Link:  Pharm/Biotech Resources

Title:  Compositions and methods for treating ileus

United States Patent:  6,911,430

Issued:  June 28, 2005

Inventors:  Gandhi; Salil Atul (Chicago, IL)

Assignee:  VipoGen, LLC (Chicago, IL)

Appl. No.:  769803

Filed:  February 3, 2004

The present invention is directed to compositions useful in treating or preventing ileus in a patient. The compositions of the invention include a pituitary adenylate cyclase activating peptide (PACAP) receptor antagonist and/or a vasoactive intestinal peptide (VIP) receptor antagonist in an amount sufficient to treat or prevent ileus in a patient. In one embodiment both a PACAP and VIP receptor antagonists are present, preferably in a combination that blocks vasoactive pituitary cyclase 1 (VPAC1), VPAC2 and pituitary adenylate cyclase 1 (PAC1) receptors. Methods of using such composition to treat or prevent ileus in a patient are also encompassed by the invention.

SUMMARY OF THE INVENTION

The invention relates to a composition for treating or preventing ileus in a patient. The composition generally comprises a pituitary adenylate cyclase activating peptide (PACAP) receptor antagonist or a vasoactive intestinal peptide (VIP) receptor antagonists that is VIP(10-28) (SEQ ID NO:2, residues 10-28). Preferably the PACAP receptor antagonists or VIP receptor antagonists is in an amount sufficient to treat or prevent ileus.

In a preferred embodiment the composition comprises a PACAP receptor antagonists and a VIP receptor antagonist. In this embodiment of the invention it is preferable if the combined amount of PACAP and VIP receptor antagonists is sufficient to treat or prevent ileus in a patient.

The amount of PACAP and VIP receptor antagonists are typically between 0.001 and 5000 μg per kg body weight of the patient being treated. In a preferred embodiment the antagonists are in an amount equal to between 50 μg and 500 μg per kg body weight of the patient being treated.

In another preferred embodiment, the composition further includes a carrier, preferably a pharmaceutically suitable carrier. Sterically stabilized micelles (SSM), sterically stabilized liposomes (SSL), or mixed micelles are examples of suitable carriers.

Preferably, the PACAP receptor antagonist is selected from a group consisting of PACAP(6-38) (SEQ ID NO:1, residues 6-38); PACAP(6-27) (SEQ ID NO:1, residues 6-27); analogues of PACAP receptor antagonists (SEQ ID NO:10) and combinations thereof and the VIP receptor antagonist is selected from a group consisting of VIP(6-28) (SEQ ID NO:2, residues 6-28); VIPhyb (SEQ ID NO:3); [D-p-Cl-Phe⁶, Leu¹⁷]VIP (SEQ ID NO:4); [Tyr⁹, Dip¹⁸]VIP(6-23) (SEQ ID NO:5); [Tyr⁹,Dip¹⁸]VIP(6-28) (SEQ ID NO:6); GH-releasing factor-(8-27)NH₂ (SEQ ID NO:7); GHRH analogues with VIP receptor binding properties (SEQ ID NO:12); [Ac-His¹, D-Phe², Lys¹⁵, Arg¹⁶, Leu²⁵]VIP(3-7)/GRF(8-27) (SEQ ID NO:8); [N-Ac-Tyr¹, D-Phe²]-GRF(1-29)NH₂ (SEQ ID NO:9); VIP(10-28) (SEQ ID NO:2, residues 10-28); VIP(11-28) (SEQ ID NO:2, residues 11-28); [Ac-Try¹, D-Phe²]-GRF(1-29) amide; and combinations thereof.

Also, preferbly the VIP antagonist is VIP(10-28) (SEQ ID NO:2, residues 10-28) and the PACAP antagonist is PACAP(6-38) (SEQ ID NO:1, residues 6-38). Preferably, the VIP and PACAP receptor antagonists included in the composition jointly inhibit binding of native peptides to vasoactive pituitary cyclase 1 (VPAC₁) receptors, VPAC₂ receptors and pituitary adenylate cyclase 1 (PAC₁) receptors.

