Lyophilized bendamustine-cyclodextrin compositions

Abstract

Described herein is a lyophilized composition comprising bendamustine and sulfobutyl ether beta-cyclodextrin (SBECD), (a) comprising a molar excess of SBECD relative to bendamustine; (b) not comprising mannitol; and (c) comprising less than about 1% by weight of moisture. Such compositions can be prepared in the form of well-formed cakes and exhibit desirable storage stability. The lyophilized compositions can be readily reconstituted and then rapidly administered to cancer patients with reduced sodium and / or sugar intake. Additionally, methods for treating cancer patients using the described compositions and methods for preparing the lyophilized compositions are described.

Description

[Background technology]

[0001] (Related Applications) This patent document claims the benefit of the filing dates under 35 U.S.C. §119(e) of U.S. Provisional Patent Application No. 63 / 419,136, filed October 25, 2022, and U.S. Patent Application No. 18 / 380,441, filed October 16, 2023, which applications are incorporated herein by reference.

[0002] FIELD OF THE INVENTION

[0003] Described herein are lyophilized compositions comprising bendamustine and sulfobutyl ether beta-cyclodextrin (SBECD), (a) comprising a molar excess of SBECD relative to bendamustine; (b) not comprising mannitol; and (c) comprising less than about 1% by weight of moisture. Such compositions can be prepared in the form of well-formed cakes and exhibit desirable storage stability. The lyophilized compositions described herein can be readily reconstituted and then rapidly administered to cancer patients with reduced sodium and / or sugar (glucose) intake. In other aspects, described herein are methods for treating patients with the described compositions and methods for preparing the described lyophilized compositions.

[0004] (background)

[0005] Bendamustine (4-[5-[bis(2-chloroethyl)amino]-1-methylbenzimidazol-2-yl]butanoic acid) is a nitrogen mustard compound that has been shown to be effective in the treatment of leukemias and lymphomas, particularly chronic lymphocytic leukemia (CLL) and indolent non-Hodgkin's lymphoma (iNHL). Furthermore, as disclosed in U.S. Pat. No. 8,703,964 (Popek et al.), conjugated forms of bendamustine have been shown to be effective against solid tumors, including lung cancer, breast cancer, and multiple and myeloma.

[0006] Because bendamustine is highly reactive with water, commercial formulations of bendamustine are often lyophilized for long-term storage. Thus, U.S. Patent No. 8,791,270 (Brittain et al.) states that bendamustine is supplied as a lyophilized product because it (like other nitrogen mustards) degrades in aqueous solutions.

[0007] The reactivity of bendamustine with water can also affect the storage stability of lyophilized bendamustine compositions, as residual water can react with the active ingredient over time, leading to deterioration of the stored product. As described in U.S. Patent No. 8,791,270, the primary degradant of lyophilized bendamustine is HP1, also known as impurity E, a compound having the following formula: (HP1) [ka]

[0008] U.S. Patent No. 8,791,270 further states that while the addition of a cryoprotectant is not required to produce a lyophilized product (see column 17, lines 43-46), the addition of mannitol is required to produce a commercially acceptable material. For example, the commercially available product Treanda® for injection (see, e.g., U.S. Patent No. 8,791,270) contains 170 mg of mannitol per vial.

[0009] Producing a properly formed and durable cake is important because cake breakage during storage / handling can result in particles of the active ingredient adhering to the stoppers of lyophilized vials. These particles can remain attached during reconstitution, resulting in lower and / or inconsistent doses of the active ingredient. Furthermore, an improperly formed cake may be evidence of the presence of multiple variants; as a result, the storage stability, reconstitution time, and other important physical properties of such cakes may not be consistent from vial to vial. For example, U.S. Patent No. 8,076,366 (Courvoisier et al.) on polymorphs of bendamustine free base demonstrates that varying the form of the active pharmaceutical ingredient can alter the physical properties of bendamustine polymorphs (e.g., shelf life, bioavailability, morphology, vapor pressure, density, color, and compressibility).

