RU2722981C1 - Method of treating malaria using a therapeutic combination of telomerase inhibitors (iimatinib mesilate) and artemether - Google Patents

Abstract

FIELD: medicine; pharmaceutics.

SUBSTANCE: present invention refers to areas of pharmacology and medicine and can be used for chemotherapy of tropical malaria caused by Plasmodium falciparum agent, especially in cases of its drug-resistant forms. Method of treating malaria involves administering a combination of preparations of Artemether and Iimatinib mesilate once a day in dosages of 0.33 mg/kg and 0.25 mg/kg respectively for three days.

EFFECT: method provides higher clinical effectiveness in malaria by overcoming drug resistance and reducing side effects of the drugs used.

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Description

FIELD OF THE INVENTION

The present invention relates to the fields of pharmacology and medicine and can be used for chemotherapy of tropical malaria caused by the pathogen Plasmodium falciparum, especially in cases of its drug-resistant forms.

State of the art

According to the WHO Global Malaria Technical Strategy 2016–2030, the priorities are to maintain the efficacy of artemisinin-based combination therapies and develop new combinations for both malaria-endemic countries and the global malaria community. Per os artemisinin monotherapy should never be used in the treatment of uncomplicated malaria, as this may contribute to the development of resistance to this drug [World Health Organization. (2015). Global technical strategy for malaria 2016-2030. World Health Organization, https://apps.who.int/iris/handle/10665/176712] / [World Health Organization. (2015). Global technical strategy for malaria 2016-2030. World Health Organization, https://apps.who.int/iris/handle/10665/176712].

Combination therapy based on artemisinin is recommended by WHO as the first and second line of treatment for uncomplicated P. falciparum malaria, as well as chloroquinine-resistant P. vivax malaria. The role of the artemisinin compound is to reduce the number of parasites during the first three days of treatment (decrease in parasite biomass), while the role of the partner drug is to eliminate the remaining parasites (cure) [World Health Organization. (2018). Artemisinin resistance and artemisinin-based combination therapy efficacy: status report. World Health Organization. https://apps.who.int/iris/handle/10665/274362. License: CC BY-NC-SA 3.0 IGO]. Ha today, artemisinin-based combination therapy continues to remain highly effective, but its use is at risk due to the emergence and spread of drug resistance of parasites to P. falciparum in many countries in Southeast Asia, in particular in Cambodia, Lao People's Democratic Republic , Myanmar, Thailand, and Vietnam, and if this drug resistance spreads further, then millions of people will be at risk again.

The main etiotropic drugs in the treatment of severe forms of tropical malaria, in accordance with the recommendations of WHO (2010), are artesunate and artemether. Artemisinin preparations very quickly show their effect, both on blood stages and on gametocytes. However, these drugs are characterized by rapid elimination from the body, which leads to relapse of malaria and the development of resistance. Therefore, WHO recommends not to use this group of drugs for monotherapy, but to combine them with the already known antimalarial drugs. Travelers returning to non-endemic countries with malignant tropical malaria can use malarone (atovaquone + proguanil), coartem (artemether + lumefantrine), dihydroartemisinin + piperachine, quinine + doxycycline or clindamycin for treatment. However, all these combinations have a number of side effects, such as: central nervous system (headache, dizziness, fatigue, difficulty falling asleep and sleeping, irritability, depression, anxiety, confusion, convulsions, fainting, fever, hallucinations); musculoskeletal system (pain in muscles, joints, swelling of the lower extremities); Gastrointestinal tract (vomiting, loss of appetite); from the cardiovascular system (brady and tachycardia, bleeding), the urinary system (painful or difficult urination). The WHO Global Malaria Program regularly publishes updated information on the situation of resistance to artemisinin derivatives in affected countries. Resistance to artemisinin derivatives does not affect the choice of drugs for drug prophylaxis, but is important from the point of view of treatment.

& Klotz, U. Eur J Clin Pharmacol (2010) 66: 1. https://doi.org/10.1007/s00228-009-0758-9]. Теломераза рассматривается как уникальный маркер опухолевого роста, а также как перспективная мишень для действия лекарственных препаратов [Kesely KR, Pantaleo A, Turrini FM, Olupot-Olupot P, Low PS (2016) Inhibition of an Erythrocyte Tyrosine Kinase with Imatinib Prevents Plasmodium falciparum Egress and Terminates Parasitemia. PLoS ONE 11(10): e0164895.doi:10.1371/journal.pone.0164895]. В ряде работ отмечается противопротозойная активность ингибиторов теломеразы, в частности иматиниба мезилата [Kesely KR, Pantaleo A, Turrini FM, Olupot-Olupot P, Low PS (2016) Inhibition of an Erythrocyte Tyrosine Kinase with Imatinib Prevents Plasmodium falciparum Egress and Terminates Parasitemia. PLoS ONE 11(10): е0164895. https://doi.org/10.1371/journal.pone.0164895]. Противомалярийный эффект иматиниба мезилата также представлен в заявке на патент США [US 2014309233 (А1) - 2014-10-16]. Индийскими учеными доказан синергетический эффект артесуната при сочетанном применении с иматиниба мезилатом [(IN2085/MUM/2015) A SYNERGISTIC COMBINATION OF ANTIMALARIAL DRUGS]. При этом, данные сведения не были систематизированы и содержащаяся в этих источниках информация не легла в основу схем лечения тропической и трехдневной малярии.In solving this problem, telomerase inhibitors can be used, whose functions include blocking the ability of unlimited cell division of a malignant tumor, which leads to apoptosis [Dong, M,

