Pharmaceutical composition for treating retinitis pigmentosa

Abstract

This invention includes, e.g., a pharmaceutical composition serving to treat retinitis pigmentosa and containing nanoparticles in which statin is encapsulated.

Description

Pharmaceutical composition for treating retinitis pigmentosa

[0001] This application claims priority to Japanese Patent Application No. 2022-012146, the entire contents of which are incorporated herein by reference. FIELD OF THE DISCLOSURE The present disclosure relates to the treatment of retinitis pigmentosa.

[0002] Retinitis pigmentosa is a disease in which the photoreceptor cells and pigment epithelial cells of the retina degenerate due to a genetic mutation, and typical symptoms include night blindness and narrowing of the visual field due to damage to the photoreceptor cells. The incidence of retinitis pigmentosa is said to be one in 4,000 to 8,000 people, but there is currently no established treatment that can restore retinal function or slow the progression of the disease, and treatment remains symptomatic.

[0003] Statins lower blood cholesterol by inhibiting HMG-CoA reductase and are widely used as therapeutic agents for hypercholesterolemia. Statins are also known to promote angiogenesis. This effect was initially observed only at high doses significantly exceeding clinical doses in animal models. However, it has been reported that pitavastatin-loaded PLGA nanoparticles selectively deliver pitavastatin to vascular endothelial cells in a lower limb ischemia model, inducing angiogenesis at low doses, and that low doses improve the symptoms of pulmonary hypertension in a pulmonary hypertension model. Clinical trials targeting critical limb ischemia and pulmonary hypertension, respectively, have now been conducted. Pitavastatin-loaded PLGA nanoparticles have also been reported to suppress tissue damage in an atherosclerosis model.

[0004] International Application Publication No. 2008 / 026702

[0005] K. Ichimura et al., Int Heart J 59, 1432-1444 (2018).S. Katsuki et al., Circulation 129, 896-906 (2014).

[0006] The present disclosure aims to provide a pharmaceutical composition for treating retinitis pigmentosa.

[0007] The present inventors discovered that inflammatory monocytes in the peripheral blood and peripherally-derived macrophages in the retina increase in retinitis pigmentosa, and that statin-loaded nanoparticles reduce peripheral blood inflammatory monocytes and peripherally-derived retinal macrophages and suppress cone cell death in retinitis pigmentosa model animals, thereby completing the present invention.

[0008] In one aspect, the present disclosure provides a pharmaceutical composition comprising a statin-loaded nanoparticle for treating retinitis pigmentosa.

[0009] The present disclosure provides a pharmaceutical composition comprising a statin-loaded nanoparticle for treating retinitis pigmentosa.

[0010] Figure 1 shows the proportion of inflammatory monocytes (IMo) in wild-type (WT) and rd10 mice (postnatal day 21 (P21): WT n = 7, rd10 n = 7; P31: WT n = 8, rd10 n = 6; P42: WT n = 5, rd10 n = 5). The central horizontal bar indicates the median, the box indicates the 25th to 75th percentile, and the whiskers indicate 1.5 times the interquartile range from the bottom and top of the box. Outliers are indicated by dots. *P < 0.05, **P < 0.01 by Wilcoxon rank-sum test. (Same for the following figures.) Figure 2 shows the proportions of monocyte subsets in retinitis pigmentosa (RP) patients (n = 31) and controls (n = 16). Figure 3 shows the correlation between the proportion of monocyte subsets and the rate of decline in retinal sensitivity (MD slope) in patients with retinitis pigmentosa (RP). Figure 4 shows the proportion of microglia (P21: WT n=8, rd10 n=8; P31: WT n=9, rd10 n=6; P42: WT n=7, rd10 n=9) (left) and the proportion of macrophages (P21: WT n=8, rd10 n=8; P31: WT n=9, rd10 n=6; P42: WT n=7, rd10 n=9) (right) among surviving cells in the retina of WT and rd10 mice. Figure 5 shows the correlation between the proportion of monocyte subsets and the rate of decline in retinal sensitivity (MD slope) in patients with retinitis pigmentosa (RP). Figure 4 shows the proportion of microglia (P21: WT n=8, rd10 n=8; P31: WT n=9, rd10 n=6; P42: WT n=7, rd10 n=9) (right) among surviving cells in the retina of WT and rd10 mice. －／－ The percentage of IMo in the peripheral blood of mice (P21:rd10 n=6, rd10; Ccl2 －／－ n=5; P31:rd10 n=7,rd10;Ccl2 －／－n=7; P42: rd10 n=5, rd10; Ccl2 －／－ n=7). Figure 6 shows the results of rd10 mice and rd10;Ccl2 －／－ The percentage of resident microglia (left) and macrophages (right) among surviving cells in the retina of mice (P21: rd10 n=6, rd10; Ccl2 －／－ n=6;P31:rd10 n=5,rd10;Ccl2 －／－ n=5;P42:rd10 n=5,rd10;Ccl2 －／－ n=5). Figure 7 shows the rd10 (rd10; Ccl2 ＋／＋ ) mice and rd10;Ccl2 －／－ TUNEL staining of the retina of a mouse (P21) (left), and the number of TUNEL-positive cells in the central, mid-peripheral, and peripheral regions of the retina in the nasal and temporal hemispheres (rd10 n=8; rd10; Ccl2 －／－ n=8) (right). Scale bar: 50 μm. Figure 8 shows the rd10 (rd10; Ccl2 ＋／＋ ) mice and rd10;Ccl2 －／－ Hematoxylin and eosin (HE) staining of the retina of a mouse (P26) (left), and the number of photoreceptor cells (rd10 n=20; rd10; Ccl2) in the central, mid-peripheral, and peripheral regions of the retina in the nasal and temporal hemispheres. －／－ n=10) (right). Scale bar: 50 μm. Figure 9 shows the rd10 (rd10; Ccl2 ＋／＋ ) mice and rd10;Ccl2 －／－ Peanut agglutinin (PNA) staining of the mouse (P42) retina (left), and the number of PNA-positive cone cells in the 200 μm and 500 μm regions from the optic nerve head (rd10 n = 21; rd10; Ccl2 －／－ n=15) (right). Scale bar: 50 μm. Figure 10 shows the rd10 (rd10; Ccl2 ＋／＋ ) mice and rd10;Ccl2 －／－Photopic electroretinogram (ERG) (left) of a mouse (P35) and ERG b-wave amplitude (rd10 n=6; rd10; Ccl2 －／－n=8) (right). Figure 11 shows the uptake of FITC into peripheral blood IMo in rd10 mice (P17) that were intravenously administered PBS or FITC-loaded nanoparticles (FITC-NP) (PBS n=4; FITC-NP n=4). The left panel shows representative data, and the right panel shows the quantification results (percentage exceeding the threshold). Figure 12 shows the uptake of FITC in retinal samples from rd10 mice (P17) that were intravenously administered PBS or FITC-NP (PBS n=4; FITC-NP n=4). The left panel shows representative data for microglia and macrophages, and the right panel shows the quantification results (percentage exceeding the threshold). Figure 13 shows the percentage of peripheral blood IMo (PBS n=10; FITC-NP n=11; PVS-NP n=14) (top) and the percentage of macrophages and microglia among surviving cells in the retina (PBS n=14; FITC-NP n=12; PVS-NP n=14) (bottom) of rd10 mice (P31) intravenously administered with PBS, FITC-NP, or pitavastatin-loaded nanoparticles (PVS-NP). Figure 14 shows PNA staining of the retina of rd10 mice (P52) intravenously administered with PBS, FITC-NP, or PVS-NP (left), and the number of PNA-positive cone cells in the regions 200 μm and 500 μm from the optic nerve head (PBS n=9; FITC-NP n=10; PVS-NP n=9) (right). Scale bar: 50 μm. Figure 15 shows photopic ERG (left) and ERG b-wave amplitude (PBS n=6; PVS-NP n=8) (right) of rd10 mice (P35) intravenously administered with PBS or PVS-NP. FIG. 16 shows the photopic ERG b-wave amplitude in rd10 mice (P49) intravenously administered with PBS (100 μl PBS), PVS-NP low (0.1 mg PVS / kg), PVS-NP middle (0.3 mg PVS / kg), or PVS-NP high (1.0 mg PVS / kg) (PBS n=8; PVS-NP low n=10; PVS-NP middle n=20; PVS-NP high n=20).FIG. 17 shows the number of PNA-positive cone cells (PBS n=5; PVS-NP low n=6; PVS-NP middle n=7; PVS-NP high n=8) in rd10 mice (P49) intravenously administered with PBS (100 μl PBS), PVS-NP low (0.1 mg PVS / kg), PVS-NP middle (0.3 mg PVS / kg), or PVS-NP high (1.0 mg PVS / kg). The left panel shows the measurement results at 250 μm from the optic nerve head, and the right panel shows the measurement results at 750 μm from the optic nerve head. FIG. 18 shows the average number of PNA-positive cone cells at the two measurement points in FIG. 17 for each mouse. FIG. 19 shows the number of PNA-positive cone cells (PBS 2 / M n=15; PVS-NP 1 / M n=14; PVS-NP 2 / M n=16) (left) and photopic ERG b-wave amplitude (PBS 2 / M n=24; PVS-NP 1 / M n=14; PVS-NP 2 / M n=16) (right) in rd10 mice (P49) intravenously administered PBS (100 μl PBS) every 2 weeks (PBS 2 / M), PVS-NP (0.75 mg PVS / kg) every 4 weeks (PVS-NP 1 / M), or PVS-NP (0.5 mg PVS / kg) every 2 weeks (PVS-NP 2 / M).

