EA035792B1 - Medication with prolonged action for treatment of multiple sclerosis (embodiments) - Google Patents

Abstract

The invention relates to oral medication for treating autoimmune diseases, which can be used in psychoneurology for treatment of multiple sclerosis. In accordance with the invention, a medication with prolonged action (retarded) is described based on a composition comprising cladribine and ribavirin in the form of gastro-resistant coated tablet. A method for treating multiple sclerosis using said medication is also described.

Description

The invention relates to pharmacology, in particular to an oral drug for the treatment of autoimmune diseases, which can be used in psychoneurology for the treatment of multiple sclerosis, in particular multiple sclerosis of a recurrent (remitting) or secondary progressive course.

Multiple sclerosis is a chronic progressive (relapsing or progressively relapsing - depending on the type of course) inflammatory-degenerative disease of the central nervous system, which is clinically manifested by disseminated organic neurological symptoms, pathomorphologically - by foci of inflammation and demyelination, followed by the formation of sclerotic plaques and sclerotic plaques in the head or the spinal cord. The main objective in the treatment of multiple sclerosis is to achieve a stable remission. The main principles on which the pharmacotherapy of multiple sclerosis is based is the focus on reducing the frequency of exacerbations, the severity of neurological symptoms, stabilizing the patient's condition, and influencing the pathological process to prevent the occurrence of further possible exacerbations.

For the treatment of multiple sclerosis, glucocorticosteroid hormones are traditionally used, which have an immunosuppressive, anti-inflammatory and anti-edema effect and thereby contribute to the regression of autoimmune-inflammatory changes in the brain and a decrease in the permeability of the blood-encephalic barrier (prednisolone, methylprednisolone, depurocortisolone, hydrocorticoid an analogue of adrenocorticotropic hormone - synacthen depot) [1]. It should be noted that when conducting therapy with glucocorticosteroid hormones, the positive effect of treatment becomes obvious in the shortest possible time, and undesirable effects, in particular suppression of the activity of the hypothalamic-pituitary-adrenal system, weight gain, stomach ulcer, osteoporosis, psychosis, appear somewhat later [ 2].

The anti-inflammatory effect of immunomodulators leads to a significant reduction in the number of exacerbations of multiple sclerosis. However, irreversible neurological deficit is not a consequence of inflammatory, but neurodegenerative processes in the central nervous system. Therefore, the presence of neuroprotective properties in the spectrum of pharmacological activity of the drug proposed for the treatment of multiple sclerosis is a significant advantage.

The closest in technical essence to the claimed invention is an immunosuppressive composition containing cladribine (leicadine®) and ribavirin as active components, which is used in the manufacture of a drug in the form of a lyophilisate. An immunosuppressive effect has been shown for a lyophilized dosage form based on a composition of cladribine and ribavirin, which is realized by inhibiting or partially limiting the process of activating autoreactive T-lymphocytes in a model of a T-cell immune response in a delayed-type hypersensitivity reaction in hybrid mice under the conditions of its intragastric (i / g) application [3].

In comparison with the parenteral route, the enteral route of administration of pharmacological agents is more preferable for a number of reasons and, first of all, in view of the ease with which the patient adheres to the regimen and the reduction in the cost of therapy, including the cost of medical care. In addition, it was found that the side effects observed in patients with chronic progressive multiple sclerosis with oral administration of cladribine are less pronounced than those registered in the conditions of administration of intravenous (iv) infusions of cladribine [4].

A limitation to the use of cladribine, including as part of combined therapy under conditions of per os administration, is its low bioavailability [5], amounting to about 37-51% [6], which is primarily due to the low stability of cladribine in an acidic stomach environment. (Normally, the basal level of pH secretion in the body of the stomach corresponds to 1.5-2.0). Cladribine is stable in alkaline and neutral media in the temperature range of 37-80 ° C; in an acidic environment, it is destroyed even at temperatures within the physiological norm. At 37 ° C and pH 2 after 6 h, 13% of cladribine is determined only in solution, at pH 1 after 2 h - less than 2% of cladribine [7].

The known composition influences the cellular immune response of experimental animals. At the same time, it should be noted that in the pathogenesis of multiple sclerosis, an important role is played not only by cellular, but also by humoral factors of immunity [8]. Therefore, in order to draw a conclusion about the possibility of attributing a biologically active substance or combinations based on it to immunotropic agents effective in multiple sclerosis, it is necessary to assess, first of all, the presence of specific pharmacological activity in conditions of modeling a specific pathological condition at the preclinical stage of the study using optimal test systems, as well as to confirm the reproducibility of the results obtained in the conditions of clinical use.

