EP0726780A1

EP0726780A1 - Treatment for rheumatoid arthritis

Info

Publication number: EP0726780A1
Application number: EP95900514A
Authority: EP
Inventors: Irwin A. Braude
Original assignee: Neurobiological Technologies Inc
Current assignee: Neurobiological Technologies Inc
Priority date: 1993-11-02
Filing date: 1994-11-02
Publication date: 1996-08-21
Also published as: LT96079A; NO961747L; AU8131694A; CA2175457A1; HU9601149D0; CZ122696A3; NO961747D0; WO1995012416A1; JPH09504792A; PL314191A1; HUT74275A

Abstract

Administration of corticotropin-releasing factor to patients suffering from one of the chronic inflammatory arthritides, such as rheumatoid arthritis, reduces episodic acute inflammatory responses to the chronic disease. Doses of administered CRF in accordance with the invention give anti-inflammatory results in a dose responsive manner even in well-established disease.

Description

TREATMENT FOR RHEUMATOID ARTHRITIS

Field of the Invention

This invention generally relates to a method of treating a patient suffering from a chronic inflam¬ matory arthritides, and more particularly to the use of corticotropin-releasing factor or its analogs in reducing swelling during episodic acute responses of chronic inflammatory conditions.

Background of the Invention

Among the diseases that plague humans are the chronic inflammatory arthritides, which include rheuma¬ toid arthritis, Reiters Syndrome, ankylosing spondyitis, psoriatic arthritis, and inflammatory bowel disease. Of these, rheumatoid arthritis is the cause of an estimated about 33,000 deaths in the United States each year. As yet, there is no cure for the disease, and the cause is uncertain. Rheumatoid arthritis sufferers periodically experience flare-ups, or episodic acute responses, of from a week up to a month of duration.

Steinman, "Autoimmune Disease," Scientific American , pp. 107-114 (September 1993) discusses several possible new approaches to treating an autoimmune disease, such as rheumatoid arthritis. In one, decoys are being designed to fit into the HLA (human lymphocyte antigen) cleft in an attempt to turn off T cells. In another, a monoclonal antibody that binds with tumor necrosis factor appears to increase joint mobility and reduce the stiffness associated with rheumatoid arthritis. However, these possible new approaches are as yet not therapeutically established as to efficacy. Assisting in the search for treatments is the fact that animal models have been developed using arthritis-susceptible rat strains. Among other possible abnormalities, the "Lewis" arthritis-susceptible rats have a deficient hypothalamic CRF response to various stimuli so that researchers can experimentally induce inflammatory arthritis and some other autoimmune diseases. In the Piebald-Viral-Glaxo ("PVG") rat model, unlike the Lewis strain rat, the animals do not appear to have a hypothal o-pituitary-adrenal ("HPA") axis defect, but are nevertheless susceptible to arthritis. U.S. Patent 5,006,330, issued April 9, 1991, inventors Sternberg et al. ,~describes use of the Lewis rat animal model in which the experimental animals developed an arthritis which mimics human rheumatoid arthritis in response to exposure to Group A strepto- coccal cell wall fragments. Sternberg et al. teach use of the model for testing the susceptibility of mammals to inflammatory diseases. Sternberg et al. describe measuring "CRH" (corticotropin-releasing hormone) after injections of various agents. CRH is an alternative term for corticotropin-releasing factor (hereinafter "CRF") , which is a 41 a ino acid neuropeptide that is present in brain and the peripheral nerve endings, and stimulates ACTH release from pituitary cells in brain and such diverse peripheral locations as nerve endings and leukocytes. Sternberg et al. also describe injections of CRH followed by measurements of ACTH and corticosterone.

Antibodies directed against CRF have been reported to partially abrogate the inflammatory response, which has led various researchers to believe that CRF is a pro-inflammatory agent. Karalis et al., "Autocrine or paracrine Inflammatory Actions of Corticotropin-Releasing Hormone in Vivo," Science , 254 ,

421-423 (1991) .

U.S. Patent 4,489,163, inventors Rivier et al., issued December 18, 1984, discloses rat CRF and its analogs. Human CRF has the same sequence as rat CRF.

There are a number of analogs of CRF known to the art.

U.S. Patent 4,415,558, inventors Vale, Jr. et al., issued November 15, 1983, discloses the synthesis of sheep CRF, analogs, and isolation of the oCRF from ovine hypothalamic extracts. The synthetic oCRF was found to lower blood pressure.

