AU1166201A - Pharmaceutical formulations comprising labdanes for the treatment of tumors or leukemias - Google Patents

Description

WO 01/34116 PCT/GROO/00033 PHARMACEUTICAL FORMULATIONS COMPRISING LABDANES FOR THE TREATMENT OF TUMORS OR LEUKEMIAS. I. INTRODUCTION 5 The present invention relates to novel compositions based on hydrated lipidic lamellar phases or liposomal compositions, prepared by combining different lipid molecules, synthetic and/or from natural sources, said compositions comprising at least one of a) labd-13-ene-8a, 10 15-diol and/or derivatives thereof; b) labd-14-ene-8, 13 diol or derivatives thereof; c) 39-hydroxy-labd-14-ene-8, 13-epoxy and/or derivatives thereof, d) a plant extract containing the aforementioned labdenes or derivatives thereof. The compositions of the invention exhibit 15 cytotoxicity against cancerous cells and are utilized for the treatment of tumors and leukemias. II. BACKGROUND OF THE INVENTION A very large number of diterpenoids possessing a 20 labdane skeleton (Figure 1) 11 CH3 13 CH -- C3 25 Figure 1I CH3 15 10 3 57 H3C 4 CH36 30 occur in nature (Connoly, J.D.; Hill, R.A Dictionary of Terpenoids, Chapman and Hall: London 1991). The interest in WO 01/34116 PCT/GROO/00033 studying labdanes is heightened due to the wide range of biological activities of these compounds (Singh, M.; Pal, M.; Sharma, R.P. Planta Med., 1999, 65, 2-8.). They comprise a decalin system and a C-6 ring, which may be open or closed 5 with an oxygen atom, as in manoyl oxide and its derivatives. Labdanes have been isolated from several plant families, such as Asteraceae, Labiateae, Cistaceae, Pinaceae, Cupressaceae, Taxodiaceae, Acanthaceae, Annonaceae, Caprifoliaceae, Solanaceae, Apocynaceae, Verbenaceae and 10 Zingiberaceae. In addition they have been isolated from marine algae of the genus Laurence, from Taonia atomaria and from the red alga Chondria tenuissima. The conifers are an important source of diterpenoids. Several labdanes have been detected in the 15 neutral fraction of the oleoresin of Araucaria excelsa, including manool as well as nor-labdanes (Caputo, R.; Mangoni, L.; Monaco, P. Phytochemistry, 1972, 11, 839-840). A variety of biological activities have been associated with labdane diterpenes including antibacterial, antifungal, 20 antiprotozoal, enzyme induction, anti-inflammatory modulation of immune cell functions, as well as cytotoxic and cytostatic effects against human leukemic cell lines. (K. Dimas et al.-Planta Med. 1998, 208-211; K. Dimas et al. Leukemia Res. 1999, 217-234; K. Dimas et al. Anticancer Res. 25 1999, 4065-4072). In addition to the (antimicrobial, enzyme and endocrine related) properties mentioned above, it is interesting that many labdane type diterpenes also exhibit significant properties against cancer cells. A number of labdane type diterpenes tested exhibited remarkable 30 antiproliferative and cytotoxic activities (Itokawa, H. et all. Planta Med. 1988, 311-315; K. Dimas et al. Planta Med. 1998, 208-211; K. Dimas et al. Leukemia Res. 1999, 217-234; K. Dimas et al. Anticancer Res. 1999, 4065-4072). -2- WO 01/34116 PCT/GROO/00033 Labdane furanoids, and forscolin derivatives are the subject of several patents and applications, including European Patent Application 93103605.7; International Patent Publication No. WO 97/45099; International Patent 5 Publication No. WO 91/02525; and International Patent Publication No. WO 85/03637. Liposomes, or phospholipid vesicles, are self assembled colloidal particles that occur naturally and can be prepared artificially (Lasic, D.D. Liposomes: from 10 Physics to Applications. Elsevier), as shown by Bangham and his students in the mid-1960s (Bangham, A.D. ed. (1983) Liposomes Letters, Academic Press). At first, they were used to study biological membranes; several practical applications, most notably in drug delivery, emerged in the 15 1970. Today, they are a very useful model, reagent and tool in various scientific disciplines, including mathematics and theoretical physics, biophysics, chemistry, colloid science, biochemistry and biology. Liposomes were introduced as drug delivery vehicles in the 1970s. Early results were, however, 20 rather disappointing, owing mainly to their colloidal and biological instability, and their inefficient and unstable encapsulation of drug molecules. Their utility was improved following basic research that increased our understanding of their stability and interaction characteristics. In 25 parallel, several pharmaceutical enterprises were founded that survived the decline in the controversial appreciation of liposomes in the 1980s and early 1990s and, eventually, put several commercial products on the market. At present, these include antifungal and anti-cancer preparations that 30 compare favorably to existing treatments, but a recent renaissance in liposome research is promising many more products to come. -3- WO 01/34116 PCT/GROO/00033 In the scientific literature, there is reference to a great number of liposomic pharmaceutical forms. Many of these are in the clinical study stage and some other have been already registered and marketed. Among the medicines 5 formulated in liposomic form, are econazole, amfotericin B, minoxidyl and some anticancer and antiviral medicines, which are in the clinical study stage. III. DETAILED DESCRIPTION OF THE INVENTION 10 It has been found that naturally occurring labdanes, such as labd-13-ene-8a, 15-diol, labd-14-ene-8, 13-diol, and 3S-hydroxy-labd-14-ene-8, 13-epoxy, exhibit biological properties in their pure state (Dimas et al., Planta Med. 1998) and may be useful as novel pharmaceutical 15 and medicinal agents. The present invention deals with preparation of hydrated lipidic lamelar phases or liposomes particularly conventional and/or PEGylated and/or protein conjugated, containing the above compounds and their derivatives or plant extracts containing them, which are 20 part of this invention. The compositions of the invention are useful for the treatment of neoplastic diseases. As used herein the term "alkyl" refers to a straight or branched, saturated hydrocarbon containing from one to about twelve carbon atoms such as, for example, 25 methyl, ethyl, n-propyl, i-propyl, n-butyl, s-butyl and t butyl, wherein one or more of the hydrogen atoms may be substituted. As used herein the term "alkenyl" refers to a straight or branched hydrocarbon containing from one to 30 about twelve carbon atoms where at least one carbon-carbon bond is unsaturated such as for example, vinyl, allyl and butenyl, wherein one or more of the hydrogen atoms may be substituted. -4- WO 01/34116 PCT/GROO/00033 As used herein the term "alkynyl" refers to a straight or branched hydrocarbon containing from one to about twelve carbon atoms where at least one carbon-carbon bond is doubly unsaturated such as for example, acetylene, 5 propynyl and