[0011] Unless otherwise specified, terms used herein have the meanings commonly understood by those skilled in the art of organic chemistry, medicine, pharmacology, molecular biology, microbiology, etc. Definitions of some terms used herein are provided below, but these definitions take precedence over common understandings in this specification.

[0012] In one aspect, the present disclosure relates to a pharmaceutical composition comprising a statin-loaded nanoparticle for treating retinitis pigmentosa.

[0013] As used herein, the term "statin" refers to a compound having HMG-CoA (3-hydroxy-3-methylglutaryl-coenzyme A) reductase inhibitory activity. Examples of statins include pitavastatin, atorvastatin, pravastatin, simvastatin, fluvastatin, and rosuvastatin. In one embodiment, the statin is pitavastatin. When referring to statins herein, the term is used to encompass the free form, pharmaceutically acceptable salts thereof, and solvates thereof. Pharmaceutically acceptable salts include alkali metal salts such as sodium salts and potassium salts, alkaline earth metal salts such as calcium salts and magnesium salts, organic amine salts such as phenethylamine salts, and ammonium salts, and solvates include solvates with water or alcohol. For example, a pharmaceutically acceptable salt of pitavastatin includes pitavastatin calcium, and a solvate of pitavastatin or a pharmaceutically acceptable salt thereof includes pitavastatin calcium hydrate (e.g., pentahydrate). The statin-loaded nanoparticles may load one or more statins, or may load other drugs in addition to the statins.

[0014] The statin-encapsulated nanoparticles of the present disclosure contain a statin inside a nanoparticle composed of a biocompatible polymer. The biocompatible polymer can be, for example, a polymer formed by polymerizing one or more monomers selected from D,L-lactide, D-lactide, L-lactide, D,L-lactic acid, D-lactic acid, L-lactic acid, glycolide, glycolic acid, ε-caprolactone, ε-hydroxyhexanoic acid, γ-butyrolactone, γ-hydroxybutyric acid, δ-valerolactone, δ-hydroxyvaleric acid, hydroxybutyric acid, and malic acid. Examples of biocompatible polymers include polylactic acid, polyglycolic acid, lactic acid-glycolic acid copolymer (poly lactide-co-glycolide, also known as PLGA), and lactic acid-aspartic acid copolymer. In one embodiment, the biocompatible polymer is PLGA.

[0015] The term PLGA includes polymers containing lactic acid or lactide and glycolic acid or glycolide in various ratios. The ratio of lactic acid or lactide to glycolic acid or glycolide may be, for example, 1:99 to 99:1, and preferably 3:1. The weight-average molecular weight of PLGA may be, for example, 5,000 to 200,000, or 15,000 to 25,000. PLGA can be synthesized by known methods. Commercially available PLGA may also be used.

[0016] The particle size of the statin-loaded nanoparticles may be, for example, 1 to 1000 nm, 2 to 500 nm, 3 to 300 nm, 10 to 300 nm, or 50 to 300 nm. The particle size may be 100 to 300 nm or 200 to 300 nm. In one embodiment, the particle size is 50 to 300 nm. In this specification, the particle size refers to the spherical equivalent diameter measured by dynamic light scattering, and is the median diameter (D ５０ ) is expressed as the median diameter (D ５０ ) is the particle size (50% diameter) at the 50% point on a cumulative curve where the total volume of the particle group is 100%. The cumulative curve and D50 can be determined using a particle size distribution analyzer such as Nanotrac Wave-EX150 (manufactured by MictotracBEL Corp.).