The objective of the claimed invention is the development of a drug for the treatment of multiple sclerosis, which provides for the oral administration of a combination of cladribine and ribavirin, which provides a pronounced therapeutic efficacy in the treatment of multiple sclerosis while reducing the manifestation of undesirable effects and / or reducing the severity of undesirable effects.

- 1 035792

0.75-1.15

75.0-115.0

62.7-69.3

1.9-2.1

5.13-5.67

8.17-9.03 to 231.0 mg

3-12

0.8-1.8

0.1-0.4

0.9-1.3

0.75-1.15

75.0-115.0

62.7-69.3

1.9-2.1

5.13-5.67

8.17-9.03 to 231.0 mg

10-20.

The technical result of the claimed invention, which can be achieved during its implementation, is the creation of a drug with high neuroprotective activity and effective in the treatment of multiple sclerosis.

In accordance with the invention, there are disclosed variants of a long-acting drug for the treatment of autoimmune diseases, including multiple sclerosis.

The inventive drug of prolonged action for the treatment of multiple sclerosis in the form of an enteric coated tablet has the following composition, mg / tab:

core tablet composition: cladribine ribavirin lactose magnesium monohydrate stearate polyvinylpyrrolidone (povidone) granulated sugar starch corn coating composition:

methacrylic acid and ethyl acrylate copolymer (1: 1) propylene glycol titanium dioxide talc

A variant of the proposed drug with prolonged action for the treatment of multiple sclerosis in the form of an enteric coated tablet has the following composition, mg / tab:

core tablet composition: cladribine ribavirin lactose magnesium monohydrate stearate polyvinylpyrrolidone (povidone) granulated sugar starch corn coating:

Acryl-EZE 93Al 8597 White (Colorcon ®)

Another object of the invention is a method for the treatment of multiple sclerosis, comprising the introduction of the above drug. The drug is taken orally for 7 consecutive days, followed by a break for 28 days (35-day therapeutic cycle) for 4 cycles. The daily dosage of tablets is taken in several doses (2-4 doses) throughout the day.

In a preferred embodiment of the specified method, treatment is carried out in relation to relapsing-remitting and secondary-progressive forms of multiple sclerosis. In case of relapsing and secondary progressive forms of multiple sclerosis, the drug is used in doses of 44.1875 and 88.375 mg of the total content of active substances in a tablet per 1 kg of body weight per cycle, respectively.

The inventive drug, made in the form of enteric tablets and proposed for the treatment of multiple sclerosis, is characterized by high bioavailability and proven neuroprotective activity in the experimental allergic encephalomyelitis (EAE) model, which indicates its corrective effect on the neurological component of multiple sclerosis. The advantage of the claimed combined dosage form lies in the fact that the therapeutic efficacy and toxicological safety of active ingredients significantly changes in the positive direction as compared to the monopreparation.

The absorption of cladribine occurs mainly with the participation of the nucleoside transporter (ENT1) of the small intestine [9], while the absorption of ribavirin is provided by the purine (CNT2) [10] and ENT1 intestinal transporters [9]. Taking these data into account, the use of delivery systems that ensure the delivery of the active components of the described combination directly into the small intestine increases their bioavailability and makes it possible to reduce the administered doses of pharmacologically active substances.

Coating with enteric coatings made it possible to create long-acting (retarded) dosage forms with delayed release of active components. Possessing alkaliphilic properties, the coating ensures the passage of the tablet through the acidic environment of the stomach in an unchanged state, and after its solubilization, the release of active components in the intestine. This approach made it possible to use the active ingredients in lower doses, which, in turn, is associated with a decrease in the manifestation of the toxic effects of the drug.

The inventive drug allows to reduce the frequency of exacerbations and the severity of neurological symptoms, to achieve stabilization of the patient's condition, while it affects the etiological component of the disease, helping to prevent the occurrence of possible exacerbations. The use of special systems for the delivery of active substances of the drug allows to increase their bioavailability under conditions of oral administration.

The most relevant model of multiple sclerosis in laboratory animals is the model of experimental allergic encephalomyelitis (EAE) [11, 12], which makes it possible to study the potential neuroprotective effect of pharmacological substances and drugs. EAE has clinical and pathogenetic manifestations similar to multiple sclerosis. The disease manifests itself in a laboratory animal as paralysis of one of the hind limbs and is accompanied by mixed perivascular infiltration of lymphocytes and macrophages in the brain and spinal cord [11]. Guinea pigs are the most suitable objects for modeling EAE.

