ZA200505111B - An allergen dosage form - Google Patents

Description

AN ALLERGEN DOSAGE FORM

Field of the Invention

This invention relates to an allergen containing pharmaceutical product and in particular to fast-dispersing solid allergen dosage forms and a method for preparing such dosage forms.

Background of the Invention

Allergy is a major health problem in countries where Western lifestyle is adapted. Furthermore, the prevalence of allergic disease is increasing in these countries. Although allergy in general may not be considered a life- threatening disease, asthma annually causes a significant number of deaths.

An exceptional prevalence in about 30% of teenagers conveys a substantial loss in quality of life, working days and money, and warrants a classification among major health problems in the Western world.

Allergy is a complex disease. Many factors contribute to the sensitisation event. Among these is the susceptibility of the individual defined by an as yet insufficiently understood interplay between several genes. Another important factor is allergen exposure above certain thresholds. Several environmental factors may be important in the sensitisation process including pollution, childhood infections, parasite infections, intestinal microorganisms, etc.

Once an individual is sensitised and the allergic immune response established, the presence of only minute amounts of allergen is efficiently translated into symptoms.

The natural course of allergic disease is usually accompanied by aggravation attwo levels. First, there is a progression of symptoms and disease severity.

For example, there is a progression from hay fever to asthma. Secondly,

dissemination in offending allergens most often occurs resulting in allergic multi-reactivity. Chronic inflammation leads to a general weakening of the mucosal defense mechanisms resulting in unspecific irritation and eventually destruction of the mucosal tissue. Infants may become sensitised primarily to foods, i.e. milk, resulting in eczema or gastrointestinal disorders; however, most often they outgrow these symptoms spontaneously. These infants are at risk of developing inhalation allergy later in their lives.

The most important allergen sources are found among the most prevalent particles of a certain size in the air we breathe. These sources are remarkably universal and include grass pollens and house dust mite faecal particles, which together are responsible for approximately 50% of all allergies. Of global importance are also animal dander, i.e. cat and dog dander, other pollens, such as mugwort pollens, and micro-fungi, such as

Alternaria. On a regional basis other pollens may dominate, such as birch pollen in Northern and Central Europe, ragweed in the Eastern and Central

United States, and Japanese cedar pollen in Japan. Insects, i.e. bee and wasp venoms, and foods each account for approximately 2% of all allergies.

Allergy, i.e. type | hyper-sensitivity, is caused by an inappropriate immunological reaction to foreign non-pathogenic substances. Important clinical manifestations of allergy include asthma, hay fever, eczema, and gastro intestinal disorders. The allergic reaction is prompt and peaks within 20 minutes upon contact with the offending allergen. Furthermore, the allergic reaction is specific in the sense that a particular individual is sensitised to particular allergen(s), whereas the individual does not necessarily show an allergic reaction to other substances known to cause allergic disease. The allergic phenotype is characterized by a pronounced inflammation of the mucosa of the target organ and by the presence of a : allergen specific antibody of the IgE class in the circulation and on the surfaced of mast-cells and basophils.

An allergic attack is initiated by the reaction of the foreign allergen with allergen specific IgE antibodies, when the antibodies are bound to high affinity IgE specific receptors on the surface of mast-cells and basophils. The mast-cells and basophils contain preformed mediators, i.e. histamine, tryptase, and other substances, which are released upon cross-linking of two or more receptor-bound IgE antibodies. IgE antibodies are cross-linked by the simultaneous binding of one allergen molecule. The cross-linking of receptor bound IgE on the surface of mast-cells also leads to release of signalling molecules responsible for the attraction of eosinophils, allergen specific T-cells, and other types of cells to the site of the allergic response.

These cells in interplay with allergen, IgE and effector cells, lead to a renewed flash of symptoms occurring 12-24 hours after allergen encounter (late phase reaction).

Allergy disease management comprises diagnosis and treatment including prophylactic treatments. Diagnosis of allergy is concerned with the demonstration of allergen specific IgE and identification of the allergen source. In many cases a careful anamnesis may be sufficient for the diagnosis of allergy and for the identification of the offending allergen source material. Most often, however, the diagnosis is supported by objective measures, such as skin prick test, blood test, or provocation test.

The therapeutic options fall in three major categories. The first opportunity is allergen avoidance or reduction of the exposure. Whereas allergen avoidance is obvious e.g. in the case of food allergens, it may be difficult or expensive, as for house dust mite allergens, or it may be impossible, as for pollen allergens. The second and most widely used therapeutic option is the prescription of classical symptomatic drugs like anti-histamines and steroids.

Symptomatic drugs are safe and efficient; however, they do not alter the natural cause of the disease, and they do not control the disease dissemination. The third therapeutic alternative is specific allergy vaccination that in most cases reduces or alleviates the allergic symptoms caused by the allergen in question.

Conventional specific allergy vaccination is a causal treatment for allergic disease. It interferes with basic immunological mechanisms resulting in persistent improvement of the patients’ immune status. Thus, the protective effect of specific allergy vaccination extends beyond the treatment period in contrast to symptomatic drug treatment. Some patients receiving the treatment are cured, and in addition, most patients experience a relief in disease severity and symptoms experienced, or at least an arrest in disease aggravation. Thus, specific allergy vaccination has preventive effects reducing the risk of hay fever developing into asthma, and reducing the risk of developing new sensitivities.

The immunological mechanism underlying successful allergy vaccination is not known in detail. A specific immune response, such as the production of antibodies against a particular pathogen, is known as an adaptive immune response. This response can be distinguished from the innate immune response, which is an unspecific reaction towards pathogens. An allergy vaccine is bound to address the adaptive immune response, which includes cells and molecules with antigen specificity, such as T-cells and the antibody producing B-cells. B-cells cannot mature into antibody producing cells without help from T-cells of the corresponding specificity. T-cells that participate in the stimulation of allergic immune responses are primarily of the

Th2 type. Establishment of a new balance between Th1 and Th2 cells has been proposed to be beneficial and central to the immunological mechanism of specific allergy vaccination. Whether this is brought about by a reduction in Th2 cells, a shift from Th2 to Th1 cells, or an up-regulation of Th1 cells is controversial. Recently, regulatory T-cells have been proposed to be important for the mechanism of allergy vaccination. According to this model regulatory T-cells, i.e. Th3 or Tr1 cells, down-regulate both Th1 and Th2 cells 5 of the corresponding antigen specificity. In spite of these ambiguities it is generally believed that an active vaccine must have the capacity to stimulate allergen specific T-cells, preferably TH1 cells.