[0010] Furthermore, U.S. Patent No. 8,791,270 notes that mannitol can reduce the solubility of bendamustine (15 mg / mL) in both ethanol and aqueous TBA. As a result, formulations according to the disclosure of U.S. Patent No. 8,791,270 are nearly completely saturated upon reconstitution at room temperature and must be delivered over an extended period to minimize the risk of precipitation. Therefore, Treanda® for injection is typically administered at a dose of 100 mg / mL for CLL. 2 120 mg / m for iNHL 2 It is given intravenously over 60 minutes.

[0011] U.S. Patent No. 9,000,021 (Sundaram et al.) discloses a liquid composition of bendamustine that can be administered at a much lower dose than saturated compositions and therefore much more rapidly. As a result, the commercially available formulation, Bendeka®, protected by U.S. Patent No. 9,000,021, can be administered much more rapidly than more fully saturated formulations, such as injectable Treanda®. Thus, Bendeka® is typically administered at a dose of 100 mg / m for CLL. 2 Intravenous infusion over 10 minutes at 120 mg / m for iNHL 2 It is infused intravenously over 10 minutes at 1000 kcal. To achieve this high solubility, Bendeka® uses organic solvents such as monothioglycerol, polyethylene glycol, and propylene glycol.

[0012] U.S. Patent Nos. 8,436,032 and 8,703,964 to Popek et al. disclose compositions containing bendamustine, a charged cyclodextrin (preferably sulfobutyl ether beta-cyclodextrin or "SBECD"), and optionally a stabilizer having an opposite charge to that of the cyclodextrin. These publications indicate that such compositions can be freeze-dried / lyophilized, but the only example (Example 21) showing a lyophilized product contains mannitol. Somewhat similarly, U.S. Pat. No. 8,383,663 (Alakhov et al.) discloses compositions in which the stabilizer is a charged cyclodextrin; although lyophilization is not exemplified in such patent, it is notable that all of the exemplified formulations contain mannitol.

[0013] (overview) It has been unexpectedly discovered that compositions comprising bendamustine and SBECD can be lyophilized in the absence of mannitol, exhibit unexpectedly excellent storage stability, and can be rapidly reconstituted with a number of pharmaceutically acceptable solvents to produce drug formulations that can be rapidly administered to cancer patients with reduced sodium and / or sugar (dextrose) intake.

[0014] One aspect described herein is a freeze-dried composition comprising bendamustine and sulfobutyl ether beta-cyclodextrin, characterized in that such composition a) contains a molar excess of sulfobutyl ether beta-cyclodextrin relative to the amount of bendamustine present; b) does not contain mannitol; and c) the moisture content of the retained moisture is less than about 1% by weight.

[0015] One aspect described herein is a method for preparing a freeze-dried composition comprising bendamustine and sulfobutyl ether beta-cyclodextrin, the method comprising: a) preparing an aqueous composition comprising water, bendamustine, and sulfobutyl ether beta-cyclodextrin, wherein the aqueous composition does not contain mannitol; b) transferring the aqueous composition to a vial; c) freezing and annealing the aqueous composition to form a frozen and annealed composition; and d) subjecting the frozen and annealed composition to a freeze-drying cycle comprising: i) a first drying step at a temperature of about -5°C to about -50°C and a pressure of about 75 to 150 mTorr; and ii) a second drying step at a temperature of about 5°C to about 50°C and a pressure of less than about 25 mTorr.