Clinical trials of a drug are a necessary stage in the development of any new drug or expansion of indications for the use of an already known drug. The revealed pharmacological effects obtained in experimental models using animals must be confirmed in the framework of controlled clinical trials, which are the most scientifically based way to obtain reliable results. Currently, the preference is given to such a design of clinical trials of drugs, which provides the most reliable data, for example, when conducting prospective controlled comparative randomized and, preferably, double-blind studies.

The therapeutic efficacy of the proposed drug was confirmed in a randomized, double-blind, placebo-controlled, multicenter clinical trial of I-II phases with the participation of 65 patients with a clinically established diagnosis of multiple sclerosis, relapsing (remitting) or secondary progressive course. The inventive drug is a combined drug that provides a combined immunomodulatory and antiviral effect, allows high-quality controlled treatment and reduce the drug load on the patient.

The active substances of the claimed dosage form, named Leukovir®, are cladribine and ribavirin, which determine the pharmacodynamic processes of the drug. It has been established that both active substances act synergistically as antiproliferative agents primarily on hematopoietic cells, including lymphocytes; exhibit an immunosuppressive effect on T-lymphocytes and B-lymphocytes, inhibit the functional activity of activated T cells, inflammatory and autoimmune processes in the body, affect the expression of regulatory and inflammatory cytokines and chemokines. The active substances also have significant pharmacodynamic differences, which, apparently, play an important role in the formation of the mechanisms of the beneficial action of the drug in multiple sclerosis.

The examples below illustrate the claimed invention, but do not limit it.

Example 1. Obtaining a drug in the form of an enteric-coated tablet.

Weigh the calculated amounts of ingredients for the preparation of a mixture for tabletting (cladribine - 10.0 g; ribavirin - 1000.0 g; lactose monohydrate - 660.0 g; magnesium stearate - 20.0 g; povidone 50.4 g; granulated sugar - 80.6 g; corn starch - 379 g), sieved, while sifting, control the granulometric composition. The required amount of alcohol and water is measured and a humidifier solution based on cladribine and povidone is prepared, controlling the completeness of their dissolution. Weighed and sieved components: ribavirin, lactose monohydrate, white sugar and a part of corn starch are placed in a container of a high-speed mixer-granulator, mixed and gradually add a humectant solution while mixing. The wetted mixture is continued to mix to obtain a wet granular mass. The resulting wet granulate is calibrated and dried to a residual moisture content of 1-3%. The dried granulate is placed in a mixer-granulator container, magnesium stearate, the rest of the corn starch are added and powdered.

The mixture for tabletting is loaded into the hopper of the tablet press and tabletted in automatic mode. At the next stage of the technological process, a mixture is prepared for coating the core tablets with a film shell. The required components (methacrylic acid and ethyl acrylate copolymer (1: 1), propylene glycol, titanium dioxide, talc, purified water) are weighed, measured and mixed until a homogeneous suspension is obtained.

The resulting core tablets are placed in a drum of an automatic coating system and a coating process is carried out. Coating is carried out until the difference between the initial and current average weight of a sample of 20 tablets is 10 mg. When the shell mass reaches 10 mg, the process of coating the tablets-cores is stopped and dried. Then the coated tablets are filled and packaged.

Example 2. Obtaining a medicinal product in the form of an enteric coated tablet (option).

A variant of the claimed medicinal product is obtained under the conditions of example 1. As a composition

- 3035792 coatings use a ready-made mixture for coating Acryl-EZE 93A18597 White (Colorcon®), containing methacrylic acid and ethyl acrylate copolymer (1: 1) type A; talc; titanium dioxide; colloidal anhydrous silicon dioxide; sodium bicarbonate; sodium lauryl sulfate.

Example 3. Study of the pharmacokinetics of the proposed medicinal product in the form of enteric tablets using a single-chamber pharmacokinetic model.

Due to the absence of the original dosage form on the pharmaceutical market and the corresponding literature data, the pharmacokinetic parameters of the claimed drug Leukovir® in the form of enteric tablets under enteral administration were compared with those for the combination of active pharmaceutical ingredients (API) cladribine and ribavirin (hereinafter - the combination of API) included in the composition of the drug Leukovir®, and administered parenterally.

Thus, the pharmacokinetics of the oral dosage form Leukovir®, administered orally (intraorally, to the root of the tongue of an experimental animal), is compared with the pharmacokinetics of an API combination, but administered subcutaneously.