[0017] The surface of the statin-loaded nanoparticles may be modified with polyethylene glycol (PEG). For example, by using a PEG-modified biocompatible polymer to produce nanoparticles, nanoparticles with PEG-modified surfaces can be obtained. Modifying the particle surface with PEG can improve the stability of the nanoparticles in the blood.

[0018] Statin-loaded nanoparticles may be produced by any production method. Statin-loaded nanoparticles can be produced, for example, by an emulsion-in-water method. In the emulsion-in-water method, two types of solvents are used: a good solvent in which a biocompatible polymer dissolves, and a poor solvent in which the biocompatible polymer does not dissolve. Those skilled in the art can select the good solvent and the poor solvent appropriately depending on the nanoparticles to be produced.

[0019] The poor solvent may be water. When water is used as the poor solvent, a surfactant may be added to the water. Examples of the surfactant include polyvinyl alcohol (PVA), lecithin, hydroxymethyl cellulose, and hydroxypropyl cellulose. In one embodiment, the poor solvent is water and the surfactant is PVA.

[0020] Examples of the good solvent include halogenated alkanes, which are organic solvents with low boiling points and poor water solubility, acetone, methanol, ethanol, ethyl acetate, diethyl ether, cyclohexane, benzene, toluene, and mixtures thereof. In one embodiment, the good solvent is acetone or a mixture of acetone and ethanol in a ratio of 2:1.

[0021] In the water emulsion method, a biocompatible polymer is first dissolved in a good solvent, and then a drug solution is added and mixed. When the good solvent containing the polymer and drug is dropped into a poor solvent under stirring, the good solvent rapidly diffuses into the poor solvent. As a result, the good solvent emulsifies in the poor solvent, forming emulsion droplets of the good solvent. Next, due to interdiffusion between the good solvent and the poor solvent, the organic solvent continuously diffuses from the emulsion into the poor solvent, reducing the solubility of the biocompatible polymer and drug in the emulsion droplets and resulting in the formation of spherical crystalline nanoparticles containing the drug. The organic solvent, which is the good solvent, is then centrifuged or evaporated under reduced pressure. The resulting nanoparticles can be used as is or after being powdered by a process such as freeze-drying.

[0022] Statin-loaded nanoparticles may be produced using a forced thin film microreactor. When using a forced thin film microreactor, a good solvent containing a polymer and a drug and a poor solvent are first introduced between two processing surfaces, one of which is arranged facing each other and rotates relative to the other. The good solvent and poor solvent are mixed in the resulting thin film fluid, causing drug-encapsulated nanoparticles to precipitate in the thin film fluid. An example of a forced thin film microreactor that can be used is the ULREA SS-11 (M Technique Co. Ltd.).

[0023] The statin-loaded nanoparticles may contain, for example, 0.01 to 99% by weight, 0.1 to 30% by weight, 0.5 to 20% by weight, or 1 to 15% by weight of statin. In one embodiment, the statin-loaded nanoparticles contain 1 to 15% by weight of statin. Herein, the statin content is expressed as the ratio of the weight of statin to the weight of the statin-loaded nanoparticles. The statin content can be determined by measuring the weight of statin extracted from a predetermined weight of statin-loaded nanoparticles and calculating the ratio of the weight of statin to the weight of the statin-loaded nanoparticles.

[0024] Statin-encapsulated nanoparticles can be complexed into redispersible aggregated particles (nanocomposites) when powdered by a process such as freeze-drying. For example, nanoparticles can be complexed into redispersible aggregated particles by drying them with an organic or inorganic substance. This complexation allows the nanoparticles to aggregate and become easily handled aggregated particles, which disperse upon contact with water during use and exhibit their properties. In one embodiment, the statin-encapsulated nanoparticles are complexed with a sugar alcohol or sucrose. The use of a substance such as a sugar alcohol can reduce variability in the encapsulation rate and also serve as an excipient, improving the handleability of the nanoparticles. Examples of sugar alcohols include mannitol, trehalose, sorbitol, erythritol, maltose, and xylitose. In one embodiment, the sugar alcohol is trehalose. Complexation can also be achieved by fluidized bed drying granulation instead of freeze-drying.

[0025] In the Examples herein, it was shown that inflammatory monocytes in the peripheral blood and peripherally derived macrophages in the retina are increased in retinitis pigmentosa, and that statin-loaded nanoparticles reduced peripheral inflammatory monocytes and peripherally derived retinal macrophages and inhibited cone cell death in a retinitis pigmentosa model animal. Therefore, statin-loaded nanoparticles can be used to treat retinitis pigmentosa.

[0026] Retinitis pigmentosa is a disease in which photoreceptors and / or pigment epithelial cells in the retina degenerate due to a genetic mutation. Retinitis pigmentosa includes pathological conditions in which rod cells, cone cells, and / or pigment epithelial cells, or two or more types of cells selected from these cells, degenerate. In retinitis pigmentosa, rod cell degeneration often precedes and cone cell degeneration gradually occurs. A condition in which only rod cells degenerate is called rod dystrophy, and a condition in which both rod cells and cone cells degenerate is called rod-cone dystrophy, both of which are included in the retinitis pigmentosa of the present disclosure. Retinitis pigmentosa may be caused by any genetic mutation, and the causative genetic mutation may be one or more.

[0027] As used herein, treatment of retinitis pigmentosa includes improving one or more symptoms or findings of retinitis pigmentosa, inhibiting or slowing the progression of the disease, and inhibiting or slowing the progression of the disease. Symptoms of retinitis pigmentosa include night blindness, narrowed visual field, decreased visual acuity, photophobia, hemeropia, color vision abnormalities, and photopsia. Findings of retinitis pigmentosa include (1) fundus findings (narrowed retinal vessels, coarse retinal color, spicule-like pigmentation, multiple white spots, optic nerve atrophy, macular degeneration), (2) abnormalities in electroretinograms (attenuated, negative, and disappearing types), (3) hyperfluorescence or hypofluorescence due to retinal pigment epithelial atrophy in fundus autofluorescence findings, and (4) abnormalities (discontinuous or disappearance) of the ellipsoid zone (IS / OS) in the fovea in optical coherence tomography.