[0016] Yet another aspect described herein is a method of treating a cancer patient with an effective amount of the described composition reconstituted from a freeze-dried composition comprising bendamustine and sulfobutyl ether beta-cyclodextrin, such composition being characterized in that: a) it contains a molar excess of sulfobutyl ether beta-cyclodextrin relative to the amount of bendamustine present; b) it does not contain mannitol; and c) the moisture content of the retained water is less than about 1% by weight. DETAILED DESCRIPTION OF THE INVENTION

[0017] Detailed Description of the Drawings and Preferred Embodiments It has been unexpectedly discovered that compositions comprising bendamustine and SBECD can be lyophilized in the absence of mannitol, exhibit unexpectedly excellent storage stability, and can be rapidly reconstituted with a number of pharmaceutically acceptable solvents to produce drug formulations that can be rapidly administered to cancer patients with reduced sodium and / or sugar (dextrose) intake.

[0018] One aspect described herein is a lyophilized composition comprising bendamustine and sulfobutyl ether beta-cyclodextrin ("SBECD"), characterized in that the lyophilized composition contains a molar excess of sulfobutyl ether beta-cyclodextrin relative to the amount of bendamustine present; is free of mannitol; and has a moisture content of less than about 1.0% by weight.

[0019] When bendamustine is combined with SBECD in an aqueous environment, the compound forms an inclusion complex at a molar ratio of 1:1. In forming such an inclusion complex, the bendamustine moiety interacts with and is protected within the cavity of the torus-like structure formed by the cyclic cyclodextrin units of SBECD, thereby protecting the bendamustine moiety from the degrading effects of the aqueous environment.

[0020] To provide a composition suitable for rapid administration to cancer patients, it is necessary to ensure that the bendamustine moiety is not completely saturated in the reconstituted solution at room temperature. Thus, in certain embodiments, the described compositions may contain a molar excess of SBECD, which ensures that all of the bendamustine precursor remains in complex form (does not precipitate) during the injection process. Preferably, the molar ratio of bendamustine to SBECD is about 1:2 to about 1:25, more preferably about 1:3 to about 1:15, even more preferably about 1:4 to about 1:10, and most preferably about 1:5 to about 1:7.

[0021] Importantly, the described compositions do not include mannitol, as this excipient may reduce the solubility of bendamustine in an aqueous environment. Preferably, the described compositions do not further include any other or similar cryoprotective compound(s) that may also have a similar adverse effect on the solubility of bendamustine.

[0022] In certain embodiments, the described compositions may include additional excipients such as soluble polymers, e.g., polyoxyethylene, poloxamer, polyvinylpyrrolidone, dextran; salts, including but not limited to, sodium chloride, magnesium chloride, calcium chloride; and lipids, including but not limited to, fatty acids, glycerol fatty acid esters, glycolipids, phospholipids; although in many cases the addition of such excipients is not necessary to produce a pharmaceutically acceptable formulation.

[0023] In some embodiments, the described compositions may further comprise a cationic stabilizer, such as those described in U.S. Pat. No. 8,436,032 (Popek et al.) and U.S. Pat. No. 8,383,623 (Alakhov et al.). Exemplary cationic agents that can be used include tertiary or quaternary ammonium compounds such as N-alkyl-N,N-dimethylamines, N-alkyl-N,N-diethylamines, N-alkyl-NN-diethanolamines, N-alkylmorpholines, N-alkylpiperidines, N-alkylpyrrolidines, N-alkyl-N,N,N-trimethylammonium, N,N-dialkyl-N,N-dimethylammonium, N-alkyl-N-benzyl-N,N-dimethylammonium, N-alkyl-pyridinium, N-alkyl-picolinium, alkylamidomethylpyridinium, carbalkoxypyridinium, N-alkylquinolinium, N-alkylisoquinolinium, N,N-alkylmethylpyrrolidinium, and 1-alkyl-2,3-dimethylimidazolium. Particularly preferred cationic adjuvants include sterically hindered tertiary amines, such as N-alkyl-NN-diisopropylamines, N-alkylmorpholines, N-alkylpiperidines, and N-alkylpyrrolidines; and quaternary ammonium compounds, such as cetylpyridinium chloride, benzyldimethyldodecylammonium chloride, dodecylpyridinium chloride, hexadecyltrimethylammonium chloride, benzyldimethyltetradecylammonium chloride, octedecyldimethylbenzylammonium chloride, and domiphen bromide.