Primarily for two reasons specific allergy vaccination in spite of its virtues, is not in widespread use. One reason is the inconveniences associated with the traditional vaccination programme that comprises repeated vaccinations, such as injections over several months. The other reason is, more importantly, the risk of allergic side reactions. Ordinary vaccinations against infectious agents are efficiently performed using a single or a few high dose immunizations. This strategy, however, cannot be used for allergy vaccination since a pathological immune response is already ongoing.

Conventional specific allergy vaccination is therefore carried out using multiple subcutaneous immunizations applied over an extended time period.

The course is divided in two phases, the up dosing and the maintenance phase. In the up dosing phase increasing doses are applied, typically over a 16-week period, starting with minute doses. When the recommended maintenance dose is reached, this dose is applied for the maintenance phase, typically with injections every six weeks. Following each injection the patient must remain under medical attendance for 30 minutes due to the risk of anaphylactic side reactions, which in principle although extremely rare could be life-threatening. In addition, the clinic should be equipped to support emergency treatment. There is no doubt that a vaccine based on a different route of administration would eliminate or reduce the risk for allergic side reactions inherent in the current subcutaneous based vaccine as well as would facilitate a more widespread use, possibly even enabling self vaccination at home.

Attempts to improve vaccines for specific allergy vaccination have been performed for over 30 years and include multifarious approaches. Several approaches have addressed the allergen itself through modification of the

IgE reactivity. Others have addressed this route of administration.

The immune system is accessible through the oral cavity and oromucosal, e.g. sublingual administration, of allergens is a known route of administration.

Conventionally, allergy vaccine using the oromucosal route consists of the periodic dosing of a solution of the allergen at intervals spaced apart by at least one day. In comparison, the therapeutic (accumulated) maintenance doses given exceeded the maintenance of the comparable subcutaneous dose by a factor of 5-500. Obvious drawbacks of this dosage form and route of administration are the problems associated with accurate and uniform self administration of the correct dose by the patient (several drops may have to be given, uniformity of the individual drops, application site accuracy, etc.).

Additionally, there is a need to refrigerate the drug and include preservatives in the formulation.

Netien et al. ("Galenica 16 — Médicaments homéopathiques” ed. 2, 1986, pages 77-99) discloses a liquid solution impregnated onto a solid particulate (granules) or conventional compressed tablets of lactose, saccharose or a mixtures of these for sublingual administration of medicaments such as allergens.

DD-A.0 107 208 discloses a process for preparing a conventional compressed tablet containing an allergen. Upon administration the tablet is dissolved by the saliva and the allergen is then absorbed through the mucosa of the oral cavity. The formulation contains a water insoluble excipient,

- namely talcum as well as paraffin and fatty acids which is not desirable because it will leave an unpleasant remnant in the mouth of the patient.

Moreover, the friction produced during the tabletting process may be detrimental to the physical stability of the allergens

EP 278 877 discloses a pharmaceutical composition for sublingual use, where a solid support is coated with a solution of an allergen when spraying the solution onto solid support globules. The resulting formulation is alleged to disintegrate rapidly, but not instantaneously. However, there is no disclosure of how to achieve the objective. Moreover, the formulation contains reducing sugars in the form of lactose, which are prone to react with allergens.

In order to ensure that as much as possible of an administered dose of a certain allergen is presented to the mucosa of the oral cavity and additionally that the contact time of the disintegrated product with the mucosa is maximised, it is very important that the dosage form disintegrates instantaneously upon contact with the saliva of the oral cavity. Fast dispersing solid dosage forms, which readily release the active ingredient in the oral cavity are known in the art.

US. Patent No 4,371,516 discloses pharmaceutical dosage forms containing active ingredients, which disintegrate rapidly in water. The pharmaceutical dosage forms comprise an open matrix network of carrier material, which disintegrate within 10 seconds.

A freeze-dried fish gelatine based carrier as disclosed in WO 00/61117 is designed to release the active ingredient instantaneously upon contact with saliva when administered in the oral cavity.

A freeze-dried modified starch carrier as disclosed in WO 00/44351 is designed to release the active ingredient instantaneously upon contact with saliva when administered in the oral cavity.

WO 99/21579 discloses a fast-dispersing dosage form comprising a vaccine and an adjuvant for oral use.

WO 02/13858 discloses fast dissolving pharmaceutical composition containing vaccines in the form of a fast dissolving “cake” for oral use. The object of WO 02/13858 appears to be to provide viral or bacterial vaccines that will stay intact in the gastrointestinal tract. This is achieved by protecting the antigen against the acidic content of the stomach by incorporating antacids such as calcium carbonate into the cake.

WO 00/51568 discloses a fast-disintegrating compressed low friability tablet that is designed to dissolve in the mouth in contact with saliva in less than 30 seconds forming an easy-to-swallow suspension.

It is alleged in U.S. Patent No 4,371,516 that the formulation is useful for oral vaccines. In the case of WO 00/61117, WO 00/44351, WO 99/21579 and

WO 02/13858, it is also alleged that the inventions are directed to non- infections immuno-modulated conditions such as systemic allergic conditions e.g. hayfever. However, there is no disclosure in any of these applications of technical information or examples of how a fast-dispersing allergen vaccine solid dosage form can be manufactured. For example, there are no indications of an appropriate dosage of a certain allergen in any of the disclosed formulation. It is very important to administer a correct dosage of an allergen to a patient, because an excess dose may induce anaphylactic shock in the patient. Furthermore, no recognition of or indications of appropriate measures in relation to stability or friability of such formulations are given.