[0028] The statin-loaded nanoparticles can be included in a pharmaceutical composition. The pharmaceutical composition may contain, for example, 0.000001 to 99.9% by weight, 0.00001 to 99.8% by weight, 0.0001 to 99.7% by weight, 0.001 to 99.6% by weight, 0.01 to 99.5% by weight, 0.1 to 99% by weight, 1 to 50% by weight, 1 to 40% by weight, 1 to 30% by weight, 1 to 20% by weight, or 1 to 15% by weight of the statin-loaded nanoparticles. The pharmaceutical composition may further contain pharmaceutically acceptable additives as needed. Examples of pharmaceutically acceptable additives include excipients, lubricants, binders, disintegrants, solubilizers, suspending agents, isotonicity agents, buffers, soothing agents, preservatives, antioxidants, coloring agents, and sweeteners.

[0029] The pharmaceutical composition may be in the form of, for example, a tablet, capsule, powder, granule, liquid, suspension, emulsion, inhalant, injection, eye drop, eye ointment, etc. Injection includes solution injection, suspension injection, emulsion injection, and injection prepared before use. In one embodiment, the pharmaceutical composition is an injection. These preparations can be prepared by conventional methods.

[0030] Statin-encapsulated nanoparticles or pharmaceutical compositions containing the same are administered to a subject in an amount capable of exerting the desired effect (referred to herein as an effective amount). The dosage and administration period can be appropriately determined by those skilled in the art depending on the subject's age, weight, health condition, and other conditions. Statin-encapsulated nanoparticles or pharmaceutical compositions containing the same can be administered, for example, in the following dosages per day: 0.001 mg / kg to 100 mg / kg, 0.003 mg / kg to 10 mg / kg, 0.005 mg / kg to 5 mg / kg, 0.01 mg / kg to 3 mg / kg, 0.01 mg / kg to 1 mg / kg, 0.01 mg / kg to 0.75 mg / kg, 0.01 mg / kg to 0.5 mg / kg, 0.01 mg / kg to 1 ... mg / kg~0.3mg, 0.01mg / kg~0.25mg, 0.01mg / kg~0.1mg, 0.01mg / kg~0.09mg, 0.01mg / kg~0.08mg, 0.01mg / kg~ 0.07mg, 0.01mg / kg ~ 0.06mg, 0.01mg / kg ~ 0.05mg, 0.01mg / kg ~ 0.04mg, 0.01mg / kg ~ 0.03mg, 0.03mg / kg ~ 1mg / k g, 0.03mg / kg to 0.75mg / kg, 0.03mg / kg to 0.5mg / kg, 0.03mg / kg to 0.3mg, 0.03mg / kg to 0.25mg, 0.03mg / kg to 0.1mg , 0.03mg / kg ~ 0.09mg, 0.03mg / kg ~ 0.08mg, 0.03mg / kg ~ 0.07mg, 0.03mg / kg ~ 0.06mg, 0.03mg / kg ~ 0.05mg, 0.1m The statin-loaded nanoparticles or pharmaceutical compositions comprising the same may be administered in a single dose or in multiple doses (e.g., 2, 3, or 4 times daily) of 0.01 mg / kg to 0.3 mg / kg or 0.03 mg / kg to 0.1 mg / kg of statin (e.g., pitavastatin calcium) per day.The statin-loaded nanoparticles or pharmaceutical compositions containing the same may be administered to an adult in an amount of 1 to 10 mg / body (e.g., 1, 2, 4, 8, or 10 mg / body) or 1 to 8 mg / body (e.g., 1, 2, 4, or 8 mg / body) of statin (e.g., pitavastatin calcium) per day. Administration may be a single dose or multiple doses. In the case of multiple doses, administration may be daily, once every few days (e.g., 2, 3, 4, 5, or 6 days), once every week or weeks (e.g., 2, 3, 4, 5, or 6 weeks), or once every month or several months (e.g., 2, 3, 4, 5, or 6 months). In one embodiment, administration is twice a week (e.g., once every 3 or 4 days) or once every 1 to 4 weeks (e.g., once every 1, 2, 3, or 4 weeks). The administration period can be, for example, one or several days (e.g., 2, 3, 4, 5, or 6 days), one or several weeks (e.g., 2, 3, 4, 5, or 6 weeks), one or several months (e.g., 2, 3, 4, 5, or 6 months), or longer. Administration can be systemic or local, and can be oral or parenteral (e.g., intravenous, intramuscular, intrabronchial, intranasal, or intraocular). In one embodiment, the statin-loaded nanoparticles or pharmaceutical compositions comprising the same are administered intravenously.

[0031] In the present disclosure, the subject is a mammal (e.g., human, mouse, rat, hamster, rabbit, cat, dog, cow, sheep, monkey, etc.), preferably a human. In one embodiment, the subject is a human subject suffering from retinitis pigmentosa (also referred to as a retinitis pigmentosa patient).

[0032] In one aspect, the present disclosure provides a method for treating retinitis pigmentosa, the method comprising administering an effective amount of a statin-loaded nanoparticle to a subject in need of treatment. In one aspect, the present disclosure provides a statin-loaded nanoparticle for treating retinitis pigmentosa. In one aspect, the present disclosure provides a use of a statin-loaded nanoparticle for the manufacture of a medicament for treating retinitis pigmentosa. In one aspect, the present disclosure provides a use of a statin-loaded nanoparticle for treating retinitis pigmentosa.

[0033] Exemplary embodiments of the present disclosure are described below. [1] A pharmaceutical composition comprising statin-encapsulated nanoparticles for treating retinitis pigmentosa. [2] The pharmaceutical composition according to claim 1, wherein the statin is pitavastatin or a pharmaceutically acceptable salt thereof. [3] The pharmaceutical composition according to claim 1 or 2, wherein the statin is pitavastatin calcium. [4] The pharmaceutical composition according to any one of claims 1 to 3, wherein the statin-encapsulated nanoparticles comprise 1 to 15% by weight of the statin. [5] The pharmaceutical composition according to any one of claims 1 to 4, wherein the statin-encapsulated nanoparticles comprise PLGA. [6] The pharmaceutical composition according to any one of claims 1 to 5, wherein the particle size of the statin-encapsulated nanoparticles is 50 to 300 nm. [7] The pharmaceutical composition according to any one of claims 1 to 6, wherein the statin-encapsulated nanoparticles comprise 1 to 15% by weight. [8] The pharmaceutical composition according to any one of claims 1 to 7, wherein the amount of the statin is 0.01 mg / kg to 0.5 mg / kg per day. [9] The pharmaceutical composition according to any one of 1 to 8, which is administered intravenously.

[10] The pharmaceutical composition according to any one of 1 to 9, which is administered twice a week or once every 1 to 4 weeks.

[0034]

[11] A method for treating retinitis pigmentosa, comprising administering an effective amount of statin-loaded nanoparticles to a subject in need of treatment.

