HK40085372B - Method for treating vaso occlusive crises associated with sickle cell disease - Google Patents

Abstract

The present invention relates to a treatment of vaso-occlusive crisis (VOC) associated with Sickle cell disease by administering a therapeutically effective amount of 4-(nitrooxy)butyl-(2S)-2-(6-methoxy-2-naphthyl) propanoate.

Description

Methods for treating vascular occlusive crisis associated with sickle cell disease

Invention Field

This invention relates to 4-(nitrooxy)butyl-(2S)-2-(6-methoxy-2-naphthyl) propionate for the treatment of vascular occlusion crisis (VOC) in sickle cell disease.

Background of the Invention

4-(nitrooxy)butyl-(2S)-2-(6-methoxy-2-naphthyl) propionate is a nitric oxide (NO)-releasing derivative of naproxen and is also known as naproxen.

4-(nitrooxy)butyl-(2S)-2-(6-methoxy-2-naphthyl)propionate

WO 98/09831 and US 6,700,011 disclose the synthesis of 4-(nitrooxy)butyl-(2S)-2-(6-methoxy-2-naphthyl)propionate.

Schnitzer T.J. et al., Osteoarthritis and Cartilage 18 (2010) 629-639, disclosed that naproxen is a NO-releasing derivative of naproxen that combines analgesic and anti-inflammatory effects with a blood pressure effect similar to, but different from, that of placebo. In a study of osteoarthritis (OA) in the knee of human patients, naproxen demonstrated clinical efficacy and safety in controlling the signs and symptoms of OA.

White W.B. et al. (Am J Cardiol 2011; 107:1338-1345) published a large-scale analysis of the effects of naproxen on blood pressure in 2,734 patients with hip or knee osteoarthritis across three pivotal trials. The analysis indicated that naproxen can alleviate some of the hypertension burden induced by most NSAIDs.

Sickle cell disease (SCD) is a group of hemoglobinopathies caused by mutations in the sixth amino acid of the β-globulin subunit of hemoglobin. The most common mutation, βS-globulin, results in the substitution of a hydrophilic glutamate residue for a hydrophobic valine residue, leading to the production of hemoglobin S, which is prone to polymerization upon deoxygenation (Belanger AM, Keggi C, Kanias T et al., Effects of nitric oxide and its congeners on sickle red blood cell deformability. Transfusion, 2015(55)2464-2472).

Under hypoxic conditions, the polymerization of HbS causes red blood cells to twist into a distinctive sickle shape and increases their hardness and brittleness, leading to hemolysis. Hemolysis, in turn, contributes to oxidative stress and platelet activation (Helms CC, Marvel M, Zhao W, Stahle M, Vest R, Kato GJ et al. Mechanisms of hemolysis-associated platelet activation. Journal of Thrombosis and Haemostasis. 2013; 11(12):2148-2154; Villagra J, Shiva S, Hunter LA, Machado RF, Gladwin MI, Kato GJ. Platelet activation in patients with sickle disease, hemolysis-associated pulmonary hypertension, and nitric oxide scavenging by cell-free hemoglobin. Blood 2007; 110(6):2166-2172). Oxidative stress, physical interactions between sickle cells and endothelium, and other factors lead to an inflammatory state in which endothelial cells and leukocytes are activated, resulting in leukocyte and multicellular adhesion to the endothelium, thereby generating VOCs. Ischemia, organ damage, pain, and potential death are all secondary to VOCs (Parise LV, Telen MJ. Erythrocyte adhesion in sickle cell disease. Current Hematology Reports. 2003; 2(2):102-108., 2003; Hoppe CC. Inflammatory mediators of endothelial injury in sickle cell disease. Hematol Oncol Clin. North Am. 2014; 28(2):265-86; Kutlar A, Embury SH. Cellular adhesion and the endothelium: P-Selectin. Hematol Oncol Clin. North Am. 2014; 28(2):265-86; Kutlar A, Embury SH. Cellular adhesion and the endothelium: P-Selectin. Hematol Oncol Clin. North Am. 2014; 28(2):265-86.). Clin.NorthAm.2014;28(2):323-339; Zhang DC, Xu CL, Manwani D, Frenette PS. Neutrophils, platelets, and inflammatory pathways at the nexus of sickle cell diseasepathophysiology.Bl ood.2016;127(7):801-839;Kim-Shapiro DB,Gladwin MT.Nitricoxide pathology and therapeutics in sickle cell disease.Clinical Hemorheologyand Microcirculation,2018;68:223-237).

Vascular occlusive crisis and its associated pain are common reasons for emergency department visits and hospitalizations in patients with sickle cell disease. Vascular occlusive crisis and its associated pain most commonly occur in the extremities, chest, and back, and are considered nociceptive, secondary to tissue damage. The typical clinical features of a pain crisis are described as a sudden onset of pain in the lower back or one or more joints or extremities. The pain may be localized or migratory, and is persistent and throbbing. Severe pain causes patients to groan, moan, cry, twist and turn, and adopt abnormal postures in unsuccessful attempts to obtain relief. Severe attacks require treatment with non-intestinal opioids in a medical center after failure to control pain with oral anesthetics and/or non-prescription NSAIDs other than those approved by the drug label. (Ballas SK, Gupta K, Adams-Graves P. Sickle cell pain: a critical reappraisal Blood, 2012; 120(18):3647-3656).

Vascular occlusion-related pain crises evolve through four phases: the prodromal phase, the initial phase, the establishment phase, and the resolution phase. Each acute pain attack is associated with inflammation, which worsens with repeated attacks, often ultimately leading to serious complications and organ damage, such as acute chest syndrome and multiple organ failure. The prodromal phase, lasting 1-2 days before a severe pain attack, is characterized by a gradual or sudden increase in pain (initial phase), peaking after 3 days, leading to the establishment phase, which continues until day 6 or 7, after which the pain begins to subside (resolution phase). The prodromal phase of the crisis is characterized by three main pathophysiological events: vascular occlusion, inflammation, and nociception. Therefore, controlling vascular occlusion-related crises during the prodromal phase, when tissue ischemia and inflammation are in their early stages, can potentially prevent or minimize pain and tissue damage. (Ballas SK, Gupta K, Adams-Graves P. Sickle cell pain: a critical reappraisal Blood, 2012; 120(18):3647-3656).

Currently, the main treatments for controlling vascular occlusive crisis include treating acute pain attacks and reducing the occurrence of vascular occlusive crisis.

Three drugs have been approved by the FDA for the treatment of vascular occlusive crisis complications in sickle cell disease: hydroxyurea, L-glutamine, and lizalizumab-tmca. All products have been shown to reduce the frequency of vascular occlusive crises, but these drugs have not shown relief from VOC-related pain.

The recently approved Adakveo product lists an 18% incidence of joint pain and a 15% incidence of back pain associated with its product in its approved packaging instructions, indicating a persistent need for pain relief. (Novartis, 2019)

Unfortunately, while hydroxyurea (Droxia) reduces the incidence of vascular occlusion (VOC), it does not eliminate it. Patients need to maintain pain relief when painful vascular occlusion crises occur. Furthermore, the Droxia package insert contains a boxed warning regarding bone marrow suppression and malignant tumors.

Currently, the FDA has not approved any products for the treatment of pain secondary to vascular occlusive crisis in patients with sickle cell disease, although many analgesics are commonly used off-label. Guidance recommends the use of NSAIDs for mild to moderate pain, but well-controlled clinical trials have not shown any effect of NSAIDs on pain secondary to vascular occlusive crisis.

With the advancement of VOCs, more than 90% of adult patients require hospitalization and pain management, including non-intestinal opioid therapy consisting of meperidine, morphine, or hydromorphone. (Ballas SK. Pain management of sickle cell disease. Hematol Oncol Clin North Am. 2005; 19(5):785-802).

Although opioid therapy is a mainstay of pain management, it remains a suboptimal approach due to its side effects, such as sedation, dizziness, nausea, vomiting, constipation, physical dependence, tolerance, and respiratory depression. Serious adverse reactions can occur with high doses or prolonged use, including opioid tolerance (leading to increased opioid dosage), immunosuppression, hormonal changes, hyperalgesia, and an increased risk of acute chest syndrome and altered opioid clearance in sickle cell patients. (Ballas SK. Current issues in sickle cell pain and its management. Hematology Am Soc Hematol Educ Program. 2007; 97-105).

Nitric oxide (NO) is a well-known free radical signaling molecule that plays a wide range of roles in biological functions, including relaxing blood vessels, increasing blood flow, reducing platelet activation, reducing the adhesion of circulating blood cells to the endothelium, and reducing thrombus formation. In response to a variety of stimuli, vascular endothelial cells produce nitric oxide, which activates guanylate cyclase, leading to elevated levels of intracellular cyclic GMP (cGMP). Extensive research has shown that nitric oxide levels are depleted in sickle cell disease and further depleted during VOC processes (Goncalves R.P., Rev Bras Hematol Hemoter 2012; 34(4):254-64).

Treatment strategies that supplement or modulate nitric oxide (NO) have been presented as potential treatments for sickle cell disease and/or symptoms.

For example, preliminary trials have shown some positive effects of inhaled NO on acute VOCs. However, currently available results do not provide sufficient evidence to determine the effectiveness of inhaled nitric oxide in treating painful (vascular occlusion) crises in patients with sickle cell disease. Furthermore, inhaled NO requires specific handling and administration.

Another publicly disclosed strategy for increasing NO production in sickle cell disease patients is supplementation with nitric oxide precursors. Summar M.L. et al. (US 2018/0289647) disclosed a method for treating sickle cell disease and its complications, including vascular occlusive crisis, involving the administration of citrulline, a precursor of arginine and endogenously produced nitric oxide (NO). US 2018/0289647 reported a study demonstrating the safety and pharmacokinetic properties of intravenous citrulline in patients with sickle cell disease. However, the clinical efficacy of citrulline requires further evaluation in clinical studies.

Therefore, an effective and safe treatment for vascular occlusive crisis in patients with sickle cell disease is a serious unmet need.

The applicant recently conducted preclinical studies and found that 4-(nitrooxy)butyl-(2S)-2-(6-methoxy-2-naphthyl) can increase cyclic guanosine monophosphate (cGMP) levels in a sickle cell animal model. Therefore, 4-(nitrooxy)butyl-(2S)-2-(6-methoxy-2-naphthyl) may play a role in reducing nitric oxide consumption in sickle cell patients, thereby improving vascular homeostasis. Furthermore, the anti-inflammatory and analgesic activities of 4-(nitrooxy)butyl-(2S)-2-(6-methoxy-2-naphthyl) can reduce inflammatory cascade reactions and pain associated with vascular occlusive crisis.

Invention Overview

It has been found that 4-(nitrooxy)butyl-(2S)-2-(6-methoxy-2-naphthyl) propionate can beneficially interfere with the pathogenesis of pain symptoms and complications associated with vascular occlusion crisis (VOC) in sickle cell anemia and alleviate pain symptoms and complications associated with VOC.

One embodiment of the present invention relates to a method for treating vascular occlusive crisis in patients with sickle cell disease, the method comprising administering a therapeutically effective amount of 4-(nitrooxy)butyl-(2S)-2-(6-methoxy-2-naphthyl) propionate to the patient in need.

Another embodiment of the invention relates to a method for treating vascular occlusive crisis in patients with sickle cell disease, the method comprising administering a therapeutically effective amount of 4-(nitrooxy)butyl-(2S)-2-(6-methoxy-2-naphthyl) propionate to a patient in need, wherein the administration of 4-(nitrooxy)butyl-(2S)-2-(6-methoxy-2-naphthyl) propionate is initiated at the onset of early prodromal signs and symptoms of vascular occlusive crisis and continues at least until the crisis is treated.

The method of the present invention has several advantages: 4-(nitrooxy)butyl-(2S)-2-(6-methoxy-2-naphthyl) propionate can be administered to the patient at home (self-administration) once the patient senses an impending crisis (prodromal phase); administration of 4-(nitrooxy)butyl-(2S)-2-(6-methoxy-2-naphthyl) propionate in the early stages of a vascular occlusion crisis can help promote and accelerate crisis resolution by reducing the cascade of events such as vascular occlusion, inflammation, and pain (as associated with a vascular occlusion crisis).

Minimizing vascular occlusion and inflammation can reduce organ and tissue damage in sickle cell patients by reducing (1) the amount of damage to organs and tissues caused by ischemia due to blockage of blood flow through capillaries, (2) the amount of damage caused by oxidative free radicals in organs and tissues where blood flow has been restored after a period of ischemia, and (3) the amount of inflammatory mediators released from damaged cells.

Reducing the intensity of pain associated with vascular occlusion crisis can alleviate or eliminate the need for opioids to manage acute pain crises associated with ischemic crises in sickle cell patients, and thus reduce hospitalizations.

Because 4-(nitrooxy)butyl-(2S)-2-(6-methoxy-2-naphthyl) propionate is well tolerated, this compound can be administered in combination with other medical treatments commonly used to treat SCD in a manner that does not interfere with such other treatments.