Summary of the Invention

The present invention concerns a pharmaceutical product suitable for oromucosal administration of an allergen comprising at least one allergen and a matrix in form of a fast-dispersing non-compressed solid dosage form characterized in that the allergen containing dosage form is stable, sufficiently robust and does not release hazardous amounts of allergen residues upon handling by the patient.

Further, a fast-dispersing non-compressed solid dosage form suitable for oromucosal administration comprising a matrix forming agent and an allergen wherein the allergen is stable and the dosage form has a low friability with respect to allergen release, the dosage form dissolves quickly and does not require an adjuvant.

In particular the invention concerns a pharmaceutical product suitable for administration of allergen comprising a fast-dispersing, non-compressed solid dosage form suitable for oromucosal administration including: (a) a matrix formed from at least one matrix-forming agent, and (b) an effective dose of an allergen for desensitizing an individual to said allergen, wherein (c) the loss of the allergen content in said dosage form is less than 50% of the initial allergen content after being held for 3 months at 25°C and 60% relative humidity, and

(d) the loss of allergen from said solid dosage form is less than about 0.5 pg allergen exiract or less than about 0.05 ug major allergen when subjected to a friability test.

In one preferred embodiment of the invention, the solid dosage form comprises fish gelatine and mannitol as matrix-forming agents.

In another preferred embodiment of the invention, the solid dosage form comprises starch and mannitol as matrix forming agents.

The present invention also provides methods of producing these solid dosage forms and methods of treating allergy by administration of these solid dosage forms.

Detailed Description of the Invention

The present invention is based on a number of surprising findings, none of which could with a reasonable expectation of success be predicted a priori.

First, it is based on the finding that it is possible to use a fast-dispersing, non- compressed dosage form for administration of an allergen, and that it is possible to obtain an effective allergy treatment by the use of such a formulation. In particular, it has been shown that it is indeed possible to obtain delivery of a sufficient amount of allergen to the immune system of the patient via the oromucosal route using a fast-dispersing non-compressed solid dosage form without eliciting an undesirable level of side effects.

Moreover, the present invention has provided the relevant dose levels for obtaining a therapeutic effect without unacceptable side effects.

Secondly, the invention is based on the finding that an effective treatment can be obtained by the use of a fast-dispersing, non-compressed dosage form without the use of an adjuvant.

Thirdly, the invention is based on the finding that it is possible to formulate an allergen as a fast-dispersing, non-compressed dosage form while meeting the special demands required by an allergen with respect to stability and low friability. In particular, it has been shown that it is possible to balance the oppositely directed requirements that the dosage form should be fast- dispersing on the one side and both stable and have low-friability on the other side so as to obtain a dosage form, which to a sufficient extent is fast- dispersing, stable and has low friablility.

Allergen proteins are susceptible to degradation that is influenced by a number of factors of the environments they are contained in. It is sought that it is pertinent for allergy treatment and in particular to allergy vaccination that the allergen is delivered intact to the immune system in therapeutically relevant doses. Thus, the allergen must remain stable during production, storage and use. The present work has shown that it is in fact possible to formulate allergen proteins in a fast-dispersing, non-compressed dosage form which is stable in respect to allergen doses and allergen activity.

Moreover, it has surprisingly been found that these formulations are indeed stable at room temperature. This finding has significant importance for the handling procedures of the final product. Cold storage at the manufacturing plant, during transport or during storage at the pharmacy is often associated with high cost, because the cooling facilities have to be closely monitored and it is very expensive to invest in reliable cooling facilities. Moreover, with respect to compliance of the patient, it is also preferable that the dosage form can be stored at room temperature.

Thus, present work has shown that it is in fact possible to formulate allergen proteins in a fastdispersing, non-compressed dosage form being therapeutically effective without the need for an adjuvant. Further such allergen containing solid dosage forms are furthermore stable at advantageous conditions.

When allergen proteins are formulated in a fast-dispersing, non-compressed dosage form, it is further advantageous that the resulting dosage form does not substantially release the allergens to the surrounding environment or to a person handling the dosage form upon direct contact. A priori non- compressed fast-dispersing solid dosage forms are characterized by a low mechanical strength compared to compressed tablets due to the inherent nature of the non-compressed matrix, which is fragile and brittle, almost wafer-like. During e.g. packing, storage, transport and handling of the dosage form by the patient, residual particles containing the allergen may be released to the environment and patient. This is especially detrimental when the active ingredient is an allergen, because the allergen can elicit an allergic reaction in a disposed person or induce an allergic reaction, such sensitisation or allergic response being dose dependent. Maximum allowable levels for environmental contamination in the form of e.g. allergen in dust have been proposed, depending on the allergen in question, to be as low as 2 micrograms major allergen per gram house dust. (Allergy.

Principles and practice (1993, 4. ed.), Mosby-Year book, Vol. | page 520).

Non-compressed fast-dispersing solid dosage forms, which are manufactured by removal of a liquid from a solidified system comprising matrix forming agents, active ingredient and other optional agents, preferably are manufactured in situ. The in situ manufacturing process generally involves removal of solvent from a solidified system of the active ingredient and the matrix forming excipients within the final container such as a blister pack. The in situ technique used commercially does not allow for conventional coating of the dosage form. Application of a coating of the dosage form would in most cases affect dispersing of the solid dosage form, thus jeopardizing the instantaneous release properties of the dosage form.

Therefore, despite the opposite nature of these requirements, the present work has shown that it is in fact possible to formulate effective dosages of allergen proteins in a fast-dispersing, non-compressed dosage form, while at the same time obtaining low-friability and maintaining the fast-dispersing property.

All of the above findings are supported by experimental laboratory work or pre-clinical experiments using test animais, where applicable, or clinical trials, where applicable.