Sexually mature male chinchilla rabbits weighing 2.5-3 kg were used in the experiments. Parts of the animals (n = 6) were injected once with the claimed drug at a dose of 150 mg / kg (in terms of the content of active ingredients), the rest (n = 6) - a combination of active ingredients in the same dose. Every 0.25; 0.5; 1; 1.5; 2; 4; 6; 8; 10 h after the introduction of the samples, the content of active substances in the blood plasma was determined using the method of high performance liquid chromatography. Blood was taken from the marginal ear vein of the animal.

The results of studying the pharmacokinetics of cladribine and ribavirin in the composition of the proposed drug Leukovir® and the combination of API are presented in table. 1.

From the presented data, it can be seen that the kinetics of absorption of cladribine when the drug is administered in the form of tablets at a dose of 150 mg / kg orally is characterized by a long half-absorption period (t _{1 / 2a} = 49.5 h), which is undoubtedly due to the very small value of its absorption constant (k _a = 0.014 h ^-1 ). After the use of tablets, C _{max of} leicadine is 6 μg / ml, C ₀ reaches a value of 276.4 μg / ml. Consequently, the pharmacokinetic parameters and the absorption constant of cladribine upon administration of the oral dosage form of Leukovir® characterize a sharp slowdown in the absorption and absorption of the active substance as compared to its absorption when the combination is administered subcutaneously.

The bioavailability of cladribine from the oral dosage form of Leukovir®, calculated from the AUC of the drugs, is 70%. Since the bioavailability of cladribine when administered subcutaneously is higher than when administered intravascularly, and is 100% of the administered dose [13, 14], it is obvious that the bioavailability of cladribine from the oral dosage form Leukovir® is very high.

Table 1

Pharmacokinetic parameters of cladribine and ribavirin in the composition of the claimed medicinal product Leukovir® and an API combination

Indicators Medicinal product "Leykovir®" API combination 1 2 3 cladribine absorption k, = 0.014 h k _a = 1.5 h ' ¹ Uta = 49.5 h t ^ a = 0.46 H Stmach = 6.0 MCG / ML C _max = 19.0 MCG / ML Co - 276.4 μg / ml Co ~ 3.2 μg / ml distribution and accumulation Vo = 0.54 l / kg Vd = 46.7 l / kg V _s3 = 9.93 l / kg V _ss = 7.8 l / kg AUC = 30.7 μg h / ml AUC = 43.9 μgh / ml elimination L = 1.11 h L = 0.63 h t'6e = 0.62 H t _Vx = 1.11 h C1 = 4.89 ml / h C1 = 3.42 ml / h MRT = 2.03 h MRT = 2.3 h bioavailability of cladribine (f) as part of the claimed product "Leukovir®" - 70% 1 2 3 Ribavirin absorption ka ⁼ 0.972 h ' ¹ k _a = 8.99 h 1st = 0.713 h P /, _a = 0.077 h Stmax = 75.5 μg / ml Stmax = 209.8 μg / ml Co = 115.6 μg / ml Co = 172.37 μg / ml

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distribution and accumulation V _d = 1.298 l / kg V _d = 0.870 l / kg V _ss = 1.635 l / kg V _ss = 1.138 l / kg AUC = 504.24 μgh / ml AUC = 1275.13 μgh / ml elimination ke = 0.213 4 ⁴ ke = 0.105 h ' ¹ B / _x = 3.25 h 1ns = 6.6 h C1 = 0.300 ml / h C1 = 0.118 ml / h MRT = 5.45 h MRT = 9.64 h bioavailability of ribavirin (f) in the composition of the claimed drug "Leukovir®" - 40%

Note: k _a - absorption rate constant;

t _{1 / 2a} is the half-absorption period;

Cm _ax - maximum concentration;

C ₀ - apparent initial concentration;

Vd is the apparent volume of distribution;

Vss is the stationary volume of distribution;

AUC is the area under the pharmacokinetic curve;

k _e is the rate constant of elimination;

t _{1 / 2e} is the half-elimination period;

Cl is the total ground clearance;

MRT - average retention time;

F - bioavailability.

The kinetics of absorption of ribavirin with the introduction of Leukovir® tablets has a longer half-absorption period (t _{1 / 2a} = 0.71 h) and almost an order of magnitude lower value of the absorption constant (k _a are 0.972 and 8.99 h ^-1, respectively). In this case, the C _{max of} ribavirin is 75.5 μg / ml, and C ₀ reaches 115.6 μg / ml. Consequently, the absorption and absorption of ribavirin is slowed down compared to the same process after subcutaneous administration of the API combination. The initial effective concentration of ribavirin and C _max after the administration of the oral dosage form of Leukovir® is significantly lower compared to the same values of the reference drug.

Example 4. Neuroprotective effect of the proposed drug in the form of enteric tablets on the EAE model.

