WO1994018977A1

WO1994018977A1 - Vinca alkaloids for the treatment of papillomavirus infection

Info

Publication number: WO1994018977A1
Application number: PCT/GB1994/000359
Authority: WO
Inventors: William Cleveland Phelps; David Craig Lobe
Original assignee: The Wellcome Foundation Limited
Priority date: 1993-02-24
Filing date: 1994-02-23
Publication date: 1994-09-01
Also published as: GB9303719D0; ZA941243B; AU6112394A; MX9401370A

Abstract

The present invention relates to the use of certain known vinca alkaloids in the preparation of medicaments useful in the treatment or prophylaxis of papillomavirus infections. Also provided are pharmaceutical formulations containing such compounds to be used in the treatment or prophylaxis of papillomavirus infections.

Description

VINCA ALKALOIDS FOR THE TREATMENT OF PAPHJϋOMAVIRUS INFECTION

The present invention relates to the use of vinca alkaloids for the treatment of papilloma virus infections.

Vinca alkaloids include vinrosidine (leurosidine), vincristine (leurocristine), vinblastine (vinca leukoblastine), vindesine and, in particular, vinoreibine. Vinca alkaloids are derived from the periwinkle plant (Vinca rosea) and are mitotic inhibitors. Vincristine is active against neoplastic diseases including leukemias, lymphomas, sarcomas and some carcinomas. It is used extensively in combination regimens for the treatment of such diseases. Vinblastine, in combination with cisplaten and bleomycia, is an agent of choice in disseminated nonseminomatous testicular cancer. It is also active against non- Hodgkin's lymphoma, choriocarcinoma, breast carcinoma, head and neck cancer, cutaneous T cell lymphomas, Kaposi's sarcoma and histiocytosis X (Letterer-Siwe disease). (American Medical Association, Drug Evaluation .Annual 1991, 1780-1782).

Vinoreibine, also known as 5'-nor-anhydrovinblastine, is a semisynthetic vinca alkaloid which has been proposed for the treatment of solid or liquid tumours, more particularly human cancers for example, in accordance with U.S. Patent Specification No. 4307100. The compound is being clinically investigated for the treatment of non-small-cell lung cancer and metastatic breast cancer.

Papillomaviruses are widespread in nature and infect most vertebrate species including humans. These viruses commonly induce a variety of benign squamous epithelial (warts and papillomas) and fibroepithelial (fibropapillomas) tumours. Over the past 10 years, the human papillomaviruses (HPVs) have been recognized as the etiological agent responsible for venereally transmitted genital warts. In particular, exophytic genital warts or condyloma which occur on the penis, vulva or in the perianal region are highly associated with infection by HPV types 6 and 11. In addition, juvenile and adult onset laryngeal papillomas are associated with infection by HPV types 6 and 11. A papillomarivus etiology for cervical dysplasia and flat genital warts is derived from numerous studies which demonstrate the presence of HPV types 16 and 18 (and other related HPVs such as 31,33,35, and 39) in more than 85% of the primary tumours. Other HPV types are associated with a variety of benign cutaneous papillomas including palmar and plantar warts, common and flat warts which are associated primarily with HPV types 1-4.

Infection of epithelial keratinocytes by papillomaviruses normally results in the induction of a benign epithelial tumor or wart. The characteristic hyperproliferation and acanthosis which is associated with such viral infections, is thought to be due to the expression of one or more of the viral early gene products including the E5, E6 and E7 proteins. These viral oncoproteins encode biochemical properties which are associated with cellular proliferation, cell cycle stimulation, and the disruption of programmed differentiation. It is thought that such activities are important to the induction of the complementary cellular machinery which is required for viral DNA replication.

We have now discovered that vinca alkaloids are effective against papillomavirus infections. These vinca alkaloids include vinoreibine, vincristine, vindesine, vinblastine and vinrosidine.