& Klotz, U. Eur J Clin Pharmacol (2010) 66: 1. https://doi.org/10.1007/s00228-009-0758-9]. Telomerase is considered as a unique marker of tumor growth, as well as a promising target for the action of drugs [Kesely KR, Pantaleo A, Turrini FM, Olupot-Olupot P, Low PS (2016) Inhibition of an Erythrocyte Tyrosine Kinase with Imatinib Prevents Plasmodium falciparum Egress and Terminates Parasitemia. PLoS ONE 11 (10): e0164895.doi: 10.1371 / journal.pone.0164895]. A number of studies have noted the antiprotozoal activity of telomerase inhibitors, in particular imatinib mesylate [Kesely KR, Pantaleo A, Turrini FM, Olupot-Olupot P, Low PS (2016) Inhibition of an Erythrocyte Tyrosine Kinase with Imatinib Prevents Plasmodium falciparum Egress Terminates. PLOS ONE 11 (10): e0164895. https://doi.org/10.1371/journal.pone.0164895]. The antimalarial effect of imatinib mesylate is also presented in the application for US patent [US 2014309233 (A1) - 2014-10-16]. Indian scientists have proven the synergistic effect of artesunate when combined with imatinib mesylate [(IN2085 / MUM / 2015) A SYNERGISTIC COMBINATION OF ANTIMALARIAL DRUGS]. At the same time, this information was not systematized and the information contained in these sources did not form the basis of treatment regimens for tropical and three-day malaria.

It should be noted that, despite the large number of antimalarial drugs, there is no ideal drug, since each individual combination of drugs or monotherapy has its own limitations, starting from their tropism (activity) in relation to certain forms of plasmodium development in the human body, side effects, toxicity and resistance. Overcoming resistance in the coming years will occur not only by creating more and more new drugs, but also by trying to find drugs that cause a “reversal” of resistance. This approach has already been tested on chloroquine-resistant tropical malaria, when antidepressant-verapamil was tested as a “reverse agent”. Thus, the emergence of multidrug resistance can seriously undermine success and increase the burden of disease. According to the WHO Global Technical Strategy, the priorities are to maintain the efficacy of artemisinin-based combination therapy, to develop new drugs and new combinations for countries where malaria is endemic, and for the global malaria community.

According to the foregoing, it becomes important to develop new combinations of antimalarial chemotherapeutic methods for treating malaria. The potentiated effect of the combination of artemisinin preparations and telomerase inhibitors will reduce the side effects of both drugs and enhance the antimalarial effect.

Disclosure of invention

The technical problem to which the invention is directed is the development of an effective combined method for the treatment of malaria, characterized by high therapeutic efficacy with relatively low toxicity and lack of drug resistance to the causative agent of tropical malaria.

The technical result of the invention is to increase the effectiveness of chemotherapy for malaria by overcoming drug resistance and reducing side effects from the drugs used.

The technical result is achieved through the implementation of a method for the treatment of malaria, which includes taking a combination of artemether and imatinib mesylate once a day in dosages of 0.33 mg / kg and 0.25 mg / kg, respectively, for three days.

A screening study of compounds from the group of telomerase inhibitors was carried out, as a result of which the most promising candidate compound, Imatinib mesylate and the artemisinin preparation, artemether, were selected. Tests of the specific antimalarial activity of a combination of artemether and imatinib mesylate were tested, which showed high efficacy with relatively low toxicity. It has been shown that imatinib mesylate is almost equally effective in both oral and injectable forms. Then, a therapeutic combination of artemether and imatinib mesylate was created and tested on laboratory animals, based on the combined use of the injectable form of Artemether and oral (capsule) Imatinib mesylate. The use of this scheme allowed to significantly reduce the toxic effect of the use of these drugs due to the potentiation of the antimalarial effect.

The mechanism of action of drugs based on artemisinin.

The antimalarial activity of artemisinin is due to its ability to interact with the iron molecules of the free heme of the malaria parasite with the formation of free radicals, leading to cell destruction. Most of the artemisinin-related drugs used today are prodrugs that are activated by hydrolysis to the dihydroartemisinin metabolite. Several lines of evidence show that artemisinin medications exert their antimalarial effect by radical formation through their peroxide linkage. At the stage when the parasite is inside the red blood cells, it consumes hemoglobin in its digestive vacuole by the hemoglobin degradation enzyme. These free radical intermediates disrupt the biomembrane and block the vacuole cysteine protease.