The term ‘“fast-dispersing dosage form” refers to dosage forms which disintegrate in less than about 90 seconds, preferably in less than about 60 seconds, preferably in less than about 30 seconds, more preferably in less than about 20, even more preferably in less than about 10 seconds in the oral cavity, even more preferred in less than about 5 seconds, and most preferably in less than about 2 seconds after being received in the oral cavity.

The solid dosage form of the invention may be in the form of tablets, capsules, lozenges or caplets.

The term “non-compressed” refers to a solid dosage form, which is manufactured by removal of a liquid from a solidified system comprising matrix forming agents, active ingredient and other suitable ingredients resulting in an allergen comprised solid matrix.

The term “solid dosage form” refers to a unit dosage form that is not a liquid, or a powder when it is administered in the oral cavity, thus “solid dosage forms” refers to e.g. tablets containing a unit dose of the active ingredient.

The term tablets, solid dosage and vaccine form are used interchangeably herein.

The term “matrix forming agent” refers to any pharmaceutically acceptable water-soluble or water-dispersible excipient that will serve as a carrier for the active ingredient in the solid dosage form.

The term “excipient” refers to any ingredient that may be added to the formulation besides the active ingredient.

The term "loss of the allergen content in said dosage form" refers to for example degradation or inactivation of the allergen in the dosage form during for example storage, transportation and use. The loss may be determined as either the loss in biological acticivity/potency or as the loss in the actual content of the allergen. Preferably, the loss of the allergen content is measured as the loss of at least one major allergen. The loss may for example be measured in an ELISA method as described in Obispo et al. (Allergy, 1997, 52, pg. 806-813 using allergen specific reagents).

The term "loss of the allergen content from said dosage form" refers to for example release of the allergenin the dosage form during, for example storage, transportation and use. The loss may be determined as either the loss in biological acticivity/potency or as the loss in the actual content of the allergen. Preferably, the loss of the allergen content is measured as the loss of at least one major allergen. The loss may for example be measured in an ELISA method as described in Obispo et al. (Allergy, 1997, 52, pg. 806-813 using allergen specific reagents).

The term “stable” refers to dosage forms where the loss in allergen content is less than 50% of the initial content after being stored for 3 months at 25 °C and 60% relative humidity in the final container either measured as the loss in biological acticivity/potency or as the loss in content of at least one major allergen. The loss may for example be measured in an ELISA method as described above.

The term “low friability” refers to the amount of allergen containing material that is lost from the dosage form when it is subjected to an extemal force.

The solid dosage form has a sufficient friability and robustness to be transported, stored and handled if the allergen containing material lost contains less than 0.5 ug allergen extract or 0.05 pg major allergen per sofid dosage form. For the purpose of the present invention, the friability may be measured by a method according to the present invention. “Tensile strength o “ is calculated according to the following equation: c = 3Wa x 9.8 Nmm¥ 2d%b where w = Peak load to fracture (kgF) a= distance between supports d = thickness of the fast-dispersing solid dosage form (mm) b = diameter of the fast-dispersing solid dosage form (mm) “Peak load to fracture” means the peak force required to fracture a unit in a three point bend test using an appropriate instrument (e.g. CT5, Engineering

Systems, 1 Loach Court, Radford Bridge Road, Nottingham NG8 1NA, UK).

The term “oromucosal administration” refers to a route of administration where the dosage form is placed under the tongue or anywhere else in the oral cavity to allow the active ingredient to come in contact with the mucosa of the oral cavity or the pharynx of the patient in order to obtain a local or systemic effect of the active ingredient. An example of an oromucosal administration route is sublingual administration.

The term “sublingual administration” refers to a route of administration, where a dosage form is placed undemeath the tongue in order to obtain a local or systemic effect of the active ingredient.

The term “allergen” refers to any naturally occurring protein or mixtures of proteins that have been reported to induce allergic, i.e. IgE mediated reactions upon their repeated exposure to an individual. Examples of naturally occurring allergens include pollen allergens (tree, weed, herb and grass pollen allergens), mite allergens (from e.g. house dust mites and storage mites), insect allergens (inhalant, saliva- and venom origin allergens), animal allergens from e.g. saliva, hair and dander from e.g. dog, cat, horse, rat, mouse, etc., fungi allergens and food allergens. The allergen may be used in the form of an allergen extract, a purified allergen, a modified allergen or a recombinant allergen or a recombinant mutant allergen, any allergen fragment above 30 amino acids or any combination thereof.

The expression "allergen extract’ as used therein refers to an extract obtained by extraction of a biological allergen source material as generally described in “Allergenic extracts’, H. Ipsen et al, chapter 20 in Allergy, principle and practise (Ed. S. Manning) 1993, Mosby-Year Book, St. Louis.

Such extract may be obtained by aqueous extraction of water soluble material followed by purification steps like filtration to obtain the solution i.e. the extract. The extract may then be subjected to further purification and/or processing like freeze-drying removing substantially all the water. Generally, an allergen extract comprises a mixture of proteins and other molecules.

Allergen proteins are often classified as a major allergen, an intermediate allergen, a minor allergen or no classification. An allergen extract generally comprises both major and minor allergens. Major allergens will generally constitute approximately 5-15% of an average allergen extract, more often about 10%. Classification of an allergen is based on an assessment of the clinical importance of the particular allergen and is given below. Examples of important major allergen found in an extract include grass group 1 and 5 and 6 allergens (e.g. Phi p 1, 5, and 6), dust mite group 1 and 2 allergens (e.g.

Der p 1, Der p 2), tree pollen allergen 1 (Bet v 1), cedar pollen allergen 1 and 2 (e.g. Cryj1, Cryj2), ragweed pollen 1 and 2 (Amb a 1, Amb a 2), cat allergen 1 (i.e. Fel d1). The average allergic person will be sensitised to and react to one or more major allergens and further may also be sensitised.and react to minor allergens.

Amounts of allergen extract referred to herein refers to the dry matter content of such allergen extracts.

Preferably the water content of the dry matter does not exceed 10%, more preferably 5% by weight.