Modeling of the pathological state was performed by intradermal inoculation of the encephalitogenic mixture to experimental animals. Sexually mature male guinea pigs weighing 250-350 g were used in the experiments.

An encephalitogenic mixture containing 100 mg of homologous spinal cord tissue homogenate, 0.1 ml of isotonic NaCl solution and 0.15 ml of Freund's complete adjuvant (the content of dry M. tuberculosis killed by heating is 5 mg / ml) was injected once into the pillow of the right hind paw at the rate of 5 μg / individual.

For 7 consecutive days, guinea pigs sensitized with an encephalitogenic mixture of control group 1 (n = 15) were injected intravenously with placebo (untreated animals); main group 2 (n = 15) - the claimed drug at a dose of 70.5 mg / kg, while the 1st administration was carried out simultaneously with the injection of the EAE-inducing mixture (mode 1); experimental group 3 (n = 15) - the claimed drug in the same dose, while the 1st administration was carried out with the manifestation of the first symptoms of EAE (on average 15.2 ± 0.8 days), i.e. after sensitization of guinea pigs (mode 2).

The clinical picture of the development and course of EAE manifested itself gradually, starting with lethargy of animals, impaired coordination of movement to paresis, dysfunction of the pelvic organs, paralysis in some animals and death. The indicators of the development, course and severity of the clinical picture of EAE were changes in the general condition and behavior of animals, the dynamics of their body weight, the presence of dysfunctions of the pelvic organs, the severity of neurological symptoms, the duration of the incubation (latent) period (LP) of manifestation of EAE symptoms.

Clinical and neurological assessment of the severity of EAE development in animals was carried out according to a 6-point system of international criteria (0-5), where 0 is no change; 1 - weak changes; 2 - mild form of EAE; 3 - changes of moderate severity; 4 - severe changes; 5 - severe form of EAE with a fatal outcome, after which the encephalolytic index (EI) was calculated by summing the points.

When determining the level of statistical significance of differences in the variational series, hereinafter, the methods of nonparametric and nonparametric statistics were used. The analysis of qualitative features was carried out using the χ test, as well as Fisher's exact test. The critical level of statistical significance when testing statistical hypotheses was taken equal to 0.05. Data were presented as X ± S _x . Statistical data processing was performed using Statistica 6.0, Biostat 4.03 software.

The clinical picture of EAE in laboratory animals of the control group was characterized by the early appearance of the first symptoms, steady progression of the disease, manifested by an increase in symptoms, which led to the death of the majority (86.7%) of untreated animals (Table 2). At the same time, general lethargy, impaired coordination of movements, paresis and paralysis of the sphincters were noted,

- 5 035792 hind limb paralysis, dysfunction of the pelvic organs (urinary incontinence, feces).

table 2

Neuroprotective activity of the claimed medicinal product (70.5 mg / kg, i.v., subchronic) on the EAE model in guinea pigs

Group, mode of administration, η LP, days Proportion of animals with EAE,% The proportion of animals with a lethal outcome,% Group 1 - active control (n = 15) 15.2 ± 0.8 100 (15/15) 86.7 (13/15) Group 2 - the claimed medicinal product, mode 1 (n = 15) 20.0 ± 1.5 ⁰ 40.0 * (6/15) 20.0 * (3/15) Group 3 - the claimed medicinal product, mode 2 (n = 15) 16.9 + 1.5 93.3 (14/15) 53.3 (8/15)

Note: here and below n is the number of animals in the group;

* - the differences are statistically significant in comparison with the control, χ ² test with subsequent processing of the data by the method of a posteriori comparisons according to Fisher's test p <0.05;

° - the same, Student's t-test.

The use of the proposed drug, starting from the day of induction of EAE (mode 1), contributed to a statistically significant change in the clinical picture in diseased individuals, regression of neurological symptoms. Thus, in individuals of group 2, the LP values of EAE development were significantly higher than those in the control (Table 2). EAE of varying severity was diagnosed only in 40.0% of the animals of group 2, while in the control group, manifestations of pathology, mainly in severe form, were in all individuals (100.0%, Table 2). Starting from the 13th day from the moment of induction of pathology and until the end of the observation period, the values of the severity index of EAE course (EI) in animals that received the claimed drug in regimen 1 were 3.0-6.5 times lower than in the control (Table 3).

In addition, it should be noted that in animals with EAE against the background of the use of the drug, a significantly lower mortality rate (20.0%) was revealed in comparison with that in the control (Table 2).