According to the present invention we therefore provide:-

a) Use of a vinca alkaloid such as vinoreibine, vincristine, vindesine, vinblastine or vinrosidine or a physiologically acceptable derivative thereof in the manufacture of a medicament for the treatment or prophylaxis of a papillomavirus infection;

b) A vinca alkaloid such as vinoreibine, vincristine, vindesine, vinblastine or vinrosidine or a physiologically acceptable derivative thereof for the treatment or prophylaxis of a papillomavirus infection;

c) A method, of treating a papillomavirus infection in a host (e.g. a human) which comprises administering to the said host an anti-papillomavirus effective amount of a vinca alkaloid such as vinoreibine, vincristine, vindesine, vinblastine or vinrosidine or a physiologically acceptable derivative thereof; and

d) An anti-papillomavirus pharmaceutical composition comprising a vinca alkaloid such as vinoreibine, vincristine, vindesine, vinrosidine or vinblastine or a physiologically acceptable derivative thereof. The vinca alkaloids vinoreibine, vinblastine and vincristine are preferred compounds of the invention.

The vinca alkaloid vinoreibine is the most preferred compound of the invention.

The vinca alkaloids according to the invention are particularly effective when the papillomavirus is human papillomavirus.

As used herein, the term "physiologically acceptable derivative" means a physiologically acceptable salt of a vinca alkaloid or any other compound which upon administration to the recipient is capable of providing (directly or indirectly) said vinca alkaloid or an antivirally active metabolite or residue thereof.

Examples of physiologically acceptable salts include salts derived from an appropriate base, such as an alkali metal (for example, sodium), an alkaline earth metal (for example, magnesium), ammonium and NX4^"1" (wherein X is C^alkyl). Physiologically acceptable salts include salts of organic carboxylic acids such as acetic, lactic, tartaric, malic, isethionic, lactobionic and succinic acids; organic sulphonic acids such as methanesulphonic, ethanesulphonic, benzenesulphonic and p-toluenesulphonic acids; and inorganic acids such as hydrochloric, sulphuric, phosphoric and sulphamic acids.

The vinca alkaloids according to the invention may be employed in combination with other antiviral therapeutic agents for the treatment of a papillomavirus infection. Examples of such further therapeutic agents include ribavirin.

The component compounds of such combinations therapy may be administered simultaneously, in either separate or combined formulations, or at different times, i.e. sequentially so that a combined effect is achieved.

In addition to the above, vinca alkaloids according to the invention may be employed as an adjuvant therapy in conjunction with ablative therapies for the treatment of papilloma virus infection such as curettage, use of laser excision, cryrosurgery or electrocautery. Such adjuvant therapy may be applied in advance of, together with or subsequent to ablative therapy. Vinca alkaloids such as those described and their physiologically acceptable derivatives (hereinafter referred to collectively as "compounds according to the invention") may be used to treat or prevent papillomavirus infections by HPV types including but not limited to HPV 1,2,3,4,6,11,16 and 18.

Examples of diseases or clinical conditions which may be treated or prevented in accordance with the present invention include genital warts particularly condyloma acuminata but may also extend to other HPV associated lesions including laryngeal papillomas, cutaneous warts, intraepithelial neoplasia, and cancers caused by papillomavirus infections.

The compounds according to the invention also referred to herein as active ingredients, may be administered to humans for prophylaxis, as an adjunct therapy, or treatment of papilloma virus infections by any suitable route including oral, rectal, nasal, topical (including, buccal, sublingual and transdermal), vaginal and parenteral (including subcutaneous, intramuscular, intravenous and intradermal) administration. It will be appreciated that the preferred route will vary with the condition and age of the recipient, the nature of the infection and the chosen active ingredient(s) or combination of active ingredients .

In general a suitable dose will be in the range of 0.1 to 250μg per kilogram body weight of the patient per day, preferably in the range of 0.1 to 50μg per kilogram body weight per day and most preferably in the range 1 to 25 μg per kilogram body weight per day. The desired dose is preferably presented as two, three or more sub-doses administered at appropriate intervals throughout the day. These sub-doses may be administered in unit dosage forms, for example, containing 2 to HOOμg, preferably 20 to 550μg of active ingredient per unit dosage form.

While it is possible for the active ingredient to be administered alone it is preferable to present it as a pharmaceutical formulation. The formulations of the present invention comprise at least one active ingredient, as above defined, together with one or more pharmaceutically acceptable carriers thereof and optionally other therapeutic agents.

Formulations include those suitable for oral, rectal, nasal, topical (including transdermal, buccal and sublingual), vaginal and parenteral (including subcutaneous, intramuscular, intravenous and intradermal) administration. The formulations may conveniently be presented in unit dosage form and may be prepared by any methods well known in the art of pharmacy. Such methods include the step of bringing into association the active ingredient with the carrier which constitutes one or more accessory ingredients. In general, the formulations are prepared by uniformly and intimately bringing into association the active ingredient with liquid carriers or finely divided solid carriers or both, and then if necessary shaping the product.