Another embodiment of the invention relates to a method for reducing the severity or duration of vascular occlusive events in individuals with sickle cell disease, the method comprising administering a therapeutically effective amount of 4-(nitrooxy)butyl-(2S)-2-(6-methoxy-2-naphthyl) propionate.

Another embodiment of the present invention is a method for mitigating organ and tissue damage caused by vascular occlusion events, the method comprising administering an effective amount of 4-(nitrooxy)butyl-(2S)-2-(6-methoxy-2-naphthyl) propionate to an individual suffering from sickle cell disease.

One embodiment of the present invention provides a method for treating pain in patients with sickle cell anemia during recurrent ischemic crisis by administering a therapeutically effective amount of 4-(nitrooxy)butyl-(2S)-2-(6-methoxy-2-naphthyl) ester propionate.

Another embodiment of the present invention is a method for treating pain secondary to sickle cell disease vascular occlusion crisis (VOC) in patients with sickle cell anemia, by combining the administration of a therapeutically effective amount of 4-(nitrooxy)butyl-(2S)-2-(6-methoxy-2-naphthyl) ester propionate with opioid therapy used during such pain crisis.

In one embodiment, the invention includes the method of the invention, wherein the pharmaceutical composition contains a therapeutically effective amount of 4-(nitrooxy)butyl-(2S)-2-(6-methoxy-2-naphthyl) ester of propionate, the pharmaceutical composition further comprising one or more pharmaceutically acceptable carriers. In one embodiment, the pharmaceutical composition is suitable for oral, nasal, topical, oral, sublingual, rectal, vaginal, or enteral administration.

The present invention also relates to 4-(nitrooxy)butyl-(2S)-2-(6-methoxy-2-naphthyl) propionate or pharmaceutical compositions comprising 4-(nitrooxy)butyl-(2S)-2-(6-methoxy-2-naphthyl) propionate and one or more pharmaceutically acceptable carriers for use in any of the treatment methods reported above.

The present invention also relates to the use of 4-(nitrooxy)butyl-(2S)-2-(6-methoxy-2-naphthyl) propionate in the preparation of a medicament for any of the treatment methods reported above.

Brief description of the attached diagram

Figure 1: A schematic diagram showing the plasma nitrite concentration (concentration-time) after intravenous administration of naproxen or 4-(nitrooxy)butyl-(2S)-2-(6-methoxy-2-naphthyl) propionate (naproxinol) in homozygous sickle cell transgenic mice. Naproxinol increases plasma nitrite concentration. N = 4–7; *p < 0.01

Figure 2: A schematic diagram showing the cGMP concentration (concentration-time) after intravenous administration of naproxen or 4-(nitrooxy)butyl-(2S)-2-(6-methoxy-2-naphthyl) propionate (naproxinol) in homozygous sickle cell transgenic mice. Naproxinol increases platelet cGMP production. N = 4–7; *p < 0.01

Invention Details

A method for treating acute pain crisis in patients with sickle cell anemia is provided. The method involves administering a therapeutically effective amount of 4-(nitrooxy)butyl-(2S)-2-(6-methoxy-2-naphthyl) propionate (naprocinol).

The following description provides specific details to provide a thorough understanding of the invention. However, those skilled in the art will understand that the invention may be practiced without these specific details. For the purposes of this specification, the following definitions will apply, and terms used in the singular will, where appropriate, also include the plural, and vice versa.

As defined herein, “treatment” refers to any reduction in the severity or duration of a vascular occlusive event, leading to the termination of the crisis, or any relief of pain associated with sickle cell anemia. Relief of pain may include a reduction in frequency, duration, or intensity. Pain intensity can be measured using standard methods such as analgesia meters, trocars, or 10-point pain scales.

As defined in this article, "prodromal signs and symptoms of vascular occlusive crisis" include: fatigue, dizziness, weakness, yellowing or pallor of the eyes, gastrointestinal symptoms such as nausea, vomiting and changes in appetite, musculoskeletal symptoms such as swelling, tenderness or stiffness of the hands/feet, and respiratory symptoms such as runny nose, cough and changes in breathing.

As used herein, the term "therapeutic effective amount" of a compound is the amount necessary or sufficient to treat or prevent diseases, disorders, and/or conditions as described herein. Effective amounts can vary depending on factors such as individual size and weight, the type of disease, or the specific compound of the invention. One skilled in the art will be able to investigate the factors included herein and determine the effective amount of the compounds of the invention without excessive experimentation.

The actual dose level of the active ingredient in the pharmaceutical composition of the present invention may vary to obtain an amount of active ingredient that effectively achieves the desired therapeutic response for a particular patient, composition and administration method, without being toxic to the patient.

The chosen dose level will depend on a variety of factors, including the activity of the specific compound of the invention used, the route of administration, the time of administration, the excretion rate of the specific compound used, the duration of treatment, other drugs, compounds and/or materials used in combination with the specific compound used, the age, sex, weight, condition, general health status and medical history of the patient to be treated, and similar factors well known in the medical field.

Clinicians with ordinary skills in the art can easily determine and prescribe the effective amount of the desired pharmaceutical composition. For example, clinicians can start with a dose of the compound of the invention used in the pharmaceutical composition below the level required to achieve the desired therapeutic effect, and gradually increase the dose until the desired effect is achieved.

Typically, the appropriate daily dose of the compounds of this invention will be the amount of the lowest dose of the compound that effectively produces a therapeutic effect. Such an effective dose usually depends on the factors mentioned above.

If desired, the effective daily dose of the active compound can be administered as two, three, four, five, six or more sub-dose at appropriate intervals throughout the day, optionally in unit dosage form.

Although the compounds of the present invention can be administered alone, it is preferred to administer the compounds as a pharmaceutical composition.

For use in this treatment, 4-(nitrooxy)butyl-(2S)-2-(6-methoxy-2-naphthyl) propionate is administered orally; the adult dose range is 100 mg/day to 3000 mg/day or 100 mg/day to 2000 mg/day, preferably 375 mg/day to 1500 mg/day, and most preferably 750 mg/day to 1500 mg/day; the pediatric dose (over 2 years old and under 16 years old) ranges from 15 to 22.5 mg/kg/day.

The exact dosage and schedule of administration will vary depending on the amount needed to provide relief in each specific case.

For use in this treatment, it is preferable to administer 4-(nitrooxy)butyl-(2S)-2-(6-methoxy-2-naphthyl) propionate to the patient starting from the onset of early prodromal signs and symptoms of vascular occlusion crisis, until the crisis is controlled. This treatment can also be used as maintenance therapy after the vascular occlusion crisis has been controlled.

The administration regimen can affect the composition of the effective dose. Several separate doses can be administered daily or sequentially, as well as alternating doses, or the dose can be administered continuously by infusion or by bolus injection. Furthermore, the dosage of the compounds of this invention can be increased or decreased proportionally depending on the urgency of the treatment or preventative situation.

As used herein, the term "pharmaceutical composition" includes formulations suitable for administration to mammals such as humans. When the compounds of the present invention are administered as pharmaceuticals to mammals such as humans, they may be given on their own or as pharmaceutical compositions comprising, for example, 0.1-99.5% (more preferably 0.5-90%) of an active ingredient in combination with a pharmaceutically acceptable carrier.

As used herein, the term "pharmaceutically acceptable carrier" is recognized in the art and includes pharmaceutically acceptable materials, compositions, or media suitable for administering the compounds of the present invention to mammals. Carriers include liquid or solid fillers, diluents, excipients, solvents, or encapsulating materials relating to carrying or transporting the subject active agent from one organ or part of the body to another organ or part of the body. Each carrier must be "acceptable" in the sense of compatibility with other components of the formulation and harmlessness to the patient. Some examples of materials that can be used as pharmaceutically acceptable carriers include: sugars, such as lactose, glucose, and sucrose; starches, such as corn starch and potato starch; cellulose and its derivatives, such as sodium carboxymethyl cellulose, ethyl cellulose, and cellulose acetate; powdered tragacanth gum; malt; gelatin; talc; excipients, such as cocoa butter and suppository waxes; oils, such as peanut oil, cottonseed oil, safflower oil, sesame oil, olive oil, corn oil, and soybean oil; glycols, such as propylene glycol; polyols, such as glycerol, sorbitol, mannitol, and polyethylene glycol; esters, such as ethyl oleate and ethyl laurate; agar; buffers, such as magnesium hydroxide and aluminum hydroxide; alginic acid; pyrogen-free water; isotonic saline; Ringer's solution; ethanol; phosphate buffer solutions; and other non-toxic and compatible substances used in pharmaceutical preparations.

Wetting agents, emulsifiers and lubricants, such as sodium dodecyl sulfate and magnesium stearate, as well as colorants, releasing agents, coating agents, sweeteners, flavoring agents and aromas, preservatives and antioxidants may also be present in the composition.

Examples of pharmaceutically acceptable antioxidants include: water-soluble antioxidants such as ascorbic acid, cysteine hydrochloride, sodium bisulfate, sodium metabisulfite, sodium sulfite, etc.; oil-soluble antioxidants such as ascorbyl palmitate, butylated hydroxyanisole (BHA), butylated hydroxytoluene (BHT), lecithin, propyl gallate, α-tocopherol, etc.; and metal chelating agents such as citric acid, ethylenediaminetetraacetic acid (EDTA), sorbitol, tartaric acid, phosphoric acid, etc.

The formulations of the present invention include those suitable for oral, nasal, topical, oral, sublingual, rectal, vaginal, and/or enteric administration. The formulations can be conveniently present in unit dosage forms and can be prepared by any method well known in the pharmaceutical field. The amount of active ingredient that can be combined with a carrier material to prepare a single dosage form is typically the amount of the compound that produces the therapeutic effect. Typically, this amount ranges from about 1% to about 99% of the active ingredient, preferably from about 5% to about 70%, and most preferably from about 10% to about 30%, within one hundred percent.

Methods for preparing these formulations or compositions include the step of combining the compounds of the present invention with a carrier and optionally one or more auxiliary components. Typically, formulations are prepared by uniformly and tightly combining the compounds of the present invention with a liquid carrier or a subdivided solid carrier, or both, and then, if desired, shaping the product.

Formulations of the present invention suitable for oral administration may be capsules, flat capsules, pills, tablets, lozenges (using a flavored base, typically sucrose and gum arabic or tragacanth gum), powders, granules, or as solutions or suspensions in aqueous or non-aqueous liquid form, or as oil-in-water or water-in-oil liquid emulsions, or as elixirs or syrups, or as soft lozenges (using an inert matrix, such as gelatin and glycerin, or sucrose and gum arabic) and/or as mouthwashes, etc., each containing a predetermined amount of the compound of the present invention as an active ingredient. The compounds of the present invention may also be administered as large pills, ointments, or pastes.

Regardless of the chosen route of administration, the compounds and/or pharmaceutical compositions of the present invention shall be formulated into pharmaceutically acceptable dosage forms using conventional methods known to those skilled in the art.

Example 1

Effects of 4-(nitrooxy)butyl-(2S)-2-(6-methoxy-2-naphthyl) propionate (naprocinol) on blood nitric oxide and cGMP levels in a sickle cell mouse model

This study was conducted to evaluate the efficacy of 4-(nitrooxy)butyl-(2S)-2-(6-methoxy-2-naphthyl) propionate (naprocinol) in increasing nitrite (a precursor of NO) and cGMP in homozygous Townes sickle cell transgenic mice.

Experimental Design

Homozygous sickle cell transgenic mice were treated with intravenous injection of 4-(nitrooxy)butyl-(2S)-2-(6-methoxy-2-naphthyl) propionate (naproxinol) (15 mg/kg), naproxen (15 mg/kg as a control), or saline (as a mediator control). One hour later, the mice were injected with thrombin (1 u/20 g) to induce platelet activation. Blood was drawn at 15, 30, and 1 hour after thrombin administration. Plasma nitrite levels were measured as a marker of nitric oxide bioavailability. cGMP levels were measured after the addition of IBMX (3-isobutyl-1-methylxanthine) (100 uM) to prevent cGMP degradation. Platelets were isolated and activation was measured by surface expression of p-selectin.

result

At 1 hour, nitrite concentrations were statistically higher with the use of naproxen compared to administration of thrombin or naproxen alone (Figure 1). At 30 and 60 minutes, cGMP levels were significantly increased with the use of naproxen compared to administration of thrombin or naproxen alone (p<0.01) (Figure 2).

The data support the assertion that 4-(nitrooxy)butyl-(2S)-2-(6-methoxy-2-naphthyl) propionate (naprocinol) is useful and helpful in treating recurrent ischemic crises in patients with sickle cell anemia. In fact, 4-(nitrooxy)butyl-(2S)-2-(6-methoxy-2-naphthyl) can increase cGMP levels, thereby reducing nitric oxide depletion and subsequent vascular lesions in sickle cell disease, which are factors leading to vascular occlusion. In addition, the anti-inflammatory components of this compound reduce inflammation and pain.

Therefore, although preferred embodiments of the invention have been described, those skilled in the art will recognize that changes and modifications can be made thereto without departing from the spirit of the invention, and it is intended that all such changes and modifications fall within the true scope of the invention.