Table 3

Influence of the claimed medicinal product (70.5 mg / kg, i / f, subchronic) on the severity of clinical manifestations of EAE in guinea pigs

Group, n, administration mode Encephalolytic index (EI) calculated at different periods after EAE induction 13 days 18 days 22 days 27 days 30 days 35 days Group 1 - active control (n - 15) 0.1 1.3 3.0 4.0 4.2 4,3 Group 2 - the claimed medicinal product, mode 1 (n = 15) 0 0.2 0.6 1.3 1.4 1.4 Group 3 - the claimed medicinal product, mode 2 (n = 15) 0.3 0.9 1.3 2,3 2.4 2.5

The introduction of the claimed drug, starting from the day of the first symptoms of EAE (mode 2), did not have a significant effect on the duration of the incubation period of the disease, in addition, the values of the indicator of the proportion of animals with EAE in groups 1 and 3 were comparable (Table 2). At the same time, the use of the proposed medicinal product somewhat softened the course of EAE, as evidenced by the values of EI, which, starting from the 18th day from the moment of induction of pathology and until the end of the observation period, were 1.4-2.3 times lower than in control (table. 3).

Significant differences between the results obtained in the experimental and control groups indicate a pronounced neuroprotective activity of the proposed drug in the simulation of autoimmune encephalomyelitis in laboratory animals.

Thus, in the course of studying the efficacy of a combined drug on an experimental model that reproduces the course of multiple sclerosis, it was shown that the most appropriate is the regimen of drug use before the symptoms of the modeled pathology develop (introduction into the sensitization phase), which corresponds to modern principles of immunopharmacology.

The claimed drug can be effective in the treatment of multiple sclerosis in humans.

Example 5. Therapeutic efficacy of the claimed medicinal product in the form of tablets

- 6,035,792 enteric soluble in a randomized, double-blind, placebo-controlled, multicenter phase I-II clinical trial.

The study involved 65 volunteers - adult patients (aged 18-50 years) of both sexes with a clinically established diagnosis of multiple sclerosis, relapsing (remitting) or secondary progressive course in the mode of inpatient observation and subsequent outpatient visits.

The volunteers were randomized into groups: patients in group 1 (n = 34) received placebo, group 2 (n = 31) - the claimed drug. The course of treatment consisted of 4 cycles at intervals of 28 days. The samples were administered to patients orally (during meals or immediately after meals) daily for 7 consecutive days at course doses of 44.1875 and 88.375 mg (in terms of the content of active ingredients) in relapsing-remitting and secondary progressive forms of multiple sclerosis, respectively. The patients were instructed not to chew the tablet or otherwise violate the integrity of the enteric coating of the tablet.

To assess the efficacy of multiple sclerosis therapy, the incidence of relapses (exacerbations) in patients, the number of active foci of demyelination according to magnetic resonance imaging (MRI) data were recorded.

These measurements were compared before the start of treatment (baseline) and after the end of therapy (56 weeks after the start of treatment). The efficacy analysis included all randomized patients who received at least 1 complete cycle of treatment with the study drug.

Neuroimaging studies were carried out using MRI of the brain, while for contrast enhancement intravenously, a non-ionic paramagnetic contrast agent Omniscan was injected. The drug used for contrast enhancement penetrates the blood-brain barrier (in pathological conditions) and selectively accumulates in active foci, providing a better image of pathology and lesions with pathological vascularization in the brain. In multiple sclerosis, multiple different sizes and shapes of foci are revealed in different parts of the brain and spinal cord [1]. The use of contrast-enhanced MRI makes it possible to objectify the activity of the pathological process, especially when using this method in dynamics in the same patient.

From the start of therapy and in the next 56 weeks, 14 out of 65 patients included in the trial had exacerbations of the underlying disease, defined as the appearance of a significant new clinical sign (symptom) or a significant clinical deterioration of an existing sign (symptom), persisting for at least 24 hours : in 4 out of 31 (12.9%) patients who took the claimed drug, and in 10 out of 34 (29.4%) patients who received placebo. At the same time, against the background of taking the proposed drug, relapses occurred only in patients with a relapsing form of multiple sclerosis (Table 4). In patients with a secondary progressive form of multiple sclerosis, the intake of the proposed drug contributed to a decrease in the frequency of relapses in comparison with the control (trend, p = 0.059).

Table 4

Influence of the claimed medicinal product used for the treatment of multiple sclerosis on the frequency of relapses

Group introduced sample, η Proportion of patients with recurrent multiple sclerosis PP,% VP,% RR and VP,% Group 1 placebo, η = 34 26.7 (4/15) 31.6 (6/19) 29.4 (10/34) Group 2, the claimed medicinal product, n = 31 21.1 (4/19) 0.0 (0/12) 12.9 (4/31)

Note: RR - relapsing-remitting form of multiple sclerosis; VP is a secondary progressive form of multiple sclerosis.