The expression “biological allergen source material” as used therein refers to any biological material comprising one or more allergens. Examples of such materials are acarids PMB (Pure Mite Body) or WMC (Whole Mite Culture), defatted or non-defatted pollens from e.g. grasses, herbs, weeds and trees, animal hair and dander, pelt, fungi mycelia and spores, insect bodies, venom or saliva and foods.

Biological allergen source materials may comprise contaminating materials, such as foreign pollen and plant and flower debris for an allergen pollen source material.

The degree of contamination should be minimised. Preferably, the content of contaminants should not exceed 10% (W/W) of the biological source material. .

Normally an allergen extract contains at least 10% protein of the dry matter content of the allergen extract as determined in a standard protein assay such as BCA or Lowry and the remainder consists of other “non-protein material,” which may be components such as lipids, carbohydrates, or bound water which originate from the biological allergen source.

An allergen extract may be formulated and stored in form of a freeze-dried material obtainable by freeze-drying a liquid allergen extract at a pressure of below 800 micro bar and for a period of up till 100 hours removing the water.

In the field of allergy extracts, there is no international accepted standardisation method. A number of different units of extract strength i.e. bio-potency exist. The methods employed and the units used normally measure the allergen content and biological activity. Examples hereof are

SQ-Units (Standardised Quality units), BAU (Biological Allergen Units), BU (biological units), UM (Units of Mass), IU (International Units) and IR (Index of Reactivity). Hence, if extracts of origins other than those disclosed herein are used, they need to be standardised against extract disclosed herein in order to determine their potency in SQ units or any of the above mentioned units. The subject matter is dealt with in “Allergenic extracts”, H. Ipsen et al, chapter 20 in Allergy, principle and practise (Ed. S. Manning) 1993, Mosby-

Year Book, St. Louis and Lawenstein H. (1980) Arb Paul Ehrlich Inst 75:122.

The bio-potency, i.e. the in vivo allergenic activity, of a given extract depends on a number of factors, the most important being the content of major allergens in the extract, which varies with the composition of the biological source material.

The amount of allergen extract in grams to be used for obtaining a desired bio-potency varies with the type of extract in question, and for a given type of extract the amount of allergen extract varies from one batch to another with the actual bio-potency of the extract.

For a given batch of extract, the amount of allergen extract in grams to be used for obtaining a desired bio-potency may be determined using the following procedure: a) The bio-potency of various amounts of a reference extract is determined using one or more immunological in vivo tests to establish a relationship between bio-potency and amount of reference extract.

Examples of the said immunological in vivo tests are Skin Prick Test (SPT), Conjunctival Provocation Test (CPT), Bronchial Challenge with

Allergen (BCA) and various clinical trials in which one or more allergy symptoms is monitored, see for example e.g. Haugaard et al. J

Allergy Clin Immunol, Vol. 91, No. 3, pp 709-722, March 1993. b) On the basis of the established relationship between bio-potency and reference extract, the bio-potency of one or more relevant doses for use in the dosage forms of the invention is selected with due consideration to a balance of the factors of i) the effect of treating or alleviating symptoms of allergy, ii) side effects recorded in the immunological in vivo tests, and iii) the variability of i) and ii) from one individual to another. The balancing is done to obtain a maximal adequate therapeutic effect without experiencing an unacceptable level of side effect. The way of balancing the factors are well known to those skilled in the art

The bio-potency of the one or more relevant doses found may be expressed in any biopotency unit available, such as SQ units, BAU, IR units, 1U, cf. above. c) From the reference extract one or more bio-potency reference standard extracts is prepared and, if used, the bio-potency unit values of the reference standard extracts are calculated on the basis of the bio-potency unit value allocated to the one or more relevant doses, e.g. such a standard for BAU can be obtained from FDA as illustrated below. d) For the reference standard extracts of each extract type, a number of parameters for evaluating the bio-potency of extracts are selected.

Examples of such evaluation parameters are total allergenic activity, the amount of defined major allergens and overall molecular composition of the extract. The total allergenic activity may be measured using an in vitro competitive immunoassay, such as ELISA and MagicLite® luminescence immunoassay (LIA), using a standardised antibody mixture raised against the extract obtained using standard methods, e.g. antibodies raised in mouse or rabbit, or a pool of allergic patients sera. The content of major allergens may e.g. be quantified by rocket immuno-electrophoresis (RIE) and compared to the reference standards. The overall molecular composition may be examined using e.g. crossed immunoelectrophoresis (CIE) and sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE). e) For a given batch of extract of unknown bio-potency (test extract), the amount of extract to be used for obtaining a desired bio-potency level (effective dose for use in the solid dosage form according to the present invention) may be determined as follows: For each evaluation parameter selected, the test extract is compared with the reference standard extracts using the relevant measurement methods as described above, and on the basis of the measurement results the amount of extract having the desired bio-potency is calculated.

SQ-Unit: The SQ-Unit is determined in accordance with ALK-Abellé A/S’s "SQ biopotency’-standardisation method, where 100,000 SQ units equal the standard subcutaneous maintenance dose. Normally 1 mg of extract contains between 100,000 and 1,000,000 SQ-Units, depending on the allergen source from which they originate and the manufacturing process used. The precise allergen amount can be determined by means of immunoassay i.e. total major allergen content and total allergen activity.

BAU (Biological Allergen Units) is biological potency units as determined according to the requirements of the FDA for allergen product described in “Quantitative determination of relative potency of allergenic extracts” (“Methods of the allergen products testing Laboratory” “ELISA competition assay”. Page 15, #49N-0012, FDA, October 1993). A dose of 100,000 SQ-

Units containing grass extract equals a content of 2600-4700 BAU according to the method above. Likewise, other extracts can be assessed according to the method above.