Methods for treating vascular occlusive crisis associated with sickle cell disease

Invention Field

This invention relates to 4-(nitrooxy)butyl-(2S)-2-(6-methoxy-2-naphthyl) propionate for the treatment of vascular occlusion crisis (VOC) in sickle cell disease.

Background of the Invention

4-(nitrooxy)butyl-(2S)-2-(6-methoxy-2-naphthyl) propionate is a nitric oxide (NO)-releasing derivative of naproxen and is also known as naproxen.

4-(nitrooxy)butyl-(2S)-2-(6-methoxy-2-naphthyl)propionate

WO 98/09831 and US 6,700,011 disclose the synthesis of 4-(nitrooxy)butyl-(2S)-2-(6-methoxy-2-naphthyl)propionate.

Schnitzer T.J. et al., Osteoarthritis and Cartilage 18 (2010) 629-639, disclosed that naproxen is a NO-releasing derivative of naproxen that combines analgesic and anti-inflammatory effects with a blood pressure effect similar to, but different from, that of placebo. In a study of osteoarthritis (OA) in the knee of human patients, naproxen demonstrated clinical efficacy and safety in controlling the signs and symptoms of OA.

White W.B. et al. (Am J Cardiol 2011; 107:1338-1345) published a large-scale analysis of the effects of naproxen on blood pressure in 2,734 patients with hip or knee osteoarthritis across three pivotal trials. The analysis indicated that naproxen can alleviate some of the hypertension burden induced by most NSAIDs.

Sickle cell disease (SCD) is a group of hemoglobinopathies caused by mutations in the sixth amino acid of the β-globulin subunit of hemoglobin. The most common mutation, βS-globulin, results in the substitution of a hydrophilic glutamate residue for a hydrophobic valine residue, leading to the production of hemoglobin S, which is prone to polymerization upon deoxygenation (Belanger AM, Keggi C, Kanias T et al., Effects of nitric oxide and its congeners on sickle red blood cell deformability. Transfusion, 2015(55)2464-2472).

Under hypoxic conditions, the polymerization of HbS causes red blood cells to twist into a distinctive sickle shape and increases their hardness and brittleness, leading to hemolysis. Hemolysis, in turn, contributes to oxidative stress and platelet activation (Helms CC, Marvel M, Zhao W, Stahle M, Vest R, Kato GJ et al. Mechanisms of hemolysis-associated platelet activation. Journal of Thrombosis and Haemostasis. 2013; 11(12):2148-2154; Villagra J, Shiva S, Hunter LA, Machado RF, Gladwin MI, Kato GJ. Platelet activation in patients with sickle disease, hemolysis-associated pulmonary hypertension, and nitric oxide scavenging by cell-free hemoglobin. Blood 2007; 110(6):2166-2172). Oxidative stress, physical interactions between sickle cells and endothelium, and other factors lead to an inflammatory state in which endothelial cells and leukocytes are activated, resulting in leukocyte and multicellular adhesion to the endothelium, thereby generating VOCs. Ischemia, organ damage, pain, and potential death are all secondary to VOCs (Parise LV, Telen MJ. Erythrocyte adhesion in sickle cell disease. Current Hematology Reports. 2003; 2(2):102-108., 2003; Hoppe CC. Inflammatory mediators of endothelial injury in sickle cell disease. Hematol Oncol Clin. North Am. 2014; 28(2):265-86; Kutlar A, Embury SH. Cellular adhesion and the endothelium: P-Selectin. Hematol Oncol Clin. North Am. 2014; 28(2):265-86; Kutlar A, Embury SH. Cellular adhesion and the endothelium: P-Selectin. Hematol Oncol Clin. North Am. 2014; 28(2):265-86.). Clin.NorthAm.2014;28(2):323-339; Zhang DC, Xu CL, Manwani D, Frenette PS. Neutrophils, platelets, and inflammatory pathways at the nexus of sickle cell diseasepathophysiology.Bl ood.2016;127(7):801-839;Kim-Shapiro DB,Gladwin MT.Nitricoxide pathology and therapeutics in sickle cell disease.Clinical Hemorheologyand Microcirculation,2018;68:223-237).

Vascular occlusive crisis and its associated pain are common reasons for emergency department visits and hospitalizations in patients with sickle cell disease. Vascular occlusive crisis and its associated pain most commonly occur in the extremities, chest, and back, and are considered nociceptive, secondary to tissue damage. The typical clinical features of a pain crisis are described as a sudden onset of pain in the lower back or one or more joints or extremities. The pain may be localized or migratory, and is persistent and throbbing. Severe pain causes patients to groan, moan, cry, twist and turn, and adopt abnormal postures in unsuccessful attempts to obtain relief. Severe attacks require treatment with non-intestinal opioids in a medical center after failure to control pain with oral anesthetics and/or non-prescription NSAIDs other than those approved by the drug label. (Ballas SK, Gupta K, Adams-Graves P. Sickle cell pain: a critical reappraisal Blood, 2012; 120(18):3647-3656).

Vascular occlusion-related pain crises evolve through four phases: the prodromal phase, the initial phase, the establishment phase, and the resolution phase. Each acute pain attack is associated with inflammation, which worsens with repeated attacks, often ultimately leading to serious complications and organ damage, such as acute chest syndrome and multiple organ failure. The prodromal phase, lasting 1-2 days before a severe pain attack, is characterized by a gradual or sudden increase in pain (initial phase), peaking after 3 days, leading to the establishment phase, which continues until day 6 or 7, after which the pain begins to subside (resolution phase). The prodromal phase of the crisis is characterized by three main pathophysiological events: vascular occlusion, inflammation, and nociception. Therefore, controlling vascular occlusion-related crises during the prodromal phase, when tissue ischemia and inflammation are in their early stages, can potentially prevent or minimize pain and tissue damage. (Ballas SK, Gupta K, Adams-Graves P. Sickle cell pain: a critical reappraisal Blood, 2012; 120(18):3647-3656).

Currently, the main treatments for controlling vascular occlusive crisis include treating acute pain attacks and reducing the occurrence of vascular occlusive crisis.

Three drugs have been approved by the FDA for the treatment of vascular occlusive crisis complications in sickle cell disease: hydroxyurea, L-glutamine, and lizalizumab-tmca. All products have been shown to reduce the frequency of vascular occlusive crises, but these drugs have not shown relief from VOC-related pain.

The recently approved Adakveo product lists an 18% incidence of joint pain and a 15% incidence of back pain associated with its product in its approved packaging instructions, indicating a persistent need for pain relief. (Novartis, 2019)

Unfortunately, while hydroxyurea (Droxia) reduces the incidence of vascular occlusion (VOC), it does not eliminate it. Patients need to maintain pain relief when painful vascular occlusion crises occur. Furthermore, the Droxia package insert contains a boxed warning regarding bone marrow suppression and malignant tumors.

Currently, the FDA has not approved any products for the treatment of pain secondary to vascular occlusive crisis in patients with sickle cell disease, although many analgesics are commonly used off-label. Guidance recommends the use of NSAIDs for mild to moderate pain, but well-controlled clinical trials have not shown any effect of NSAIDs on pain secondary to vascular occlusive crisis.

With the advancement of VOCs, more than 90% of adult patients require hospitalization and pain management, including non-intestinal opioid therapy consisting of meperidine, morphine, or hydromorphone. (Ballas SK. Pain management of sickle cell disease. Hematol Oncol Clin North Am. 2005; 19(5):785-802).

Although opioid therapy is a mainstay of pain management, it remains a suboptimal approach due to its side effects, such as sedation, dizziness, nausea, vomiting, constipation, physical dependence, tolerance, and respiratory depression. Serious adverse reactions can occur with high doses or prolonged use, including opioid tolerance (leading to increased opioid dosage), immunosuppression, hormonal changes, hyperalgesia, and an increased risk of acute chest syndrome and altered opioid clearance in sickle cell patients. (Ballas SK. Current issues in sickle cell pain and its management. Hematology Am Soc Hematol Educ Program. 2007; 97-105).

Nitric oxide (NO) is a well-known free radical signaling molecule that plays a wide range of roles in biological functions, including relaxing blood vessels, increasing blood flow, reducing platelet activation, reducing the adhesion of circulating blood cells to the endothelium, and reducing thrombus formation. In response to a variety of stimuli, vascular endothelial cells produce nitric oxide, which activates guanylate cyclase, leading to elevated levels of intracellular cyclic GMP (cGMP). Extensive research has shown that nitric oxide levels are depleted in sickle cell disease and further depleted during VOC processes (Goncalves R.P., Rev Bras Hematol Hemoter 2012; 34(4):254-64).

Treatment strategies that supplement or modulate nitric oxide (NO) have been presented as potential treatments for sickle cell disease and/or symptoms.

For example, preliminary trials have shown some positive effects of inhaled NO on acute VOCs. However, currently available results do not provide sufficient evidence to determine the effectiveness of inhaled nitric oxide in treating painful (vascular occlusion) crises in patients with sickle cell disease. Furthermore, inhaled NO requires specific handling and administration.

Another publicly disclosed strategy for increasing NO production in sickle cell disease patients is supplementation with nitric oxide precursors. Summar M.L. et al. (US 2018/0289647) disclosed a method for treating sickle cell disease and its complications, including vascular occlusive crisis, involving the administration of citrulline, a precursor of arginine and endogenously produced nitric oxide (NO). US 2018/0289647 reported a study demonstrating the safety and pharmacokinetic properties of intravenous citrulline in patients with sickle cell disease. However, the clinical efficacy of citrulline requires further evaluation in clinical studies.

Therefore, an effective and safe treatment for vascular occlusive crisis in patients with sickle cell disease is a serious unmet need.

The applicant recently conducted preclinical studies and found that 4-(nitrooxy)butyl-(2S)-2-(6-methoxy-2-naphthyl) can increase cyclic guanosine monophosphate (cGMP) levels in a sickle cell animal model. Therefore, 4-(nitrooxy)butyl-(2S)-2-(6-methoxy-2-naphthyl) may play a role in reducing nitric oxide consumption in sickle cell patients, thereby improving vascular homeostasis. Furthermore, the anti-inflammatory and analgesic activities of 4-(nitrooxy)butyl-(2S)-2-(6-methoxy-2-naphthyl) can reduce inflammatory cascade reactions and pain associated with vascular occlusive crisis.

Invention Overview

It has been found that 4-(nitrooxy)butyl-(2S)-2-(6-methoxy-2-naphthyl) propionate can beneficially interfere with the pathogenesis of pain symptoms and complications associated with vascular occlusion crisis (VOC) in sickle cell anemia and alleviate pain symptoms and complications associated with VOC.

One embodiment of the present invention relates to a method for treating vascular occlusive crisis in patients with sickle cell disease, the method comprising administering a therapeutically effective amount of 4-(nitrooxy)butyl-(2S)-2-(6-methoxy-2-naphthyl) propionate to the patient in need.

Another embodiment of the invention relates to a method for treating vascular occlusive crisis in patients with sickle cell disease, the method comprising administering a therapeutically effective amount of 4-(nitrooxy)butyl-(2S)-2-(6-methoxy-2-naphthyl) propionate to a patient in need, wherein the administration of 4-(nitrooxy)butyl-(2S)-2-(6-methoxy-2-naphthyl) propionate is initiated at the onset of early prodromal signs and symptoms of vascular occlusive crisis and continues at least until the crisis is treated.

The method of the present invention has several advantages: 4-(nitrooxy)butyl-(2S)-2-(6-methoxy-2-naphthyl) propionate can be administered to the patient at home (self-administration) once the patient senses an impending crisis (prodromal phase); administration of 4-(nitrooxy)butyl-(2S)-2-(6-methoxy-2-naphthyl) propionate in the early stages of a vascular occlusion crisis can help promote and accelerate crisis resolution by reducing the cascade of events such as vascular occlusion, inflammation, and pain (as associated with a vascular occlusion crisis).

Minimizing vascular occlusion and inflammation can reduce organ and tissue damage in sickle cell patients by reducing (1) the amount of damage to organs and tissues caused by ischemia due to blockage of blood flow through capillaries, (2) the amount of damage caused by oxidative free radicals in organs and tissues where blood flow has been restored after a period of ischemia, and (3) the amount of inflammatory mediators released from damaged cells.

Reducing the intensity of pain associated with vascular occlusion crisis can alleviate or eliminate the need for opioids to manage acute pain crises associated with ischemic crises in sickle cell patients, and thus reduce hospitalizations.

Because 4-(nitrooxy)butyl-(2S)-2-(6-methoxy-2-naphthyl) propionate is well tolerated, this compound can be administered in combination with other medical treatments commonly used to treat SCD in a manner that does not interfere with such other treatments.

Another embodiment of the invention relates to a method for reducing the severity or duration of vascular occlusive events in individuals with sickle cell disease, the method comprising administering a therapeutically effective amount of 4-(nitrooxy)butyl-(2S)-2-(6-methoxy-2-naphthyl) propionate.