[0024] Polycationic compounds such as oligoamines or polyamines or PEGylated oligoamines or polyamines can also be used as stabilizers in the described compositions.Preferred polycationic compounds include oligoamines such as spermine, spermidine, putrescine, cadaverine, etc., polyamines such as polyethyleneimine, polyspermine, polyputrescine, polycadaverine, etc.; and the PEGylated oligoamines and polyamines of the above group.Particularly preferred is PI2080, polyethyleneimine 2000 conjugated with PEG8000.

[0025] One preferred class of cationic stabilizers is polypeptides containing about 5 to about 50, more preferably about 6 to about 20, amino acids, at least about 50% of which are positively charged. Most preferably, such charged amino acids are arginines. Particularly preferred members of this class include polyarginines and thermolysin-digested protamines (hereinafter referred to as low molecular weight protamines or "LMWPs").

[0026] In certain embodiments, hydrophobically modified oligoamines or polyamines may also be used. Preferred stabilizers of this type include, for example, acetylspermine, acetylpolyspermine, acetylpolyethyleneimine, butyrylspermine, butyrylpolyspermine, butyrylpolyethyleneimine, lauroylspermine, lauroylpolyspermine, lauroylpolyethyleneimine, stearoylspermine, stearoylpolyspermine, and stearoylpolyethyleneimine.

[0027] Furthermore, in certain embodiments, cationic polysaccharides and synthetic polycationic polymers can also be used in the described compositions. Exemplary cationic polysaccharides include, for example, chitosan, deacetylated chitosan, quaternized cellulose, quaternized amylase, quaternized amylopectin, quaternized partially hydrolyzed cellulose, quaternized partially hydrolyzed amylase, and quaternized partially hydrolyzed amylopectin. Examples of synthetic polycationic polymers include, for example, Polyquaternium 2 (poly[bis(2-chloroethyl)ether-alt-1,3-bis[3-dimethylamino)propyl]-urea, quaternized); Polyquaternium 11 (poly(1-vinylpyrrolidone-co-dimethylammonium ethyl methacrylate), quaternized); Polyquaternium 16 and 44 (copolymers of vinylpyrrolidone and quaternized vinylimidazole); and Polyquaternium 46 (copolymers of vinylcaprolactam, vinylpyrrolidone and quaternized vinylimidazole).

[0028] Cationic cyclic polysaccharides useful as stabilizers may contain any one or a mixture of cationic groups, but generally, such compounds contain amino, guanidine, or quaternary ammonium groups. Exemplary aminocyclodextrins that are suitable for use include, for example, amino-alpha-cyclodextrin, amino-beta-cyclodextrin, and amino-gamma-cyclodextrin, each having a substitution level of preferably about 4 to about 10. Preferred aminocyclodextrins of this type include hexakis(6-amino-6-deoxy)alpha-cyclodextrin, heptakis(6-amino-6-deoxy)beta-cyclodextrin, octakis(6-amino-6-deoxy)gamma-cyclodextrin, and heptakis(6-amino-6-deoxy)beta-cyclodextrin. Other cationic cyclopolysaccharides that can be used include guanidino-cyclodextrins, preferably having a substitution level of about 4 to about 10, with heptakis(6-guanidino-6-deoxy)beta-cyclodextrin being particularly preferred; and alkylamino-cyclodextrins, preferably having a substitution level of about 4 to about 10, with 6-deoxy-6-(3-hydroxy)propylamino beta-cyclodextrin being particularly preferred; and ammonium-cyclodextrins, preferably having a substitution level of 4 to 9, such as 2-hydroxy-N,N,N-trimethylpropaneammonium-cyclodextrin.

