Title: Method of treating or preventing Type 1 diabetes by oral administration of insulin
United States Patent: 6,703,361
Issued: March 9, 2004
Inventors: Weiner; Howard L. (Brookline, MA); Eisenbarth; George (Wellesley, MA); Hafler; David Allen (West Newton, MA); Zhang; Zhengyi (Walden, MA)
Assignee: AutoImmune Inc. (Pasadena, CA)
Appl. No.: 203929
Filed: December 2, 1998
Disclosed herein are methods for treating or preventing a disease in mammals having the characteristics of Type 1 diabetes comprising administering insulin or disease suppressive fragments of insulin or analogs thereof in oral or aerosol dosage forms to said mammals. Also disclosed herein are pharmaceutical formulation or dosage forms for use in the methods.
SUMMARY OF THE INVENTION
It has unexpectedly been discovered that oral administration of insulin is an effective treatment for eliminating or reducing the need for insulin in Type 1 diabetics. Oral insulin can prevent or ameliorate beta cell destruction and thereby decrease or eliminate traditional parenteral insulin therapy.
Orally administrable pharmaceutical formulations containing insulin are prepared and administered to mammals who have manifested symptoms of Type 1 diabetes and/or diagnosed as having Type 1 diabetes. Additionally, subjects who are at risk for developing Type 1 diabetes (i.e. have demonstrated a predisposition to developing Type 1 diabetes through suitable means, such as genetic studies and analysis) are treated with similar oral preparations of insulin.
Pharmaceutical formulations for oral or enteral administration to treat Type 1 diabetes are prepared from commercially available insulin and a pharmaceutically acceptable carrier suitable for oral ingestion. The quantity of insulin in each dose may be between 1 mg and 1000 mg. However the total dose required for treatment varies according to the individual. Generally, the total quantity of insulin required in practicing the present invention is a much larger dose than is the dosage that is administered parenterally to protect an individual afflicted with Type 1 diabetes against ketoacidosis.
Additionally, an aerosol delivery system can be made with similar dosages of insulin as above with a pharmaceutically suitable carrier or diluent. These and other improvements will be described in the following descriptions, drawings and the appended claims.
DETAILED DESCRIPTION OF THE INVENTION
All patent applications, patents and literature references referred to herein are hereby incorporated by reference in their entirety.
The present invention addresses the need for an alternate to existing methods for the treatment of Type 1 diabetes from an autoimmune model and in particular at treatment for the prevention of diabetes. Because Type 1 patients are predominantly adolescents, it is believed that long term insulin therapy will no longer be required due to preservation of undamaged beta cell function if treatment is initiated at the onset of the disorder using the compositions and methods of the present invention. In addition, if the methods of the present invention are initiated at a time when some beta cell function still exists, parenteral insulin therapy can be reduced. Thus, the present invention provides means whereby long term insulin therapy would be reduced or no longer be required.
It has now been unexpectedly discovered that oral and/or aerosol administration of insulin (or disease-suppressive fragments of insulin or analogs thereof) is effective for the treatment and prevention of Type 1 diabetes. This is a radical departure from traditional (parenteral) insulin therapy in that insulin is administered in order to damp down or shut off the hosts autoimmune response and not for its endocrinologic (metabolic) effect. Oral administration of insulin has not proved to be effective in treating any form of diabetes because proteolytic enzymes present in the stomach and digestive system degrade the polypeptide before it can reach the bloodstream. In addition, intranasal administration of insulin has also not previously been shown to be effective in treating any form of diabetes.
Without wishing to be bound by theory of operation it is believed that the oral or aerosol administration of insulin pursuant to the present invention affects the immunological pathogenesis of Type 1 diabetes through the elicitation of suppressor T-cells.
In the following discussions the following terms shall have the meaning ascribed to them below.
"Treatment" shall mean the treatment of active disease in patients with some level of undamaged, insulin-producing beta cells as well as prophylactic administration for use in patients having a high risk for developing the disease.
"Oral administration" shall mean both oral administration and enteral administration (direct incubation into the stomach).
