shown to interfere with peritrophic membrane synthesis, impair or limit digestion and assimilation of nutrients. As a result, reproduction is also impaired due to lack of resources.

Also, the composition according to the invention also allows the prevention of re-infestations and over-infestations of a parasitic disease caused by a hematophagous nematode in a mammal, comprising as active principle a benzoylurea, in which the action of the active principle on the haematophagous nematode is exerted on and in the vector. Preferably the vector is a mosquito.

The compositions according to the invention therefore advantageously also allow an action on the mosquito which is the vector of transmission, the destruction or limitation of this vector of nematode parasitosis being desirable for the control of said parasitosis but also for the comfort of the animal as well as for limiting the transmission of diseases other than this vector. In addition, the specific action on the mosquito, when it has had its blood meal and ingested the active ingredient, will also be expressed on the hematophagous nematode parasite that the mosquito will have ingested at the same time and the larvae of the parasite hematophagous nematode will then be, inside the vector itself, exposed to deleterious contact with the blood also taken from the host and loaded with active ingredient ingested by the mosquito.

Also, the invention also relates to a pharmaceutical composition for human or veterinary use, comprising as active ingredient a benzoylurea chosen from diflubenzuron, chlorfluazuron, flufenoxuron, hexaflumuron, triflumuron or lufenuron, their salts or their derivatives, taken alone or in combination, administered at a dose greater than or equal to 20 mg/kg of mammal to be treated, for example greater than or equal to 30 mg/kg of mammal, greater than or equal to 40 mg/kg of mammal, greater than or equal to 50 mg/kg mammalian, greater than or equal to 60 mg/kg mammalian, greater than or equal to 70 mg/kg mammalian, greater than or equal to 80 mg/kg mammalian or greater than or equal to 90 mg / kg of mammal, to disturb the metabolism of chitin, in particular in the pharynx of an arthropod vector of a parasitic disease, which is preferentially a mosquito.

The Applicant has therefore been able to demonstrate, surprisingly, that the composition comprising as active ingredient a benzoylurea also allows use in interrupting the transmission of parasitic diseases transmitted by an arthropod, preferably a mosquito, of a first host to a second host, by controlling the arthropod or mosquito that feeds on the first host. Such a composition thus makes it possible to interrupt the transmission of the parasitic disease induced by the arthropod or the mosquito from the first host to the second host. In particular, it limits the reproduction of mosquitoes.

Indeed, the active ingredient benzoylurea which is preferably chosen from diflubenzuron, chlorfluazuron, flufenoxuron, hexaflumuron, triflumuron or lufenuron, their salts or their derivatives, taken alone or in combination, more preferably still lufenuron, has an action on the vector of the infection which is generally a mosquito or, more generally, an arthropod vector of a parasitic disease.

Thus, the present invention relates to prophylaxis , ie all the measures to be taken to prevent diseases. The composition according to the invention therefore makes it possible to prevent the appearance, propagation or aggravation of parasitic diseases, preferentially parasitic diseases transmitted by arthropods or mosquitoes, more preferentially parasitic diseases caused by a hematophagous nematode in a mammal such as such as heartworm disease.

Preferably, the pharmaceutical composition for human or veterinary use, for its use according to the invention, is characterized in that the parasitic disease is heartworm disease transmitted to a dog or a cat by mosquitoes.

Preferably, the pharmaceutical composition for human or veterinary use, for its use according to the invention, is characterized in that the composition is in the form of a tablet, a chewing gum (soft chew) or a chewable tablet.

More particularly, the invention also relates to a pharmaceutical composition for human or veterinary use, for its use in interrupting the transmission of parasitic diseases caused by hematophagous nematodes transmitted by mosquitoes from a first host to a second host , in which the first host is selected from domestic animals, wild animals, birds or human beings, comprising as active principle a benzoylurea chosen from diflubenzuron, chlorfluazuron, flufenoxuron, hexaflumuron, triflumuron or lufenuron, their salts or their derivatives, taken alone or in combination, and wherein said composition is used for the control of mosquitoes which feed on the first host and thereby interrupt the transmission of parasitic disease caused by a hematophagous nematode induced by the mosquito from the first host to the second host.