Another embodiment of the present invention is a method for mitigating organ and tissue damage caused by vascular occlusion events, the method comprising administering an effective amount of 4-(nitrooxy)butyl-(2S)-2-(6-methoxy-2-naphthyl) propionate to an individual suffering from sickle cell disease.

One embodiment of the present invention provides a method for treating pain in patients with sickle cell anemia during recurrent ischemic crisis by administering a therapeutically effective amount of 4-(nitrooxy)butyl-(2S)-2-(6-methoxy-2-naphthyl) ester propionate.

Another embodiment of the present invention is a method for treating pain secondary to sickle cell disease vascular occlusion crisis (VOC) in patients with sickle cell anemia, by combining the administration of a therapeutically effective amount of 4-(nitrooxy)butyl-(2S)-2-(6-methoxy-2-naphthyl) ester propionate with opioid therapy used during such pain crisis.

In one embodiment, the invention includes the method of the invention, wherein the pharmaceutical composition contains a therapeutically effective amount of 4-(nitrooxy)butyl-(2S)-2-(6-methoxy-2-naphthyl) ester of propionate, the pharmaceutical composition further comprising one or more pharmaceutically acceptable carriers. In one embodiment, the pharmaceutical composition is suitable for oral, nasal, topical, oral, sublingual, rectal, vaginal, or enteral administration.

The present invention also relates to 4-(nitrooxy)butyl-(2S)-2-(6-methoxy-2-naphthyl) propionate or pharmaceutical compositions comprising 4-(nitrooxy)butyl-(2S)-2-(6-methoxy-2-naphthyl) propionate and one or more pharmaceutically acceptable carriers for use in any of the treatment methods reported above.

The present invention also relates to the use of 4-(nitrooxy)butyl-(2S)-2-(6-methoxy-2-naphthyl) propionate in the preparation of a medicament for any of the treatment methods reported above.

Brief description of the attached diagram

Figure 1: A schematic diagram showing the plasma nitrite concentration (concentration-time) after intravenous administration of naproxen or 4-(nitrooxy)butyl-(2S)-2-(6-methoxy-2-naphthyl) propionate (naproxinol) in homozygous sickle cell transgenic mice. Naproxinol increases plasma nitrite concentration. N = 4–7; *p < 0.01

Figure 2: A schematic diagram showing the cGMP concentration (concentration-time) after intravenous administration of naproxen or 4-(nitrooxy)butyl-(2S)-2-(6-methoxy-2-naphthyl) propionate (naproxinol) in homozygous sickle cell transgenic mice. Naproxinol increases platelet cGMP production. N = 4–7; *p < 0.01

Invention Details

A method for treating acute pain crisis in patients with sickle cell anemia is provided. The method involves administering a therapeutically effective amount of 4-(nitrooxy)butyl-(2S)-2-(6-methoxy-2-naphthyl) propionate (naprocinol).

The following description provides specific details to provide a thorough understanding of the invention. However, those skilled in the art will understand that the invention may be practiced without these specific details. For the purposes of this specification, the following definitions will apply, and terms used in the singular will, where appropriate, also include the plural, and vice versa.

As defined herein, “treatment” refers to any reduction in the severity or duration of a vascular occlusive event, leading to the termination of the crisis, or any relief of pain associated with sickle cell anemia. Relief of pain may include a reduction in frequency, duration, or intensity. Pain intensity can be measured using standard methods such as analgesia meters, trocars, or 10-point pain scales.

As defined in this article, "prodromal signs and symptoms of vascular occlusive crisis" include: fatigue, dizziness, weakness, yellowing or pallor of the eyes, gastrointestinal symptoms such as nausea, vomiting and changes in appetite, musculoskeletal symptoms such as swelling, tenderness or stiffness of the hands/feet, and respiratory symptoms such as runny nose, cough and changes in breathing.

As used herein, the term "therapeutic effective amount" of a compound is the amount necessary or sufficient to treat or prevent diseases, disorders, and/or conditions as described herein. Effective amounts can vary depending on factors such as individual size and weight, the type of disease, or the specific compound of the invention. One skilled in the art will be able to investigate the factors included herein and determine the effective amount of the compounds of the invention without excessive experimentation.

The actual dose level of the active ingredient in the pharmaceutical composition of the present invention may vary to obtain an amount of active ingredient that effectively achieves the desired therapeutic response for a particular patient, composition and administration method, without being toxic to the patient.

The chosen dose level will depend on a variety of factors, including the activity of the specific compound of the invention used, the route of administration, the time of administration, the excretion rate of the specific compound used, the duration of treatment, other drugs, compounds and/or materials used in combination with the specific compound used, the age, sex, weight, condition, general health status and medical history of the patient to be treated, and similar factors well known in the medical field.

Clinicians with ordinary skills in the art can easily determine and prescribe the effective amount of the desired pharmaceutical composition. For example, clinicians can start with a dose of the compound of the invention used in the pharmaceutical composition below the level required to achieve the desired therapeutic effect, and gradually increase the dose until the desired effect is achieved.

Typically, the appropriate daily dose of the compounds of this invention will be the amount of the lowest dose of the compound that effectively produces a therapeutic effect. Such an effective dose usually depends on the factors mentioned above.

If desired, the effective daily dose of the active compound can be administered as two, three, four, five, six or more sub-dose at appropriate intervals throughout the day, optionally in unit dosage form.

Although the compounds of the present invention can be administered alone, it is preferred to administer the compounds as a pharmaceutical composition.

For use in this treatment, 4-(nitrooxy)butyl-(2S)-2-(6-methoxy-2-naphthyl) propionate is administered orally; the adult dose range is 100 mg/day to 3000 mg/day or 100 mg/day to 2000 mg/day, preferably 375 mg/day to 1500 mg/day, and most preferably 750 mg/day to 1500 mg/day; the pediatric dose (over 2 years old and under 16 years old) ranges from 15 to 22.5 mg/kg/day.

The exact dosage and schedule of administration will vary depending on the amount needed to provide relief in each specific case.

For use in this treatment, it is preferable to administer 4-(nitrooxy)butyl-(2S)-2-(6-methoxy-2-naphthyl) propionate to the patient starting from the onset of early prodromal signs and symptoms of vascular occlusion crisis, until the crisis is controlled. This treatment can also be used as maintenance therapy after the vascular occlusion crisis has been controlled.

The administration regimen can affect the composition of the effective dose. Several separate doses can be administered daily or sequentially, as well as alternating doses, or the dose can be administered continuously by infusion or by bolus injection. Furthermore, the dosage of the compounds of this invention can be increased or decreased proportionally depending on the urgency of the treatment or preventative situation.

As used herein, the term "pharmaceutical composition" includes formulations suitable for administration to mammals such as humans. When the compounds of the present invention are administered as pharmaceuticals to mammals such as humans, they may be given on their own or as pharmaceutical compositions comprising, for example, 0.1-99.5% (more preferably 0.5-90%) of an active ingredient in combination with a pharmaceutically acceptable carrier.

As used herein, the term "pharmaceutically acceptable carrier" is recognized in the art and includes pharmaceutically acceptable materials, compositions, or media suitable for administering the compounds of the present invention to mammals. Carriers include liquid or solid fillers, diluents, excipients, solvents, or encapsulating materials relating to carrying or transporting the subject active agent from one organ or part of the body to another organ or part of the body. Each carrier must be "acceptable" in the sense of compatibility with other components of the formulation and harmlessness to the patient. Some examples of materials that can be used as pharmaceutically acceptable carriers include: sugars, such as lactose, glucose, and sucrose; starches, such as corn starch and potato starch; cellulose and its derivatives, such as sodium carboxymethyl cellulose, ethyl cellulose, and cellulose acetate; powdered tragacanth gum; malt; gelatin; talc; excipients, such as cocoa butter and suppository waxes; oils, such as peanut oil, cottonseed oil, safflower oil, sesame oil, olive oil, corn oil, and soybean oil; glycols, such as propylene glycol; polyols, such as glycerol, sorbitol, mannitol, and polyethylene glycol; esters, such as ethyl oleate and ethyl laurate; agar; buffers, such as magnesium hydroxide and aluminum hydroxide; alginic acid; pyrogen-free water; isotonic saline; Ringer's solution; ethanol; phosphate buffer solutions; and other non-toxic and compatible substances used in pharmaceutical preparations.

Wetting agents, emulsifiers and lubricants, such as sodium dodecyl sulfate and magnesium stearate, as well as colorants, releasing agents, coating agents, sweeteners, flavoring agents and aromas, preservatives and antioxidants may also be present in the composition.

Examples of pharmaceutically acceptable antioxidants include: water-soluble antioxidants such as ascorbic acid, cysteine hydrochloride, sodium bisulfate, sodium metabisulfite, sodium sulfite, etc.; oil-soluble antioxidants such as ascorbyl palmitate, butylated hydroxyanisole (BHA), butylated hydroxytoluene (BHT), lecithin, propyl gallate, α-tocopherol, etc.; and metal chelating agents such as citric acid, ethylenediaminetetraacetic acid (EDTA), sorbitol, tartaric acid, phosphoric acid, etc.

The formulations of the present invention include those suitable for oral, nasal, topical, oral, sublingual, rectal, vaginal, and/or enteric administration. The formulations can be conveniently present in unit dosage forms and can be prepared by any method well known in the pharmaceutical field. The amount of active ingredient that can be combined with a carrier material to prepare a single dosage form is typically the amount of the compound that produces the therapeutic effect. Typically, this amount ranges from about 1% to about 99% of the active ingredient, preferably from about 5% to about 70%, and most preferably from about 10% to about 30%, within one hundred percent.

Methods for preparing these formulations or compositions include the step of combining the compounds of the present invention with a carrier and optionally one or more auxiliary components. Typically, formulations are prepared by uniformly and tightly combining the compounds of the present invention with a liquid carrier or a subdivided solid carrier, or both, and then, if desired, shaping the product.

Formulations of the present invention suitable for oral administration may be capsules, flat capsules, pills, tablets, lozenges (using a flavored base, typically sucrose and gum arabic or tragacanth gum), powders, granules, or as solutions or suspensions in aqueous or non-aqueous liquid form, or as oil-in-water or water-in-oil liquid emulsions, or as elixirs or syrups, or as soft lozenges (using an inert matrix, such as gelatin and glycerin, or sucrose and gum arabic) and/or as mouthwashes, etc., each containing a predetermined amount of the compound of the present invention as an active ingredient. The compounds of the present invention may also be administered as large pills, ointments, or pastes.

Regardless of the chosen route of administration, the compounds and/or pharmaceutical compositions of the present invention shall be formulated into pharmaceutically acceptable dosage forms using conventional methods known to those skilled in the art.

Example 1

Effects of 4-(nitrooxy)butyl-(2S)-2-(6-methoxy-2-naphthyl) propionate (naprocinol) on blood nitric oxide and cGMP levels in a sickle cell mouse model

This study was conducted to evaluate the efficacy of 4-(nitrooxy)butyl-(2S)-2-(6-methoxy-2-naphthyl) propionate (naprocinol) in increasing nitrite (a precursor of NO) and cGMP in homozygous Townes sickle cell transgenic mice.

Experimental Design

Homozygous sickle cell transgenic mice were treated with intravenous injection of 4-(nitrooxy)butyl-(2S)-2-(6-methoxy-2-naphthyl) propionate (naproxinol) (15 mg/kg), naproxen (15 mg/kg as a control), or saline (as a mediator control). One hour later, the mice were injected with thrombin (1 u/20 g) to induce platelet activation. Blood was drawn at 15, 30, and 1 hour after thrombin administration. Plasma nitrite levels were measured as a marker of nitric oxide bioavailability. cGMP levels were measured after the addition of IBMX (3-isobutyl-1-methylxanthine) (100 uM) to prevent cGMP degradation. Platelets were isolated and activation was measured by surface expression of p-selectin.

result

At 1 hour, nitrite concentrations were statistically higher with the use of naproxen compared to administration of thrombin or naproxen alone (Figure 1). At 30 and 60 minutes, cGMP levels were significantly increased with the use of naproxen compared to administration of thrombin or naproxen alone (p<0.01) (Figure 2).

The data support the assertion that 4-(nitrooxy)butyl-(2S)-2-(6-methoxy-2-naphthyl) propionate (naprocinol) is useful and helpful in treating recurrent ischemic crises in patients with sickle cell anemia. In fact, 4-(nitrooxy)butyl-(2S)-2-(6-methoxy-2-naphthyl) can increase cGMP levels, thereby reducing nitric oxide depletion and subsequent vascular lesions in sickle cell disease, which are factors leading to vascular occlusion. In addition, the anti-inflammatory components of this compound reduce inflammation and pain.

Therefore, although preferred embodiments of the invention have been described, those skilled in the art will recognize that changes and modifications can be made thereto without departing from the spirit of the invention, and it is intended that all such changes and modifications fall within the true scope of the invention.

Invention Field

This invention relates to 4-(nitrooxy)butyl-(2S)-2-(6-methoxy-2-naphthyl) propionate for the treatment of vascular occlusion crisis (VOC) in sickle cell disease.