"Individuals at risk" for Type 1 diabetes shall mean a) individuals having a blood relative with Type 1 diabetes; b) autoantibody-positive individuals without overt Type 1 diabetes. These auto antibodies include cytoplasmic islet cell autoantibodies, insulin antibodies and glutamic acid decarboxylase autoantibodies; c) individuals with Histocompatibility (HLA) type DR3 or DR4DQW8; d) individuals with glucose abnormalities such as a loss of first phase insulin secretion on glucose tolerance tests.
"Mammal" shall mean any organism having an immune system and therefore susceptible to Type 1 diabetes.
"Active disease", shall mean autoimmune destruction of islet beta cells.
"Aerosol" refers to finely divided solid or liquid particles that may be created using a pressurized system such as a nebulizer. The liquid or solid source material contains insulin and/or disease suppressive fragments of insulin and analogs thereof as defined herein.
"Disease suppressive fragments" of insulin includes any peptide or polypeptide containing partial amino acid sequences or moieties of insulin and possessing the ability to treat or prevent a disease having the characteristics of Type 1 diabetes. Such fragments need not possess the autoantigenic or endocrinologic (metabolic) properties of the entire insulin molecule.
"Analogs" of insulin or disease suppressive fragments thereof refers to compounds that are structurally related to insulin or disease suppressive fragments thereof which possess the same biologic activity, i.e., the ability to suppress or prevent disease symptoms of Type 1 diabetes, upon oral or aerosol administration. By way of non-limiting example, the term includes peptides having amino acid sequences which differ from the amino acid sequence of insulin or disease suppressive fragments thereof by one or more amino acid residues while still retaining the disease suppressive activity of insulin or its ability to prevent or alleviate the symptoms of Type 1 diabetes. These analogs do not necessarily need to possess the endocrinologic effects of insulin.
In accordance with the present invention, experiments were performed in which NOD (non-obese diabetic) mice, which develop diabetes spontaneously between 11 and 52 weeks of age, had a lower incidence of diabetes at all doses of orally administered insulin in a dose-dependent manner. In all of the animals which received the highest dose of oral insulin (1 mg), 100% of the treated animals failed to develop diabetes.
Although it is fairly easy to control the symptoms of Type 1 diabetes with parenteral insulin, it is difficult to normalize a patient's blood sugar throughout 24 hours utilizing traditional insulin therapy given as 1 or 2 injections a day. Thus, the present invention provides a method for treating or preventing a disease having the characteristics of Type 1 diabetes in a mammal comprising administering to a mammal, suffering from or at risk for Type 1 diabetes, an effective amount of an oral insulin dosage form to treat or prevent the symptoms of diabetes.
It should be noted that the methods of the present invention will not eliminate the need for parenteral insulin therapy in patients with damaged beta cells who do not produce enough insulin to regulate their blood sugar. However, using the methods and compositions of the present invention, newly diagnosed Type 1 diabetic patients or those at risk for the disease (as defined above), who have substantially intact (undamaged) beta cells, will not go on to develop Type 1 diabetes and parenteral insulin administration may be eliminated. In addition, it is believed that the methods and compositions of the present invention will reduce the amount of insulin needed by those individuals having some beta cell function (who are able to produce some level of insulin) by halting progression of the disease.
Insulin for use in the present invention can be obtained from numerous commercial sources such as Novo Laboratories (Danbury, Conn.), Nordisk-USA (Rockville, Md.) and Eli Lilly and Co. (Indianapolis, Ind.). Porcine-derived insulin, human semi-synthetic insulin (Nordisk-USA) and cloned recombinant insulin (Eli Lilly) can be used when practicing the method of the present invention.
Disease suppressive fragments and analogs of insulin for use in the present invention can be synthesized using well known solid phase synthesis techniques (Merrifield, R. B. Fed. Proc. Am. Soc. Ex. Biol. 21: 412, 1962 and J. Am. Chem. Soc. 85: 2149, 1963; Mitchel, A. R. et al., J. Am. Chem. Soc. 98: 7357, 1976; Tam, J. et al., J. Am. Chem. Soc. 105: 6442, 1983). Analogs can be constructed by identifying an equivalent amino acid sequence and using the peptide synthesis techniques disclosed above.