A generally similar peptide, sauvagine, was described in Regulatory Peptides , 2 , pp. 1-13 (1981).

Sauvagine is a 40 amino acid peptide and has been reported to have biological activity in lowering blood pressure in mammals and stimulating the secretion of

ACTH and /3-endorphin.

U.S. Patent 4,528,189, inventors Lederis et al., issued July 9, 1985, and U.S. Patent 4,533,654, inventors Lederis et al., issued August 6, 1985, disclose peptides similar to the rat and sheep CRF and analogs thereof, and found this white "acker and carp urotensin respectively to stimulate ACLH and to lower blood pressure. The CRF-related peptide, white sucker urotensin, has an amino acid sequence the same as the carp urotensin, except the amino acid at the 24 position is Isoleucine and the amino acid at the 27 position is

Glutamic Acid.

Ling et al., BBRC, 122 , pp. 1218-1224 (1984), disclose the structure of goat CRF, which is the same as that for sheep CRF. Esch et al. , BBRC - 122 , pp. 899-905 (1984) , disclose the structure of bovine CRF which differs from sheep and goat CRF only by one amino acid residue (number 33 which is Asparagine rather than the number 33 Serine of goat and sheep CRF) . Porcine CRF has been isolated and characterized by Patthy et al., Proc . Natl . Acad. Sci . , 82, pp. 8762-8766 (1985). Por¬ cine CRF shares a common amino acid sequence (residues 1-39) with rat/human CRF and differs from these only in position 40 and 41. Residue 40 can be either dsparagine or isoleucine and residue 41 is phenylalanine-amide.

U.S. Patent 4,801,612, inventor Wei, issued January 31, 1989, discloses the use of inhibiting an inflammatory response (acute) in the skin or mucosal membranes of a patient by administering Corticotropin- Releasing Factor, or its analogs, and U.S. Patent 5,137,871, issued August 11, 1992, inventor Wei, describes the use of CRF (or a salt or analog thereof) in treating a patient for injury to or disease of the brain, nervous system, or musculature in which edema is a factor.

Summary of the Invention

Administration of corticotropin-releasing factor to patients suffering from one of the chronic inflammatory arthritides, such as rheumatoid arthritis, reduces episodic acute inflammatory responses to the disease. Doses of CRF in accordance with the invention give anti-inflammatory results in a dose responsive manner even in well-established disease. Thus, practice of the invention provides a therapeutic treatment for these unremitting diseases that are refractory to current therapies.

Therapeutic treatment in accordance with the invention will be under the supervision of a health care professional, usually a physician, and may be in conjunction with other drugs and treatments. Because anti-inflammatory effects and other ameliorating results are experienced within several days when treating episodic acute inflammatory responses that typically would otherwise last for one week up to months, patients receive effective relief of uncomfortable or even incapacitating symptoms in an inventive course of treatment, although practice of the invention is not a cure.

Brief Description of the Drawings Figure " is a perspective view illustrating the paws of two mycobacterium induced arthritis- susceptible male Lewis "LEW/N" rats where paw 10 is a control and paw 12 has been injected with Mycobacterium to induce arthritis; Figure 2 graphically illustrates foot pad swelling (with one unit equivalent to 0.001 inches) in an animal model of arthritis-susceptible rats as a function of time for control animals and animals treated in accordance with the invention at two different doses (50 and 100 μg CRF; injected subcutaneously, per kg of body weight) , with the foot pad swelling measurement being made of mycobacterium injected paws (left hind) ;

Figure 3 is similar to Fig. 2, but illustrates measurements of the paws opposite to the injected paws in the transverse plane (right hind) ;

Figure 4 graphically illustrates the plot of arthritis scores as a function of time for the right hind paw of Fig. 3;

Figure 5 is similar to Fig. 4, but is of the other pair of paws (left and right front) ;

Figure 6, including panels A-E, is similar to Fig. 2 but plots the larger dose (100 μg/kg body weight) administered subcutaneously in the mycobacterium injected foot pad (left hind) in accordance with the invention beginning at times delayed up to 40 days after induction of disease;

Figure 7, including panels A-E, is similar to Fig. 6 but is of the opposite foot pad in the traverse plane (right hind) ; and Figure 8 graphically illustrates plots of arthritis scores in a manner similar to that of Fig. 4, but in the format similar to that of Fig. 6.