Artemether has become the drug of choice from artemisinin derivatives. Artemether is an antimalarial drug from the group of artemisin derivatives, which is the main etiotropic drug in the treatment of severe forms of tropical malaria (in accordance with WHO recommendations). Artemether is active against all plasmodia, including those that may be resistant to other antimalarial drugs. Artemether gives greater treatment effectiveness than quinine, a traditional anti-malarial drug. Clinical trials have shown that Artemether treatment for malaria is 96% compared with 64% for quinine. A noticeable effect of artemether therapy on cancerous tumors has also been discovered. In particular, the drug significantly inhibits the growth of cerebral glioma and pancreatic cancer. Artemether has the following formula:

Gross formula С16Н26О5 м.m. 298.3746. The main pharmacokinetic indices: elimination half-life: 2 hours; plasma protein binding: 95.4%; molar mass: 298.

The mechanism of action of imatinib mesylate

The function of telomerase inhibitors includes blocking the ability of unlimited division of parasite cells, followed by destruction. The specific inhibition of erythrocyte tyrosine kinases, which are critical in the life cycle of the parasite, is a therapeutic target for blocking the spread of the parasite, while avoiding the persistent mechanisms associated with mutagenic events in the parasite genome. Imatinib mesylate (1-Methyl-4- (4 - ((4-Methyl-3 - ((4- (pyridin-3-yl) pyrimidin-2-yl) amino) phenyl) -carbamoyl) benzyl) piperazine methanesulfonate) has following formula:

The minimum effective dose determined by the authors in preclinical studies for the drug imatinib mesylate is 0.5 mg / kg, then it was reduced by 2 times in combination with artemether, which was reduced by three (33 mg / kg).

The proposed method for the treatment of malaria using a combination of drugs derived from artemisinin and imatinib mesylate, eliminates drug resistance and increase the effectiveness of antimalarial therapy. The authors conducted a preclinical study of the selected candidates, as a result of which the most promising candidates were determined - an artemether was selected from the group of artemisinin derivatives, and imatinib mesylate from the telomerase derived inhibitors. Due to the optimally selected treatment regimen, it was possible to halve the dose of imatinib to 0.25 mg / kg, and artemether three times to 33 mg / kg.

Imatinib mesylate showed almost the same efficacy, both with the oral and parenteral routes of administration. Based on the protocol for selecting GLF, the most effective form of oral medication, capsules, was determined.

Taking into account the physicochemical properties of the preparation, two-component solid hydroxypropyl cellulose capsules were selected as the optimal dosage form of imatinib mesylate. This is due to ease of use, economic feasibility and accessibility of this form. This dosage method does not provoke food reactions, and also eliminates unpleasant odors and increases the effectiveness of drugs due to the faster action of the drug.

The dosage form of artemether is ready for use in the form of intramuscular injections.

The studies were carried out in vivo on the model of rodent malaria P. berghei, supported in IMPiTM them. E.I. Marcinovsky on white outbred mice of both sexes. The strain NK65 obtained in 1980 from the Liverpool School of Tropical Medicine was used. The study was conducted on 60 outbred white mice weighing 20 g., Obtained from the laboratory animal nursery "KrolInfo" (Moscow region, Orekhovo-Zuevsky district). Animals were kept in vivarium in individual cages on a standard diet. The light mode was 12 hours of light and 12 hours of darkness. The air temperature was maintained in the range of 18-22 ° C, relative humidity - 50-70%.

All experiments were carried out with the observance of the rules of the European Convention for the Protection of Vertebrate Animals Used for Experimental and other Scientific Purposes (ETS 123), Strasbourg (1986), as well as in accordance with the "Guidelines for conducting preclinical studies of drugs" (Mironov AN [ed.], T. 1, Grif and K, Moscow, 2012).

A vertical comparison was made when parasitemia was assessed daily from the time the drug was administered. The kinetic curves of changes in the content of parasites in the blood during the entire development of the infection were studied. The untreated mice infected with P. berghei served as a negative control.

Animals were divided into 4 groups of 15 mice each: group 1 - animals receiving standard treatment with artemether at a dose of 100 mg / kg for three days, group 2 - animals receiving standard treatment with imatinib mesylate at a dose of 0.5 mg / kg for three days, group 3 - animals that received artemether in the form of injections and imatinib mesylate per os 1 time per day for 3 days according to the claimed method and group 4 - animals infected with malaria without treatment. Animal blood sampling was performed daily to evaluate parasitemia.

Statistical analysis of the data was performed taking into account the comparison of changes in these indicators in dynamics, both within each group (Wilcoxon test) and between groups (Mann-Whitney test). As a result of the analysis of the results, a statistically significant (p = 0.007) decrease in the level of parasitemia was revealed with the use of artemether and imatinib mesylate in the declared dosages, the total course of which was 3 days.

The proposed method provides high treatment efficiency with relatively low toxicity and the absence of drug resistance to the causative agent of tropical malaria. The method is intended for the treatment of transmissible protozoa, primarily malaria, which will reduce the number of deaths from this infection and reduce the economic damage from malaria.

Claims (1)

A method for treating malaria, including taking a combination of artemether and imatinib mesylate once a day in dosages of 0.33 mg / kg and 0.25 mg / kg, respectively, for three days.