butynyl, wherein one or more of the hydrogen atoms may be substituted. As used herein the term "cycloalkyl" refers to a cyclic hydrocarbon containing from three to about twelve carbon atoms such as, for example, cyclopropyl, cyclobutyl, 10 cyclopentyl and cyclohexyl, wherein one or more of the hydrogen atoms may be substituted. As used herein the term "aralkyl" refers to a straight or branched, saturated hydrocarbon containing from one to about twelve carbon atoms, which is substituted with 15 an aromatic ring such as, for example, benzyl and phenethyl, wherein one or more of the hydrogen atoms may be substituted. As used herein the term "heterocyclyl" refers to a cyclic hydrocarbon, wherein at least one carbon atom has 20 been replaced by a heteroatom such as, for example, nitrogen, oxygen or sulfur, containing from three to about twelve atoms such as, for example, furan, pyran and imidazole. As used herein the term "dialkylaminoalkyl" refers 25 to a straight or branched, saturated hydrocarbon containing from one to about twelve carbon atoms, which is connected to a tertiary amino group containing two alkyl groups such as, for example, diethylaminoethyl. Preferably, the dialklyaminoalkyl group is present as the acid addition salt 30 resulting from reaction with either an inorganic or organic acid. As used herein the terms "alkylthioketones", "alkenylthioketones", "alkynylthioketones", -5- WO 01/34116 PCT/GROO/00033 "cycloalkylthioketones", "aralkylthioketones" and "heterocyclothioketones" refer to a thioketone connected to a further radical. As used herein the terms "alkylcarbonyl", "alkenylcarbonyl", "alkynylcarbonyl", "cycloalkylcarbonyl" and "aralkylcarbonyl"refer to a carbonyl connected to a further radical. As used herein the term "sugars" refers hexoses or pentoses in their pyranose or furanose state or 10 disaccharides containing hexose-hexose, pentose-pentose, hexose-pentose or pentose-hexose in their pyranose or furanose state. These sugars may be substituted with amino or halogen groups, preferably chlorine, bromine or iodine. 1. Labdanes of the Invention 15 The labdanes of the present invention include: A. Formula I, LABD-13-ENE-8c,15-DIOL (I) CH3 20 CH3- OH LH0 25 H3C CH3 25 Wherein R wherein R is selected from the group consisting of H, alkylcarbonyl, alkenylcarbonyl, alkynylcarbonyl, cycloalkylcarbonyl, aralkylcarbonyl, alkyl, 30 alkenyl, alkynyl, cycloalkyl, aralkyl, dialkylaminoalkyl, alkylthioketones, alkenylthioketones, alkynylthioketones, cycloalkylthioketones, aralkylthioketones, heterocyclylthioketones and sugars. -6 - WO 01/34116 PCT/GROO/00033 B. Formula II LABD-14-ENE-8, 13-DIOL (II) CH3 5CH3 OH , H2 CH3 H3C' CH3 II 10 Wherein R wherein R is selected from the group consisting of H, alkylcarbonyl, alkenylcarbonyl, alkynylcarbonyl, cycloalkylcarbonyl, aralkylcarbonyl, alkyl, alkenyl, alkynyl, cycloalkyl, aralkyl, dialkylaminoalkyl, 15 alkylthioketones, alkenylthioketones, alkynylthioketones, cycloalkylthioketones, aralkylthioketones, heterocyclylthioketones and sugars. C. Formula III 20 38-HYDROXY-LABD-14-ENE-8, 13-EPOXY CH3 CH2 CH3 0 25 CH3 H3C CH3 III Wherein R, is =0, OR 2 , or a halogen selected from 30 the group consisting of chlorine, bromine or iodine. R 2 is selected from the group consisting of H, alkylcarbonyl, alkenylcarbonyl, alkynylcarbonyl, cycloalkylcarbonyl, aralkylcarbonyl, alkyl, alkenyl, alkynyl, cycloalkyl, -7- WO 01/34116 PCT/GROO/00033 aralkyl, dialkylaminoalkyl, alkylthioketones, alkenylthioketones, alkynylthioketones, cycloalkylthioketones, aralkylthioketones, heterocyclylthioketones and sugars. 5 For the above derivatives, when R or R 2 is dialkylaminoalkyl, the diethylaminoethyl group is preferred and a suitable acid addition salt is derived from inorganic or organic acid i.e hydrochloride, hydrobromide, sulfate, phosphate, acetate, oxalate, tartrate, citrate, maleate or 10 fumarate. When R or R 2 is aralkyl, phenylalkyl groups can be substituted by 1, 2 and 3 identical or different substituents such as halogen, Cl-C3-alkyl, Cl-C3-alkoxy, hydroxy, nitro, amino, trifluoromethyl, cyano and azodo. In addition to the optical centers of the labdane 15 nucleus, the substituents may also have chiral centers, which contribute to the optical properties of the compounds to the invention. This invention embraces all the optical isomers and racemic forms of the compounds according to the invention where such compounds have chiral centers in 20 addition to those of the labdane nucleus. The labdanes, labd-13-ene 8a, 15-diol (I) and its derivative labd-13-ene 8a , 15-yl acetate as well as 38 substituted-labd-14-ene-8, 13-epoxy when 3-substitue is hydroxy (OH) (III) or acetoxy (0 Ac) groups have been 25 detected into the extracts and essential oils of the plant Cistus creticus subsp. eriocephalus, and then identified for the first time (Anastassaki, Demetzos et al. Planta Med. 1999 735-739) using GC-MS (Gas Chromatography-Mass Spectrometry) methodology. The above compounds have been 30 isolated in their pure state and their structures have been determined using spectroscopic methods, mainly NMR (Nuclear Magnetic Resonanse) (Demetzos et al. unpublished data). The labdane, labd-14-ene-8, 13-diol (II) namely sclareol has -8- WO 01/34116 PCT/GR00/00033 been isolated from Clary sage (Salvia sclarea Linn), as well as from Cistus incanus subsp. creticus (Ulubelen A., et al. Phytochemistry 1985, 1386; Demetzos C., Ph. D Thesis, Athens 1990). 5 2. Liposome Preparation The present invention provides liposomal formulations comprising one or more of the above described compounds. Any liposomal formulation known to those of skill in the art may be applied to the above described 10 labdane compounds. The lipids useful for the preparation of hydrated lipidic lamelar phases or liposomes comprising labdanes and/or their derivatives are described. The lipid molecules may be, but are not limited to, naturally occurring lipids 15 such as HSPC (hydrogenated soy phosphatidylcholine), EPC (a mixture of saturated and unsaturated lipids from eggs) SPS (soy phosphatidylserine as sodium salt) and lipids isolated from natural sources (i.e. plants, marine organism and animal tissues) as mixtures of lipids and some synthetic 20 lipids like: DSPC (distearoylphosphatidylcholine), DMPC (dimyristoylphosphatidylcholine) and DPPC (dipalmytoylphosphatidylcholine) DOPC (dioleoylphosphatidylcholine), which are saturated esters of phosphatidylcholine. Polyethylene glycol (PEG)-lipid 25 conjugates have been used to improve circulation times for liposomes encapsulated drugs and may be used in compositions of the present invention. PEG-PE(phosphatidylethanolamine) have been used for preparing long circulating liposomes, and may be used in 30 the compositions of the invention. PEG-lipid conjugates may also be used. Examples of PEG-lipid conjugates include 1,2 Diacyl-sn-glycero-3-Phosphoethanolamine