The present invention is also directed to a method for treating or preventing ileus in a patient. The method comprises administering to a patient in need of such treatment the composition described above. In this embodiment of the invention the PACAP and/or VIP antagonist typically are administered in an amount effective to activate or augment intestinal transit in the patient.

The compositions of the invention are generally administered intravenously, intra-arterially, intra-nasally, aerosol administration, nebulization, inhalation, insufflation, intratracheally, intraarticularly, orally, transdermally, subcutaneously, or topically onto mucous membranes. In a preferred embodiment the composition is administered intravenously or orally. Preferably the patient is a human and treatment is for postoperative ileus or paralytic ileus, wherein the composition is administered pre-operatively, intra-operatively, post-operatively, or a combination thereof.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The present invention is directed to compositions and methods for the treatment or prevention of ileus. Different types of ileus may be treated and/or prevented using the methods of the invention. The methods are particularly suitable for treating and/or preventing postoperative ileus, postpartum ileus, paralytic ileus. "Postoperative ileus" (POI), which may follow surgery such as laparotomy, may be characterized by such symptoms as, for example, obstruction of the gut, particularly in the colon, resulting in nausea, vomiting, lack of passage of flatus and/or stools, abdominal distention and lack of bowel sounds. This condition generally lasts from about 2 to about 5 days, but may endure longer, including up to about one week. Longer durations are generally characteristic of a more severe form of ileus, termed postoperative paralytic ileus, which may affect other portions of the GI tract in addition to the colon.

"Post-partum ileus" generally refers to obstruction of the gut, particularly the colon, following parturition. Both natural and surgically assisted procedures during parturition may lead to postpartum ileus treated by the present invention. Symptoms of post-partum ileus and postoperative ileus are similar. "Paralytic ileus" refers to the general condition in which peristalsis stops, i.e., paralysis of the bowel wall, resulting in the obstruction of the bowel.

The term "patient" refers to animals, including mammals, preferably humans. It is also not intended that the present invention be limited to only humans. For example, animals such as horses are known to suffer from post-operative ileus. Indeed, it is a common and serious complication of colic surgery in the horse. See J. N. King and E. L. Gerring, "The Action of Low Dose Endotoxin on Equine Bowel Motility," Equine Vet. J. 23:11 (1991).

The phrase "effective amount" or "amount sufficient" is intended to mean that amount of active ingredient(s), e.g., VIP and/or PACAP receptor antagonist, which provides a therapeutic benefit in treating or preventing ileus in a patient. An example of such a therapeutic benefit is the activation or augmentation of intestinal transit in the patient being treated.

The compositions generally include a pituitary adenylate cyclase activating peptide (PACAP) receptor antagonist or a vasoactive intestinal peptide (VIP) receptor antagonist, e.g., VIP(10-28) (SEQ ID NO:2, residues 10-28). In a preferred embodiment the composition comprises both a PACAP and VIP receptor antagonist. Preferable the composition is effective at inhibiting the native peptide from binding to the following receptors: vasoactive pituitary cyclase 1 (VAPC₁) receptor, VPAC₂ receptor and pituitary adenylate cyclase 1 (PAC₁) receptor.

In a preferred in embodiment the VIP antagonists is a nonspecific VPAC₁/VAPC₂ receptor antagonists and the PACAP antagonist is a nonspecific PAC₁/VPAC₂ receptor. Preferably, the VIP and PACAP antagonist in the composition jointly block a VPAC₁, VAPC₂, and PAC₁ receptor.

The term "PACAP receptor antagonist" means a receptor antagonist with a binding coefficient for PAC₁/VPAC₂ receptors, preferably the binding coefficient is equal to or greater than the native PACAP peptide.