Analogs can be provided using the known amino acid sequence of insulin as disclosed in Atlas of Protein Sequence and Structure, Natl. Biochem. Res. Foundation, vol. 5, pgs. 209-211.
Disease-suppressive analogs and fragments can also be obtained using recombinant DNA techniques well-known in the art.
Disease suppressive fragments of insulin and analogs thereof can be identified using routine experimentation using suitable in vivo systems such as those of Examples 1-5 below.
Pursuant to the present invention, insulin or disease suppressive fragments or analogs thereof are introduced into a mammal suffering from or at risk for a disease having the characteristics of Type 1 diabetes, orally or enterally, in an amount of between about 2 mg per kg body weight of said mammal and about 10 mg per kg body weight of said mammal per day, and may be administered in a single dose form or multiple dose forms. Preferably, the insulin is administered in an amount between about 2.5 mg and about 5.0 mg per kg body weight of said mammal per day. The exact amount to be administered will vary depending on the severity and stage of a patient's disease and the physical condition of the patient.
The present invention also is directed to oral dosage forms and pharmaceutical formulations for administration to mammals suffering from or at risk for diseases having the characteristics of Type 1 diabetes. It will be understood that any statistically significant attenuation in the disease symptoms of Type 1 diabetes pursuant to the treatment of the present invention is within the scope of the invention.
Each oral formulation according to the present invention may additionally comprise inert constituents including pharmaceutically acceptable carriers, diluents, fillers, solubilizing or emulsifying agents and salts as is well-known in the art. For example, tablets may be formulated in accordance with conventional procedures employing solid carriers well-known in the art. Capsules employed in the present invention may be made from any pharmaceutically acceptable material such as gelatin or cellulose derivatives. Sustained release oral delivery systems and/or enteric coatings for orally administered dosage forms are also contemplated such as those described in U.S. Pat. No. 4,704,295 issued Nov. 3, 1987, U.S. Pat. No. 4,556,552 issued Dec. 3, 1985, U.S. Pat. No. 4,309,404 issued Jan. 5, 1982 and U.S. Pat. No. 4,309,406 issued Jan. 5, 1982.
Examples of solid carriers include bentonite, silica and other commonly used carriers. Further non-limiting examples of carriers and diluents which may be used in the formulations of the present invention include saline and any physiologically buffered saline solution such as phosphate buffered saline (PBS) and water.
It will be appreciated that the unit content of active ingredient or ingredients contained in an individual dose of each dosage form need not in itself constitute an effective amount since the necessary effective amount can be reached by administration of a plurality of dosage units.
The preferred route of administration of the dosage forms of the present invention is orally or enterally. Preferred oral or enteral pharmaceutical formulations or dosage forms may comprise for example, between about 1 mg and about 1000 mg of insulin.
In an alternative preferred embodiment of the present invention the pharmaceutical formulations or dosage forms of the present invention can also be administered to mammals suffering from diseases having the characteristics of Type 1 diabetes in aerosol form. It is expected that lower amounts of insulin, disease suppressive fragments or analogs thereof will be required using aerosol administration for treating or preventing Type 1 diabetes as has been found when treating experimental allergic encephalomyelitis (EAE) with myelin basic protein (MBP) and adjuvant arthritis with collagen as disclosed in co-pending U.S. patent application Ser. No. 454,486 filed Dec. 20, 1989. The amounts of insulin or disease suppressive fragments or analogs thereof which may be administered in an aerosol dosage form would be between about 0.1 mg and 10 mg per kg body weight of a mammal per day and may be administered in single dosage form or multiple dosage forms. The exact amount to be administered will vary depending on the state and severity of a patient's disease and the physical condition of the patient.
The aerosol pharmaceutical formulations of the present invention may include, as optional ingredients, pharmaceutically acceptable carriers, diluents, solubilizing or emulsifying agents, and salts of the type that are well-known in the art. Examples of such substances include normal saline solutions, such as physiologically buffered saline solutions, and water.