The compositions for their uses according to the invention for human or veterinary use are preferably administered to mammals. Mammals can be symptomatic but are usually asymptomatic. By way of non-limiting example of mammals, mention may be made of animals of the family Bovidae, Canidae, Equidae, Felidae, Leporidae, Mustelidae, Ursidae and Man. Furthermore, mammals known as “new companion animals” (acronym NAC) are also concerned by the present invention.

Preferably, the target mammals are Canidae or Felidae.

More preferably, the mammals are dogs or cats.

The composition according to the invention is advantageously in a form suitable for systemic administration.

According to a preferred embodiment, such systemic administration is oral administration. In another embodiment, it is topical administration. In another embodiment, it is parenteral (injectable, in particular subcutaneous) administration.

Administration by the systemic route denotes administration at a site remote from the site of administration, in which resides at least some of the target parasites, here hematophagous nematodes.

Thanks to systemic administration, at least part of the benzoylurea active ingredient which is preferably chosen from diflubenzuron, chlorfluazuron, flufenoxuron, hexaflumuron, triflumuron or lufenuron, their salts or their derivatives, taken alone or in combination, reaches the target hematophagous nematode via the bloodstream of the recipient which is here a mammalian host, or alternatively via other bodily fluids (lymphatic fluids) and/or via tissues (e.g. skin or adipose tissue). Systemic administration differs from contact administration in which the surface of the parasite's body is directly exposed to the active ingredient.

Typically, the hematophagous nematode, preferentially Dirofilaria immitis larvae, ingests the systemically administered active ingredient benzoylurea with the blood, other body fluids and/or tissues of the recipient. Systemic administration can be carried out in several forms, for example by oral, parenteral or topical administration in which the active ingredient benzoylurea is absorbed transdermally.

In certain embodiments, the benzoylurea active ingredient is administered orally in unit dose form, such as, for example, a tablet, a chewing gum (soft chew), a chewable tablet (chew tablet), a pill , powder, granules, tablet, paste, solution, suspension (aqueous or non-aqueous), emulsion (oil-in-water or water-in-oil), elixir or syrup.

Preferably, the composition is in the form of a chewing gum (soft chew) or a chewable tablet (chew tablet).

Such compositions in the form of a chewing gum (soft chew) or a chewable tablet (chew tablet) are generally easy to administer to mammals, in particular cats and dogs, preferably dogs, and can be effectively used to dose veterinary drugs to these animals. Such tablets or gums advantageously make it possible to deliver pharmaceutical unit doses. These compositions are advantageously solid at room temperature and, after oral administration, will be chewed by the mammal and are soft because the product has a plastic texture during the chewing process in the mouth. These compositions can in particular recall the texture and taste of cooked minced meat, which makes them particularly easy to administer to a dog or a cat.

Alternatively, oral administration can be effected through the food or drink of the animal to be treated. The composition can thus be dispersed directly in the food, as a coating, or else in the form of granules or of liquid which are added to the food or to the final drink.

The composition that is the subject of the invention can also be administered topically using a transdermal formulation (that is to say passing through the skin) or else via the mucous membranes.

The composition according to the invention can be administered parenterally, for example by intramuscular injection, intravenous injection, subcutaneous injection, implant (for example, subcutaneous implant) or infusion.

Mammals can receive the composition as defined above every 1, 2, 3, 4, 5 or 6 months, or receive an annual, semi-annual, quarterly, bi-monthly, monthly, weekly or daily dosage. Preferably, the composition according to the invention is administered every one, two or three months, more preferentially every month.

Preferably, the composition according to the invention also comprises a second active principle. The presence of one or more additional active principles can advantageously make it possible to broaden the spectrum of antiparasitic action of the composition. The presence of one or more additional active ingredients can also complete or supplement the action of the first active ingredient on hematophagous nematodes, by acting for example on other stages of development.

By way of non-limiting example of active ingredient that can be used, mention may be made of the following ecto- and endoparasitic agents: albendazole, amitraz, amprolium, antimony, atovaquone, benzimidazole, dichlorvos, diethylcarbamazine, diminazene aceturate, disophenol, dithiazine iodide, epsipantel, fenbendazole, fenthion, furazolidone, glucuronate, imidocarb dipropionate, mebendazole, meglumine antimoniate, melasronin, metronidazole, milbemycin oxime, moxidectin, naproxen, niclosamide, nifurtimox, paromomycin, parvaquone, pentamidine isethionate, piperazine, praziquantel, primaquine, selamectin, spiramycin, spiramycin, trimethoprim, sulfadimethoxine, sulfamethazine, tetramisole, thiabendazole, toltrazuril, toluene, trimetrexate, their salts or their derivatives, taken alone or in combination.