For topical administration the formulations are preferably applied as an ointment or cream containing the active ingredient in an amount of, for example, 0.1 to 1.5% w/w preferably 0.5 to 1.0% w/w of the active ingredient. When formulated in an ointment, the active ingredient may be employed with either a paraffinic or a water-miscible ointment base. Alternatively, the active ingredient may be formulated in a cream with an oil-in-water cream base or in a water in oil base. Such creams may be administered from at least once weekly to about twice daily, for example from once daily to twice weekly.

If desired, the aqueous phase of the cream base may include, for example, at least 30% w/w of a polyhydric alcohol, i.e. an alcohol having two or more hydroxyl groups such as propylene glycol, butane- 1, 3 -diol, mannitol, sorbitol, glycerol and polyethylene glycol and mixtures thereof. The topical formulations may desirably include a compound which enhances absorption or penetration of the active ingredient through the skin or other affected areas. Examples of such dermal penetration enhancers include dimethylsulphoxide and related analogues.

The oily phase of the emulsions may be constituted from known ingredients in a known manner. While this phase may comprise merely an emulsifier (otherwise known as an emulgent), it desirably comprises a mixture of at least one emulsifier with a fat or an oil or with both a fat and an oil. Preferably, a hydrophilic emulsifier is included together with a lipophilic emulsifier which acts as a stabilizer. It is also preferred to include both an oil and a fat. Together, the emulsifier(s) with or without stabilizer(s) make up the so- called emulsifying wax, and the wax together with the oil and/or fat make up the so- called emulsifying ointment base which forms the oily dispersed phase of the cream formulations. Emulgents and emulsion stabilizers suitable for use in the formulation of the present invention include Tween 60, Span 80, cetostearyl alcohol, myristyl alcohol, glycerol mono-stearate and sodium lauryl sulphate.

The choice of suitable oils or fats for the formulation is based on achieving the desired cosmetic properties, since the solubility of the active compound in most oils likely to be used in pharmaceutical emulsion formulations is very low. Thus the cream should preferably be a non-greasy, non-staining and washable product with suitable consistency to avoid leakage from tubes or other containers. Straight or branched chain, mono- or dibasic alkyl esters such as di-isoadipate, isocetyl stearate, propylene glycol diester of coconut fatty acids, isopropyl myristate, decyl oleate, isopropyl palmitate, butyl stearate, 2-ethylhexyl palmitate or a blend of branched chain esters known as Crodamol CAP may be used, the last three being preferred esters. These may be used alone or in combination depending on the properties required. Alternatively, high melting point lipids such as white soft paraffin and/or liquid paraffin or other mineral oil can be used.

Formulations suitable for transdermal administration may be presented as discrete patches adapted to remain in intimate contact with the epidermis of the recipient for a prolonged period of time. Such patches suitably contain the active compound in 1) an optionally buffered, aqueous solution or 2) dissolved and/or dispersed in an adhesive or 3) dispersed in a polymer. A suitable concentration of the active compound is about 0.1% to 35% w/w, preferably about 3% to 15% w/w. As one particular possibility, the active compound may be delivered from the patch by electrotransport or iontophoresis, as generally described in Pharmaceutical Research. 3,(6), 318 (1986).

Formulations of the present invention suitable for oral administration may be presented as discrete units such as capsules or tablets each containing a predetermined amount of the active ingredient; as a powder or granules; as a solution or a suspension in an aqueous or non-aqueous liquid; or as an oil-in-water liquid emulsion or a water-in-oil liquid emulsion. The active ingredient may also be presented as a bolus, electuary or paste. Oral formulations may further include other agents conventional in the art, such as sweeteners, flavouring agents and thickeners.

A tablet may be made by compression or moulding, optionally with one or more accessory ingredients. Compressed tablets may be prepared by compressing in a suitable machine the active ingredient in a free-flowing form such as a powder or granules, optionally mixed with a binder (e.g. povidone, gelatin, hydroxypropylmethyl cellulose), lubricant, inert diluent, preservative, disintegrant (e.g. sodium starch glycollate, cross- linked povidone, cross-linked sodium carboxymethyl cellulose), surface-active or dispersing agent. Moulded tablets may be made by moulding in a suitable machine a mixture of the powdered compound moistened with an inert liquid diluent. The tablets may optionally be coated or scored and may be formulated so as to provide slow or controlled release of the active ingredient therein using, for example, hydroxypropylmethylcellulose in varying proportions to provide the desired release profile.