The route of administration of insulin or disease suppressive fragments or analogs thereof according to this alternate embodiment of the present invention is in an aerosol or inhaled form. The insulin and related compounds of the present invention can be administered as a dry powder or in an aqueous solution. Preferred aerosol pharmaceutical formulations may comprise for example, a physiologically-acceptable buffered saline solution containing between about 1 mg and about 1000 mg of insulin, disease suppressive fragments or analogs thereof.
Dry aerosol in the form of finely divided solid particles of insulin, disease suppressive fragments or analogs thereof that are not dissolved or suspended in a liquid are also useful in the practice of the present invention. The insulin may be in the form of dusting powders and comprise finely divided particles having an average particle size of between about 1 and 5 microns, preferably between 2 and 3 microns. Finely divided particles may be prepared by pulverization and screen filtration using techniques well known in the art. The particles may be administered by inhaling a predetermined quantity of the finely divided material, which can be in the form of a powder.
Specific non-limiting examples of the carriers and/or diluents that are useful in the aerosol pharmaceutical formulations of the present invention include water and physiologically-acceptable buffered saline solutions such as phosphate buffered saline solutions pH 7.0-8.0.
The pharmaceutical formulations of the present invention may be administered in the form of an aerosol spray using for example, a nebulizer such as those described in U.S. Pat. No. 4,624,251 issued Nov. 25, 1986; U.S. Pat. No. 3,703,173 issued Nov. 21, 1972; U.S. Pat. No. 3,561,444 issued Feb. 9, 1971 and U.S. Pat. No. 4,635,627 issued Jan. 13, 1971. The aerosol material is inhaled by the subject to be treated.
Other systems of aerosol delivery, such as the pressurized metered does inhaler (MDI) and the dry powder inhaler as disclosed in Newman, S. P. in Aerosols and the Lung, Clarke, S. W. and Davia, D. eds. pp. 197-224, Butterworths, London, England, 1984, can be used when practicing the present invention.
Aerosol delivery system of the type disclosed herein are available from numerous commercial sources including Fisons Corporation (Bedford, Mass.), Schering Corp. (Kenilworth, N.J.) and American Pharmoseal Co., (Valencia, Calif.).
It is expected that the methods of the present invention are particularly well-suited for use in pediatric or adolescent patients developing Type 1 diabetes or the first year of onset of hyperglycemia in whom the secondary effects of the disease (such as vascular damage, kidney damage and diabetic retinopathy) have not been totally manifested. These are also the patients in whom the traumatic effects of daily insulin injections are usually most severely felt.
As shown in the examples presented below, oral administration of insulin to NOD mice reduced the numbers of these mice which subsequently went on to develop diabetes at all dosages tested. In addition, at the highest dose used (1 mg), none of the mice went on to develop diabetes. In addition, as shown in Example 2, the effects of oral insulin were not due to a reduction in the serum glucose concentrations in these animals and was thus not a metabolic effect. In addition, as shown in Example 3 below, feeding NOD mice pancreatic extract also led to a diminution in the number of animals which developed diabetes although to a lesser extent than those that received oral insulin.
Preliminary experiments have shown that NOD mice fed 1 mg of insulin had fewer inflammatory immune system cells surrounding the pancreas (a condition known as insulitis) than PBS-fed NOD mice (data not shown). Therefore, oral administration of insulin to NOD mice appeared to be affecting the infiltration of immune system cells into the pancreas and thus halting disease progression by preserving beta cell function.
Claim 1 of 14 Claims
What is claimed is:
1. An oral pharmaceutical solid dosage form for suppressing autoimmune destruction of pancreatic .beta.-cells in a human subject, comprising an amount of a composition comprising insulin effective to suppress said destruction, wherein said dosage form upon oral administration to said subject is effective to suppress said destruction, but not effective to cause reduction of blood glucose levels within four hours of said oral administration, said dosage form being free of ingredients which would permit the insulin molecule to pass through the digestive tract in a sufficiently intact form to cause said reduction of blood glucose levels.