[12] Use of statin-loaded nanoparticles for the manufacture of a medicament for treating retinitis pigmentosa.

[13] Use of statin-loaded nanoparticles for treating retinitis pigmentosa.

[0035] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples in any sense.

[0036] 1. Materials and Methods Animals WT (C57BL / 6J) mice, B6.CXB1-Pde6β ｒｄ１０ / J(rd10) mice, and B6.129S4-Ccl2 ｔｍ１Ｒｏｌ / J(Ccl2 －／－ ) Mice were purchased from Jackson Laboratory (West Grove, PA). Rd10 mice were transfected with Ccl2 －／－ Crossed with mice and rd10;Ccl2－／－ was produced.

[0037] Patients and Control Subjects: Because blood monocytes can be affected by systemic diseases such as cardiovascular disease, hypertension, and diabetes, subjects were selected to be generally healthy and relatively young, aged <45 years. Patients with retinitis pigmentosa (RP) were diagnosed based on a history of night blindness, characteristic fundus findings (e.g., bone spicule-like pigmentation in the mid-peripheral and peripheral retina), visual field constriction and / or ring scotoma, and reduced or absent a- and b-wave amplitudes on electroretinograms. Patients with cone dystrophy, cone-rod dystrophy, Bietti crystalline retinopathy, uveitis, or systemic diseases were excluded. Participants were consecutively recruited in 2017 and 2018, and blood samples were collected from 31 RP patients and 16 age- and sex-matched healthy subjects. RP patients were followed for at least one year and underwent at least three HFA10-2 tests to obtain mean deviation (MD) slopes. The analysis used the subject's visual acuity at the time of blood collection, the HFA10-2 test results closest to blood collection, and the MD slope. The test results for the right eye of each subject were used for the analysis.

[0038] Clinical Examination: Subjects' best-corrected visual acuity (BCVA) was measured using a 5-m Landolt decimal VA chart (CV-6000; Tomey, Nagoya, Japan) or a single-letter Landolt test card (HP-1258; Handaya, Tokyo). Values ​​were converted to the logarithm of the minimum separation threshold angle (logMAR). Refractive error was corrected at each visit using multiple lenses of different diopters to ensure best-corrected visual acuity. Visual acuity was based on the smallest Landolt C letter that the subject was able to correctly answer 60% or more times (3 / 5). Automated static perimetry was performed using a Humphrey Field Analyzer (HFA; Humphrey Instruments, San Leandro, CA) using the central 10-2 Swedish Interactive Thresholding Algorithm Standard Program. Lenses were calibrated according to the test distance. If the test was not reliable enough (i.e., fixation failure >20%, false positives >15%, or false negatives >33%), the visual field test was repeated.

[0039] Flow cytometry Immunolabeled cells were analyzed on a BD FACSVerse system (BD Biosciences, Franklin Lakes, NJ) using FlowJo software. Samples were prepared and analyzed as follows.

[0040] Mouse blood monocytes: Peripheral blood was collected from mice by cardiac puncture, and red blood cells were lysed with VersaLyse Lysing solution (Becton Dickinson Biosciences, San Jose, CA) for 10 minutes at room temperature. Cells were washed twice with ice-cold FACS buffer (phosphate-buffered saline (PBS) containing 2% fetal bovine serum (FBS)). Fc receptors were blocked with anti-mouse CD16 / CD32 (eBioscience) for 5 min at 4°C, followed by incubation on ice for 20 min with antibodies against mouse CD192 (CCR2) (Alexa Fluor 647-conjugated, clone SA203G11; Biolegend, San Diego, CA), CD11b (BV421-conjugated, clone M1 / 70; Biolegend), Ly-6C (Alexa Fluor 488-conjugated, clone HK1.4; Biolegend), Ly-6G (allophycocyanin [APC]-cy7-conjugated, clone 1A8; Biolegend), and CX3CR1 (phycoerythrin [PE]-conjugated, clone SA011F11; Biolegend). Dead cells were excluded using the fluorescent marker 7-AAD (BD Pharmingen, San Diego, CA). Inflammatory monocytes are CD11b ＋ Ly-6C ｈｉ Ly-6G ｌｏ－ｎｅｇ were identified as cells.

[0041] Mouse microglia and macrophages. Mouse retinas were collected from excised eyes, minced, and digested in a water bath at 37°C for 30 minutes (1.2 mg / ml collagenase D [Roche Diagnostics, Indianapolis, IN] and 40 μg / ml DNase I [Sigma-Aldrich, St. Louis, MO]). After digestion, the tissue was dissociated by pipetting to obtain a single-cell suspension. The cells were washed twice with ice-cold FACS buffer (PBS containing 2% FBS). Fc receptors were blocked with anti-mouse CD16 / CD32 (eBioscience) for 10 min at 4°C, followed by incubation on ice for 20 min with antibodies against mouse CD11c (PE-Cy7-conjugated, clone N418; Biolegend), CD45 (APC-conjugated, clone 30-F11; Biolegend), Ly-6C (APC-cy7-conjugated, clone HK1.4; Biolegend), Ly-6G (APC-cy7-conjugated, clone 1A8; Biolegend), CD11b (PE-conjugated, clone M1 / 70; Biolegend), CD192 (CCR2) (FITC-conjugated, clone SA203G11; Biolegend), and CX3CR1 (BV421-conjugated, clone SA011F11; Biolegend). Dead cells were excluded using 7-AAD (BD Pharmingen). Microglia expressed CD11b ｈｉ CD11c ｍｉｄ CD45 ｍｉｄ Ly-6G ｌｏ Ly-6C ｌｏ Macrophages are defined as CD11b ｈｉ CD11c ｈｉ CD45 ｈｉ Ly-6G ｌｏ Ly-6C ｌｏ In each experiment, wild-type retinas were used as controls for gating microglia and macrophages.