-N

[Methoxy(Polyethylene Glycol)-2000], in which the term acyl -9- WO 01/34116 PCT/GROO/00033 represents myristoyl , palmitpoyl, stearoyl and oleoyl groups. Conventional or PEGylated liposomes containing cholesterol or cholic acid (transferosomes) in various 5 concentrations by combining different phospholipids may also be utilized in the compositions of the invention. Cholesterol may regulate the stability of liposomes and therefore the inclusion of cholesterol in liposomes may be beneficial for the controlled release of the liposome 10 associated compounds, such as the labdanes of the present invention. Because of the prolonged liposome circulation in blood and enhanced stability due to steric stabilization by surface-grafted polymers, the polymer-coated long circulating liposomes have been referred to as sterically 15 stabilized liposomes (Papahadjopoulos, D. et al. (1991) Proc. Natl. Acad. Sci. U.S.A. 88. 11460-11464). The optimal stability of this type of liposome is obtained at around 5 mol% of PEG-lipid (PEG molecular weight 2000 Da (Lasic, D.D. (1994) Angew. Chem, Int. Ed. Engl. 33, 1785-1799). 20 Liposomes may be prepared by combining different synthetic lipids or natural lipids isolated from natural sources, such as lipids from plants and/or marine organisms and/or animal tissues. Liposomes may be prepared not only by combining different phospholipids but also by combining phospholipids 25 with different levels of cholesterol and cholic acid (in its salt form). Immunoliposomes are either conventional or sterically stabilized liposomes, which have specific proteins on their surface acting as recognition centers. 30 Immunoliposomes may be prepared using the noncovalent biotin-advidin method and covalent bonding of proteins with the liposomes surface. -10- WO 01/34116 PCT/GROO/00033 The PE derivatives of PEG with a terminal carbonyl group (Di acyl-PE-PEG-COOH) or with a terminal maleimidyl group (Di acyl-PE-PEG-Mal) may be synthesized according to K. Maruyama et al. B.B.A (1995) 1234, 74-80. 5 The use of immunoliposomes in the treatment of tumors resulted in a marked improvement in the drugs efficacy not only in comparison to the drug on its own but also compared to conventional liposomes. Liposomes of different sizes and characteristics 10 require different methods of preparation. The most simple and widely used method for preparation of MLV (Multilamelar Vesicles) is the thin-film hydration procedure in which a thin film of lipids is hydrated with an aqueous buffer at a temperature above the transition temperature of lipids. For 15 lipophilic compounds such as the labdanes and their derivatives part of this invention, the REV (Reverse-Phase Evaporation), techniques is more suitable for the compounds encapsulation. In brief, different MLV liposomes composed of DSPC, DPPC, DMPC, DOPE, Soy Phosphatidylserine as sodium 20 salt with or without cholesterol or cholic acid (as a salt) and PEGylated liposomes with or without cholesterol or cholic acid (as a salt) may be prepared by hydration with a buffer such as TES (N-tris-[hydroxymethyll methyl 2-amino ethanesulfonic acid), MES (2-[N-morpholinol ethanesulfonic 25 acid], HEPES (N-[2-hydroxyethyl]-piperazine-N-2 ethanesulfonic acid), after the removal of the organic solvent (Chloroform) in which labdanes and their derivatives have been dissolved. The removal of the organic solvent in vacuum or 30 under an inert gas results in the hydration of the lipids which form into multilayer liposomes upon vigorous shaking of the lipid film in an aqueous solution. The lipophilic labdanes incorporate into lipid bilayers, while the -11- WO 01/34116 PCT/GROO/00033 hydroDhilic derivatives thereof are encapsulated in the liposomes. The aqueous medium used in hydrating the dried lipid film is preferably pyrogen free. The medium preferably contains physiological salt, such as NaCl, sufficient to 5 produce a near-physiologic osmolarity (about 300 mOs). The liposome dispersion is sized to achieve a size distribution of vesicles in a size range preferably between about 0.1 and 0.5 microns. The sizing serves to eliminate larger liposomes and to produce a defined size range having 10 optimal pharmacokinetic properties. One preferred method for achieving the desired size distribution of liposome sizes is by extrusion of liposomes through a small-pore polycarbonate membrane sizes whose selected pore sizes such as 0.1, 0.2 or 0.4 microns, correspond approximately to the size 15 distribution of liposomes after one or more passes through the membrane. Typically the liposomes are extruded through the membranes several times until the size distribution stabilises (Shokai et al, 1978). The liposomes dispersion is further treated to remove free labdanes, i.e. labdanes which 20 are not intimately associated with the lipid bilayers. The suspension can be pelted by high-speed centrifugation after dilution, leaving free labdanes and very small liposomes in the supernatant.~ Another method uses gel filtration by molecular sieve chromatography to separate liposomes from 25 free labdanes. Sephadex (G-75) gel filtration was used in order to remove the free labdanes. In one embodiment, the final encapsulated liposomal labdane dispersion has the following characteristics: 30 1. L iposome sizes range between about 0.1 to 0.25 microns 2. Liposome-encapsulated labdanes about 80%-90% 3. The dispersion has a lipid concentration of at least 5 mg total lipid/ml, and near physiological osmolarity. -12- WO 01/34116 PCT/GROO/00033 The dispersion may be sterilized by filtration through a conventional 0.22-micron depth filter. 