Background of the Invention

4-(nitrooxy)butyl-(2S)-2-(6-methoxy-2-naphthyl) propionate is a nitric oxide (NO)-releasing derivative of naproxen and is also known as naproxen.

4-(nitrooxy)butyl-(2S)-2-(6-methoxy-2-naphthyl)propionate

WO 98/09831 and US 6,700,011 disclose the synthesis of 4-(nitrooxy)butyl-(2S)-2-(6-methoxy-2-naphthyl)propionate.

Schnitzer T.J. et al., Osteoarthritis and Cartilage 18 (2010) 629-639, disclosed that naproxen is a NO-releasing derivative of naproxen that combines analgesic and anti-inflammatory effects with a blood pressure effect similar to, but different from, that of placebo. In a study of osteoarthritis (OA) in the knee of human patients, naproxen demonstrated clinical efficacy and safety in controlling the signs and symptoms of OA.

White W.B. et al. (Am J Cardiol 2011; 107:1338-1345) published a large-scale analysis of the effects of naproxen on blood pressure in 2,734 patients with hip or knee osteoarthritis across three pivotal trials. The analysis indicated that naproxen can alleviate some of the hypertension burden induced by most NSAIDs.

Sickle cell disease (SCD) is a group of hemoglobinopathies caused by mutations in the sixth amino acid of the β-globulin subunit of hemoglobin. The most common mutation, βS-globulin, results in the substitution of a hydrophilic glutamate residue for a hydrophobic valine residue, leading to the production of hemoglobin S, which is prone to polymerization upon deoxygenation (Belanger AM, Keggi C, Kanias T et al., Effects of nitric oxide and its congeners on sickle red blood cell deformability. Transfusion, 2015(55)2464-2472).

Under hypoxic conditions, the polymerization of HbS causes red blood cells to twist into a distinctive sickle shape and increases their hardness and brittleness, leading to hemolysis. Hemolysis, in turn, contributes to oxidative stress and platelet activation (Helms CC, Marvel M, Zhao W, Stahle M, Vest R, Kato GJ et al. Mechanisms of hemolysis-associated platelet activation. Journal of Thrombosis and Haemostasis. 2013; 11(12):2148-2154; Villagra J, Shiva S, Hunter LA, Machado RF, Gladwin MI, Kato GJ. Platelet activation in patients with sickle disease, hemolysis-associated pulmonary hypertension, and nitric oxide scavenging by cell-free hemoglobin. Blood 2007; 110(6):2166-2172). Oxidative stress, physical interactions between sickle cells and endothelium, and other factors lead to an inflammatory state in which endothelial cells and leukocytes are activated, resulting in leukocyte and multicellular adhesion to the endothelium, thereby generating VOCs. Ischemia, organ damage, pain, and potential death are all secondary to VOCs (Parise LV, Telen MJ. Erythrocyte adhesion in sickle cell disease. Current Hematology Reports. 2003; 2(2):102-108., 2003; Hoppe CC. Inflammatory mediators of endothelial injury in sickle cell disease. Hematol Oncol Clin. North Am. 2014; 28(2):265-86; Kutlar A, Embury SH. Cellular adhesion and the endothelium: P-Selectin. Hematol Oncol Clin. North Am. 2014; 28(2):265-86; Kutlar A, Embury SH. Cellular adhesion and the endothelium: P-Selectin. Hematol Oncol Clin. North Am. 2014; 28(2):265-86.). Clin.NorthAm.2014;28(2):323-339; Zhang DC, Xu CL, Manwani D, Frenette PS. Neutrophils, platelets, and inflammatory pathways at the nexus of sickle cell diseasepathophysiology.Bl ood.2016;127(7):801-839;Kim-Shapiro DB,Gladwin MT.Nitricoxide pathology and therapeutics in sickle cell disease.Clinical Hemorheologyand Microcirculation,2018;68:223-237).

Vascular occlusive crisis and its associated pain are common reasons for emergency department visits and hospitalizations in patients with sickle cell disease. Vascular occlusive crisis and its associated pain most commonly occur in the extremities, chest, and back, and are considered nociceptive, secondary to tissue damage. The typical clinical features of a pain crisis are described as a sudden onset of pain in the lower back or one or more joints or extremities. The pain may be localized or migratory, and is persistent and throbbing. Severe pain causes patients to groan, moan, cry, twist and turn, and adopt abnormal postures in unsuccessful attempts to obtain relief. Severe attacks require treatment with non-intestinal opioids in a medical center after failure to control pain with oral anesthetics and/or non-prescription NSAIDs other than those approved by the drug label. (Ballas SK, Gupta K, Adams-Graves P. Sickle cell pain: a critical reappraisal Blood, 2012; 120(18):3647-3656).

Vascular occlusion-related pain crises evolve through four phases: the prodromal phase, the initial phase, the establishment phase, and the resolution phase. Each acute pain attack is associated with inflammation, which worsens with repeated attacks, often ultimately leading to serious complications and organ damage, such as acute chest syndrome and multiple organ failure. The prodromal phase, lasting 1-2 days before a severe pain attack, is characterized by a gradual or sudden increase in pain (initial phase), peaking after 3 days, leading to the establishment phase, which continues until day 6 or 7, after which the pain begins to subside (resolution phase). The prodromal phase of the crisis is characterized by three main pathophysiological events: vascular occlusion, inflammation, and nociception. Therefore, controlling vascular occlusion-related crises during the prodromal phase, when tissue ischemia and inflammation are in their early stages, can potentially prevent or minimize pain and tissue damage. (Ballas SK, Gupta K, Adams-Graves P. Sickle cell pain: a critical reappraisal Blood, 2012; 120(18):3647-3656).

Currently, the main treatments for controlling vascular occlusive crisis include treating acute pain attacks and reducing the occurrence of vascular occlusive crisis.

Three drugs have been approved by the FDA for the treatment of vascular occlusive crisis complications in sickle cell disease: hydroxyurea, L-glutamine, and lizalizumab-tmca. All products have been shown to reduce the frequency of vascular occlusive crises, but these drugs have not shown relief from VOC-related pain.

The recently approved Adakveo product lists an 18% incidence of joint pain and a 15% incidence of back pain associated with its product in its approved packaging instructions, indicating a persistent need for pain relief. (Novartis, 2019)

Unfortunately, while hydroxyurea (Droxia) reduces the incidence of vascular occlusion (VOC), it does not eliminate it. Patients need to maintain pain relief when painful vascular occlusion crises occur. Furthermore, the Droxia package insert contains a boxed warning regarding bone marrow suppression and malignant tumors.

Currently, the FDA has not approved any products for the treatment of pain secondary to vascular occlusive crisis in patients with sickle cell disease, although many analgesics are commonly used off-label. Guidance recommends the use of NSAIDs for mild to moderate pain, but well-controlled clinical trials have not shown any effect of NSAIDs on pain secondary to vascular occlusive crisis.

With the advancement of VOCs, more than 90% of adult patients require hospitalization and pain management, including non-intestinal opioid therapy consisting of meperidine, morphine, or hydromorphone. (Ballas SK. Pain management of sickle cell disease. Hematol Oncol Clin North Am. 2005; 19(5):785-802).

Although opioid therapy is a mainstay of pain management, it remains a suboptimal approach due to its side effects, such as sedation, dizziness, nausea, vomiting, constipation, physical dependence, tolerance, and respiratory depression. Serious adverse reactions can occur with high doses or prolonged use, including opioid tolerance (leading to increased opioid dosage), immunosuppression, hormonal changes, hyperalgesia, and an increased risk of acute chest syndrome and altered opioid clearance in sickle cell patients. (Ballas SK. Current issues in sickle cell pain and its management. Hematology Am Soc Hematol Educ Program. 2007; 97-105).

Nitric oxide (NO) is a well-known free radical signaling molecule that plays a wide range of roles in biological functions, including relaxing blood vessels, increasing blood flow, reducing platelet activation, reducing the adhesion of circulating blood cells to the endothelium, and reducing thrombus formation. In response to a variety of stimuli, vascular endothelial cells produce nitric oxide, which activates guanylate cyclase, leading to elevated levels of intracellular cyclic GMP (cGMP). Extensive research has shown that nitric oxide levels are depleted in sickle cell disease and further depleted during VOC processes (Goncalves R.P., Rev Bras Hematol Hemoter 2012; 34(4):254-64).

Treatment strategies that supplement or modulate nitric oxide (NO) have been presented as potential treatments for sickle cell disease and/or symptoms.

For example, preliminary trials have shown some positive effects of inhaled NO on acute VOCs. However, currently available results do not provide sufficient evidence to determine the effectiveness of inhaled nitric oxide in treating painful (vascular occlusion) crises in patients with sickle cell disease. Furthermore, inhaled NO requires specific handling and administration.

Another publicly disclosed strategy for increasing NO production in sickle cell disease patients is supplementation with nitric oxide precursors. Summar M.L. et al. (US 2018/0289647) disclosed a method for treating sickle cell disease and its complications, including vascular occlusive crisis, involving the administration of citrulline, a precursor of arginine and endogenously produced nitric oxide (NO). US 2018/0289647 reported a study demonstrating the safety and pharmacokinetic properties of intravenous citrulline in patients with sickle cell disease. However, the clinical efficacy of citrulline requires further evaluation in clinical studies.

Therefore, an effective and safe treatment for vascular occlusive crisis in patients with sickle cell disease is a serious unmet need.

The applicant recently conducted preclinical studies and found that 4-(nitrooxy)butyl-(2S)-2-(6-methoxy-2-naphthyl) can increase cyclic guanosine monophosphate (cGMP) levels in a sickle cell animal model. Therefore, 4-(nitrooxy)butyl-(2S)-2-(6-methoxy-2-naphthyl) may play a role in reducing nitric oxide consumption in sickle cell patients, thereby improving vascular homeostasis. Furthermore, the anti-inflammatory and analgesic activities of 4-(nitrooxy)butyl-(2S)-2-(6-methoxy-2-naphthyl) can reduce inflammatory cascade reactions and pain associated with vascular occlusive crisis.

Invention Overview

It has been found that 4-(nitrooxy)butyl-(2S)-2-(6-methoxy-2-naphthyl) propionate can beneficially interfere with the pathogenesis of pain symptoms and complications associated with vascular occlusion crisis (VOC) in sickle cell anemia and alleviate pain symptoms and complications associated with VOC.

One embodiment of the present invention relates to a method for treating vascular occlusive crisis in patients with sickle cell disease, the method comprising administering a therapeutically effective amount of 4-(nitrooxy)butyl-(2S)-2-(6-methoxy-2-naphthyl) propionate to the patient in need.

Another embodiment of the invention relates to a method for treating vascular occlusive crisis in patients with sickle cell disease, the method comprising administering a therapeutically effective amount of 4-(nitrooxy)butyl-(2S)-2-(6-methoxy-2-naphthyl) propionate to a patient in need, wherein the administration of 4-(nitrooxy)butyl-(2S)-2-(6-methoxy-2-naphthyl) propionate is initiated at the onset of early prodromal signs and symptoms of vascular occlusive crisis and continues at least until the crisis is treated.

The method of the present invention has several advantages: 4-(nitrooxy)butyl-(2S)-2-(6-methoxy-2-naphthyl) propionate can be administered to the patient at home (self-administration) once the patient senses an impending crisis (prodromal phase); administration of 4-(nitrooxy)butyl-(2S)-2-(6-methoxy-2-naphthyl) propionate in the early stages of a vascular occlusion crisis can help promote and accelerate crisis resolution by reducing the cascade of events such as vascular occlusion, inflammation, and pain (as associated with a vascular occlusion crisis).

Minimizing vascular occlusion and inflammation can reduce organ and tissue damage in sickle cell patients by reducing (1) the amount of damage to organs and tissues caused by ischemia due to blockage of blood flow through capillaries, (2) the amount of damage caused by oxidative free radicals in organs and tissues where blood flow has been restored after a period of ischemia, and (3) the amount of inflammatory mediators released from damaged cells.

Reducing the intensity of pain associated with vascular occlusion crisis can alleviate or eliminate the need for opioids to manage acute pain crises associated with ischemic crises in sickle cell patients, and thus reduce hospitalizations.

Because 4-(nitrooxy)butyl-(2S)-2-(6-methoxy-2-naphthyl) propionate is well tolerated, this compound can be administered in combination with other medical treatments commonly used to treat SCD in a manner that does not interfere with such other treatments.

Another embodiment of the invention relates to a method for reducing the severity or duration of vascular occlusive events in individuals with sickle cell disease, the method comprising administering a therapeutically effective amount of 4-(nitrooxy)butyl-(2S)-2-(6-methoxy-2-naphthyl) propionate.

Another embodiment of the present invention is a method for mitigating organ and tissue damage caused by vascular occlusion events, the method comprising administering an effective amount of 4-(nitrooxy)butyl-(2S)-2-(6-methoxy-2-naphthyl) propionate to an individual suffering from sickle cell disease.

One embodiment of the present invention provides a method for treating pain in patients with sickle cell anemia during recurrent ischemic crisis by administering a therapeutically effective amount of 4-(nitrooxy)butyl-(2S)-2-(6-methoxy-2-naphthyl) ester propionate.