Formulations suitable for topical administration in the mouth include lozenges comprising the active ingredient in a flavoured basis, usually sucrose and acacia or tragacanth; pastilles comprising the active ingredient in an inert basis such as gelatin and glycerin, or sucrose and acacia; and mouthwashes comprising the active ingredient in a suitable liquid carrier.

Formulations for rectal administration may be presented as a suppository with a suitable base comprising for example cocoa butter or a salicylate.

Formulations suitable for vaginal administration may be presented as pessaries, tampons, creams, gels, pastes, foams or spray formulations containing in addition to the active ingredient such carriers as are known in the art to be appropriate.

Formulations suitable for parenteral administration include aqueous and non-aqueous isotonic sterile injection solutions which may contain anti-oxidants, buffers, bacteriostats and solutes which render the formulation isotonic with the blood of the intended recipient; and aqueous and non-aqueous sterile suspensions which may include suspending agents and thickening agents. The formulations may be presented in unit-dose or multi-dose sealed containers, for example, ampoules and vials, and may be stored in a freeze-dried (lyophilized) condition requiring only the addition of the sterile liquid carrier, for example water for injections, immediately prior to use. Extemporaneous injection solutions and suspensions may be prepared from sterile powders, granules and tablets of the kind previously described. Preferred unit dosage formulations are those containing a daily dose or unit, daily sub- dose, as herein above recited, or an appropriate fraction thereof, of an active ingredient.

Vincristine, vinblastine and vindesine are commercially available (Eli Lilly and Company, Indiana IN 46285). Vinoreibine may be prepared in accordance with the procedures described in the above-mentioned U.S. Patent Specification No. 4307100. Vinblastine and vincristine may be prepared in accordance with the procedures described in the US Patent Specification No. 4279817. Vinrosidine may be prepared in accordance with the procedures described in the U.S. Patent Specification No. 3205220. Corresponding physiologically acceptable derivatives may be prepared in a conventional manner.

The invention is illustrated by the following Examples of Pharmaceutical Formulations, Biological Data and Toxicity Data.

Examples of Pharmaceutical Formulations

These examples are intended to illustrate the invention and are not limiting in any way.

Example 1

Cream Amount

Active Ingredient l.OOg

Glycerol 2.00g

Cetostearyl Alcohol 6.75g

Sodium Lauryl Sulfate 0.75g

White Soft Paraffin 12.50g

Liquid Paraffin 5.00g

Chlorocresol 0.10g

Purified Water to lOO.OOg o The active compounds are mixed with purified water and glycerol and heated to 70 C. o The remaining ingredients are heated together at 70 C. The two parts are added together and emulsified. The cream is cooled and filled into containers. Example 2

Cream Amount

Active Ingredient 1. OOg

Mineral Oil, Heavy 5.00g

Polawax 7.50g

Propylene Glycol 40. OOg

White Petrolatum 12.50g

Sodium Edetate 0.1 Og

Purified Water to lOO.OOg o A solution of sodium edetate in water is heated to 70-75 C and added to a mixture of the mineral oil, white petrolatum and polawax, heated to the same temperature. The o propylene glycol is added and the mixture is allowed to cool to 50-55 C. The two active o compounds are added, mixed and allowed to cool to 25-30 C. Sufficient purified water is added to achieve the proper batch weight. The cream is filled into containers.

Biological Data

Anti-Papilloma Virus Activity

A SCID-Ra Model

Vinoreibine, vincristine and vinblastine were tested for in vivo activity against papillomavirus using the SCID-Ra animal model. Compounds were evaluated in at least ten separate experiments conducted with the SCID-Ra model. The procedure involved transplanting donor rabbit tissue to the back of mice and subsequently infecting this tissue with cottontail rabbit papillomavirus (CRPV). After 24 hours post-infection developing lesions were treated with a vinca alkaloid in either an aqueous cream or an aqueous formulation in combination with an oral formualtion. Lesion scores were reduced in mice treated topically. The results are summarised in the table below. B Rabbit Back Model

Activity of vinoreibine against papillomavirus was also demonstrated by using the rabbit back model. In this model five New Zealand White rabbits per treatment group were infected on both dorsal surfaces with 10 dilution of CRPV. The right side served as a contralateral control and was untreated. On the left side the drug was applied in either 0.3% w/w or 1.5% w/w aqueous cream formulation beginning on day 15 of the study and applied two - five times per week for three weeks. No significant effect was observed on the untreated right side or on the rabbits treated with a placebo cream. However, there was significant inhibition of lesion development on the left side of the rabbits treated with vinoreibine. The results are summarised in the table below.