3. Therapeutic Use of The Compositions of the Invention 5 The formulations of the invention are useful for treating mammalian cancers or conditions related thereto. By "treating" it is meant that the formulations are administered to inhibit or reduce the rate of cancer-cell proliferation in an effort to induce partial or total 10 remission, for example, inhibiting cell division by promoting microtubule formation. For instance, the formulations of the invention are useful for treating, but not limited to, cancers of the blood, breast, lung, ovary, prostate, head, neck, brain, testes, kidney, pancreas, bone, 15 spleen, liver, and bladder; AIDS-related cancers, such as Kaposi's sarcoma; leukemia (e.g., acute leukemia such as acute lymphocytic leukemia and acute myelocytic leukemia); and the like. Preferably, the cancer to be treated is a leukemia. The formulations can be used alone or in 20 combination with other chemotherapeutics. The dose of the composition of the invention to be administered, whether a single-unit dose, multi-unit dose, or a daily dose, will of course vary with the particular analog or derivative employed based on potency, administration route, patient 25 weight, and the nature of the patient's condition. The actual administered amount is to be decided by the supervising physician and may depend on multiple factors, such as, the age, condition, file history, etc., of the patient in question. 30 The dose can be determined by a physician upon conducting routine experiments. Prior to administration to humans, the efficacy is preferably shown in animal models. -13- WO 01/34116 PCT/GROO/00033 Any animal model for cancer, preferably leukemia, known in the art can be used. The subject, or patient, to be treated using the methods of the invention is an animal, e.g., a mammal, and 5 is preferably human, and can be a fetus, child, or adult. Preferably, the formulations of the invention are administered parenterally (intravenously, subcutaneously, intramuscularly, intraspinally, intraperitoneally, and the like). For parenteral administration, the formulations of 10 the invention will normally be formulated as a solid, liquid, semisolid, gel, suspension, emulsion, or solution that, can be diluted in an aqueous medium to a concentration suitable for administration. The formulations of the invention can also be administered transdermally. 15 The present formulations can include additional pharmaceuticals and thus can serve as base formulation for polypharmacy. Such additional pharmaceuticals can be included and distributed in the formulation or added to the formulation prior to administration. For example, the 20 formulations of the invention and other pharmaceuticals can be combined in an i.v. bag prior to administration. Additional pharmaceuticals can, for example, other chemotherapeutics. The formulations of the invention can include 25 additional suitable, pharmaceutically acceptable excipients. Preferred additional excipients, are those listed in the Physician's Desk Reference, 54th edition, 881-887, Medical Economics Company (2000), i.e., water, aqueous vehicles such as saline, Ringer's solution, or dextrose solution. Other 30 examples of suitable excipients, such as binders and fillers are listed in Remington's Pharmaceutical Sciences, 18th Edition, ed. Alfonso Gennaro, Mack Publishing Co. Easton, PA, 1995 and Handbook of Pharmaceutical Excipients, 3rd -14- WO 01/34116 PCT/GROO/00033 Edition, ed. Arthur H. Kibbe, American Pharmaceutical Association, Washington D.C. 2000, both of which are incorporated herein by reference. Whatever excipient is incorporated into the present formulations, preferably, that 5 excipient is sterile when added, or sterilized during the same process that sterilizes the formulation. For parenteral administration as an aqueous solution, preferably, the present formulations are suitably buffered and isotonic. Furthermore, for parenteral 10 administration, the formulations of the invention should be sterile. An embodiment of the present invention includes a sterilization step. The sterilization may be carried out in several ways, e.g., by using a bacteriological filter, by incorporating sterilizing agents into the composition, by 15 irradiation, or by heating. Sterilization may be effected, for example, by filtration, e.g., through a 0.2 Am pore size filter. Other methods of sterilizing known to those skilled in the art can also be employed. Suitable sterile and non sterile excipients are commercially available from: EM 20 Industries, Inc., Hawthorne, NY.; J.T Baker, Inc., Hayward, CA; Spectrum Quality Products, Inc., Gardena CA; Fisher Scientific International, Inc., Hampton NH; Aldrich Chemical Co., Inc., Milwaukee WI; Abbott Laboratories, Inc., North Chicago IL; Baxter Healthcare Corporation, Deerfield IL; and 25 Amresco, Inc., Cleveland OH. To formulate aqueous parenteral dosage forms for injection, an aqueous medium, e.g., physiological saline or purified water, paclitaxel solubilizers, and any additional components are mixed in sanitized equipment, filtered, and 30 packaged according to well known methods in the art (for a discussion see e.g., Remington's Pharmaceutical Sciences, Alfonso R. Gennaro ed., Mack Publishing Co. Easton, PA, 19th ed., 1995, Chapter 87). A formulation of the invention can -15- WO 01/34116 PCT/GROO/00033 by prepared in sterile form, such as a sterile solid, liquid, semisolid, gel, suspension, emulsion, or solution, preferably, as a sterile liquid concentrate