By way of non-limiting example of active ingredient that can be used, mention may also be made of the following antihelminthic agents: thiabendazole, mebendazole, albendazole, their salts or their derivatives, taken alone or in combination.

By way of non-limiting example of an active ingredient that can be used, mention may also be made of the following insecticides: coumaphos, carbamates such as propoxur, pyrethroids such as permethrin, arylpyrazoles such as fipronil, neonicotinoids such as imidaclopid and avermectins such as ivermectin, their salts or their derivatives, taken alone or in combination.

Preferably, the second active ingredient is a compound known for its adulticidal or macrofilaricidal activity against hematophagous nematodes. Thus, the second active principle of the composition according to the invention makes it possible to act on hematophagous nematodes, such as Dirofilaria immitis for example, at the adult stage. The composition according to the invention thus allows action at all stages of hematophagous nematodes, namely:
- the microfilariae stage;
- the larval stages L1, L2, L3, L4;
- the immature forms stage; And
- the adult stage. ;
but also an action on the vectors of hematophagous nematodes.

The second active principle is thus advantageously a compound known for its adulticidal activity of hematophagous nematodes chosen from melasronine or moxidectin.

The invention also relates to a method for preventing or interrupting the transmission of a disease caused by a hematophagous nematode, such as dirofilariasis, by application, in a mammal, preferably a dog or a cat, infested with said disease which is parasitic or likely to be, of an effective dose of a benzoylurea chosen from diflubenzuron, chlorfluazuron, flufenoxuron, hexaflumuron, triflumuron or lufenuron, their salts or their derivatives, taken alone or in combination. Said method consists in acting preferentially at all stages of development of the hematophagous nematode. Advantageously, said method consists in also acting concomitantly on the vectors of the hematophagous nematode, in particular their intermediate hosts such as the mosquito for heartworm disease.

The invention also relates to a method for controlling the spread of a parasitic disease caused by hematophagous nematodes, such as dirofilariasis, by application, in a mammal, preferably a dog or a cat, infested with said parasitic disease. or likely to be, of an effective dose of a benzoylurea chosen from diflubenzuron, chlorfluazuron, flufenoxuron, hexaflumuron, triflumuron or lufenuron, their salts or their derivatives, taken alone or in combination.

Controlling the spread of disease generally means reducing, eradicating and/or preventing the spread of disease.

It also relates to a kit suitable for implementing a method for controlling a parasitic disease caused by hematophagous nematodes as described above. Said kit advantageously comprises one or more packaging units composed of at least one composition comprising as active principle a benzoylurea chosen from diflubenzuron, chlorfluazuron, flufenoxuron, hexaflumuron, triflumuron or lufenuron, their salts or derivatives thereof, taken alone or in combination, and preferably instructions for use for the administration of said composition to a mammal, preferably a dog or a cat, infested by said parasitic disease or likely to be so.

Finally, the subject of the invention is a pharmaceutical product for human or veterinary use comprising as active principle:
- a benzoylurea chosen from diflubenzuron, chlorfluazuron, flufenoxuron, hexaflumuron, triflumuron or lufenuron, their salts or their derivatives, taken alone or in combination, and
- at least one other active ingredient chosen from albendazole, amitraz, amprolium, antimony, atovaquone, benzimidazole, dichlorvos, diethylcarbamazine, diminazene aceturate, disophenol, dithiazine iodide, epsiprantel, fenbendazole, fenthion, furazolidone, glucuronate, imidocarb dipropionate, mebendazole, meglumine antimonate, melasronin, metronidazole, milbemycin oxime, moxidectin, naproxen, niclosamide, nifurtimox, paromomycin, parvaquone, pentamidine isethionate, piperazine, praziquantel, primaquine, selamectin, spiramycin, sulfadiazine, trimethoprim, sulfadimethoxine, sulfamethazine, tetramisole, thiabendazole, toltenazuril trimetrexate, thiabendazole, mebendazole, albendazole, coumaphos, carbamates such as propoxur, pyrethroids such as permethrin, arylpyrazoles such as fipronil, isoxazolines such as fluralaner, afoxolaner, sarolaner, lotilaner, neonicotinoids such as imidaclopid and avermectins such as ivermectin, their salts or their derivatives and their mixtures, taken alone or in combination, preferably moxidectin or melasronin, as a combination product for simultaneous, separate or spread out use for its use in the treatment and/ or preventing a parasitic disease caused by a blood-sucking nematode in a mammal.