Detailed Description of the Preferred Embodiments It is possible that earlier reports, which found the presence of CRF in the joints of mammals with inflammatory arthritis and suggested CRF was a pro- inflammatory agent, may be correct because it is possible that the peptide may be either pro-inflammatory or anti-inflammatory, depending upon the amount of endogenous peptide produced, how the "inflammatory" cell responds to CRF or when CRF appears during the course of the inflammatory response. However, the following description of the work demonstrates that administration of CRF can be therapeutically effective in inhibiting episodic acute and chronic inflammatory responses in a dose-responsive manner, and therefore this invention is a therapeutic method for treating patients with chronic inflammatory arthritides, such as rheumatoid arthritis. Practice of this invention uses CRF. By "CRF" are meant to be included the analogs and CRF-related peptides known to the art. Therapeutic formations of CRF may be prepared for storage by mixing CRF having the desired degree of purity with optional physiologically acceptable carriers, excipients or stabilizers, in the form of lyophilized cake or aqueous solutions. Acceptable carriers, excipients or stabilizers are nontoxic to recipients at the dosages and concentrations employed when administered, and include buffers such as phosphate, citrate, and other organic acids; anti- oxidants including ascorbic acid; low molecular weight (less than about 10 residues) polypeptides; proteins, such as serum albumin, gelatin or immunoglobulins. Other components can include glycine, glutamine, asparagine, arginine, or lysine; monosaccharides, disaccharides, and other carbohydrates including glucose, mannose, or dextrins; chelating agents such as EDTA; sugar alcohols such as mannitol or sorbitol; salt- forming counterions such as sodium; and/or" nonionic surfactants such as Tween, Pluronics, or PEG.

Administration may be by any mode of admini¬ stration known in the art, including, but not limited to, intra-articular, intravenous, intrathecal, subcu¬ taneous, injection, intranasal, oral, or via an implanted device. Suitable implants include, for example, gel foam, wax, or microparticle-based implants. Topical administration preferably includes agents or apparatus to facilitate skin delivery, such as solubilizing agents or directed delivery systems as are known and being developed in the rapidly emerging technologies of skin delivery systems.

Therapeutically effective doses of CRF or its analogs in practicing this invention preferably are at least about 0.01 μg/kg in humans. For systemic administration (e.g. subcutaneous and intravenous) , more preferred doses are in the range of about 0.1 to about 50 μg/kg, and most preferred about 1 to about 30 μg/kg. For local administration (e.g. intra-articular) , the preferred dose is in a range of about 1 to about 100 μg/kg. Administration of CRF doses may be infused slowly, such as subcutaneously or intradermally, or may be injected directly into an afflicted body part.

Patients treated will be under the care of a health care professional, such as a physician, who may herself administer the therapeutic composition including

CRF or may prescribe such for the patient's self administration (such as, for example, preloaded syringes) . Systemic forms of administration are particularly preferred due to the frequent multiple sites of episodic situations, or flares. Unfortunately, although treatments in accordance with the invention, as further illustrated hereinafter, are shown efficacious, when treatment is stopped then efficacy also ceases. As with many other different types of therapies, the therapeutic method of this invention may be^r combined with other pharmaceuticals and other therapeutic approaches to the disease being treated.

Administration of CRF in accordance with this invention may potentially be continued for up -to about three weeks, but side effects (e.g. Cushing's Syndrome) may tend to develop after prolonged intake. Thus, practice of this invention is primarily contemplated for treating acute, episodic flares, and CRF administration can be undertaken up to forty days after an episodic acute inflammation occurs. Although the peptides are generally water soluble as typically synthesized, they may be admini¬ stered in the form of pharmaceutically acceptable non-toxic salts, such as acid addition salts. Illustra¬ tive acid addition salts are hydrochloride, hydrobro- mide, sulfate, sulphate, acetate, citrate, benzoate, succinate, malate, ascorbate, tartrate, or the like. In addition to the fact that CRF may be administered in any pharmacologically acceptable carrier, depending upon the desired mode of administration it may be formulated along with liquid carrier into liposomes, microcapsules, polymers, or wax-based and controlled release prepara¬ tions, or be formulated into tablet, pill, or capsule forms.