[0042] Human blood monocytes. Whole blood (8 ml) was collected from the antecubital vein of each subject using BD Vacutainer CPT cell preparation tubes containing sodium heparin (BD Biosciences). The resulting samples were immediately (within 30 minutes) subjected to density gradient separation of mononuclear cells. The isolated mononuclear cells were then pelleted by low-speed centrifugation (200 g) and aliquoted into 5 ml tubes in PBS containing 2% FBS. Samples were stored in a freezer at -80°C until analysis and thawed 30 minutes prior to analysis. For immunolabeling, cells were washed twice with ice-cold FACS buffer (PBS containing 2% FBS). Fc receptors were blocked with anti-mouse CD16 / CD32 (eBioscience) for 5 min at 4°C, followed by incubation on ice for 20 min with antibodies against the following: human CD56 (NCAM) (PerCP / Cy5.5-conjugated, clone HCD56; Biolegend), CD19 (PerCP / Cy5.5-conjugated, clone HIB19; Biolegend), HLA-DR (APC-conjugated, clone L243; Biolegend), CD14 (PE-conjugated, clone M5E2; Biolegend), CD16 (BV421-conjugated, clone 3G8; Biolegend), CD192 (CCR2) (FITC-conjugated, clone K036C2; Biolegend), and CX3CR1 (PEcy7-conjugated, clone 2A9-1; Biolegend). Dead cells were excluded using 7-AAD (BD Pharmingen). Monocytes were identified as HLA-DR ＋ CD2 － CD19 － CD56 － These cells were classified into three subsets according to the expression levels of CD14 and CD16.

[0043] Retinal whole-mount staining. Mouse eyes were enucleated and fixed in 4% paraformaldehyde for 1 hour at 4°C. After removing the cornea and lens, the retina was separated from the posterior eye cup. Each retina was blocked for 1 hour with PBS containing 10% skim milk and 0.3% Triton-X 100 (9002-93-1; Wako) and then incubated overnight at 4°C with fluorescein isothiocyanate (FITC)-conjugated peanut agglutinin (PNA) (1:100, L7381; Sigma-Aldrich). Fluorescent images were captured using a fluorescence microscope (BZ-X700; Keyence, Osaka, Japan). The number of PNA-positive cone cells was counted using Image J ver. 1.52a software (US National Institutes of Health [NIH]) in the superior, inferior, temporal, and nasal 0.015625 mm images located at 200 μm, 250 μm, 500 μm, or 750 μm from the optic nerve head. ２ The counts were performed in retinal areas of 100 mm and the values ​​for each area were averaged. The observers were blinded to the names and conditions of the samples and the analysis was performed.

[0044] Histological examination: Mouse eyes were enucleated, fixed in 4% paraformaldehyde (in PBS) for 24 hours, and mounted in paraffin. Sections (5 μm thick) were prepared along the horizontal meridian and stained with hematoxylin and eosin (H&E). Five sections were randomly selected from each eye. Cell counts in the outer nuclear layer (ONL) were measured in 100 μm sections of the central (200 μm from the optic nerve head), mid-peripheral (500 μm from the optic nerve head), and peripheral (1000 μm from the optic nerve head) regions of the nasal and temporal hemispheres of the retina. ２ The tissue samples were assigned numbers and letters, and the analysis was performed blinded to the observer.

[0045] TUNEL staining. TUNEL staining was performed using the ApopTag Fluorescein In Situ Apoptosis Detection Kit (Merck Millipore, Darmstadt, Germany) according to the manufacturer's instructions. Immunofluorescence images were acquired using a fluorescence microscope (BZ-X700; Keyence). Immunofluorescence images were obtained from 10,000 μm sections of the central (200 μm from the optic nerve), mid-peripheral (500 μm from the optic nerve), and peripheral (1,000 μm from the optic nerve) regions of the nasal and temporal hemispheres. ２ The number of TUNEL-positive cells in each square area was obtained using Image J software, ver. 1.52 a. The ONL area of ​​each square area was measured, and the density of TUNEL-positive cells in the ONL was calculated and expressed as cells / mm ２ The analysis was performed blindly without the observers being informed of the names and conditions of the samples.

[0046] Electroretinogram (ERG) Photopic ERG was recorded through an LED contact lens using the PuREC system (PC-100; Mayo Corporation, Aichi, Japan). Mice were anesthetized with an intraperitoneal injection of ketamine (100 mg / kg) and xylazine (10 mg / kg), and body temperature was maintained at 37°C with a heating pad. Pupils were dilated with 0.5% tropicamide and 0.5% phenylephrine hydrochloride. After topical application of oxbuprocaine, an LED contact lens was attached to the cornea of ​​the mouse. A reference electrode was placed on the tongue, and a ground electrode was clipped to the tail. Mice were monitored at 30 cd / m ２ The animals were then adapted for 10 minutes to a white light background with an intensity of 3.0 cd·s / m ２ Sixteen photopic flashes were taken and averaged.

[0047] Preparation of PLGA Nanoparticles. Nanoparticles (NPs) were prepared using PLGA polymer (Wako Pure Chemical Industries, Osaka, Japan) with an average molecular weight of 20,000 and a lactide / glycolide ratio of 75:25. FITC (D Dojindo Laboratories, Kumamoto, Japan) or pitavastatin calcium (Wako, Osaka, Japan) (hereafter simply referred to as pitavastatin (PVS)) was incorporated into the PLGA nanoparticles. Nanoparticles were fabricated using an ULREA SS-11 (M Technique Co. Ltd., Osaka, Japan). For FITC-NPs, a tank containing liquid A (aqueous solution containing 2.0% polyvinyl alcohol (PVA)) was pressurized to 0.3 MPa and moved at a set temperature of 43°C (measured temperature: approximately 40°C) at a rate of 120 ml / min. Next, Liquid B (a solution containing PLGA, FITC, acetone, and ethanol in a weight ratio of 4.04:0.20:63.84:31.92) was transferred at 100 mL / min at a setpoint of 41°C (measured at approximately 30°C). Liquids A and B were reacted on a rotating disk rotating at 1000 rpm with a back pressure of 0.02 MPa. The solvent in the resulting mixture was removed by distillation using an evaporator. The resulting suspension was then purified to remove excess PVA and unencapsulated reagents and lyophilized to powder. For PVS-NP, a tank containing Liquid A (aqueous solution containing 0.17% PVA) was pressurized to 0.3 MPa and transferred at a rate of 156 mL / min at a setpoint of 25°C (measured at approximately 24°C). Next, liquid B (a solution containing PLGA, PVS, acetone, and ethanol in a weight ratio of 0.7:0.15:66.10:33.05) was transferred at 100 ml / min at a set temperature of 25°C (measured value: approximately 24°C). Liquids A and B were reacted on a rotating disk rotating at 400 rpm with a back pressure of 0.02 MPa. The solvent in the resulting mixture was removed by distillation using an evaporator, and the resulting mixture was powdered by freeze-drying. FITC-NP and PVS-NP contained 6.8 ± 0.4% (w / v) FITC and 2.79 ± 0.05% (w / v) PVS, respectively.The particle diameters were measured using Nanotrac Wave-EX150 (MicrotracBEL Corp.) The particle diameters were 252 nm for FITC-NP and 202 nm for PVS-NP.