Another embodiment of the present invention is a method for treating pain secondary to sickle cell disease vascular occlusion crisis (VOC) in patients with sickle cell anemia, by combining the administration of a therapeutically effective amount of 4-(nitrooxy)butyl-(2S)-2-(6-methoxy-2-naphthyl) ester propionate with opioid therapy used during such pain crisis.

In one embodiment, the invention includes the method of the invention, wherein the pharmaceutical composition contains a therapeutically effective amount of 4-(nitrooxy)butyl-(2S)-2-(6-methoxy-2-naphthyl) ester of propionate, the pharmaceutical composition further comprising one or more pharmaceutically acceptable carriers. In one embodiment, the pharmaceutical composition is suitable for oral, nasal, topical, oral, sublingual, rectal, vaginal, or enteral administration.

The present invention also relates to 4-(nitrooxy)butyl-(2S)-2-(6-methoxy-2-naphthyl) propionate or pharmaceutical compositions comprising 4-(nitrooxy)butyl-(2S)-2-(6-methoxy-2-naphthyl) propionate and one or more pharmaceutically acceptable carriers for use in any of the treatment methods reported above.

The present invention also relates to the use of 4-(nitrooxy)butyl-(2S)-2-(6-methoxy-2-naphthyl) propionate in the preparation of a medicament for any of the treatment methods reported above.

Brief description of the attached diagram

Figure 1: A schematic diagram showing the plasma nitrite concentration (concentration-time) after intravenous administration of naproxen or 4-(nitrooxy)butyl-(2S)-2-(6-methoxy-2-naphthyl) propionate (naproxinol) in homozygous sickle cell transgenic mice. Naproxinol increases plasma nitrite concentration. N = 4–7; *p < 0.01

Figure 2: A schematic diagram showing the cGMP concentration (concentration-time) after intravenous administration of naproxen or 4-(nitrooxy)butyl-(2S)-2-(6-methoxy-2-naphthyl) propionate (naproxinol) in homozygous sickle cell transgenic mice. Naproxinol increases platelet cGMP production. N = 4–7; *p < 0.01

Invention Details

A method for treating acute pain crisis in patients with sickle cell anemia is provided. The method involves administering a therapeutically effective amount of 4-(nitrooxy)butyl-(2S)-2-(6-methoxy-2-naphthyl) propionate (naprocinol).

The following description provides specific details to provide a thorough understanding of the invention. However, those skilled in the art will understand that the invention may be practiced without these specific details. For the purposes of this specification, the following definitions will apply, and terms used in the singular will, where appropriate, also include the plural, and vice versa.

As defined herein, “treatment” refers to any reduction in the severity or duration of a vascular occlusive event, leading to the termination of the crisis, or any relief of pain associated with sickle cell anemia. Relief of pain may include a reduction in frequency, duration, or intensity. Pain intensity can be measured using standard methods such as analgesia meters, trocars, or 10-point pain scales.

As defined in this article, "prodromal signs and symptoms of vascular occlusive crisis" include: fatigue, dizziness, weakness, yellowing or pallor of the eyes, gastrointestinal symptoms such as nausea, vomiting and changes in appetite, musculoskeletal symptoms such as swelling, tenderness or stiffness of the hands/feet, and respiratory symptoms such as runny nose, cough and changes in breathing.

As used herein, the term "therapeutic effective amount" of a compound is the amount necessary or sufficient to treat or prevent diseases, disorders, and/or conditions as described herein. Effective amounts can vary depending on factors such as individual size and weight, the type of disease, or the specific compound of the invention. One skilled in the art will be able to investigate the factors included herein and determine the effective amount of the compounds of the invention without excessive experimentation.

The actual dose level of the active ingredient in the pharmaceutical composition of the present invention may vary to obtain an amount of active ingredient that effectively achieves the desired therapeutic response for a particular patient, composition and administration method, without being toxic to the patient.

The chosen dose level will depend on a variety of factors, including the activity of the specific compound of the invention used, the route of administration, the time of administration, the excretion rate of the specific compound used, the duration of treatment, other drugs, compounds and/or materials used in combination with the specific compound used, the age, sex, weight, condition, general health status and medical history of the patient to be treated, and similar factors well known in the medical field.

Clinicians with ordinary skills in the art can easily determine and prescribe the effective amount of the desired pharmaceutical composition. For example, clinicians can start with a dose of the compound of the invention used in the pharmaceutical composition below the level required to achieve the desired therapeutic effect, and gradually increase the dose until the desired effect is achieved.

Typically, the appropriate daily dose of the compounds of this invention will be the amount of the lowest dose of the compound that effectively produces a therapeutic effect. Such an effective dose usually depends on the factors mentioned above.

If desired, the effective daily dose of the active compound can be administered as two, three, four, five, six or more sub-dose at appropriate intervals throughout the day, optionally in unit dosage form.

Although the compounds of the present invention can be administered alone, it is preferred to administer the compounds as a pharmaceutical composition.

For use in this treatment, 4-(nitrooxy)butyl-(2S)-2-(6-methoxy-2-naphthyl) propionate is administered orally; the adult dose range is 100 mg/day to 3000 mg/day or 100 mg/day to 2000 mg/day, preferably 375 mg/day to 1500 mg/day, and most preferably 750 mg/day to 1500 mg/day; the pediatric dose (over 2 years old and under 16 years old) ranges from 15 to 22.5 mg/kg/day.

The exact dosage and schedule of administration will vary depending on the amount needed to provide relief in each specific case.

For use in this treatment, it is preferable to administer 4-(nitrooxy)butyl-(2S)-2-(6-methoxy-2-naphthyl) propionate to the patient starting from the onset of early prodromal signs and symptoms of vascular occlusion crisis, until the crisis is controlled. This treatment can also be used as maintenance therapy after the vascular occlusion crisis has been controlled.

The administration regimen can affect the composition of the effective dose. Several separate doses can be administered daily or sequentially, as well as alternating doses, or the dose can be administered continuously by infusion or by bolus injection. Furthermore, the dosage of the compounds of this invention can be increased or decreased proportionally depending on the urgency of the treatment or preventative situation.

As used herein, the term "pharmaceutical composition" includes formulations suitable for administration to mammals such as humans. When the compounds of the present invention are administered as pharmaceuticals to mammals such as humans, they may be given on their own or as pharmaceutical compositions comprising, for example, 0.1-99.5% (more preferably 0.5-90%) of an active ingredient in combination with a pharmaceutically acceptable carrier.

As used herein, the term "pharmaceutically acceptable carrier" is recognized in the art and includes pharmaceutically acceptable materials, compositions, or media suitable for administering the compounds of the present invention to mammals. Carriers include liquid or solid fillers, diluents, excipients, solvents, or encapsulating materials relating to carrying or transporting the subject active agent from one organ or part of the body to another organ or part of the body. Each carrier must be "acceptable" in the sense of compatibility with other components of the formulation and harmlessness to the patient. Some examples of materials that can be used as pharmaceutically acceptable carriers include: sugars, such as lactose, glucose, and sucrose; starches, such as corn starch and potato starch; cellulose and its derivatives, such as sodium carboxymethyl cellulose, ethyl cellulose, and cellulose acetate; powdered tragacanth gum; malt; gelatin; talc; excipients, such as cocoa butter and suppository waxes; oils, such as peanut oil, cottonseed oil, safflower oil, sesame oil, olive oil, corn oil, and soybean oil; glycols, such as propylene glycol; polyols, such as glycerol, sorbitol, mannitol, and polyethylene glycol; esters, such as ethyl oleate and ethyl laurate; agar; buffers, such as magnesium hydroxide and aluminum hydroxide; alginic acid; pyrogen-free water; isotonic saline; Ringer's solution; ethanol; phosphate buffer solutions; and other non-toxic and compatible substances used in pharmaceutical preparations.

Wetting agents, emulsifiers and lubricants, such as sodium dodecyl sulfate and magnesium stearate, as well as colorants, releasing agents, coating agents, sweeteners, flavoring agents and aromas, preservatives and antioxidants may also be present in the composition.

Examples of pharmaceutically acceptable antioxidants include: water-soluble antioxidants such as ascorbic acid, cysteine hydrochloride, sodium bisulfate, sodium metabisulfite, sodium sulfite, etc.; oil-soluble antioxidants such as ascorbyl palmitate, butylated hydroxyanisole (BHA), butylated hydroxytoluene (BHT), lecithin, propyl gallate, α-tocopherol, etc.; and metal chelating agents such as citric acid, ethylenediaminetetraacetic acid (EDTA), sorbitol, tartaric acid, phosphoric acid, etc.

The formulations of the present invention include those suitable for oral, nasal, topical, oral, sublingual, rectal, vaginal, and/or enteric administration. The formulations can be conveniently present in unit dosage forms and can be prepared by any method well known in the pharmaceutical field. The amount of active ingredient that can be combined with a carrier material to prepare a single dosage form is typically the amount of the compound that produces the therapeutic effect. Typically, this amount ranges from about 1% to about 99% of the active ingredient, preferably from about 5% to about 70%, and most preferably from about 10% to about 30%, within one hundred percent.

Methods for preparing these formulations or compositions include the step of combining the compounds of the present invention with a carrier and optionally one or more auxiliary components. Typically, formulations are prepared by uniformly and tightly combining the compounds of the present invention with a liquid carrier or a subdivided solid carrier, or both, and then, if desired, shaping the product.

Formulations of the present invention suitable for oral administration may be capsules, flat capsules, pills, tablets, lozenges (using a flavored base, typically sucrose and gum arabic or tragacanth gum), powders, granules, or as solutions or suspensions in aqueous or non-aqueous liquid form, or as oil-in-water or water-in-oil liquid emulsions, or as elixirs or syrups, or as soft lozenges (using an inert matrix, such as gelatin and glycerin, or sucrose and gum arabic) and/or as mouthwashes, etc., each containing a predetermined amount of the compound of the present invention as an active ingredient. The compounds of the present invention may also be administered as large pills, ointments, or pastes.

Regardless of the chosen route of administration, the compounds and/or pharmaceutical compositions of the present invention shall be formulated into pharmaceutically acceptable dosage forms using conventional methods known to those skilled in the art.

Example 1

Effects of 4-(nitrooxy)butyl-(2S)-2-(6-methoxy-2-naphthyl) propionate (naprocinol) on blood nitric oxide and cGMP levels in a sickle cell mouse model

This study was conducted to evaluate the efficacy of 4-(nitrooxy)butyl-(2S)-2-(6-methoxy-2-naphthyl) propionate (naprocinol) in increasing nitrite (a precursor of NO) and cGMP in homozygous Townes sickle cell transgenic mice.

Experimental Design

Homozygous sickle cell transgenic mice were treated with intravenous injection of 4-(nitrooxy)butyl-(2S)-2-(6-methoxy-2-naphthyl) propionate (naproxinol) (15 mg/kg), naproxen (15 mg/kg as a control), or saline (as a mediator control). One hour later, the mice were injected with thrombin (1 u/20 g) to induce platelet activation. Blood was drawn at 15, 30, and 1 hour after thrombin administration. Plasma nitrite levels were measured as a marker of nitric oxide bioavailability. cGMP levels were measured after the addition of IBMX (3-isobutyl-1-methylxanthine) (100 uM) to prevent cGMP degradation. Platelets were isolated and activation was measured by surface expression of p-selectin.

result

At 1 hour, nitrite concentrations were statistically higher with the use of naproxen compared to administration of thrombin or naproxen alone (Figure 1). At 30 and 60 minutes, cGMP levels were significantly increased with the use of naproxen compared to administration of thrombin or naproxen alone (p<0.01) (Figure 2).

The data support the assertion that 4-(nitrooxy)butyl-(2S)-2-(6-methoxy-2-naphthyl) propionate (naprocinol) is useful and helpful in treating recurrent ischemic crises in patients with sickle cell anemia. In fact, 4-(nitrooxy)butyl-(2S)-2-(6-methoxy-2-naphthyl) can increase cGMP levels, thereby reducing nitric oxide depletion and subsequent vascular lesions in sickle cell disease, which are factors leading to vascular occlusion. In addition, the anti-inflammatory components of this compound reduce inflammation and pain.

Therefore, although preferred embodiments of the invention have been described, those skilled in the art will recognize that changes and modifications can be made thereto without departing from the spirit of the invention, and it is intended that all such changes and modifications fall within the true scope of the invention.

Invention Field

This invention relates to 4-(nitrooxy)butyl-(2S)-2-(6-methoxy-2-naphthyl) propionate for the treatment of vascular occlusion crisis (VOC) in sickle cell disease.

Background of the Invention

4-(nitrooxy)butyl-(2S)-2-(6-methoxy-2-naphthyl) propionate is a nitric oxide (NO)-releasing derivative of naproxen and is also known as naproxen.

4-(nitrooxy)butyl-(2S)-2-(6-methoxy-2-naphthyl)propionate

WO 98/09831 and US 6,700,011 disclose the synthesis of 4-(nitrooxy)butyl-(2S)-2-(6-methoxy-2-naphthyl)propionate.

