WO2017202789A1

WO2017202789A1 - Methods and pharmaceutical compositions for the treatment of filovirus infections

Info

Publication number: WO2017202789A1
Application number: PCT/EP2017/062308
Authority: WO
Inventors: Vincent Lotteau
Original assignee: INSERM (Institut National de la Santé et de la Recherche Médicale); Ens - Ecole Normale Supérieure de Lyon; Centre National De La Recherche Scientifique (Cnrs); Université Claude Bernard Lyon 1
Priority date: 2016-05-23
Filing date: 2017-05-22
Publication date: 2017-11-30

Abstract

The present invention relates to methods and pharmaceutical compositions for the treatment of filovirus infections. Although several antivirals have shown efficacy against Ebola virus infection in vitro or in animal models, few of them have been yet assessed in human beings with Ebola virus disease. The inventors aimed at identifying novel antivirals showing efficacy against Ebola virus infection. Gemcitabine and obatoclax were identified and their synergistic effects with favipiravir were demonstrated. In particular, the present invention relates to a method of treating a filovirus infection in a subject in need thereof comprising administering to the subject a therapeutically effective combination of favipiravir and Obatoclax. The present invention also relates to a method of treating a filovirus infection in a subject in need thereof comprising administering to the subject a therapeutically effective combination of favipiravir and gemcitabine.

Description

METHODS AND PHARMACEUTICAL COMPOSITIONS FOR THE TREATMENT

OF FILO VIRUS INFECTIONS

FIELD OF THE INVENTION:

The present invention relates to methods and pharmaceutical compositions for the treatment of filovirus infections.

BACKGROUND OF THE INVENTION:

The family Filoviridae (Filovirus) is the taxonomic home of several related viruses that form filamentous infectious viral particles (virions), and encode their genome in the form of single-stranded negative-sense RNA. Two members of the family that are commonly known are Ebola virus and Marburg virus. Both viruses, and some of their lesser known relatives, cause severe disease in humans and nonhuman primates in the form of viral hemorrhagic fevers. The Ebola virus was named after the Ebola River in Zaire, Africa, near where the first outbreak was noted by Dr. Ngoy Mushola in 1976 after a significant outbreaks in both Yambuku, Zaire (now the Democratic Republic of the Congo), and Nzara, in western Sudan. There are three distinct species of Ebola virus which cause fatal disease in humans: Zaire ebolavirus (ZEBOV) (also known as EBOV), Sudan ebolavirus (SEBOV) and Ivory Coast ebolavirus (ICEBOV). Among humans, the Ebola virus is transmitted by direct contact with infected body fluids such as blood. The incubation period of Ebola virus infection varies from two days to four weeks. Symptoms are variable too, but the onset is usually sudden and characterised by high fever, prostration, myalgia, arthralgia, abdominal pains and headache. These symptoms progress to vomiting, diarrhea, oropharyngeal lesions, conjunctivitis, organ damage (notably the kidney and liver) by co-localized necrosis, proteinuria, and bleeding both internal and external, commonly through the gastrointestinal tract. Death or recovery to convalescence occurs within six to ten days of onset of symptomology. Although several antivirals have shown efficacy against Ebola virus infection in vitro or in animal models, few of them have been yet assessed in human beings with Ebola virus disease. Thus, there exists a huge need in the art for an effective curative treatment against Ebola Virus Disease. In September 2014, while the Ebola outbreak was at its peak, the World Health Organization released a short list of drugs suitable for EVD research. Favipiravir, an antiviral developed for the treatment of severe influenza, was one of these. A recent clinical trial showed that favipiravir monotherapy merits further study in patients with medium to high viremia, but not in those with very high viremia (PLoS Med. 2016 Mar l;13(3):el001967).

SUMMARY OF THE INVENTION:

The present invention relates to methods and pharmaceutical compositions for the treatment of filovirus infections. In particular, the present invention is defined by the claims.

DETAILED DESCRIPTION OF THE INVENTION:

The present invention relates to a method of treating a filovirus infection in a subject in need thereof comprising administering to the subject a therapeutically effective combination of favipiravir and Obatoclax.

The present invention also relates to a method of treating a filovirus infection in a subject in need thereof comprising administering to the subject a therapeutically effective combination of favipiravir and gemcitabine.

The term "filovirus" refers collectively to members of the Filoviridae family of single stranded (-) R A viruses including Ebola and Marburg viruses. As used herein, the term "Ebola virus" refers to a member of the family Filoviridae, are associated with outbreaks of highly lethal hemorrhagic fever in humans and nonhuman primates. Human pathogens include Ebola Zaire, Ebola Sudan, and Ebola Ivory Coast. Ebola Reston is a monkey pathogen and is not considered a significant human pathogen. In some embodiments of the invention, said Ebola virus is Ivory Coast Ebola virus (ICEBOV), Zaire Ebola virus (ZEBOV or EBOV), Sudan Ebola Virus (SEBOV), or a new strain or species of Ebola virus.