A method for treating a patient in accordance with this invention involves patients suffering from one of the chronic inflammatory arthritides. By chronic inflammatory arthritides are meant to include rheumatoid arthritis, Reiters Syndrome, ankylosing spondylitis, psoriatic arthritis, and inflammatory bowel disease. Treatments are particularly useful for episodic acute inflammations and provide anti-inflammatory results in a dose responsive manner. Experiments demonstrate that regardless of the time administered (e.g. up to about forty days after an episodic acute inflammation) , practice of the invention reduces inflammation even in well established disease; however, when treatment is discontinued, then the inflammatory symptoms have been found to reoccur. Thus, the present invention is most likely a treatment rather than a cure.

EXPERIMENTAL

Therapeutic efficacy was demonstrated with a rat adjuvant arthritis model in which arthritis- susceptible male Lewis "LEW/N" rats had killed Myco¬ bacterium injected into the left-hind foot paw to induce arthritis. With reference generally to Fig. 1, approxi¬ mately sixteen days post-induction of the disease animals (i.e. animals treated with saline) had paws illustrated by paw 10; however, shortly after disease is induced, the mycobacterium injected paws 12 (and later, as will be described, other paws) experience foot pad swelling. The foot pad swelling is a signal of inflammation. As is known, inflammation is manifested by redness, swelling, heat and pain as a reaction of the body against injury or assault. Five days after induction of the disease in the rats, CRF was administered subcutaneously twice a day at either a dose per administration of 50 μg/kg or 100 μg/kg. The twice a day administrations were continued for a period of 20 days. By approximately 16 days post-induction, the CRF treated animals have comparatively little swelling or inflammation.

Starting with the first day of administration (that is, day 5 after having injected the killed Myco¬ bacterium) , the amount of swelling was determined by the use of calipers in measuring the thickness of left hind (injected) paw. This measurement served as a determination for the degree of "primary," or acute, inflammation. Subsequently (usually about an additional 10-12 days) the right hind paw also swells and becomes inflamed. This represents a chronic inflammatory response.

Turning to Fig. 2, the primarily inflamed left hind paw swelling data (measured through day 32) is shown for control rats, for rats receiving twice a day administrations of CRF at 50 μg/kg body weight, and for rats receiving twice a day administrations of CRF at 100 μg/kg body weight. The vertical axis is measured in units where one unit is equivalent to 0.001 inches. As is shown by the Fig. 2 data, administrations of CRF in accordance with the invention gave anti-inflammatory results and in a dose responsive manner. The three graphs of Fig. 2 all begin five days after the left hind paw was challenged with Mycobacterium. With twice a day injection of 50 μg/kg CRF, there was reduced swelling relative to control. Results were even of greater significance with administrations of 100 μg/kg.

Turning to Fig. 3, data similar to that of Fig. 2 are represented, but the degree of foot pad swelling being measured is that of the right hind paw and thus represents a chronic inflammatory response. Administration of CRF at doses of either 50 μg/kg or 100 μg/kg were begun five days after challenge, as with Fig. 2, but the right hind paw has a swelling on-set later than does the left hind paw illustrated by the Fig. 2 data. The right hind paw also experiences less swelling than the left hind paw. Of course, the right hind paw is not itself directly challenged as is the left hind paw. Nevertheless, as seen, beginning about day 11, the right hind paw begins to swell; however, for animals receiving CRF in accordance with the invention, very little swelling (for either the 50 μg/kg body weight or the 100 μg/kg body weight) is experienced.

Turning to Fig. 4, the animals as in Fig. 3 were also assessed for the extent of arthritis by using a s ring system in which "0" indicated no arthritis and "4" represented severe arthritis. The arthritis scores were made by evaluating a combination of factors including the percent involvement of the foot pads plus the overall symptoms of the disease (which include swelling, redness, and disfigurement) . The Fig. 4 data shows that both doses of CRF (50 μg/kg and 100 μg/kg) are active in reducing the arthritis scores, although the 100 μg/kg dose appears to show a greater effect. The right hind paw of the animals were used for the Fig. 4 scoring.

With Fig. 5, conducted similarly to the just described Fig. 4, the two front paws were evaluated. That is, Figs 4 and 5 both represent chronic, rather than acute, situations. However, the front paws used for the Fig. 5 data experienced an on-set of swelling and other symptoms even more delayed and less pronounced than for the right hind paws of Fig. 4. As is seen particularly with the Fig. 5 data, administrations of CRF in accordance with this invention are very effective in t eating for the clinical manifestations of chronic inflammatory arthritis.