The native peptide sequence of PACAP is His-Ser-Asp-Gly-Ile-Phe-Thr-Asp-Ser-
Tyr-Ser-Arg-Tyr-Arg-Lys-Gln-Met-Ala-Val-Lys-Lys-Tyr-Leu-Ala-Ala-Val-Leu-Gly-
Lys-Arg-Tyr-Lys-Gln-Arg-Val-Lys-Asn-Lys-NH2 (SEQ ID NO:1).

Active variations of the natural PACAP peptide are well known in the art, for example, as discussed in the article by Robberecht et al in Eur. J. Biochem. 1992 Jul. 1;207(1):239-46.

Non-limiting examples of preferred PACAP receptor antagonists include PACAP(6-38) (SEQ ID NO:1, residues 6-38); PACAP(6-27) (SEQ ID NO:1, residues 6-27); analogues of PACAP receptor antagonists (SEQ ID NO:10) and combinations thereof. In one embodiment the preferred PACAP receptor antagonist comprises amino acid residues 1-3 of SEQ ID NO:1, namely His-Ser-Asp. In this embodiment, it is preferably that residues 3, 6, 7, and 23 of PACAP (SEQ ID NO:1) are conserved.

Preferably the PACAP receptor antagonist comprises the following structural description: amino acid number 1 ("AA1") is absent, His or Tyr; amino acid number 2 ("AA2") is absent, Ser, Ala or D-Arg; amino acid number 3 ("AA3") is absent, or Asp; amino acid number 4 ("AA4") is absent, Gly, Ala, or Cys; amino acid number 5 ("AA5") is absent, Ile, Val, or Thr; amino acid number 6 ("AA6") is Phe; amino acid number 7 ("AA7") is Thr; amino acid number 8 ("AA8") is Asp, Ser, Glu, or Asn; amino acid number 9 ("AA9") is Ser, Asn, Glu, or Asp; amino acid number 10 ("AA10") is Tyr, or Leu; amino acid number 11 ("AA11") is Ser, Thr, or Arg; amino acid number 12 ("AA12") is Arg or Lys; amino acid number 13 ("AA13") is Tyr, Leu, or Val; amino acid number 14 ("AA14") is Arg, Leu, or Gln; amino acid number 15 ("AA15") is Lys, Gly, Cys, Ala, or Glu; amino acid number 16 ("AA16") is Gln, Ala, Lys, or Gly; amino acid number 17 ("AA17") is Met, Leu, Ile, or Ala; amino acid number 18 ("AA18") is Ala, Ser, or Arg; amino acid number 19 ("AA19") is Val, Ala, Gln, or Leu; amino acid number 20 ("AA20") is Lys, Gln, or Arg; amino acid number 21 ("AA21") is Lys or Arg; amino acid number 22 ("AA22") is Tyr or Leu; amino acid number 23 ("AA23") is Leu; amino acid number 24 ("AA24") is Ala, Asn, Glu, or Gln; amino acid number 25 ("AA25") is Ala, Ser, Gly, or Asp; amino acid number 26 ("AA26") is Val, Ile, Leu; amino acid number 27 ("AA27") is Leu, Ile, Val, or Met; amino acid number 28 ("AA28") is Gly, absent, Asn, or Ser; amino acid number 29 ("AA29") is Lys, absent, Ser, or Arg; and amino acid number 30 ("AA30") is Arg, absent or Gln (SEQ ID NO:10).

The term "VIP receptor antagonist" means a receptor antagonist with a binding coefficient for VPAC1/VPAC2 receptors, preferably the binding coefficient is equal to or greater than the native VIP peptide.

The peptide sequence of VIP is His-Ser-Asp-Ala-Val-Phe-Thr-Asp-Asn-Tyr-Thr-
Arg-Leu-Arg-Lys-Gln-Met-Ala-Val-Lys-Lys-Tyr-Leu-Asn-Ser-Ile-Leu-Asn-NH2
(SEQ ID NO:2).