[0048] In vivo biodistribution of nanoparticles. 17-day-old (P17) rd10 mice were intravenously injected with a single dose of FITC-NP (0.5 mg FITC-NP / 100 μl PBS). Two hours later, blood samples were collected and analyzed for FITC uptake into IMo by flow cytometry. 24 hours after intravenous injection of FITC-NP, retinas were collected and analyzed for FITC uptake into macrophages and microglia. Blood cells were labeled with mouse Ly-6C (APC-cy7-conjugated, clone HK1.4; Biolegend) and Ly-6G (PerCP / Cy5.5-conjugated, clone 1A8; Biolegend) and the following antibodies: CD192 (CCR2) (Alexa Fluor 647-conjugated, clone SA203G11; Biolegend), CD11b (BV421-conjugated, clone M1 / 70; Biolegend), and CX3CR1 (PE-conjugated, clone SA011F11; Biolegend). FITC expression was detected for CD11b. ＋ Ly-6C ｈｉ Ly-6G ｌｏ－ｎｅｇThe uptake of FITC-NPs was evaluated in IMo. CD192 (CCR2) (FITC-conjugated, clone SA203G11; Biolegend) was not used to evaluate the cellular uptake of FITC-NPs. Retinal cells were stained with the following antibodies: CD11c (PE-Cy7-conjugated, clone N418; Biolegend), CD45 (APC-conjugated, clone 30-F11; Biolegend), Ly-6C (APC-cy7-conjugated, clone HK1.4; Biolegend), Ly-6G (APC-cy7-conjugated, clone 1A8; Biolegend), CD11b (PE-conjugated, clone M1 / 70; Biolegend), and CX3CR1 (BV421-conjugated, clone SA011F11; Biolegend). FITC fluorescence in microglia and macrophages was then measured.

[0049] rd10 mice were divided into three groups on P21: PBS group (100 μl PBS), FITC-NP group (0.5 mg FITC-NP / 100 μl PBS), and PVS-NP group (0.0065 mg PVS / 0.5 mg PVS-NP / 100 μl PBS; equivalent to 0.325 mg PVS / kg body weight). PBS, FITC-NP, or PVS-NP was administered intravenously via the tail vein twice a week (once every 3 or 4 days) from P21 until the end of each experiment.

[0050] Dose-finding study To determine the optimal dose of PVS-NP, rd10 mice were divided into four groups at P21 for a dose-finding study: PBS group (100 μl PBS), PVS-NP low group (0.1 mg PVS / kg), PVS-NP middle group (0.3 mg PVS / kg), and PVS-NP high group (1.0 mg PVS / kg). PVS-NP was administered intravenously via the tail vein once a week from P21 until the end of each experiment. Photopic ERG and the number of PNA-positive cone cells were analyzed at P49.

[0051] To determine the optimal administration method of PVS-NP, rd10 mice were divided into three groups at P21 for a dose-finding study: a group receiving PBS (100 μl PBS) every two weeks, a group receiving PVS-NP (0.75 mg PVS / kg) every four weeks, and a group receiving PVS-NP (0.5 mg PVS / kg) every two weeks. From P21 until the end of each experiment, the drug was administered intravenously via the tail vein at the respective administration intervals. At P49, photopic ERG and the number of PNA-positive cone cells were analyzed.

[0052] Statistical Analysis: The correlation coefficient between the MD slope in the HFA10-2 test and the proportions of monocyte subsets in RP patients was analyzed using Spearman's rank correlation test. Comparison of data between pairs of groups was performed using the Wilcoxon rank sum test. A p value of 0.05 or less was considered significant. Statistical analysis of the data was performed using JMP1 Pro 13.0.0 software (SAS, Cary, NC).

[0053] 2. Results Increased inflammatory monocytes in the peripheral blood of rd10 mice and RP patients To investigate whether RP is associated with an increased number of circulating monocytes, we analyzed the number of inflammatory monocytes (IMo) in the blood of rd10 mice, a clinically relevant model of RP with Pde6b mutation. In rd10 mice, rod cell death begins around P18, and most rods are lost by P30. This is followed by gradual cone degeneration. Peripheral blood from wild-type (WT) and rd10 mice was analyzed by flow cytometry at P21, P31, and P42. Compared to WT mice, CD11b levels were significantly higher in rd10 mice. ＋ Ly-6C ｈｉ Ly-6G ｌｏ The number of IMo was significantly increased at P21 (p<0.01), P31 (p<0.01), and P42 (p<0.05) (Fig. 1). These cells also highly expressed CCR2 and CX3CR1 (data not shown).

[0054] Next, we evaluated the changes in monocytes in RP patients. Peripheral blood samples from the subjects were analyzed by flow cytometry, and monocytes were identified as CD14 ＋ CD16 ＋＋ non-classical, CD14 ＋＋CD16 ＋ intermediate, and CD14 ＋＋ CD16 － As a result, there was no significant difference in the percentage of total monocytes between RP patients and controls, but subset analysis showed that CD14 ＋＋ CD16 ＋ A significant increase in the proportion of intermediate monocyte subsets was observed (p=0.0098, Figure 2), and these cells also highly expressed CCR2 and CX3CR1 (data not shown). ＋＋ CD16 ＋ A higher proportion of the intermediate monocyte subset was associated with a greater MD slope (rho = -0.4933, p = 0.0042) (Fig. 3). These results suggest that RP is associated with increased peripheral blood IMo in both humans and animal models.

[0055] Changes in retinal microglia and macrophages in rd10 mice To examine the recruitment of IMo to the retina of rd10 mice, flow cytometry analysis of retinal myeloid cells was performed. Retinal microglia and macrophages can be distinguished using the surface markers CD45 and CD11c, and retinal cells were stained for CD11b, CD11c, CD45, Ly6C, Ly6G, CCR2, and CX3CR1. Retinas from WT mice contained CD11b. ｈｉ CD11c ｍｉｄ CD45 ｍｉｄ Ly-6G ｌｏ Ly-6C ｌｏ Microglia were present, but CD11b ｈｉ CD11c ｈｉ CD45 ｈｉ Ly-6G ｌｏ Ly-6C ｌｏ Macrophages were absent, whereas increases in these cell populations were observed in the retinas of rd10 mice at P21, P31, and P42 (p<0.01, Figure 4).