In the experiments summarized by the data of Figs. 2-5, treatments began five days after induction of the disease. Another set of experiments were undertaken when the disease was induced as before, and the animals were then treated in accordance with the invention (at 100 μg/kg doses administered twice daily subcutaneously) for a period of 20 days, except that the course of treatment began five days, 10 days, 15 days, 25 days, or 40 days after disease was induced. These experiments are summarized by the data of Figs. 6-8. Turning to Fig. 6, panels A-E illustrate measurements taken of the left hind foot pad. Panel A plots the foot pad thickness for the control rats and for rats who received treatment beginning on day 5 after induction of the disease (indicated by the open arrow) and ending on day 20 (indicated by the filled in, or closed, arrow) . Thus, beginning promptly after treatment in accordance with the invention five days after induction of disease, footpad thickness was considerably reduced with respect to the control, and the thickness reductions continued until treatment was discontinued, at which time swelling began and continued until by about day 60 there was substantially no difference between the previously treated footpad and the control (never treated) footpad. Similarly, panel B illustrates data for the control and test rats with treatment beginning on day 10 and ending on day 30, panel C with treatment beginning on day 15 and ending on day 35, panel D with treatment beginning on day 25 and ending on day 45, and panel E with treatment beginning on day 40 and ending on day 60. These data demonstrate that when treating with CRF it profoundly reduced foot pad swelling, even in well established disease such as illustrated by panel E. Thus, panel E of Fig. 6 had treatment begun forty days after induction of disease, yet promptly after treatment was begun, the treated footpad experienced reduced swelling.

Turning to Fig. 7, the data illustrated by panels A-E are similar to those described for Fig. 6, but the foot pad swelling was measured in the animals' right hind foot pad. That is, as with Fig. 3, since the degree of foot pad swelling being measured is that of the right hind paw (where the left hind paw is the site of mycobacterium injections and may represent acute flares) , the right hind paw may represent chronic inflammatory responses. Once again, these data demonstrate that administering CRF in accordance with the invention profoundly reduces swelling, even in established disease, for chronic inflammatory conditions. ^r In experiments similar to Figs. 6 and 7, but where the animals were assessed for the extent of arthritis by using a scoring system such as is described for Fig. 4, practice of the invention adds significantly against overall arthritic condition, although perhaps less than seen in reducing foot pad swelling. Turning to Fig. 8, in each of panels A-E animals receiving treatment are indicated for the times when treatment was commenced by the open arrows. The times when treatments stopped are indicated by the filled in, or closed, arrows.

Thus, with reference to panel A of Fig. 8, five days after an animal's left hind footpad had been challenged by the killed Mycobacterium, administrations of CRF in accordance with the invention were begun in the right hind footpad and were continued for a period of twenty days. During the course of treatment, the arthritis scores went down with respect to the control, but when the treatment was discontinued, these scores rose. Thus, practice of this invention is therapeutic as opposed to prophylactic. However, it is important to note, as illustrated by panel D of Fig. 8, ιat starting treatment in accordance with the invention as late as 25 days into the disease was still efficacious.

It is to be understood that while the invention has been described above in conjunction with preferred specific embodiments, the description and examples are intended to illustrate and not limit the scope of the invention, which is defined by the scope of the appended claims.

Claims

In is Claimed:

1. A method for treating a patient suffering from one of the chronic inflammatory arthritides, comprising: administering a therapeutically effective dose of CRF to the patient.

2. The method as in claim 1 wherein the patient is suffering from rheumatoid arthritis.

3. The method as in claim 1 wherein the dose administered is at least about 0.01 μg/kg body weight.

4. The method as in claim 1 wherein the administration is by infusion or absorption.

5. The method as in claim 1 wherein the administration is local injection in a dose of from about 1 to about 100 μg/kg.

6. A method of treating a patient suffering from rheumatoid arthritis, comprising: administering to the patient an amount of a neuropeptide, the neuropeptide consisting essentially corticotropin-releasing factor, including salts, analogs, or salts of analogs thereof, in an amount effective to decrease inflammation of an afflicted body portion.

7. The method as in claim 6 wherein the administering reduces episodic acute inflammatory responses in the patient.

8. The method as in claim 6 wherein the administering is topical, intra-articular, intravenous, intrathecal, subcutaneous, injection, intranasal, oral, or via an implanted device.

9. The method as in claim 7 wherein the administering is undertaken within about forty days after an episodic acute inflammation.

10. The method as in claim 9 wherein the administering is continued for not greater than about three continuous weeks.