The method of the present invention is particularly suitable for the treatment of filovirus diseases, in particular Ebola virus disease. As used herein, the term "Ebola virus disease" (EVD), formerly known as Ebola haemorrhagic fever, is a severe, often fatal illness in humans. The incubation period, that is, the time interval from infection with the virus to onset of symptoms is 2 to 21 days. Humans are not infectious until they develop symptoms. First symptoms are the sudden onset of fever fatigue, muscle pain, headache and sore throat. This is followed by vomiting, diarrhoea, rash, symptoms of impaired kidney and liver function, and in some cases, both internal and external bleeding (e.g. oozing from the gums, blood in the stools). Laboratory findings include low white blood cell and platelet counts and elevated liver enzymes. As used herein, the term "treatment" or "treat" refer to both prophylactic or preventive treatment as well as curative or disease modifying treatment, including treatment of subjects at risk of contracting the disease or suspected to have contracted the disease as well as subjects who are ill or have been diagnosed as suffering from a disease or medical condition, and includes suppression of clinical relapse. The treatment may be administered to a subject having a medical disorder or who ultimately may acquire the disorder, in order to prevent, cure, delay the onset of, reduce the severity of, or ameliorate one or more symptoms of a disorder or recurring disorder, or in order to prolong the survival of a subject beyond that expected in the absence of such treatment. By "therapeutic regimen" is meant the pattern of treatment of an illness, e.g., the pattern of dosing used during therapy. A therapeutic regimen may include an induction regimen and a maintenance regimen. The phrase "induction regimen" or "induction period" refers to a therapeutic regimen (or the portion of a therapeutic regimen) that is used for the initial treatment of a disease. The general goal of an induction regimen is to provide a high level of drug to a subject during the initial period of a treatment regimen. An induction regimen may employ (in part or in whole) a "loading regimen", which may include administering a greater dose of the drug than a physician would employ during a maintenance regimen, administering a drug more frequently than a physician would administer the drug during a maintenance regimen, or both. The phrase "maintenance regimen" or "maintenance period" refers to a therapeutic regimen (or the portion of a therapeutic regimen) that is used for the maintenance of a subject during treatment of an illness, e.g., to keep the subject in remission for long periods of time (months or years). A maintenance regimen may employ continuous therapy (e.g., administering a drug at a regular intervals, e.g., weekly, monthly, yearly, etc.) or intermittent therapy (e.g., interrupted treatment, intermittent treatment, treatment at relapse, or treatment upon achievement of a particular predetermined criteria [e.g., disease manifestation, etc.]).

In some embodiments, the subject is infected, or is at risk of being infected with a filo virus. Diagnosis may be performed by any suitable means. One skilled in the art will understand that a subject to be treated according to the present invention may have been identified using standard tests or may have been identified, without examination, as one at high risk due to the presence of one or more risk factors (e.g., exposure to Ebola virus, etc.). In some embodiments, the subject is infected but is asymptomatic (i.e. the symptoms are not detected). In some embodiments, the diagnosis is performed by detecting filovirus virus nucleic acids in a sample obtained from the subject by any method familiar to one of skill in the art. Such methods typically include the methods based on the detecting the filovirus virus nucleic acids expression. Filovirus nucleic acids may be detected in a R A sample, preferably after amplification. For instance, the isolated RNA may be subjected to coupled reverse transcription and amplification, such as reverse transcription and amplification by polymerase chain reaction (RT-PCR), using specific compound primers that are specific for a filovirus nucleic acid (e.g. those encoding the nucleoprotein (NP) and the four virion structural proteins (VP40, VP35, VP30, and VP24). For instance, a RT-PCR Assay is intended for the in vitro qualitative detection of filovirus RNA in clinical specimens, including whole blood, serum, plasma, and urine, from individuals meeting filovirus clinical and/or epidemiological criteria (for example, clinical signs and symptoms associated with filovirus, contact with a probable or confirmed filovirus case, history of travel to geographic locations where filovirus cases were detected, or other epidemiologic links for which filovirus testing may be indicated as part of a public health investigation).

As used herein, the term "favipiravir" refers to 6-fluoro-3-hydroxy-2- pyrazinecarboxamide (also known as T-705) which is a compound useful for the prevention and treatment of viral infectious diseases, particularly influenza viral infectious diseases. Favipiravir is a nucleotide analogue approved for novel or re-emerging influenza in Japan (Furuta et al, 2013). Said compound is extensively described in the European Patent n° EP1112743B1 as well as methods for obtaining said compound. European Patent n° EP2407166B1 describes tablet which contains a high quantity of 6-fluoro-3-hydroxy-2- pyrazinecarboxamide or a salt thereof and has superior release characteristics.