that can be dissolved or dispersed in a sterile aqueous medium or any 5 other injectable sterile medium prior to parenteral administration. To formulate and administer transdermal dosage forms, well known transdermal delivery mediums such as lotions, creams, and ointments and transdermal delivery 10 devices such as patches can be used (Ghosh, T.K.; Pfister, W.R.; Yum, S.I. Transdermal and Topical Drug Delivery Systems, Interpharm Press, Inc. p. 249-297, incorporated herein by reference). For example, a reservoir type patch design can comprise a backing film coated with an adhesive, 15 and a reservoir compartment comprising a formulation of the invention, that is separated from the skin by a semipermeable membrane (e.g., U.S. Patent 4,615,699, incorporated herein by reference). The adhesive coated backing layer extends around the reservoir's boundaries to 20 provide a concentric seal with the skin and hold the reservoir adjacent to the skin. Gels, semisolids, and solid forms, containing the active can be prepared according to well known methods. For instance, by mixing in a standard V-blender, preferably, 25 under anhydrous conditions. The homogeneous mixture can be passed through a screen mesh if desired. A comprehensive discussion on formulating solid forms is presented in Remington's Pharmaceutical Sciences, Alfonso R. Gennaro ed., Mack Publishing Co. Easton, PA, 19th ed., 1995, Chapter 92, 30 incorporated herein by reference. The dosage form of the invention may be provided in single-unit dose container forms or multi-unit-dose container forms by aseptically filling suitable containers -16- WO 01/34116 PCT/GROO/00033 with the sterile solution to a prescribed active content as described above. It is intended that these filled containers will allow rapid dissolution of the composition upon reconstitution with appropriate sterile diluents in 5 situ, giving an appropriate sterile solution of desired active concentration for administration. As used herein, the term "suitable containers" means a container capable of maintaining a sterile environment, such as a vial, capable of delivering a vacuum dried product hermetically sealed by 10 a stopper means. Additionally, suitable containers implies appropriateness of size, considering the volume of solution to be held upon reconstitution of the vacuum dried composition; and appropriateness of container material, generally Type I glass. The stopper means employed, e.g., 15 sterile rubber closures or an equivalent, should be understood to be that which provides the aforementioned seal, but which also allows entry for the purpose of introduction of diluent, e.g., sterile Water for Injection, USP, Normal Saline, USP, or 5% Dextrose in Water, USP, for 20 the reconstitution of the desired active solution. These and other aspects of the suitability of containers for pharmaceutical products such as those of the invention are well known to those skilled in the practice of pharmaceutical arts. 25 The present invention will be further understood by reference to the following non-limiting examples. The following examples are provided for illustrative purposes only and are not to be construed as limiting the invention's scope in any manner. 30 -17- WO 01/34116 PCT/GROO/00033 IV. EXAMPLES Example 1. Labd-13-ene, 8a-ol, 15-yl acetate Labd-13-ene, 8a, 15 diol (I) (50 mg) was dissolved in 2 ml of Ac20 - Py (acetic anhydrate-pyridine) for 48 5 hours at room temperature. The reaction mixture evaporated in vacuum to remove the solvents The purity as well the identification of the compound labd-13-ene, 8a-ol, 15-yl acetate was tested by TLC (Thin Layer Chromatography) and GC-MS (Gas Chromatography-Mass Spectrometry), using 0 chromatography data. Compound was obtained in its pure state (47 mg). Example 2. Labd-13-ene-8a-ol 15-yl -9 (or -a)-D (or -L) pyrano (or furano)sides as monosaccharides or as 5 disaccharides Labd-14-ene-8a-ol 13-yl- S (or -a)-D( or -L) pyrano (or furano)sides as monosaccharides or as disaccharides. 3-yl- f (or -a)-D( or -L)-pyrano (or furano)sides as 0 monosaccharides or as disaccharides,Labd-14-ene, 8, 13-epoxy As an example Condensation of Labd-13-ene-8a, 15-diol (I) with 2,3,4,6-tetra-O-acetyl-a-D-glucopyranosyl bromide was carried out in a two-phase system consisting of chloroform 5 1.25M aqueous potassium hydroxide solution and benzyltriethylammonium bromide as catalyst. After a simple work up, followed by column chromatography, the labdane glycosides glycosides were isolated in 30% yield. 0 Example 3. Thiomidazolide derivative of 39-hydroxy -labd 14-ene-8, 13-epoxy 38-hydroxy -labd-14-ene-8, 13-epoxy, was converted to its thiomidazolide ( 45% yield) by treatment with N, N' -18- WO 01/34116 PCT/GROO/00033 thiocarbonyldiimidazole (Rasmunssen, J.R. (1980) J.Org. Chem. 45, 2725-2727). Example 4. Preparation of Liposomes 5 Liposomes containing encapsulated or incorporated compounds I, II, III (Formulas I, II, III) and their derivatives, were prepared according to methods previously described ( Juliano, R. L., Stamp, D. Biochem. Biophys. Res. Commun. 63, 651 (1975)). LO In brief, lipid of 5 mg DMPC was dissolved in organic solvent (i.e chloroform) and then was evaporated under vacuum into the well of glass tube. Compounds I, II, III (Formulas I, II, III) at I 0% molar ratio were dissolved in chloroform and mixed with L5 the lipid prior to evaporation. In order to form liposomes, 1 ml of iso-osmotic buffer (TES 100 m M +NaCl 100 m M) p H = 7.5 and 300 mOs was added to the dried lipid film, and the mixture was dispersed by vortex with continuous temperature control; the usual temperature for preparation of liposomes 0 was 35 o C. In order to reduce the size of the liposomes the resultant large vesicles were extruded ten times through an extruder device with polycarbonated membrane with a pore size of 200 nm. The liposomes were passed through Sephadex G-75 to remove the free compound in all cases. 