Before the start of therapy in patients of experimental groups 1 and 2, the number of demyelination foci accumulating a contrast agent was comparable (40 and 49, respectively), which indicates the activity of the pathological process in patients of both groups. 56 weeks after the start of placebo use in patients with multiple sclerosis, the number of active foci did not differ significantly from the initial values (Table 5). At the same time, the number of active foci of demyelination in patients with the use of the proposed drug decreased and was registered only in 2 out of 31 patients (Table 5). At the same time, in 1 of the indicated research subjects, both at the beginning and at the end of the study, 1 active focus was detected, and in 2 patient the number of foci accumulating a contrast agent decreased from 9 to 1.

Analysis of neuroimaging parameters according to MRI data of the brain after taking the claimed drug revealed stabilization of the process and the absence of new active foci of demyelination. The data obtained indicate the ability of the proposed drug to restore impaired neurological functions in patients with different forms of development of multiple sclerosis.

Table 5

Dynamics of active foci of demyelination according to MRI data with the introduction of a contrast agent in patients with multiple sclerosis before and after therapy with the claimed drug

Group introduced sample, η The number of "active" foci in the brain before therapy after therapy Group 1 placebo, η = 34 40 41 Group 2, the claimed medicinal product, η = 31 49 2

Thus, the use of the claimed medicinal product in the form of enteric tablets in the relapsing-remitting form of multiple sclerosis at a dose of 44.1875 mg of the total content of active ingredients in a tablet per 1 kg of body weight and in the secondary progressive form of multiple sclerosis at a dose of 88.375 mg of the total content of active ingredients in a tablet per 1 kg of body weight in 7-day cycles with an interval of 28 days for 4 courses allowed to significantly increase the degree of restoration of impaired neurological functions in patients with different severity and development of the disease.

Example 6. Toxic safety of the claimed medicinal product.

An analysis of the comparison of the results on toxic safety during the treatment of patients with multiple sclerosis with the claimed drug in the form of enteric tablets and the registered drug Leikladin® 0.1% for injection showed the following.

In the case of the drug Leikladin® 0.1% for injection (intravenous administration of cladribine at a dose of 0.5 mg / kg of body weight during the course, the total course dose is 2.5 mg / kg), anemia of 1 tbsp. - 20.93%, 2 tbsp. - 2.3%; lymphopenia 1 tbsp. - 20.93%, 2 tbsp. - 11.63%; thrombocytopenia 1 tbsp. 13.95%.

In the case of the claimed medicinal product (enteric tablets for oral administration, total course dose - 3.5 mg / kg), anemia - 0%, lymphopenia - 1 tbsp. - 12.9%, thrombocytopenia - 0%.

This indicates that the inventive oral dosage form exhibits low hematotoxicity compared to injection leachodine.

Moreover, a comparative analysis of data from the work of Giovannoni on the drug cladribine [15] and the claimed drug showed that the proposed innovative drug in the form of enteric tablets containing cladribine and ribovirin is several times less toxic. So, in the case of the drug cladribine (manufacturer, Merck KGaA), with a comparable course dose, lymphopenia of 1 tbsp was noted. - 26.3%; 2 tbsp. - 37.7%; 3 tbsp. - 24.9%; 4 tbsp. - 0.7% and only 10.2% of patients with grade 0. Other changes in the blood count (hemoglobin, neurophils, platelets) with a toxicity degree from 1 to 4 are shown. In addition, treatment with cladribine tablets was associated with an increased risk of developing herpes zoster [16], which indicates a decrease in the body's immune defense.

The inventive drug is enteric-coated tablets and has a distinct pharmacokinetic profile from cladribine in uncoated tablets, which favorably affects the reduction of toxicity.

The model pharmacokinetics of the proposed drug in the form of enteric tablets for oral administration is characterized by a relief deceleration of the absorption of cladribine and a gradual achievement of C _max = 6000 ng / ml without an acute peak, a high degree of accumulation of the active substance in the body (AUC = 30920 nghh / ml) with a bioavailability of 70 tablets %, which indicates a new dosage form of prolonged action. For a relatively short period of time (T _1/2 = 0.62 h), the concentration of cladribine a in the blood plasma decreases by 50%. This period for the claimed medicinal product is almost 2 times shorter than for the API combination without the formation of a tablet mass.