[0056] Involvement of the CCL2 / CCR2 axis in cone cell death in rd10 mice. To investigate the role of IMo and peripherally derived macrophages, we cultured Ccl2-deficient rd10 mice (rd10; Ccl2 －／－ Ccl2 deficiency resulted in decreased peripheral blood IMo at P21, P31, and P42 (p<0.05, p<0.01, and p<0.01, respectively; Figure 5). －／－ In mouse retinas, macrophages were significantly reduced at P21 and P31 (both p<0.05) and slightly reduced at P42 (p=0.06), whereas the proportion of resident microglia was significantly reduced at rd10;Ccl2 －／－ Mouse and rd10;Ccl2 ＋／＋ There was no significant difference between the RD10 mice and the RD10 mice (Figure 6). These data indicate that the CCL2 / CCR2 axis is important for IMo / macrophage recruitment in RD10 mice.

[0057] Next, we evaluated the effect of Ccl2 deficiency on rod and cone degeneration in rd10 mice. TUNEL staining at P21, when rod cell death peaked, revealed that rd10;Ccl2 －／－ Mouse and rd10;Ccl2 ＋／＋ There was no significant difference in the number of TUNEL-positive cells in the external nuclear layer (ONL) between rd10 and rd10 mice (Fig. 7). Consistent with this, HE staining at P26 showed no significant difference in ONL thickness in the presence or absence of Ccl2 (Fig. 8), suggesting that Ccl2 deficiency may not affect rod degeneration in rd10 mice. In contrast, cone cell density assessed by PNA labeling was significantly higher in rd10 and rd10 mice than in Ccl2 mice at P52. ＋／＋ rd10;Ccl2 compared to mice －／－ The cone function was also analyzed by photopic ERG. The photopic ERG b wave was significantly higher in rd10;Ccl2 mice (Fig. 9). ＋／＋ rd10;Ccl2 compared to mice －／－The CCL2 / CCR2 axis promotes the recruitment and engraftment of peripherally derived macrophages into the retina, which contributes to cone degeneration in rd10 mice (Figure 10).

[0058] Drug delivery to peripheral blood IMo and retinal macrophages Drug delivery to peripheral blood IMo and migrated macrophages using PLGA nanoparticles was investigated. FITC-loaded nanoparticles were injected into the tail vein of P17 rd10 mice, and Ly-6C was detected 2 hours after injection. ｈｉ The specificity of drug delivery was evaluated by analyzing the delivery of FITC to IMo. FITC-NPs efficiently introduced FITC into a large number of IMo (p<0.05, Figure 11). The drug delivery efficiency to retinal microglia and macrophages was analyzed 24 hours after intravenous injection of nanoparticles. FITC-NP administration resulted in FITC introduction into 3.1±1.7% of macrophages. In contrast, FITC was not detected in microglia even after administration of FITC-NPs (Figure 12). These results indicate that nanoparticles are a promising drug delivery system that targets IMo and peripherally derived macrophages, but not microglia.

[0059] Using this drug delivery system, the efficacy of pitavastatin-loaded nanoparticles (PVS-NP) was evaluated in rd10 mice. rd10 mice were intravenously administered PBS, FITC-NP, or PVS-NP twice weekly starting on P21. At P31, blood IMo and retinal macrophages were significantly reduced in the PVS-NP group compared with the PBS group (Figure 13). No significant differences were observed in the proportion of microglia among the three treatment groups (Figure 13). Cone density at P52 was significantly maintained in the PVS-NP group compared with the PBS and FITC-NP groups (Figure 14). Furthermore, photopic ERG waves at P35 were significantly maintained in the PVS-NP group compared with the PBS group (Figure 15).

[0060] To determine the optimal dose of PVS-NP, a dose-finding study was conducted on rd10 mice at P21, divided into four groups: PBS group (100 μl PBS), PVS-NP low group (0.1 mg PVS / kg), PVS-NP middle group (0.3 mg PVS / kg), and PVS-NP high group (1.0 mg PVS / kg). PVS-NP was intravenously administered via the tail vein once a week from P21 until the end of each experiment. Photopic ERG and the number of PNA-positive cone cells were analyzed at P49. Photopic ERG b-waves were significantly higher in the PVS-NP middle and PVS-NP high groups compared to the PBS group (p<0.05) (FIG. 16). Similarly, for the number of PNA-positive cone cells, cone degeneration was significantly suppressed in the PVS-NP middle group and the PVS-NP high group compared to the PBS group (p<0.01) (FIGS. 17 and 18).

[0061] To determine the optimal administration method for PVS-NP, a dosage-finding study was conducted by dividing the subjects into three groups based on the concentration calculated from the PVS-NP middle group (0.3 mg PVS / kg): a PBS (100 μl PBS) group administered every two weeks, a PVS-NP (0.75 mg PVS / kg) group administered every four weeks, and a PVS-NP (0.5 mg PVS / kg) group administered every two weeks. PVS-NP was administered intravenously via the tail vein at each administration interval from P21 to the end of each experiment. Photopic ERG and the number of PNA-positive cone cells were analyzed at P49. The photopic ERG b-wave was significantly higher in the PVS-NP (0.75 mg PVS / kg) group administered every four weeks compared to the PBS group (p<0.01) (Figure 19). Regarding the number of PNA-positive cone cells, cone degeneration was significantly suppressed in the PVS-NP (0.75 mg PVS / kg) every 4 weeks administration group and the PVS-NP (0.5 mg PVS / kg) every 2 weeks administration group compared to the PBS group (p<0.05) (FIG. 20).

[0062] These results indicate that statin-loaded nanoparticles are a promising treatment option for retinitis pigmentosa.

Claims

1. A pharmaceutical composition for treating retinitis pigmentosa, comprising statin-encapsulated nanoparticles.

2. The pharmaceutical composition according to claim 1, wherein the statin-encapsulated nanoparticles contain 1 to 15% by weight of statin.

3. The pharmaceutical composition according to claim 1, wherein the statin-encapsulated nanoparticles contain PLGA.

4. The pharmaceutical composition according to claim 1, wherein the particle size of the statin-encapsulated nanoparticles is 50 to 300 nm.

5. The pharmaceutical composition according to claim 1, comprising 1 to 15% by weight of statin-encapsulated nanoparticles.

6. The pharmaceutical composition according to claim 1, wherein the amount of statin is administered at 0.01 mg / kg to 0.5 mg / kg per day.

7. The pharmaceutical composition according to claim 1, which is administered intravenously.

8. The pharmaceutical composition according to any one of claims 1 to 7, wherein the statin is pitavastatin or a pharmaceutically acceptable salt thereof.

9. The pharmaceutical composition according to claim 8, wherein the statin is calcium pitavastatin.