According to a particular embodiment of the invention, the subject of the invention is a pharmaceutical product for human or veterinary use comprising:
- as the first active principle, a benzoylurea chosen from diflubenzuron, chlorfluazuron, flufenoxuron, hexaflumuron, triflumuron or lufenuron, their salts or their derivatives, taken alone or in combination, and
- as second active principle a compound chosen from macrocyclic lactones, as a combination product for simultaneous, separate or spread out use over time for its use in the treatment and/or prevention of a parasitic disease caused by a nematode hematophagus in a mammal.

The macrocyclic lactones are preferentially chosen from ivermectin, doramectin, moxidectin, abamectin, selamectin or milbemycin oxime, preferentially ivermectin.

The administration of the macrocyclic lactone can be orally, topically or by injection. Preferably, the administration of the macrocyclic lactone is intradermal and/or subcutaneous. These can be chewing gums, spot-ons, injectable suspensions or implants.

In order to limit its use, the macrocyclic lactone is generally administered after diagnosis, in the mammal to be treated, of the presence of the hematophagous nematode, such as for example Dirofilaria immitis , preferentially in the blood of the mammal.

The present invention will now be illustrated by means of the following examples:
Example 1: Effect of I ufenuron on the development of a nematode free Caenorhabditis elegans and on the motility of the L3 stages of a parasitic nematode Haemonchus contortus

The administration of lufenuron at higher doses than those required for efficacy against fleas, on nematodes ( Caenorhabditis elegans ) throughout their development cycle (from the egg to the adult stage = dynamic model) shows an inhibition part of the cycle. At the same doses, lufenuron induced a general reduction in the motility of L3 larvae (static model). These last results are unexpected and new, because the action of lufenuron usually manifests itself only with a certain latency and always on the stages subsequent to those which have been exposed to it, the progeny being affected by the contaminated adults.
Example 2 : Tolerance of l ufenuron in dogs

Various toxicity tests have been carried out on dogs in order to assess their tolerance to lufenuron.

An acute toxicity test with a dose of 200 mg of product administered per kg (200 mg/kg) was carried out on dogs.

No impact on the health of the dogs was observed except for a slight weight loss.

A test with a dose of 50 mg/kg was also carried out on six-week-old puppies receiving 50 mg/kg on three consecutive days for a period of three months. The effects observed are vomiting and dehydration without affecting the growth of the animals.

In addition, other tests were carried out in parallel, by administering a dose of 100 mg/kg of lufenuron coupled with proprietary insecticides such as carbaryl, permethrin or chlorpyrifos over 3 consecutive days for a period of six months. The only effect observed is a slight loss of appetite.

Conclusion: Lufenuron administered even at high doses in dogs of all ages does not present any major health risks.
Example 3 : Evolution of plasma concentrations of ufenuron in the rat

Different doses of lufenuron were administered to rats in order to monitor the plasma concentration over time.

These doses are 10 mg/kg; 50mg/kg and 100mg/kg.

The results shown in Figure 1 show that there seems to be a saturation of the absorption after 10 mg/kg.

The results shown in Figure 2 show an extrapolation of the concentration of lufenuron in adipose tissue in dogs dosed at 10, 50 and 100 mg/kg.

At a dose of 10 mg/kg, lufenuron is found at concentrations greater than 10 µg/g in the adipose tissue during the first twenty days following administration of the treatment.

With larger doses such as the 50 mg/kg and 100 mg/kg dose, the concentrations observed over time are higher.

Conclusion: The administration of higher doses in rats and potentially in dogs makes it possible to have greater bioavailability of Lufenuron over time and thus to fight effectively against nematode larvae, more particularly Dirofilaria immitis larvae between the stages. L4 and L5, where new quantities of chitins must be synthesized.
Example 4 : Study of the effectiveness of the use of l ufénuron against the development of Dirofilaria immitis from the L3 stage to the adult stage

A study was conducted to determine the effectiveness of lufenuron in countering the development of L3 larvae of Dirofilaria immitis (Georgia III strain characterized as resistant to Macrocyclic Lactones) in dogs in combination or not with a macrocyclic lactone (Ivermectin) .