As used herein, the term "obatoclax" has its general meaning in the art and refers to 2- (2-((3,5-Dimethyl-lH-pyrrol-2-yl)methylene)-3-methoxy-2H-pyrrol-5-yl)-lH-indole

(Systematic IUAPC name).

As used herein, the term "gemcitabine" has its general meaning in the art and refers to 4-amino- 1 -(2-deoxy-2,2-dif uoro-P-D-erythro-pentofuranosyl)pyrimidin-2( 1 H)-on

(Systematic IUAPC name).

As used herein the term "co-administering" as used herein means a process whereby the combination of favipiravir and obatoclax or gemcitabine, is administered to the same patient. Favipiravir and obatoclax or gemcitabine may be administered simultaneously, at essentially the same time, or sequentially. Favipiravir and obatoclax or gemcitabine do not need to be administered by means of the same vehicle. Favipiravir and obatoclax or gemcitabine inhibitor may be administered one or more times and the number of administrations of each component of the combination may be the same or different.

As used herein, the term "therapeutically effective combination" as used herein refers to an amount or dose of favipiravir together with the amount or dose of obatoclax or gemcitabine that is sufficient to treat the filovirus infection. The "therapeutically effective amount" is determined using procedures routinely employed by those of skill in the art such that an "improved therapeutic outcome" results. It will be understood, however, that the total daily usage of the compounds and compositions of the present invention will be decided by the attending physician within the scope of sound medical judgment. The specific therapeutically effective dose level for any particular subject will depend upon a variety of factors including the disorder being treated and the severity of the disorder; activity of the specific compound employed; the specific composition employed, the age, body weight, general health, sex and diet of the subject; the time of administration, route of administration, and rate of excretion of the specific compound employed; the duration of the treatment; drugs used in combination or coincidential with the specific polypeptide employed; and like factors well known in the medical arts. For example, it is well within the skill of the art to start doses of the compound at levels lower than those required to achieve the desired therapeutic effect and to gradually increase the dosage until the desired effect is achieved. However, the daily dosage of the products may be varied over a wide range from 0.01 to 1,000 mg per adult per day. Typically, the compositions contain 0.01, 0.05, 0.1, 0.5, 1.0, 2.5, 5.0, 10.0, 15.0, 25.0, 50.0, 100, 250 and 500 mg of the active ingredient for the symptomatic adjustment of the dosage to the subject to be treated. A medicament typically contains from about 0.01 mg to about 500 mg of the active ingredient, preferably from 1 mg to about 100 mg of the active ingredient. An effective amount of the drug is ordinarily supplied at a dosage level from 0.0002 mg/kg to about 20 mg/kg of body weight per day, especially from about 0.001 mg/kg to 7 mg/kg of body weight per day.