Non-limiting examples of preferred VIP receptor antagonists include:

Analogues of GHRH have VIP receptor binding properties and amino acid residues 3, 11, 14, 16, 17, 19, 32 are preferably conserved and more preferably residues 2, 6, 10, 15, 20, 23, 27, 33, and 37 are also conserved. In a preferred embodiment the analogue comprises the following structural description: AA1 is Tyr or His; AA2 is Ala, Val, or Ser; AA3 is Asp; AA4 is Ala, Gly, or Asp; AA5 is Ile, Leu, or Met; AA6 is Phe or Leu; AA7 is Thr, Ser, Asn, or Asp; AA8 is Asn, Ser, Thr, Lys, or Arg; AA9 is Ser, Asn, Ala, or Asp; AA10 is Tyr or Leu; AA11 is Arg; AA12 is Lys, Arg, Asp, or Asn; AA13 is Val, Ile, Leu, Ala or Tyr; AA14 is Leu; AA15 is Gly, Ser, or Val; AA16 is Gln; AA17 is Leu; AA18 is Ser, Tyr, or Arg; AA19 is Ala; AA20 is Arg or Gln; AA21 is Lys, Asn, or Arg; AA22 is Leu, Val, Tyr, or Phe; AA23 is Leu or Ile; AA24 is Gln or His; AA25 is Asp, Glu, Ser, Thr, or Trp; AA26 is Ile or Leu; AA27 is Met or Thr; AA28 is Ser, Asn, or Ala; AA29 is Arg, Lys, or Val; AA30 is Gln, Arg, or His; AA31 is Gln, Val, or Leu; AA32 is Gly; AA33 is Glu, Gly, or Ala; AA34 is Ser, Arg, Ala, Val, Gly, or Glu; AA35 is Asn, Ile, Ser, or Glu; AA36 is Gln, Ser, Met, Thr, or Glu; AA37 is Glu, Ser, Ile, Met, or Asp; AA38 is Arg, Gln, Leu, or Glu; AA39 is Gly, Arg, Glu, or Asp; AA40 is Ala, Pro, Ser, or Asp; AA41 is Arg, Lys, Glu, Asp, Asn, Thr, or Ser; AA42 is Ala, Val, Ser, Phe, Leu or absent; AA43 is Arg, Val, Asn, Ser, or Glu; AA44 is Leu, Arg, Pro, or absent (SEQ ID NO:12).

In one preferred embodiment of the composition, the VIP receptor antagonist is VIP(10-28) (SEQ ID NO:2, residues 10-28) and the PACAP receptor antagonist is PACAP(6-38) (SEQ ID NO:1, residues 6-38).

It is not intended that the present invention be limited only the peptides specifically disclosed. The PACAP and VIP antagonist disclosed herein are simply for illustrative purposes only. A variety of peptide derivatives are contemplated, including peptides where additional amino acids are added to the carboxy terminus. Alternatively, peptides are contemplated where amino acids are added to the amino terminus. The present invention contemplates peptides having the above primary structure wherein certain amino acids are substituted or deleted. The present invention also contemplates peptide derivatives having a combination of the above-described changes, such as where amino acids are added to both the amino and carboxy termini.

In another embodiment, the present invention also contemplates peptides protected from endoprotease degradation by the substitution of L-amino acids in said peptides with their corresponding D-isomers. It is not intended that the present invention be limited to particular amino acids and particular D-isomers. This embodiment is feasible for all amino acids, except glycine; that is to say, it is feasible for all amino acids that have two stereoisomeric forms. By convention these mirror-image structures are called the D and L forms of the amino acid. These forms cannot be interconverted without breaking a chemical bond. With rare exceptions, only the L forms of amino acids are found in naturally occurring proteins.

In one embodiment, mimetics are provided. Mimetics of the present invention are peptides having sequence homology to the above-described peptides, PACAP and VIP receptor antagonists and further maintain the ability to function as antagonists.