The term “effective dose of an allergen for desensitization” shall mean a dose which when taken once or repeatedly in a monodose or in incremental doses results in, for example, an adaptive immune response and thus serves as means to desensitise allergic patients. Preferably, the term shall mean the amount of allergen in each dosage form necessary to induce an adaptive immune response after repeated administration of said solid dosage forms in accordance with a treatment regimen (over a period ranging from a few applications to at least one daily application over several months). Preferably desensitization includes the alleviation of allergic symptoms upon administration of the dose. Clinical allergy symptoms include rhinitis, conjunctivitis, asthma, urticaria, eczema, which includes reactions in the skin, eyes, nose, upper and lower airways with common symptoms such as redness and itching of eyes and nose, itching and runny nose, coaching, weezing, shortness of breathe, itching, and swelling of tissue. “Uniformity of content” as used herein refers to the variation of the doses unit from the stated dose. “Water content’ as used herein refers to the content of residual water in a solid dosage unit determined quantitatively using the Karl Fischer titration principle. This method is based on the principle that a given amount of Ix leads to a transformation of an equivalent amount of water (European

Pharmacopoeia (EP) 3% edition, 2.5.12).

As used herein “Water activity a,” is the effective water in a sample. Water activity measurements are carried out using methods known to the person skilled in the art, for example chilled mirror dew point technology, relative humidity with sensors that change electrical resistance or capacitance or using a lithium chloride electrode: a, can be calculated according to the following equation: aw = p/ps =ERH (%)/100 where p = partial pressure of water vapor at the surface of the product ps = saturation pressure, or the partial pressure of water vapor above pure water at the product temperature.

ERH = equilibrium relative humidity.

The term "about" or "approximately" means within an acceptable range for the particular value as determined by one of ordinary skill in the art, which will depend in part on how the value is measured or determined, e.g., the limitations of the measurement system. For example, "about" can mean a

Claims (103)

PCT/DK2003/000814 ® 95 CLAIMS:

1. A pharmaceutical product suitable for administration of allergen comprising a fast-dispersing, solid dosage form suitable for oromucosal administration including: (a) a matrix formed from at least one matrix-forming agent, and (b) an effective dose of an allergen for desensitizing an individual to said allergen, wherein said solid dosage form has an allergen extract content from about 0.5 ng/dosage form to 5 mg/dosage form.

2. A pharmaceutical product suitable for administration of allergen comprising a fast-dispersing, solid dosage form suitable for oromucosal administration including: (a) a matrix formed from at least one matrix-forming agent, and (b) an effective dose of an allergen for desensitizing an individual to said allergen, wherein said solid dosage form has a major allergen content from about 0.05 pg/dosage form to 0.5 mg/dosage form.

3. A pharmaceutical product according to any one of claims 1 or 2 which is in the form of a non-compressed solid dosage form. 4 A pharmaceutical product suitable for administration of allergen comprising a fast-dispersing, non-compressed solid dosage form suitable for oromucosal administration including: (a) a matrix formed from at least one matrix-forming agent, and AMENDED SHEET

PCT/DK2003/000814 ® 96 (b) an effective dose of an allergen for desensitizing an individual to said allergen, wherein (c) the loss of the allergen content in said dosage form is less than 50% of the initial allergen content after being held for 3 months at 25°C and 60% relative humidity, and (d) the loss of allergen content from said solid dosage form is less than about 0.5 ug allergen extract or less than about 0.05 ug major allergen when subjected to a friability test.

3S. A pharmaceutical product according to claim 4 wherein the friability is measured in a friability test comprising the following steps (a) placing individual sealed blisters each containing a solid dosage form in equipment suitable for friability measurements; (b) moving the sealed blister containing the solid dosage form for an appropriate time and at an appropriate velocity; (c) removing the sealed blister containing the solid dosage form ; (d) opening the blister and placing the solid dosage form and any residues in a container; (e) removing the solid dosage form from the container leaving any joose residuals in said container, (f) performing an allergen specific assay on said residues determining the allergen content in said residues; and optionally calculating the percentage allergen content in said residues of the total allergen content of the solid dosage form unit.

6. A pharmaceutical product according to claim 5, wherein (a) between 1 and 100 blisters containing the solid dosage form are used, (b) an equipment for friability measurements as described in European Pharmacopoeia 2.9.7 is used AMENDED SHEET

PCT/DK2003/000814 ® - (c) the solid dosage forms are rotated for 100 turns at 251 mpm, and (d) the allergen specific assay is an immunochemical allergen specific assay.

7. A pharmaceutical product according to claim 5 or 6, wherein the allergen specific assay is an enzyme-linked immunosorbant assay.

8. A pharmaceutical product according to any one of claims 1-7 containing from about 2.5 pg to about 3.75 mg allergen extract.

9. A pharmaceutical product according to claim 8 containing from about 2.5 pg to about 2.5 mg allergen extract.

10. A pharmaceutical product according to claim 9 containing from about 25 pg to about 2.5 mg allergen extract.

11. A pharmaceutical product according to claim 10 containing from about 25 pg to about 1.25 mg allergen extract.

12. A pharmaceutical product according to claim 11 containing from about 25 ug to about 1 mg allergen extract.

13. A pharmaceutical product according to claim 12 containing from about 25 ug to about 750 pg allergen extract.

14. A pharmaceutical product according to any one of claims 1-7 containing from about 0.25 pg to about 0.25 mg major allergen.

15. A pharmaceutical product according to claim 14 containing from about 2.5 pg to about 0.25 mg major allergen. AMENDED SHEET

® PCT/DK2003/000814

16. A pharmaceutical product according to claim 15 containing from about 2.5 pg to about 0.125 mg major allergen.

17. A pharmaceutical product according to claim 16 containing from about 2.5 pg to about 0.1 mg major allergen.

18. A pharmaceutical product according to claim 17 containing from about 2.5 pg to about 75 pg major allergen.

19. A pharmaceutical product according to any one of claims 1-7 containing a dose from about 65 to about 15,000 BAU.

20. A pharmaceutical product according to claim 19 containing a dose of about 650 to about 15,000 BAU.

21. A pharmaceutical product according to claim 20 containing a dose of about 650 to about 6,000 BAU.

22. A pharmaceutical product according to claim 21 containing a dose of about 650 to about 4,700 BAU.

23. A pharmaceutical product according to claim 22 containing a dose of about 650 to about 3,500 BAU.

24. A pharmaceutical product according to any one of claims 19-23, wherein the allergen is a grass pollen allergen.

25. A pharmaceutical product according to any one of the preceding claims comprising a major grass pollen allergen selected from the group consisting of grass group 1 allergen, grass group 2/3 allergen, grass group 5 allergen and grass group 6 allergen. AMENDED SHEET

® PCT/DK2003/000814

26. A pharmaceutical product according to any one of the preceding claims comprising a major grass pollen allergen selected from the group consisting of mite group 1 allergen, and mite group 2 allergen.