The total clearance of cladribine from the claimed agent increases by 1.4 times, and the average lifetime of an active substance molecule in the body practically does not change (2.03 and 2.3 h).

Pharmacokinetic data indicate the interaction of cladribine and ribavirin in the composition of the proposed drug in the form of tablets at the stages of absorption, distribution and excretion. The interaction does not prevent the creation of an effective concentration in the blood plasma and contributes to a change in the nature of the distribution of active substances in the body and the rate of elimination of substances towards the optimization of processes, which is confirmed by clinical trials.

According to the clinical pharmacokinetics of cladribine tablets [16], after oral administration by the patient, rapid absorption occurs. Cmax in blood plasma is 22-29 ng / ml and is achieved in 0.51.5 hours. AUC = 80-101 ngch / ml.

The relative bioavailability is about 40% [16].

The volume of distribution of cladribine is large. Vd is 482 ± 185 l, and the intracellular concentration of the drug is several hundred times higher than the corresponding concentration in blood plasma.

The half-life of cladribine is about 23 hours.

Renal clearance (23.1 l / h) and extrarenal (22.7 l / h) are equivalent.

The rate of absorption of cladribine in tablets is evidence that the drug is absorbed mainly in the stomach, and liquid secretions of the stomach affect the toxicity of cladribine in the direction of its increase. Cladribine in oral tablets is rapidly absorbed, but slowly excreted from the body, and the excessive accumulated amount of active metabolites in cells contributes not only to an increase in therapeutic efficacy, but also to the development of numerous toxic side effects [16].

A decrease in the toxic effect of the proposed drug by more than 10 times compared to the toxicity of cladribine indicates a significant advantage of the developed dosage form.

The presence of antiviral activity in the claimed drug is of great importance in the treatment of multiple sclerosis due to the undoubted role of viral infections in the onset and development of the disease.

The ability to use a more convenient route of administration compared to intravenous administration is of no small importance.

The inventive drug in the form of enteric tablets can be recommended for use in clinical practice as a drug with neuroprotective properties for the complex therapy of relapsing-remitting and secondary progressive forms of multiple sclerosis.

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8. Voronina, T.A. Guidelines for the study of the immunotropic activity of pharmacological substances / R.M. Khaitov, I.S. Gushchin, B.V. Pinegin, A.I. Zebrov // Guide to experimental (preclinical) study of new pharmacological substances / ed. RU. Khabrieva. - M., 2005. - Part 4. - S. 501-514.

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Claims (5)

CLAIM 1. A drug of prolonged action for the treatment of multiple sclerosis in the form of an enteric coated tablet of the following composition, mg / tab .: core tablet composition: cladribine - 0.75-1.15, ribavirin - 75.0-115.0, lactose monohydrate - 62.7-69.3, magnesium stearate - 1.9-2.1, polyvinylpyrrolidone - 5.13-5, 67, granulated sugar - 8.17-9.03, corn starch up to 231.0 mg, coating composition: methacrylic acid and ethyl acrylate copolymer (1: 1) - 3-12, propylene glycol - 0.8-1.8, titanium dioxide - 0.1-0.4, talc - 0.9-1.3. 2. A drug of prolonged action for the treatment of multiple sclerosis in the form of an enteric coated tablet of the following composition, mg / tab .: core tablet composition: cladribine - 0.75-1.15, ribavirin - 75.0-115.0, lactose monohydrate - 62.7-69.3, magnesium stearate - 1.9-2.1, polyvinylpyrrolidone - 5.13-5, 67, granulated sugar - 8.17-9.03, corn starch up to 231.0 mg, coating: Acryl-EZE 93А18597 White (Colorcon®) - 10-20, - 10 035792 containing methacrylic acid and ethyl acrylate copolymer (1: 1), titanium dioxide, talc, anhydrous colloidal silicon dioxide, sodium bicarbonate, sodium lauryl sulfate. 3. A method of treating multiple sclerosis, characterized in that the patient is administered a drug according to claim 1 or 2. 4. The method according to claim 3, characterized in that a course of treatment is carried out, in which the drug according to claim 1 or 2 is taken orally for 7 consecutive days, followed by a break for 28 days for 4 cycles, while the daily the dosage of tablets is administered in several doses, preferably 2-4 doses, throughout the day. 5. The method according to claim 4, characterized in that the treatment is carried out in relation to relapsing and secondary-progressive forms of multiple sclerosis, while the drug according to claim 1 or 2 is used in a dose of 44.1875 mg / kg of the total content of active substances per course with a relapsing-remitting form of sclerosis and at a dose of 88.375 mg / kg of the total content of active ingredients per course with a secondary-progressive form of sclerosis.