5 The liposomal composition was: 1. DMPC 10 mg in 2 ml TES 100 m M + NaCl 100 m M. a. 5 mg DMPC/compound I (formula I) (0.25 mg) b. 5 mg DMPC/compound II (formula II) (0.25 mg) c. 5 mg DMPC/compound III (formula III) (0. 25 mg) 0 The drug concentration in all cases was 250 pg/ml The results showed that into the above composition of liposomes the encapsulation was >80%. The retention of -19- WO 01/34116 PCT/GROO/00033 the compounds into this particular liposome formulation was studied and found to be time dependent. Example 5. Cytotoxic activity of labd-13-ene-8a, 15-diol 5 encapsulated in liposomal carriers The following pharmacological methods were used for the evaluation of the biological activities of the compounds of the invention. Cell cultures 10 Human cancer cell lines were used for in vitro drug testing. The cells were maintained as exponentially proliferating suspension cultures in RPMI-1640 medium (supplemented with 10% heat inactivated foetal calf serum, 2mM L-Glutamine and 50 pg/ml gentamycin and incubated at 37 15 'C, in a humidified atmosphere with 5% C0 2 . Peripheral blood mononuclear cells (PBML) were also isolated from normal donors using the Ficoll-Hypaque method and cultured as the cancer cell lines. Cytotoxic activity 20 To determine the cytotoxicity, log-phase cells from each cell line, resting and activated PBML (1x106 cells/ml), were incubated with free compound or liposomal formulation for 48 h, in 96-well flat-bottomed micro plates. The initial inoculation densities for each cell 25 line are presented in table (1) and were determined taking into account cell mass and growth rate (Monks A., Scudiero D., Skehan P., Shomaker R., Paull K., Vistica D., Hose C et al. Feasibility of a High-Flux Anticancer Drug screen using a diverse panel of cultured human tumor cell lines. JNCI 30 1991; 83(11): 757-766 Paul KD, Shomaker RH, Hodes L, Monks A, Scudiero DA, Rubinstein L., Plowman J and Boyd MR. Tumor Cell Lines: Development of Mean Graph and Compare Algorithm. JNCI 1989; :81(14): 1088-1092). Viability of the cells was -20- WO 01/34116 PCT/GROO/00033 assessed by trypan blue dye exclusion, at the beginning of the experiment and was always greater than 98%. Cells were added at the appropriate inoculation densities in 96-well micro titer plates and preincubated for 5 24 hours in a moist atmosphere of 5% C02 in air at 37oC, to allow stabilization prior to addition of the test compounds. To determine their activity, the free compound or liposomal formulation were added at the same time to each cell line. Cultures, where an equivalent amount of DMSO was added, used 10 as controls. After the addition of the test agents the cells were cultured in micro plates for an additional 48 h under the same conditions. Each test agent was inoculated at five concentrations (10-4 to 10-8 M). The activity for each compound on each cell line was determined by the MTT method 15 with modifications. Briefly 4 h before the end of the 48h incubation period, MTT (3-(4,5-dimethylthiazol-2-yl)-2-5 diphenyl tetrazolium bromide, Sigma-Aldrich) dissolved in PBS (Phosphate buffered saline), was added in the cell cultures to give a final concentration of 50 pg/ml. At the 20 end of the 48 h incubation period, DMSO was added to the wells and the optical density was measured with an ANTHOS HT II Microelisa reader, using a test wavelength of 550 nm. The data represent the means of experiments done in triplicates and were analyzed using a two-tailed 25 Student's t-test. Three parameters G150, TGI and LC50 were estimated using the MTT method. Briefly G150 is the concentration where 100*(T-T0)/(C-T0)=50 and measures the growth inhibitory power of the test compound. TGI is the 30 concentration of the test agent where 100* (T-T0)/(C-TO)=0 and measures the cytostatic effect. Finally LC50 is the concentration of the drug where 100* (T-TO)/TO=-50 and measures the cytotoxic effect of the drug. At the above -21- WO 01/34116 PCT/GROO/00033 formulas used for the calculation of the three parameters, T is the optical density of the test well after a 48h period of exposure to test compound; TO is the optical density at the time zero (when the drug is added) and C is the optical 5 density of the control well (cells incubated for 48h with no additives). Results The leukemic cell lines CCRF-CEM, MOLT4, HUT78 (T cells), RPMI 8226 (B cell line), HL60 (promyelocytic cell 10 line), K562 (proerythrocytes) and the multi- drug resistant (MDR) cell lines: CCRF-CEM/C2, HL60/MX1 and HL601MX2 were used. All cell lines were grown and tested for viability as described above. Free compounds and encapsulated (as described above) were tested according to the method 15 described under cytotoxic activity (see Biological activity, above). They were also tested for cytotoxicity as described in Biological Activity against normal PBML resting or activated by the addition of 5yg/ml PHA-P. Results for free labd-13-ene-8a, 15-diol (means of GI50, TGI, LC50) expressed 20 in 4M are summarized in Table 1 while of encapsulated in liposomes in Tables 2 and 3. -22- WO 01/34116 PCT/GROO/00033 TABLE 1 Labd-13-ene-8, GI50 TGI LC50 15 diol CCRF-CEM 75.74 141.08 200 5 CCRF-CEM/C2 