C Human Wart Tissue Xenografts

A third assay system was employed to confirm the activity of vinoreibine against papillomavirus infected tissue. In this model, fresh tissue from human cutaneous or mucosal warts is grafted on to a well vascularized bed in an implantation chamber on the dorsum of immunocompromised mice. After one week post grafting the human wart tissue grafts were treated topically with an aqueous cream formulation vinoreibine (days 7 and 9), and necropsied at three weeks. The results are summarised in the table below.

Results

A SCID-Ra Model

Vinca Alkaloid Formulation Dosage Dosing % Inhibition frequencv in AUC*

Vinoreibine topical 0.1% w/w 4x/wkl,5x/wks 23 2-6

Vinoreibine topical 0.1% w/w 4x/wkl,5x/wks 74

+ oral 0.05% w/w 2-6

Vinoreibine topical 0.3% w/w 4x/wkl,5x/wks 58 2-6

Vinoreibine topical 1.0% w/w 2x/wks 1-6 42,56

Vinblastine topical 1.5% 2x/wk 1,1 x/wks 73 2-6

Vincristine topical 0.3% w/w 2x/wkl-2, 62 reduced to 0.15% 3x/wk3, 5x/wks 4-6

*AUC = area under the curve of mean lesion scores relative to untreated animals.

B Rabbit Back Model

Dosage Dosing Frequency Start of Dosing % Inhibition in AUL relative to date of infection

0.3% w/w 5 x/wks 3-6 + 14 days 66

0.9% w/w 5 x/wks 3-6 + 14 days 90

1.5% w/w 2 x/wks 3-6 + 14 days 73,70

3% w/w 2 x/wks 3-6 + 14 days 52 C Human Wart Tissue Xenografts

Treatment with 1% Vinoreibine (topical) caused 100% inhibition of growth of HPV infected cells.

Toxicity Data

Many studies have been published which contain toxicity data of the vinca alkaloids vinoreibine, vincristine and vinblastine having been administered systemically, such as Nouvelle Revue Francaise dΗematologie (1989) 31:77-84, Drugs Today (1992) 28(3) : 160-162 and Seminars in Oncology (1989) April, Vol 16. No. 2. Suppl. 4 : 37-40.

In our own experiments it was found that in the rabbit back model (B) slight dermal irritation was seen with daily topical application of vinoreibine at both 0.3% and 0.9% w/w topical formulations. In the SCID-Ra model (A) daily application of doses greater than 0.3% caused dermal irritation.

Claims

1. Use of a vinca alkaloid or a physiologically acceptable derivative thereof in the manufacture of a medicament for the treatment or prophylaxis of a papillomavirus infection.

2. Use of vinoreibine or a physiologically acceptable derivative thereof in the manufacture of a medicament for the treatment or prophylaxis of a papillomavirus infection.

3. Use according to any of the above claims wherein the papilloma virus is a human papillomavirus.

4. A method of treating a papillomavirus infection in a host which comprises administering to the said host an anti-papillomavirus effective amount of a vinca alkaloid or a physiologically acceptable salt thereof.

5. A method of treating a papillomavirus infection in a host which comprises administering to the said host an anti-papillomavirus effective amount of a vinoreibine or a physiologically acceptable salt thereof.

6. A method of treatment according to any of Claims 4 or 5 in which the host is a human and the papillomavirus.is human papillomavirus.

7. A method of treatment according to any of Claims 4 or 5 in which the host is a human and the virus is human papillomavirus 1,2,3,4,6,11,16 or 18 or any combination thereof.

8. An anti-papillomavirus pharmaceutical composition comprising a vinca alkaloid or a physiologically acceptable salt thereof and a pharmaceutically acceptable excipient.

9. An anti-papillomavirus pharmaceutical composition according to Claim 8 comprising vinoreibine or a physiologically acceptable salt thereof.

10. An anti-papilloma virus pharmaceutical composition according to Claims 8 or 9 which is adapted for topical use.