Schnitzer T.J. et al., Osteoarthritis and Cartilage 18 (2010) 629-639, disclosed that naproxen is a NO-releasing derivative of naproxen that combines analgesic and anti-inflammatory effects with a blood pressure effect similar to, but different from, that of placebo. In a study of osteoarthritis (OA) in the knee of human patients, naproxen demonstrated clinical efficacy and safety in controlling the signs and symptoms of OA.

White W.B. et al. (Am J Cardiol 2011; 107:1338-1345) published a large-scale analysis of the effects of naproxen on blood pressure in 2,734 patients with hip or knee osteoarthritis across three pivotal trials. The analysis indicated that naproxen can alleviate some of the hypertension burden induced by most NSAIDs.

Sickle cell disease (SCD) is a group of hemoglobinopathies caused by mutations in the sixth amino acid of the β-globulin subunit of hemoglobin. The most common mutation, βS-globulin, results in the substitution of a hydrophilic glutamate residue for a hydrophobic valine residue, leading to the production of hemoglobin S, which is prone to polymerization upon deoxygenation (Belanger AM, Keggi C, Kanias T et al., Effects of nitric oxide and its congeners on sickle red blood cell deformability. Transfusion, 2015(55)2464-2472).

Under hypoxic conditions, the polymerization of HbS causes red blood cells to twist into a distinctive sickle shape and increases their hardness and brittleness, leading to hemolysis. Hemolysis, in turn, contributes to oxidative stress and platelet activation (Helms CC, Marvel M, Zhao W, Stahle M, Vest R, Kato GJ et al. Mechanisms of hemolysis-associated platelet activation. Journal of Thrombosis and Haemostasis. 2013; 11(12):2148-2154; Villagra J, Shiva S, Hunter LA, Machado RF, Gladwin MI, Kato GJ. Platelet activation in patients with sickle disease, hemolysis-associated pulmonary hypertension, and nitric oxide scavenging by cell-free hemoglobin. Blood 2007; 110(6):2166-2172). Oxidative stress, physical interactions between sickle cells and endothelium, and other factors lead to an inflammatory state in which endothelial cells and leukocytes are activated, resulting in leukocyte and multicellular adhesion to the endothelium, thereby generating VOCs. Ischemia, organ damage, pain, and potential death are all secondary to VOCs (Parise LV, Telen MJ. Erythrocyte adhesion in sickle cell disease. Current Hematology Reports. 2003; 2(2):102-108., 2003; Hoppe CC. Inflammatory mediators of endothelial injury in sickle cell disease. Hematol Oncol Clin. North Am. 2014; 28(2):265-86; Kutlar A, Embury SH. Cellular adhesion and the endothelium: P-Selectin. Hematol Oncol Clin. North Am. 2014; 28(2):265-86; Kutlar A, Embury SH. Cellular adhesion and the endothelium: P-Selectin. Hematol Oncol Clin. North Am. 2014; 28(2):265-86.). Clin.NorthAm.2014;28(2):323-339; Zhang DC, Xu CL, Manwani D, Frenette PS. Neutrophils, platelets, and inflammatory pathways at the nexus of sickle cell diseasepathophysiology.Bl ood.2016;127(7):801-839;Kim-Shapiro DB,Gladwin MT.Nitricoxide pathology and therapeutics in sickle cell disease.Clinical Hemorheologyand Microcirculation,2018;68:223-237).

Vascular occlusive crisis and its associated pain are common reasons for emergency department visits and hospitalizations in patients with sickle cell disease. Vascular occlusive crisis and its associated pain most commonly occur in the extremities, chest, and back, and are considered nociceptive, secondary to tissue damage. The typical clinical features of a pain crisis are described as a sudden onset of pain in the lower back or one or more joints or extremities. The pain may be localized or migratory, and is persistent and throbbing. Severe pain causes patients to groan, moan, cry, twist and turn, and adopt abnormal postures in unsuccessful attempts to obtain relief. Severe attacks require treatment with non-intestinal opioids in a medical center after failure to control pain with oral anesthetics and/or non-prescription NSAIDs other than those approved by the drug label. (Ballas SK, Gupta K, Adams-Graves P. Sickle cell pain: a critical reappraisal Blood, 2012; 120(18):3647-3656).

Vascular occlusion-related pain crises evolve through four phases: the prodromal phase, the initial phase, the establishment phase, and the resolution phase. Each acute pain attack is associated with inflammation, which worsens with repeated attacks, often ultimately leading to serious complications and organ damage, such as acute chest syndrome and multiple organ failure. The prodromal phase, lasting 1-2 days before a severe pain attack, is characterized by a gradual or sudden increase in pain (initial phase), peaking after 3 days, leading to the establishment phase, which continues until day 6 or 7, after which the pain begins to subside (resolution phase). The prodromal phase of the crisis is characterized by three main pathophysiological events: vascular occlusion, inflammation, and nociception. Therefore, controlling vascular occlusion-related crises during the prodromal phase, when tissue ischemia and inflammation are in their early stages, can potentially prevent or minimize pain and tissue damage. (Ballas SK, Gupta K, Adams-Graves P. Sickle cell pain: a critical reappraisal Blood, 2012; 120(18):3647-3656).

Currently, the main treatments for controlling vascular occlusive crisis include treating acute pain attacks and reducing the occurrence of vascular occlusive crisis.

Three drugs have been approved by the FDA for the treatment of vascular occlusive crisis complications in sickle cell disease: hydroxyurea, L-glutamine, and lizalizumab-tmca. All products have been shown to reduce the frequency of vascular occlusive crises, but these drugs have not shown relief from VOC-related pain.

The recently approved Adakveo product lists an 18% incidence of joint pain and a 15% incidence of back pain associated with its product in its approved packaging instructions, indicating a persistent need for pain relief. (Novartis, 2019)

Unfortunately, while hydroxyurea (Droxia) reduces the incidence of vascular occlusion (VOC), it does not eliminate it. Patients need to maintain pain relief when painful vascular occlusion crises occur. Furthermore, the Droxia package insert contains a boxed warning regarding bone marrow suppression and malignant tumors.

Currently, the FDA has not approved any products for the treatment of pain secondary to vascular occlusive crisis in patients with sickle cell disease, although many analgesics are commonly used off-label. Guidance recommends the use of NSAIDs for mild to moderate pain, but well-controlled clinical trials have not shown any effect of NSAIDs on pain secondary to vascular occlusive crisis.

With the advancement of VOCs, more than 90% of adult patients require hospitalization and pain management, including non-intestinal opioid therapy consisting of meperidine, morphine, or hydromorphone. (Ballas SK. Pain management of sickle cell disease. Hematol Oncol Clin North Am. 2005; 19(5):785-802).

Although opioid therapy is a mainstay of pain management, it remains a suboptimal approach due to its side effects, such as sedation, dizziness, nausea, vomiting, constipation, physical dependence, tolerance, and respiratory depression. Serious adverse reactions can occur with high doses or prolonged use, including opioid tolerance (leading to increased opioid dosage), immunosuppression, hormonal changes, hyperalgesia, and an increased risk of acute chest syndrome and altered opioid clearance in sickle cell patients. (Ballas SK. Current issues in sickle cell pain and its management. Hematology Am Soc Hematol Educ Program. 2007; 97-105).

Nitric oxide (NO) is a well-known free radical signaling molecule that plays a wide range of roles in biological functions, including relaxing blood vessels, increasing blood flow, reducing platelet activation, reducing the adhesion of circulating blood cells to the endothelium, and reducing thrombus formation. In response to a variety of stimuli, vascular endothelial cells produce nitric oxide, which activates guanylate cyclase, leading to elevated levels of intracellular cyclic GMP (cGMP). Extensive research has shown that nitric oxide levels are depleted in sickle cell disease and further depleted during VOC processes (Goncalves R.P., Rev Bras Hematol Hemoter 2012; 34(4):254-64).

Treatment strategies that supplement or modulate nitric oxide (NO) have been presented as potential treatments for sickle cell disease and/or symptoms.

For example, preliminary trials have shown some positive effects of inhaled NO on acute VOCs. However, currently available results do not provide sufficient evidence to determine the effectiveness of inhaled nitric oxide in treating painful (vascular occlusion) crises in patients with sickle cell disease. Furthermore, inhaled NO requires specific handling and administration.

Another publicly disclosed strategy for increasing NO production in sickle cell disease patients is supplementation with nitric oxide precursors. Summar M.L. et al. (US 2018/0289647) disclosed a method for treating sickle cell disease and its complications, including vascular occlusive crisis, involving the administration of citrulline, a precursor of arginine and endogenously produced nitric oxide (NO). US 2018/0289647 reported a study demonstrating the safety and pharmacokinetic properties of intravenous citrulline in patients with sickle cell disease. However, the clinical efficacy of citrulline requires further evaluation in clinical studies.

Therefore, an effective and safe treatment for vascular occlusive crisis in patients with sickle cell disease is a serious unmet need.

The applicant recently conducted preclinical studies and found that 4-(nitrooxy)butyl-(2S)-2-(6-methoxy-2-naphthyl) can increase cyclic guanosine monophosphate (cGMP) levels in a sickle cell animal model. Therefore, 4-(nitrooxy)butyl-(2S)-2-(6-methoxy-2-naphthyl) may play a role in reducing nitric oxide consumption in sickle cell patients, thereby improving vascular homeostasis. Furthermore, the anti-inflammatory and analgesic activities of 4-(nitrooxy)butyl-(2S)-2-(6-methoxy-2-naphthyl) can reduce inflammatory cascade reactions and pain associated with vascular occlusive crisis.

Invention Overview

It has been found that 4-(nitrooxy)butyl-(2S)-2-(6-methoxy-2-naphthyl) propionate can beneficially interfere with the pathogenesis of pain symptoms and complications associated with vascular occlusion crisis (VOC) in sickle cell anemia and alleviate pain symptoms and complications associated with VOC.

One embodiment of the present invention relates to a method for treating vascular occlusive crisis in patients with sickle cell disease, the method comprising administering a therapeutically effective amount of 4-(nitrooxy)butyl-(2S)-2-(6-methoxy-2-naphthyl) propionate to the patient in need.

Another embodiment of the invention relates to a method for treating vascular occlusive crisis in patients with sickle cell disease, the method comprising administering a therapeutically effective amount of 4-(nitrooxy)butyl-(2S)-2-(6-methoxy-2-naphthyl) propionate to a patient in need, wherein the administration of 4-(nitrooxy)butyl-(2S)-2-(6-methoxy-2-naphthyl) propionate is initiated at the onset of early prodromal signs and symptoms of vascular occlusive crisis and continues at least until the crisis is treated.

The method of the present invention has several advantages: 4-(nitrooxy)butyl-(2S)-2-(6-methoxy-2-naphthyl) propionate can be administered to the patient at home (self-administration) once the patient senses an impending crisis (prodromal phase); administration of 4-(nitrooxy)butyl-(2S)-2-(6-methoxy-2-naphthyl) propionate in the early stages of a vascular occlusion crisis can help promote and accelerate crisis resolution by reducing the cascade of events such as vascular occlusion, inflammation, and pain (as associated with a vascular occlusion crisis).

Minimizing vascular occlusion and inflammation can reduce organ and tissue damage in sickle cell patients by reducing (1) the amount of damage to organs and tissues caused by ischemia due to blockage of blood flow through capillaries, (2) the amount of damage caused by oxidative free radicals in organs and tissues where blood flow has been restored after a period of ischemia, and (3) the amount of inflammatory mediators released from damaged cells.

Reducing the intensity of pain associated with vascular occlusion crisis can alleviate or eliminate the need for opioids to manage acute pain crises associated with ischemic crises in sickle cell patients, and thus reduce hospitalizations.

Because 4-(nitrooxy)butyl-(2S)-2-(6-methoxy-2-naphthyl) propionate is well tolerated, this compound can be administered in combination with other medical treatments commonly used to treat SCD in a manner that does not interfere with such other treatments.

Another embodiment of the invention relates to a method for reducing the severity or duration of vascular occlusive events in individuals with sickle cell disease, the method comprising administering a therapeutically effective amount of 4-(nitrooxy)butyl-(2S)-2-(6-methoxy-2-naphthyl) propionate.

Another embodiment of the present invention is a method for mitigating organ and tissue damage caused by vascular occlusion events, the method comprising administering an effective amount of 4-(nitrooxy)butyl-(2S)-2-(6-methoxy-2-naphthyl) propionate to an individual suffering from sickle cell disease.

One embodiment of the present invention provides a method for treating pain in patients with sickle cell anemia during recurrent ischemic crisis by administering a therapeutically effective amount of 4-(nitrooxy)butyl-(2S)-2-(6-methoxy-2-naphthyl) ester propionate.

Another embodiment of the present invention is a method for treating pain secondary to sickle cell disease vascular occlusion crisis (VOC) in patients with sickle cell anemia, by combining the administration of a therapeutically effective amount of 4-(nitrooxy)butyl-(2S)-2-(6-methoxy-2-naphthyl) ester propionate with opioid therapy used during such pain crisis.