42.27 74.96 107.65 MOLT4 32.32 76.22 120.11 HUT78 109.14 186 200 RPMI 8226 42.2 80.08 117.96 K562 87.08 159 200 10 HL60 47.69 69.74 91.8 HL60/MX1 52.32 80.1 107.87 HL601/MX2 43.81 73.14 102.48 MEAN 59.15 104.48 138.65 PBML (resting) >>100 >>100 >>100 L5 PBML 66.2 >>100 >>100 (stimulating) -23- WO 01/34116 PCT/GROO/00033 TABLE 2 Labd-13-ene-8, G150 'TGI LC5O 15 diol, DPPC CCRF-CEM 28.74 52.23 75.72 5 CCRF-CEM/C2 19.12 46.55 73.99 MOLT4 24.61 52.41 80.21 HUT78 13.98 49.41 83.39 RPMI 8226 5.48 38.72 75.54 K562 35.30 78.84 122.39 0 HL60 33.92 56.36 78.80 HL60/MX1 18.54 46.17 73.79 HL601/MX2 0.62 17.81 61.78 MEAN 20.03 48.72 80.62 5 TABLE 3 Labd-13-ene-8, GI50 'TGI LC50 15 diol, DMPC CCRF-CEM 28.56 51.93 75.30 CCRF-CEM/C2 5.14 10.41 55.36 0 MOLT4 29.72 - 54.75 79.78 HUT78- 6.04 28.65 66.19 RPMI 8226 7.98 38.20 73.70 K562 27.24 58.60 89.95 HL60 32.63 55.21 77.80 5 HL60/MX1 26.18 50.87 75.57 HL601/MX2 _ 1.65 8.36 49.79 MEAN 18.35- 39.66 71.49 The effect of the above used formulations against 0 the MDR cell lines are summarized in table 4. The Resistant Factor (RF) is defined as follows: GI50 of the MDR daughter -24- WO 01/34116 PCT/GROO/00033 cell line / GISO of the parental cell line. The (-) represents a parental cell line more resistant than the daughter MDR line. TABLE 4 5 RF (G150) CCRF CEM/C2 HL 60/MX1.1 HL60/MC2 Labd-13-ene-8a, 0.6 1.1 0.9 15 diol /DPPC 0.6 -2 -55 /DMPC -6 1 -20 10 Labd-13-ene-diol was also tested at 100puM against NCI-H460, MCF-7 and SF-268 (one dose primary assay). The results are summarized below (Table 5) . Minus symbol denotes cytotoxic activity. L5 TABLE 5 Growth Percentages NCI-H460 MCF-7 SF-268 Concentration (Lung cancer) (Breast (CNS cancer) cancer) 20 100p"M -80 -89 -88 Example 6. Cytotoxic activity of labd-14-ene-8, 13-diol encapsulated in liposomal carriers Labd-14-ene-8, 13-diol was also encapsulated into .5 liposomes as described above and tested as labd-13-ene-8a, 15-diol. Results are presented in the corresponding tables below (Tables 6-10) TABLE 6 Labd-14-ene-8, GI50 TGI LC50 0 13 diol CCRF-CEM 35.00 60.00 85.00 -25- WO 01/34116 PCT/GROO/00033 Labd-14-ene-8, G150 TGI LC50 13 diol CCRF-CEM/C2 29.05 52.41 75.78 MOLT4 31.60 54.66 77.72 HUT78 33.68 56.09 78.49 RPMI 8226 14.94 42.84 70.73 5 K562 35.58 57.45 79.33 HL60 41.48 60.72 79.95 HL60/MX1 42.94 61.90 80.86 HL601/MX2 31.41 54.12 76.83 MEAN 32.85 55.58 78.30 L PBML (rest-ing) 34.6 63.8 93.1 PBML 33.1 61.0 89.0 (stimulating) TABLE 7 L5 Labd-14-ene-8, GI50 TGI LC50 13 diol, DPPC CCRF-CEM 33.34 56.03 78.72 CCRF-CEM/C2 32.10 55.24 78.38 MOLT4- 28.43 55.50 82.58 20 HUT78 6.22 42.52 79.81 RPMI 8226 5.10 45.58 82.62 K562 55.67 113.74 171.80 HL60 39.50 59.98 80.46 HL60/MX1 7.65 33.05 66.51 .5 HL601/MX2 2.21 - 8.78 54.00 MEAN 23.36 52.27 86.10 -26- WO 01/34116 PCT/GROO/00033 TABLE 8 Labd-14-ene-8, G150 TGI LC50 13 diol, DMPC CCRF-CEM 43.15 68.64 94.14 5 CCRF-CEM/C2 30.50 57.03 83.57 MOLT4 61.02 127.90 194.78 HUT78 4.18 27.78 71.43 RPMI 8226 37.99 67.33 96.68 K562 53.48 105.24 157.01 10 HL60 58.12 89.87 121.62 HL60/MX1 37.36 75.36 113.36 HL601/MX2 28.71 61.37 94.02 MEAN 39.39 75.61 114.07 15 TABLE 9 RF (G150) CCRF CEM/C2 HL 60/MX1.1 HL60/MC2 Labd-13-ene-8a, 0.8 1 0.8 15 diol /DPPC 0.97 -5 -18 20 /DMPC 0.7 0.64 -2 Example 7. Cytotoxic activity of labd-13-ene-8a, 15-yl acetate The cytotoxic activity of the derivative of Labd 25 13-ene-8a, 15-diol i.e. labd-13-ene-8a, 15-yl acetate was also assayed in the same manner as described above(Tables 10-13) TABLE 10 Labd-13-ene-8, GI50 TGI LC50 30 15-yl acetate CCRF-CEM 69.09 128.17 187.00 -27- WO 01/34116 PCT/GROO/00033 Labd-13-ene-8, G150 TGI LC50 15-yl acetate CCRF-CEM/C2 46.77 78.83 110.88 MOLT4 42.80 89.95 137.10 HUT78 95.18 164.00 200.00 RPMI 8226 41.31 68.43 95.55 5 K562 78.19 162.00 200.00 HL60 44.79 67.04 89.29 HL60/MX1 53.92 80.14 106.36 HL601/MX2 38.78 69.90 101.03 MEAN 56.76 100.94 136.36 10 PBML (resting) >>100 >>100 >>100 PBML (stimulating) 65.9 >>100 >>100 TABLE 11 Labd-13-ene-8, GI50 TGI LCSO 15 15-yl acetate, DPPC CCRF-CEM 31.52 53.40 75.28 CCRF-CEM/C2 37.01 58.22 79.43 MOLT4 32.~39 56.62 80.85 HUT78 20.60 52.18 83.76 20 RPMI 8226 33.97 65.74 97.52 K562 76.94 164.92 252.91 HL60 41.76 61.70 81.65 HL60/MX1 9.60 40.58 71.56 HL601/MX2- 8.87 40.21 71.34 25 MEAN 32.52 65.95 99.37 -28- WO 01/34116 PCT/GROO/00033 TABLE 12 Labd-13-ene-8, GI50 TGI LC50 15-yl acetate, DMPC CCRF-CEM 31.33 53.97 76.60 5 CCRF-CEM/C2 19.22 46.13 73.05 MOLT4 29.50 55.33 81.16 HUT78 4.60 25.63 65.04 RPMI 8226 31.93 56.59 81.24 K562 63.86 131.28 198.70 10 HL60 37.66 61.22 84.77 HL60/MX1 14.17 45.20 76.23 HL601/MX2 23.69 49.63 75.56 MEAN 28.44 58.33 90.26 L5 TABLE 13 RF (GI50) CCRF HL HL60/MC2 CEM/C2 60/MX1.1 Labd-13-ene-8a, 15- 0.7 1.2 0.9 yl acetate /DPPC 1.15 -4 -5 0 /DMPC 0.61 -2.7 0.6 Conclusion The free and in liposome encapsulated labdanes are cytotoxic against cancer cell lines and are not affected by 5 the multi-drug-resistance phenotype of the cell lines tested. They also exhibit reduced cytotoxicity against normal, resting or activated, human PBML. The present invention is not to be limited in 0 scope by the specific embodiments described herein. Indeed, -29- WO 01/34116 PCT/GROO/00033 various modifications of the invention in addition to those described herein will become apparent to those skilled in the art from the foregoing description and accompanying figures. Such modifications are intended to fall within the 5 scope of the appended claims. Various references are cited herein, the disclosures of which are incorporated by reference in their entireties. -30-