One common methodology for evaluating mimetics for sequence homology, and more importantly statistically significant similarities, is to use a Monte Carlo analysis using an algorithm written by Lipman and Pearson to obtain a Z value. According to this analysis, a Z value greater than 6 indicates probable significance, and a Z value greater than 10 is considered to be statistically significant. W. R. Pearson and D. J. Lipman, Proc. Natl. Acad. Sci. (USA), 85:2444-2448 (1988); D. J. Lipman and W. R. Pearson, Science, 227:1435-1441 (1985). In the present invention, synthetic polypeptides useful in therapy are those peptides with statistically significant sequence homology and similarity (Z value of Lipman and Pearson algorithm in Monte Carlo analysis exceeding 6), while maintaining the antagonistic function.

The composition of the invention typically comprises VIP and PACAP receptor antagonists in an amount sufficient to treat or prevent ileus in a patient. Preferably the PACAP and VIP antagonists in combination are in an amount of equal to between 0.001 and 5000 μg per kg body weight of the patient being treated or more preferably in an amount between 50 and 500 μg per kg body weight of the patient being treated.

The composition of the invention generally comprises a ratio of 10:1 to 1:10, preferably 5:1 to 1:5 and more preferably between 4:1 to 1:4, VIP-receptor antagonists to PACAP receptor antagonists by weight. In one preferred embodiment the ratio is 1:1.

Often, the composition of the invention further includes a carrier. The carrier may be any pharmaceutically suitable carrier selected on the basis of the chosen route of administration and standard pharmaceutical practice as described, for example, in Remington's Pharmaceutical Sciences (Mack Pub. Co., Easton, Pa., 1980), the disclosures of which are hereby incorporated herein by reference, in their entirety.

In one embodiment, the carrier is sterically stabilized micelles (SSM), sterically stabilized liposomes (SSL), or mixed micelles. Methods of making and using such carriers is fully taught and described in U.S. Pat. Nos. 6,217,886, 6,348,214, 6,322,810, and 6,197,333, the disclosures of which are incorporated herein by reference.

Compositions of the present invention can be administered to a patient in a variety of forms adapted to the chosen route of administration, e.g., orally or parenterally. Parenteral administration in this respect includes administration by the following routes: intravenous, intramuscular, subcutaneous, rectal, intraocular, intrasynovial, transepithelial including transdermal, ophthalmic, sublingual and buccal; topically including ophthalmic, dermal, ocular, rectal, and nasal inhalation via insufflation aerosol. In a preferred embodiment the composition is administered intravenously or orally and the patient is a human suffering from postoperative ileus or paralytic ileus. The composition is preferably administered pre-operatively, intra-operatively, post-operatively, or a combination thereof.

The active composition may be orally administered, for example, with an inert diluent or with an assimilable edible carrier, or it may be enclosed in hard or soft shell gelatin capsules, or it may be compressed into tablets, or it may be incorporated directly with the food of the diet. For oral therapeutic administration, the active composition may be incorporated with excipient and used in the form of ingestible tablets, buccal tablets, troches, capsules, elixirs, suspensions, syrups, wafers, and the like. Such compositions and preparations should preferably contain at least 0.1% of active composition. The percentage of the compositions and preparations may, of course, be varied and may conveniently be, for example, from about 2 to about 6% of the weight of the unit. The amount of active composition in such therapeutically useful compositions is preferably such that a suitable dosage will be obtained. Preferred compositions or preparations according to the present invention may be prepared so that an oral dosage unit form contains from about 0.1 to about 1000 mg of active composition.

The tablets, troches, pills, capsules and the like may also contain one or more of the following: a binder, such as gum tragacanth, acacia, corn starch or gelatin; an excipient, such as dicalcium phosphate; a disintegrating agent, such as corn starch, potato starch, alginic acid and the like; a lubricant, such as magnesium stearate; a sweetening agent such as sucrose, lactose or saccharin; or a flavoring agent, such as peppermint, oil of wintergreen or cherry flavoring. When the dosage unit form is a capsule, it may contain, in addition to materials of the above type, a liquid carrier. Various other materials may be present as coatings or to otherwise modify the physical form of the dosage unit. For instance, tablets, pills, or capsules may be coated with shellac, sugar or both.