According to the invention, favipiravir and obatoclax or gemcitabine are administered to the subject in the form of a pharmaceutical composition. Typically, favipiravir and obatoclax or gemcitabine may be combined with pharmaceutically acceptable excipients, and optionally sustained-release matrices, such as biodegradable polymers, to form therapeutic compositions. "Pharmaceutically" or "pharmaceutically acceptable" refer to molecular entities and compositions that do not produce an adverse, allergic or other untoward reaction when administered to a mammal, especially a human, as appropriate. A pharmaceutically acceptable carrier or excipient refers to a non-toxic solid, semi-solid or liquid filler, diluent, encapsulating material or formulation auxiliary of any type. In the pharmaceutical compositions of the present invention for oral, sublingual, subcutaneous, intramuscular, intravenous, transdermal, local or rectal administration, the active principle, alone or in combination with another active principle, can be administered in a unit administration form, as a mixture with conventional pharmaceutical supports, to animals and human beings. Suitable unit administration forms comprise oral-route forms such as tablets, gel capsules, powders, granules and oral suspensions or solutions, sublingual and buccal administration forms, aerosols, implants, subcutaneous, transdermal, topical, intraperitoneal, intramuscular, intravenous, subdermal, transdermal, intrathecal and intranasal administration forms and rectal administration forms. Typically, the pharmaceutical compositions contain vehicles which are pharmaceutically acceptable for a formulation capable of being injected. These may be in particular isotonic, sterile, saline solutions (monosodium or disodium phosphate, sodium, potassium, calcium or magnesium chloride and the like or mixtures of such salts), or dry, especially freeze-dried compositions which upon addition, depending on the case, of sterilized water or physiological saline, permit the constitution of injectable solutions. The pharmaceutical forms suitable for injectable use include sterile aqueous solutions or dispersions; formulations including sesame oil, peanut oil or aqueous propylene glycol; and sterile powders for the extemporaneous preparation of sterile injectable solutions or dispersions. In all cases, the form must be sterile and must be fluid to the extent that easy syringability exists. It must be stable under the conditions of manufacture and storage and must be preserved against the contaminating action of microorganisms, such as bacteria and fungi. Solutions comprising compounds of the invention as free base or pharmacologically acceptable salts can be prepared in water suitably mixed with a surfactant, such as hydroxypropyl cellulose. Dispersions can also be prepared in glycerol, liquid polyethylene glycols, and mixtures thereof and in oils. Under ordinary conditions of storage and use, these preparations contain a preservative to prevent the growth of microorganisms. Favipiravir and obatoclax or gemcitabine can be formulated into a composition in a neutral or salt form. Pharmaceutically acceptable salts include the acid addition salts (formed with the free amino groups of the protein) and which are formed with inorganic acids such as, for example, hydrochloric or phosphoric acids, or such organic acids as acetic, oxalic, tartaric, mandelic, and the like. Salts formed with the free carboxyl groups can also be derived from inorganic bases such as, for example, sodium, potassium, ammonium, calcium, or ferric hydroxides, and such organic bases as isopropylamine, trimethylamine, histidine, procaine and the like. The carrier can also be a solvent or dispersion medium containing, for example, water, ethanol, polyol (for example, glycerol, propylene glycol, and liquid polyethylene glycol, and the like), suitable mixtures thereof, and vegetables oils. The proper fluidity can be maintained, for example, by the use of a coating, such as lecithin, by the maintenance of the required particle size in the case of dispersion and by the use of surfactants. The prevention of the action of microorganisms can be brought about by various antibacterial and antifungal agents, for example, parabens, chlorobutanol, phenol, sorbic acid, thimerosal, and the like. In many cases, it will be preferable to include isotonic agents, for example, sugars or sodium chloride. Prolonged absorption of the injectable compositions can be brought about by the use in the compositions of agents delaying absorption, for example, aluminium monostearate and gelatin. Sterile injectable solutions are prepared by incorporating the active compounds in the required amount in the appropriate solvent with several of the other ingredients enumerated above, as required, followed by filtered sterilization. Generally, dispersions are prepared by incorporating the various sterilized active ingredients into a sterile vehicle which contains the basic dispersion medium and the required other ingredients from those enumerated above. In the case of sterile powders for the preparation of sterile injectable solutions, the typical methods of preparation are vacuum-drying and freeze-drying techniques which yield a powder of the active ingredient plus any additional desired ingredient from a previously sterile- filtered solution thereof. Upon formulation, solutions will be administered in a manner compatible with the dosage formulation and in such amount as is therapeutically effective. The formulations are easily administered in a variety of dosage forms, such as the type of injectable solutions described above, but drug release capsules and the like can also be employed. For parenteral administration in an aqueous solution, for example, the solution should be suitably buffered if necessary and the liquid diluent first rendered isotonic with sufficient saline or glucose. These particular aqueous solutions are especially suitable for intravenous, intramuscular, subcutaneous and intraperitoneal administration. In this connection, sterile aqueous media which can be employed will be known to those of skill in the art in light of the present disclosure. Some variation in dosage will necessarily occur depending on the condition of the subject being treated. The person responsible for administration will, in any event, determine the appropriate dose for the individual subject.

The invention will be further illustrated by the following figures and examples. However, these examples and figures should not be interpreted in any way as limiting the scope of the present invention. FIGURES:

Figure 1 shows virus infectivity titers (in copy number) measured with 3 concentrations of obatoclaxe (10, 30 or 90 nM) with increasing concentration of favipiravir.

Figure 2 shows virus infectivity titers (in percentage of copy number relatively to untreated control) measured with one concentration of gemcitabine (9nM) with increasing concentration of favipiravir.

EXAMPLE:

The inventors aimed at identifying novel antivirals showing efficacy against Ebola virus infection. Gemcitabine and obatoclax were identified and their synergistic effects with favipiravir were demonstrated (Figures 1 and 2).

REFERENCES:

Throughout this application, various references describe the state of the art to which this invention pertains. The disclosures of these references are hereby incorporated by reference into the present disclosure.

Claims

CLAIMS:

1. A method of treating a filovirus infection in a subject in need thereof comprising administering to the subject a therapeutically effective combination of favipiravir and obatoclax.

2. A method of treating a filovirus infection in a subject in need thereof comprising administering to the subject a therapeutically effective combination of favipiravir and gemcitabine.

3. The method of claim 1 or 2 for the treatment of filovirus diseases, in particular Ebola virus disease.

4. The method of claim 1 or 2 wherein the subject is infected, or is at risk of being infected with a filovirus.