Claims (14)

1. A pharmaceutical composition, comprising: a therapeutically effective amount at least one compound of Formula 1, mixtures thereof or a plant extract containing at 5 least one compound of Formula 1 or mixtures thereof, LOR 10Q6O Formula 1 wherein R is selected from the group consisting of H, alkylcarbonyl, alkenylcarbonyl, alkynylcarbonyl, 15 cycloalkylcarbonyl, aralkylcarbonyl, alkyl, alkenyl, alkynyl, cycloalkyl, aralkyl, dialkylaminoalkyl, alkylthioketones, alkenylthioketones, alkynylthioketones, cycloalkylthioketones, aralkylthioketones, heterocyclylthioketones and sugars; and a carrier or 20 diluent.

2. The pharmaceutical composition according to claim 1, wherein the pharmaceutical composition is formulated for enteral, parenteral and topical use. 25

3. The pharmaceutical composition according to claim 1, wherein the pharmaceutical composition is encapsulated in the internal part of lipidic lamellar phases or liposomes, or incorporated into lipid bilayers of lipidic lamellar 0 phases or liposomes.

4. The pharmaceutical composition according to any one of claims 1, 2 or 3, wherein the pharmaceutical -31- WO 01/34116 PCT/GROO/00033 composition is formulated for treating a subject with a disease or disorder related to cancer.

5. A pharmaceutical composition, comprising: a 5 therapeutically effective amount at least one compound of Formula 2, mixtures thereof or a plant extract containing at least one compound of Formula 2 or mixtures thereof, 10 OR OH 15 Formula 2 wherein R is selected from the group consisting of H, alkylcarbonyl, alkenylcarbonyl, alkynylcarbonyl, cycloalkylcarbonyl, aralkylcarbonyl, alkyl, alkenyl, alkynyl, cycloalkyl, aralkyl, dialkylaminoalkyl, 20 alkylthioketones, alkenylthioketones, alkynylthioketones, cycloalkylthioketones, aralkylthioketones, heterocyclylthioketones and sugars; and a carrier or diluent. 25

6. The pharmaceutical composition according to claim 5, wherein the pharmaceutical composition is formulated for enteral, parenteral and topical use.

7. The pharmaceutical composition according to claim 30 5, wherein the pharmaceutical composition is encapsulated in the internal part of lipidic lamellar phases or liposomes, or incorporated into lipid bilayers of lipidic lamellar phases or liposomes. -32- WO 01/34116 PCT/GROO/00033

8. The pharmaceutical composition according to any one of claims 5, 6 or 7, wherein the pharmaceutical composition is formulated for treating a subject with a disease or disorder related to cancer. 5

9. A pharmaceutical composition, comprising: a therapeutically effective amount at least one compound of Formula 3, mixtures thereof or a plant extract containing at least one compound of Formula 3 or mixtures thereof, L0 CH3 CH2 CH3 0 .5 CH3 R1 H3C CH3 wherein R 1 is selected from the group consisting of 0 =0, OR 2 , or a halogen selected from the group consisting of chlorine, bromine or iodine, and wherein R 2 is selected from the group consisting of H, alkylcarbonyl, alkenylcarbonyl, alkynylcarbonyl, cycloalkylcarbonyl, aralkylcarbonyl, alkyl, alkenyl, alkynyl, cycloalkyl, aralkyl, dialkylaminoalkyl, 5 alkylthioketones, alkenylthioketones, alkynylthioketones, cycloalkylthioketones, aralkylthioketones, heterocyclylthioketones and sugars; and a carrier or diluent. 0

10. The pharmaceutical composition according to claim 9, wherein the pharmaceutical composition is formulated for enteral, parenteral and topical use. -33- WO 01/34116 PCT/GROO/00033

11. The pharmaceutical composition according to claim 9, wherein the pharmaceutical composition is encapsulated in the internal part of lipidic lamellar phases or liposomes, or incorporated into lipid bilayers of lipidic lamellar 5 phases or liposomes.

12. The pharmaceutical composition according to any one of claims 9, 10 or 11, wherein the pharmaceutical composition is formulated for treating a subject with a 0 disease or disorder related to cancer.

13. A method of treating a subject with cancer comprising administering to the patient a therapeutically effective amount of the pharmaceutical composition of any 5 one of claims 1-12.

14. The method of claim 13, wherein the cancer is a leukemia. 0 -34-