A syrup or elixir may contain the active composition, sucrose as a sweetening agent, methyl and propylparabens as preservatives, a dye and flavoring, such as cherry or orange flavor. Of course, any material used in preparing any dosage unit form is preferably pharmaceutically pure and substantially non-toxic in the amounts employed. In addition, the active composition may be incorporated into sustained-release preparations and formulations.

The forms suitable for injectable use include, for example, sterile aqueous solutions or dispersions and sterile powders for the extemporaneous preparation of sterile injectable solutions or dispersions. In all cases, the form is preferably sterile and fluid to provide easy syringability. It is preferably stable under the conditions of manufacture and storage and is preferably preserved against the contaminating action of microorganisms such as bacteria and fungi. The carrier may be a solvent or dispersion medium containing, for example, water, ethanol, polyol (for example, glycerol, propylene glycol, liquid polyethylene glycol and the like), suitable mixtures thereof, and vegetable oils. The proper fluidity can be maintained, for example, by the use of a coating, such as lecithin, by the maintenance of the required particle size in the case of dispersion, and by the use of surfactants. The prevention of the action of microorganisms may be achieved by various antibacterial and antifungal agents, for example, parabens, chlorobutanol, phenol, sorbic acid, thimerosal and the like. In many cases, it will be preferable to include isotonic agents, for example, sugars or sodium chloride. Prolonged absorption of the injectable compositions may be achieved by the use of agents delaying absorption, for example, aluminum monostearate and gelatin.

Sterile injectable solutions may be prepared by incorporating the active composition in the required amount, in the appropriate solvent, with various of the other ingredients enumerated above, as required, followed by filtered sterilization. Generally, dispersions may be prepared by incorporating the sterilized active ingredient into a sterile vehicle that contains the basic dispersion medium and the required other ingredients from those enumerated above. In the case of sterile powders for the preparation of sterile injectable solutions, the preferred methods of preparation may include vacuum drying and the freeze drying technique which yield a powder of the active ingredient, plus any additional desired ingredient from the previously sterile-filtered solution thereof.

As noted above, the relative proportions of active ingredient and carrier may be determined, for example, by the solubility and chemical nature of the composition, chosen route of administration and standard pharmaceutical practice.

The dosage of the compositions of the present invention that will be most suitable for prophylaxis or treatment will vary with the form of administration, the particular composition chosen and the physiological characteristics of the particular patient under treatment. Generally, small dosages may be used initially and, if necessary, increased by small increments until the desired effect under the circumstances is reached.

The present compositions may also be prepared by any of the available methods of pharmacy. In those embodiments wherein a carrier is included, the carrier with the active ingredient are brought into association by uniformly and intimately admixing the active ingredient with liquid carriers or finely divided solid carriers or both, and then, in necessary, shaping the product into the desired presentation.

It is also envisioned that controlled release means or delivery devices can be used to administer the compositions disclosed herein. These means are well known in the art, such as described in U.S. Pat. Nos. 5,345,556, 5,427,798, 5,486,362, 5,591,767, 5,639,476, 5,674,533, and 5,733,566, for example, the disclosures of which are incorporated herein by reference. The dosage forms can be used to provide slow or controlled release VIP, PACAP, or a combination thereof.

Although preferred embodiments of the invention have been described in the foregoing description, it will be understood that the invention is not limited to the specific embodiments disclosed herein but is capable of numerous modifications by one of ordinary skill in the art.

Claim 1 of 20 Claims

1. A pharmaceutical receptor antagonists composition for treating or reducing ileus in a patient consisting of:

a pituitary adenylate cyclase activating peptide (PACAP) receptor antagonist and a vasoactive intestinal peptide (VIP) receptor antagonist, wherein the PACAP receptor antagonist and VIP receptor antagonist are in an amount sufficient to treat or reduce ileus and at least one pharmaceutical acceptable ingredient.

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