27. A pharmaceutical product according to any one of claims 1-24, wherein the allergen content loss is less than about 30 % of the initial content after being held for 3 months at 25°C and 60% relative humidity.

28. A pharmaceutical product according to claim 27, wherein the allergen content loss is less than about 20 % of the initial content after being held for 3 months at 25°C and 60% relative humidity.

29. A pharmaceutical product according to claim 28, wherein the allergen content loss is less than about 15 % of the initial content after being held for 3 months at 25°C and 60% relative humidity.

30. A pharmaceutical product according to claim 29, wherein the allergen content loss is less than about 10% of the initial content after being held for 3 months at 25°C and 60% relative humidity.

31. A pharmaceutical product according to claim 30, wherein the allergen content loss is less than about 5% of the initial content after being held for 3 months at 25°C and 60% relative humidity.

32. A pharmaceutical product according to claim 31, wherein the allergen content loss is less than about 2% of the initial content after being held for 3 months at 25°C and 60% relative humidity.

33. A pharmaceutical product according to any one of claims 1-32, wherein the loss from each solid dosage form is less than about 0.25 ug allergen extract. AMENDED SHEET

® PCT/DK2003/000814

34. A pharmaceutical product according to claim 33, wherein the loss from each solid dosage form is less than about 0.15 ug allergen extract.

35. A pharmaceutical product according to claim 34, wherein the loss from each solid dosage form is less than about 0.075 pg allergen extract.

36. A pharmaceutical product according to claim 35, wherein the loss from each solid dosage form is less than about 0.025 pg allergen extract.

37. A pharmaceutical product according to claim 36, wherein the loss from each solid dosage form is less than about 0.01 pg allergen extract.

38. A pharmaceutical product according to claim 1-32, wherein the loss from each solid dosage form is less than about 0.025 pg major allergen.

39. A pharmaceutical product according to claim 38, wherein the loss from each solid dosage form is less than about 0.015 pg major allergen.

40. A pharmaceutical product according to claim 39, wherein the loss from each solid dosage form is less than about 0.0075 pg major allergen.

41. A pharmaceutical product according to claim 40, wherein the loss from each solid dosage form is less than about 0.0025 ug major allergen.

42. A pharmaceutical product according to claim 41, wherein the loss from each solid dosage form is less than about 0.001 pg major allergen.

43. A pharmaceutical product according to any one of claims 1-42, wherein the matrix is formed by subliming a solution comprising said allergen and at least one matrix-forming agent. AMENDED SHEET

PCT/DK2003/000814 ® 101

44. A pharmaceutical product according to any one of claims 1-43, wherein the water content of the dosage form is between about 2 % and about 8% by weight.

45. A pharmaceutical product according to any one of claims 1-40, wherein one matrix-forming agent is gelatine.

46. A pharmaceutical product according to claim 45, wherein the gelatine comprises fish gelatine.

47. A pharmaceutical product according to claims 45 or 46, wherein a further matrix-forming agent is mannitol.

48. A pharmaceutical product according to claim 47, wherein the ratio of fish gelatine to mannitol is from about 2:20 to about 20:1.

49. A pharmaceutical product according to claim 48, wherein the ratio of fish gelatine to mannitol is from about 2:10 to about 10:1.

50. A pharmaceutical product according to claim 49, wherein the ratio of fish gelatine to mannitol is from about 3:5.5 to about 6.5:3.

51. A pharmaceutical product according to claim 50, wherein the ratio of fish gelatine to mannitol is 4:3.

52. A pharmaceutical product according to claim 50, wherein the ratio of fish gelatine to mannitol is s 6.5:5.5.

53. A pharmaceutical product according to claim 50, wherein the ratio of fish gelatine to mannitol is 6.0:5.08. AMENDED SHEET

Py PCT/DK2003/000814

54. A pharmaceutical product according to 47-53, wherein the matrix is formed from a solution comprising about 2 to about 10% WAW fish gelatine and about 1 to about 10% mannitol W/W.

55. A pharmaceutical product according to claim 54, wherein the solution comprises about 3 to about 6.5% W/W fish gelatine and about 3 to about 5.5 % W/W mannitol.

56. A pharmaceutical product according to claim 55, wherein the solution comprises about 6.5 % W/W fish gelatine and about 5.5 % W/W mannitol.

57. A pharmaceutical product according to claim 55, wherein the solution comprises 6.0 % W/W fish gelatine and 5.08 % W/W mannitol.

58. A pharmaceutical product according to any one of claims 1-40, wherein one matrix-forming agent is starch.

59. A pharmaceutical product according to claim 58, wherein a further matrix-forming agent is mannitol.

60. A pharmaceutical product according to claim 59, wherein the ratio of starch to mannitol is from about 2:20 to about 20:1.

61. A pharmaceutical product according to claim 59, wherein the ratio of starch to mannitol is from about 2:10 to about 10:1.

62. A pharmaceutical product according to claims 59-61, wherein the matrix is formed from a solution comprising 3-6.5% W/W starch and 3-

5.5% W/W mannitol. AMENDED SHEET

® PCT/DK2003/000814

63. A pharmaceutical product according to any one of claims 1-62, which disintegrates in human saliva within about 80 seconds.

64. A pharmaceutical product according to claim 63, which disintegrates in human saliva within about 2 seconds.

65. A pharmaceutical product according to any one of claims 1-64, wherein the allergen is selected from the group consisting of tree polien allergens, weed pollen allergens, herb pollen allergens, grass pollen allergens, mite allergens, insect allergens, venom allergens, animal hair allergens, dander allergens and food allergens.