A total of twenty dogs were used for the study. The latter were all over the age of six months and had not taken macrocyclic lactone treatment in the three months before the start of the study.

Dogs selected for the study had previously tested negative for Dirofilaria immitis infection.

This study required the distribution of twenty dogs into four groups as follows:

Group 1: Group of six dogs treated with doses of Lufenuron greater than or equal to 100 mg/kg;

Group 2: Control group of six untreated dogs;

Group 3: Group of four dogs treated with doses of ivermectin greater than or equal to 6 µg/kg; And

Group 4: Group of four dogs treated with doses of Ivermectin greater than or equal to 6 µg/kg combined with doses of Lufenuron greater than or equal to 100 mg/kg.

The treatment was administered to the dogs orally directly incorporated into their diet according to the following frequencies:

Group 1: Treatment administered on days -35, -7, 21, 49, 77, 105 and 133;

Group 2: Untreated group;

Group 3: Treatment administered on days -35, -7, 21, 49, 77, 105 and 133; And

Group 4: Treatment administered on days -35, -7, 21, 49, 77, 105 and 133.

Dogs were started on treatment prior to infection with Dirofilaria immitis , with 0 being the day study subjects became infected. In parallel, throughout the duration of the study, the weight of the animals was monitored and blood samples were taken on a regular basis.

The efficacy of the various treatments is then evaluated in relation to the control group 2 after euthanasia of the subjects of the study and collection of skin samples (including the subcutaneous tissue).

Surprisingly, the results of the study made it possible to demonstrate on the one hand that Lufenuron administered at a dose greater than or equal to 100 mg/kg is well tolerated by the subjects and on the other hand that a treatment to Lufenuron of infected dogs in group 1 was effective.

Treatment of group 3 infected dogs with ivermectin alone provides satisfactory results, but the active ingredient is found in animal excreta, which is likely to cause lethal and sublethal effects on a range of non-target invertebrates. , such as Diptera, Coleoptera and benthic organisms.

Finally, treatment with Ivermectin at a dose greater than or equal to 6 µg/kg associated with a dose of Lufenuron greater than or equal to 100 mg/kg also makes it possible to control and/or limit the spread of parasitic infestations by worms, particularly by Dirofilaria immitis . However, this group 4 treatment causes more side effects than in group 1 or 3 dogs.

Claims (9)

Pharmaceutical composition for human or veterinary use, for its use in the treatment and/or prevention of a parasitic disease caused by a hematophagous nematode in a mammal, comprising as active principle a benzoylurea chosen from diflubenzuron, chlorfluazuron, flufenoxuron, hexaflumuron, triflumuron or lufenuron, their salts or their derivatives, taken alone or in combination. Composition for its use according to Claim 1, characterized in that the active principle is lufenuron. Composition for its use according to one of the preceding claims, characterized in that it is in a form suitable for systemic administration. Composition for its use according to one of the preceding claims, characterized in that the mammal is a dog or a cat. Composition for its use according to one of the preceding claims, characterized in that the parasitic disease caused by a hematophagous nematode is heartworm disease ( Dirofilaria immitis) . Composition for its use according to one of the preceding claims, characterized in that it is in the form of a chewing gum (soft chew) or a chewable tablet (chew tablet). Pharmaceutical composition for human or veterinary use, for its use in the prevention of re-infestations and over-infestations of a parasitic disease caused by a hematophagous nematode in a mammal, comprising as active principle a benzoylurea chosen from diflubenzuron, chlorfluazuron, flufenoxuron, hexaflumuron, triflumuron or lufenuron, their salts or their derivatives, taken alone or in combination. Pharmaceutical composition for human or veterinary use, for use in interrupting the transmission of parasitic diseases caused by blood-sucking nematodes transmitted by mosquitoes from a first host to a second host, wherein the first host is selected from animals domestic animals, wild animals, birds or human beings, comprising as active ingredient a benzoylurea chosen from diflubenzuron, chlorfluazuron, flufenoxuron, hexaflumuron, triflumuron or lufenuron, their salts or their derivatives, taken alone or in combination, and wherein said composition is used for the control of mosquitoes which feed on the first host and thereby interrupt the transmission of parasitic disease caused by a mosquito-induced hematophagous nematode from the first host to the second host. Composition for its uses according to one of the preceding claims, characterized in that it also comprises a second active principle chosen from moxidectin or melarsomine.