In one embodiment, the invention includes the method of the invention, wherein the pharmaceutical composition contains a therapeutically effective amount of 4-(nitrooxy)butyl-(2S)-2-(6-methoxy-2-naphthyl) ester of propionate, the pharmaceutical composition further comprising one or more pharmaceutically acceptable carriers. In one embodiment, the pharmaceutical composition is suitable for oral, nasal, topical, oral, sublingual, rectal, vaginal, or enteral administration.

The present invention also relates to 4-(nitrooxy)butyl-(2S)-2-(6-methoxy-2-naphthyl) propionate or pharmaceutical compositions comprising 4-(nitrooxy)butyl-(2S)-2-(6-methoxy-2-naphthyl) propionate and one or more pharmaceutically acceptable carriers for use in any of the treatment methods reported above.

The present invention also relates to the use of 4-(nitrooxy)butyl-(2S)-2-(6-methoxy-2-naphthyl) propionate in the preparation of a medicament for any of the treatment methods reported above.

Brief description of the attached diagram

Figure 1: A schematic diagram showing the plasma nitrite concentration (concentration-time) after intravenous administration of naproxen or 4-(nitrooxy)butyl-(2S)-2-(6-methoxy-2-naphthyl) propionate (naproxinol) in homozygous sickle cell transgenic mice. Naproxinol increases plasma nitrite concentration. N = 4–7; *p < 0.01

Figure 2: A schematic diagram showing the cGMP concentration (concentration-time) after intravenous administration of naproxen or 4-(nitrooxy)butyl-(2S)-2-(6-methoxy-2-naphthyl) propionate (naproxinol) in homozygous sickle cell transgenic mice. Naproxinol increases platelet cGMP production. N = 4–7; *p < 0.01

Invention Details

A method for treating acute pain crisis in patients with sickle cell anemia is provided. The method involves administering a therapeutically effective amount of 4-(nitrooxy)butyl-(2S)-2-(6-methoxy-2-naphthyl) propionate (naprocinol).

The following description provides specific details to provide a thorough understanding of the invention. However, those skilled in the art will understand that the invention may be practiced without these specific details. For the purposes of this specification, the following definitions will apply, and terms used in the singular will, where appropriate, also include the plural, and vice versa.

As defined herein, “treatment” refers to any reduction in the severity or duration of a vascular occlusive event, leading to the termination of the crisis, or any relief of pain associated with sickle cell anemia. Relief of pain may include a reduction in frequency, duration, or intensity. Pain intensity can be measured using standard methods such as analgesia meters, trocars, or 10-point pain scales.

As defined in this article, "prodromal signs and symptoms of vascular occlusive crisis" include: fatigue, dizziness, weakness, yellowing or pallor of the eyes, gastrointestinal symptoms such as nausea, vomiting and changes in appetite, musculoskeletal symptoms such as swelling, tenderness or stiffness of the hands/feet, and respiratory symptoms such as runny nose, cough and changes in breathing.

As used herein, the term "therapeutic effective amount" of a compound is the amount necessary or sufficient to treat or prevent diseases, disorders, and/or conditions as described herein. Effective amounts can vary depending on factors such as individual size and weight, the type of disease, or the specific compound of the invention. One skilled in the art will be able to investigate the factors included herein and determine the effective amount of the compounds of the invention without excessive experimentation.

The actual dose level of the active ingredient in the pharmaceutical composition of the present invention may vary to obtain an amount of active ingredient that effectively achieves the desired therapeutic response for a particular patient, composition and administration method, without being toxic to the patient.

The chosen dose level will depend on a variety of factors, including the activity of the specific compound of the invention used, the route of administration, the time of administration, the excretion rate of the specific compound used, the duration of treatment, other drugs, compounds and/or materials used in combination with the specific compound used, the age, sex, weight, condition, general health status and medical history of the patient to be treated, and similar factors well known in the medical field.

Clinicians with ordinary skills in the art can easily determine and prescribe the effective amount of the desired pharmaceutical composition. For example, clinicians can start with a dose of the compound of the invention used in the pharmaceutical composition below the level required to achieve the desired therapeutic effect, and gradually increase the dose until the desired effect is achieved.

Typically, the appropriate daily dose of the compounds of this invention will be the amount of the lowest dose of the compound that effectively produces a therapeutic effect. Such an effective dose usually depends on the factors mentioned above.

If desired, the effective daily dose of the active compound can be administered as two, three, four, five, six or more sub-dose at appropriate intervals throughout the day, optionally in unit dosage form.

Although the compounds of the present invention can be administered alone, it is preferred to administer the compounds as a pharmaceutical composition.

For use in this treatment, 4-(nitrooxy)butyl-(2S)-2-(6-methoxy-2-naphthyl) propionate is administered orally; the adult dose range is 100 mg/day to 3000 mg/day or 100 mg/day to 2000 mg/day, preferably 375 mg/day to 1500 mg/day, and most preferably 750 mg/day to 1500 mg/day; the pediatric dose (over 2 years old and under 16 years old) ranges from 15 to 22.5 mg/kg/day.

The exact dosage and schedule of administration will vary depending on the amount needed to provide relief in each specific case.

For use in this treatment, it is preferable to administer 4-(nitrooxy)butyl-(2S)-2-(6-methoxy-2-naphthyl) propionate to the patient starting from the onset of early prodromal signs and symptoms of vascular occlusion crisis, until the crisis is controlled. This treatment can also be used as maintenance therapy after the vascular occlusion crisis has been controlled.

The administration regimen can affect the composition of the effective dose. Several separate doses can be administered daily or sequentially, as well as alternating doses, or the dose can be administered continuously by infusion or by bolus injection. Furthermore, the dosage of the compounds of this invention can be increased or decreased proportionally depending on the urgency of the treatment or preventative situation.

As used herein, the term "pharmaceutical composition" includes formulations suitable for administration to mammals such as humans. When the compounds of the present invention are administered as pharmaceuticals to mammals such as humans, they may be given on their own or as pharmaceutical compositions comprising, for example, 0.1-99.5% (more preferably 0.5-90%) of an active ingredient in combination with a pharmaceutically acceptable carrier.

As used herein, the term "pharmaceutically acceptable carrier" is recognized in the art and includes pharmaceutically acceptable materials, compositions, or media suitable for administering the compounds of the present invention to mammals. Carriers include liquid or solid fillers, diluents, excipients, solvents, or encapsulating materials relating to carrying or transporting the subject active agent from one organ or part of the body to another organ or part of the body. Each carrier must be "acceptable" in the sense of compatibility with other components of the formulation and harmlessness to the patient. Some examples of materials that can be used as pharmaceutically acceptable carriers include: sugars, such as lactose, glucose, and sucrose; starches, such as corn starch and potato starch; cellulose and its derivatives, such as sodium carboxymethyl cellulose, ethyl cellulose, and cellulose acetate; powdered tragacanth gum; malt; gelatin; talc; excipients, such as cocoa butter and suppository waxes; oils, such as peanut oil, cottonseed oil, safflower oil, sesame oil, olive oil, corn oil, and soybean oil; glycols, such as propylene glycol; polyols, such as glycerol, sorbitol, mannitol, and polyethylene glycol; esters, such as ethyl oleate and ethyl laurate; agar; buffers, such as magnesium hydroxide and aluminum hydroxide; alginic acid; pyrogen-free water; isotonic saline; Ringer's solution; ethanol; phosphate buffer solutions; and other non-toxic and compatible substances used in pharmaceutical preparations.

Wetting agents, emulsifiers and lubricants, such as sodium dodecyl sulfate and magnesium stearate, as well as colorants, releasing agents, coating agents, sweeteners, flavoring agents and aromas, preservatives and antioxidants may also be present in the composition.

Examples of pharmaceutically acceptable antioxidants include: water-soluble antioxidants such as ascorbic acid, cysteine hydrochloride, sodium bisulfate, sodium metabisulfite, sodium sulfite, etc.; oil-soluble antioxidants such as ascorbyl palmitate, butylated hydroxyanisole (BHA), butylated hydroxytoluene (BHT), lecithin, propyl gallate, α-tocopherol, etc.; and metal chelating agents such as citric acid, ethylenediaminetetraacetic acid (EDTA), sorbitol, tartaric acid, phosphoric acid, etc.

The formulations of the present invention include those suitable for oral, nasal, topical, oral, sublingual, rectal, vaginal, and/or enteric administration. The formulations can be conveniently present in unit dosage forms and can be prepared by any method well known in the pharmaceutical field. The amount of active ingredient that can be combined with a carrier material to prepare a single dosage form is typically the amount of the compound that produces the therapeutic effect. Typically, this amount ranges from about 1% to about 99% of the active ingredient, preferably from about 5% to about 70%, and most preferably from about 10% to about 30%, within one hundred percent.

Methods for preparing these formulations or compositions include the step of combining the compounds of the present invention with a carrier and optionally one or more auxiliary components. Typically, formulations are prepared by uniformly and tightly combining the compounds of the present invention with a liquid carrier or a subdivided solid carrier, or both, and then, if desired, shaping the product.

Formulations of the present invention suitable for oral administration may be capsules, flat capsules, pills, tablets, lozenges (using a flavored base, typically sucrose and gum arabic or tragacanth gum), powders, granules, or as solutions or suspensions in aqueous or non-aqueous liquid form, or as oil-in-water or water-in-oil liquid emulsions, or as elixirs or syrups, or as soft lozenges (using an inert matrix, such as gelatin and glycerin, or sucrose and gum arabic) and/or as mouthwashes, etc., each containing a predetermined amount of the compound of the present invention as an active ingredient. The compounds of the present invention may also be administered as large pills, ointments, or pastes.

Regardless of the chosen route of administration, the compounds and/or pharmaceutical compositions of the present invention shall be formulated into pharmaceutically acceptable dosage forms using conventional methods known to those skilled in the art.

Example 1

Effects of 4-(nitrooxy)butyl-(2S)-2-(6-methoxy-2-naphthyl) propionate (naprocinol) on blood nitric oxide and cGMP levels in a sickle cell mouse model

This study was conducted to evaluate the efficacy of 4-(nitrooxy)butyl-(2S)-2-(6-methoxy-2-naphthyl) propionate (naprocinol) in increasing nitrite (a precursor of NO) and cGMP in homozygous Townes sickle cell transgenic mice.

Experimental Design

Homozygous sickle cell transgenic mice were treated with intravenous injection of 4-(nitrooxy)butyl-(2S)-2-(6-methoxy-2-naphthyl) propionate (naproxinol) (15 mg/kg), naproxen (15 mg/kg as a control), or saline (as a mediator control). One hour later, the mice were injected with thrombin (1 u/20 g) to induce platelet activation. Blood was drawn at 15, 30, and 1 hour after thrombin administration. Plasma nitrite levels were measured as a marker of nitric oxide bioavailability. cGMP levels were measured after the addition of IBMX (3-isobutyl-1-methylxanthine) (100 uM) to prevent cGMP degradation. Platelets were isolated and activation was measured by surface expression of p-selectin.

result

At 1 hour, nitrite concentrations were statistically higher with the use of naproxen compared to administration of thrombin or naproxen alone (Figure 1). At 30 and 60 minutes, cGMP levels were significantly increased with the use of naproxen compared to administration of thrombin or naproxen alone (p<0.01) (Figure 2).

The data support the assertion that 4-(nitrooxy)butyl-(2S)-2-(6-methoxy-2-naphthyl) propionate (naprocinol) is useful and helpful in treating recurrent ischemic crises in patients with sickle cell anemia. In fact, 4-(nitrooxy)butyl-(2S)-2-(6-methoxy-2-naphthyl) can increase cGMP levels, thereby reducing nitric oxide depletion and subsequent vascular lesions in sickle cell disease, which are factors leading to vascular occlusion. In addition, the anti-inflammatory components of this compound reduce inflammation and pain.

Therefore, although preferred embodiments of the invention have been described, those skilled in the art will recognize that changes and modifications can be made thereto without departing from the spirit of the invention, and it is intended that all such changes and modifications fall within the true scope of the invention.

Claims (6)

1. Use of 4-(nitrooxy)butyl-(2S)-2-(6-methoxy-2-naphthyl) propionate as the sole active agent in the preparation of a medicament for the treatment of vascular occlusive crisis in patients with sickle cell anemia.

2. The use according to claim 1, wherein 4-(nitrooxy)butyl-(2S)-2-(6-methoxy-2-naphthyl) propionate is administered during the prodromal phase of vascular occlusion crisis and during vascular occlusion crisis.

3. The use according to claim 1 or claim 2, wherein the treatment comprises reducing the severity or duration of vascular occlusive crisis.

4. The use according to claim 1 or claim 2, wherein the treatment includes treating pain associated with vascular occlusive crisis.

5. The use according to claim 1 or claim 2, wherein the treatment comprises reducing or preventing organ and tissue damage caused by vascular occlusive crisis.

6. The use according to claim 1, wherein 4-(nitrooxy)butyl-(2S)-2-(6-methoxy-2-naphthyl) propionate is administered as a pharmaceutical composition, said pharmaceutical composition further comprising one or more pharmaceutically acceptable carriers.