66. A pharmaceutical product according to claim 65, wherein the allergen is in the form of an extract, a purified allergen, a modified allergen or a recombinant allergen or a mutant of a recombinant allergen or any combination thereof.

67. A pharmaceutical product according to claims 65-66, wherein the allergen is grass pollen allergen.

68. A pharmaceutical product according to claim 67, wherein the allergen is in the form of grass pollen extract.

69. A pharmaceutical product according to claims 65-66, wherein the allergen is dust mite allergen.

70. A pharmaceutical product according to claim 68, wherein the allergen is in the form of a dust mite extract.

71. A pharmaceutical product according to any one of claims 1-70 comprising at least two different allergens. AMENDED SHEET

® PCT/DK2003/000814

72. A pharmaceutical product according to any one of claims 1-71 wherein the dosage form comprises one or more excipients.

73. A pharmaceutical product according to claim 72, containing an excipient selected from the group consisting of antacids, diluents, mucoadhesive agents, enhancer, flavouring agents, taste masking agents, preservatives, antioxidants, surfactants, viscosity enhancers, coloring agents, pH modifiers and sweeteners.

74. A pharmaceutical product according to any one of claims 1-73, further comprising an adjuvant.

75. The pharmaceutical product of claim 74, wherein the adjuvant is selected from the group consisting of aluminium salts, non-toxic bacterial fragments, cytokines, cholera toxin, detoxified fractions cholera toxin, chitosan, heat-labile fragments of E.coli, detoxified fractions heat-labile fragments of E.coli, saponins, lipopoly-saccharides, muramy! dipeptide, liposomes, Immune stimulatory DNA sequences and lactide/glycolide microparticular polymers.

76. A pharmaceutical product according to any one of claims 1-75, further comprising an anti-allergic drug.

77. A pharmaceutical product according to claim 76, wherein the anti- allergic drug is an antihistamine.

78. A multi dosage container comprising a plurality of solid dosages forms of any one of claims 1-77.

79. A multidosage container according to claim 78, wherein the multi dosage container is a blister pack. AMENDED SHEET

PCT/DK2003/000814 ® 105

80. A multi dosage container according to any one of claims 78-79 wherein each solid dosage form contains the same amount of allergens.

81 Use of a pharmaceutical product of any one of claims 1-77 in the manufacture of a medicament for oromucosal treatment of allergy or alleviating symptoms of allergy.

82. A method of producing a fast-dispersing, non-compressed solid and stable dosage form having low friability, comprising at least one matrix forming agent and being suitable for oromucosal administration comprising an effective dose for desensitizing an individual to at least one allergen, comprising the steps of (a) preparing an aqueous solution comprising said at least one allergen and said at least one matrix forming agent, (b) introducing the solution into one or more depressions in a mould (c) subjecting the loaded mould to freezing and freeze-drying using standard conditions of shelf temperature and chamber pressure to obtain said solid dosage form in each depression.

83. A method according to claim 82 wherein step (b) comprises introducing the solution into depressions in a multilayer laminated blister sheet.

84. The dosage form as defined in claims 1-77, wherein the solid dosage form has a water activity of 0.4-0.5 85 A kit for treatment of allergy or for alleviating allergy symptoms comprising a) a plurality of solid oral dosage forms in a sealed container, each of said solid oral dosage forms being held in a sealed enclosure and comprising an effective amount of an allergen suitable for AMENDED SHEET

® PCT/DK2003/000814 oromucosal administration; and b) each of said solid dosage forms containing the same amount of the allergen.

86. A kit according to claim 85 further comprising instructions for using the multiple solid dosage forms.

87. A kit according to claims 85-86, wherein the dosage form is a fast- dispersing dosage form.

88. A kit according to claims 85-87, wherein each of the solid dosage forms are located in individually sealed blisters in a multiple blister pack.

89. A kit according to claims 85-88, wherein the solid dosage forms comprise gelatine.

90. A kit according to claim 89, wherein the solid dosage forms further comprise mannitol.

91. A kit according to claims 89-90, wherein the gelatine is fish gelatine.

92. Akt according to claims 85-91, wherein the effective amount of allergen is between about 2.5 pg — about 3.75 mg extract solid dosage form.

93. A pharmaceutical product comprising an orally administerable solid dosage form comprising a matrix formed of at least one pharmaceutically acceptable material, an effective amount of an allergen for desensitizing a human to said allergen, said dosage form having an allergen content at least about 50% of the initial allergen content after being held for 3 months at 25°C and 60% relative humidity. AMENDED SHEET

) PCT/DK2003/000814

94. A pharmaceutical product according to any of claims 1-77 or 93, wherein the product is selected from the group consisting of a lozenge, tablet, a capsule and a caplet.

95 A pharmaceutical product according to any one of claims 1-77 or 93-94 for oromucosal treatment of allergy or alleviation of allergy symptoms.

96. Use of a solid dosage form as defined in any of claims 1-77 for oromucosal treatment of allergy or alleviation of allergy symptoms.

97. A pharmaceutical product according to any one of claims 1 to 77 or 93 to 95, substantially as herein described with reference to and as illustrated in any of the examples.

98. A container according to claim 78 or claim 79 or claim 80, substantially as herein described with reference to and as illustrated in any of the examples.

99. Use according to claim 81, substantially as herein described with reference to and as illustrated in any of the examples.

100. A method according to claim 82 or claim 83, substantially as herein described with reference to and as illustrated in any of the examples.

101. A dosage form according to claim 84, substantially as herein described with reference to and as illustrated in any of the examples.

102. A kit according to any one of claims 85 to 92, substantially as herein described with reference to and as illustrated in any of the examples. AMENDED SHEET

® PCT/DK2003/000814

103. Use according to claim 96, substantially as herein described with reference to and as illustrated in any of the examples. AMENDED SHEET