[0029] In certain embodiments, particularly preferred cationic polysaccharides include, for example, hexakis(6-amino-6-deoxy)alpha-cyclodextrin, heptakis(6-amino-6-deoxy)beta-cyclodextrin, octakis(6-amino-6-deoxy)gamma-cyclodextrin, heptakis(6-guanidino-6-deoxy)beta-cyclodextrin, octakis(6-guanidino-6-deoxy)gamma-cyclodextrin, 2-hydroxy-N,N,N-trimethylpropaneammonium-cyclodextrin, and 6-deoxy-6-(3-hydroxy)propylaminobeta-cyclodextrin, with 6-deoxy-6-(3-hydroxy)propylaminobeta-cyclodextrin being particularly preferred.

[0030] If a stabilizer is present, it may be present in a molar ratio of about 5:1 to about 1:1000, preferably about 1:4 to about 1:100, based on the molar amount of SBECD present.

[0031] In certain embodiments, the described compositions have a moisture content of less than about 1.0% by weight. Preferably, such compositions have a moisture content of less than 0.75% by weight, and more preferably, a moisture content of less than about 0.6% by weight. Although essentially dry compositions can be prepared by extending the duration of the freeze-drying cycle, compositions that retain very little moisture (more than about 0.2% by weight or more than about 0.34% by weight) exhibit desirable long-term storage stability.

[0032] In another aspect, described herein is a method for preparing the lyophilized composition described, wherein the composition comprises bendamustine and sulfobutyl ether beta-cyclodextrin. The method comprises the steps of:

[0033] a) preparing an aqueous composition comprising water, bendamustine and sulfobutyl ether beta-cyclodextrin, and no mannitol;

[0034] b) transferring the aqueous composition into a vial;

[0035] c) freezing and annealing the aqueous composition to form a frozen and annealed composition;

[0036] d) subjecting the frozen and annealed composition to a freeze-drying cycle comprising the steps of:

[0037] i) a first drying step at a temperature of about −5° C. to about −50° C. and a pressure of about 75 to about 150 mTorr;

[0038] ii) A second drying step at a temperature of about 5°C to about 50°C and a pressure of less than about 25 mTorr.

[0039] The aqueous composition of step a) can be prepared by dissolving a solid bendamustine precursor, such as bendamustine hydrochloride and / or bendamustine hydrochloride monohydrate, in an aqueous SBECD solution, or by mixing an aqueous SBECD solution with an aqueous stock solution of bendamustine. As described above, the molar ratio of bendamustine to SBECD can be about 1:2 to about 1:25, more preferably about 1:3 to about 1:15, even more preferably about 1:4 to about 1:10, and most preferably about 1:5 to about 1:7.

[0040] The aqueous composition of step a) is vigorously mixed, optionally subjected to ultrasonication, to obtain a homogeneous and equilibrated aqueous solution. In certain preferred embodiments, the aqueous SBECD solution used to prepare the described compositions may contain at least 4% SBECD, and more preferably, such solution contains at least 10% SBECD.

[0041] In certain embodiments, the stabilizer and excipient (if either or both are present) are preferably introduced into the composition by adding them to a pre-prepared aqueous homogeneous equilibrium solution of bendamustine and SBECD. These agents may be added as pure substances or as aqueous solutions, and are preferably mixed using gentle agitation.

[0042] The homogeneous equilibrium aqueous solution can then be aseptically filtered into sterile containers, filled into appropriately sized vials, partially stoppered, and loaded into a freeze-drying apparatus. The solution is then freeze-dried to produce the described composition.

[0043] The vials used in step b) and the stoppers present to partially seal the vials are constructed of materials that are suitable for the lyophilization process and are chemically resistant to the pre-lyophilization solution. Such materials are well known to those skilled in the art and are commercially available. Most preferably, 25 cc / 20 mm Type 1 amber glass vials fitted with 20 mm chlorobutyl fluoropolymer-coated lyophilization stoppers and sealed with orange Flip-Off® aluminum overseals may be used in the described method.

[0044] The freezing / annealing step is typically carried out between about -20°C and about -50°C until the pre-lyophilization solution is completely frozen and annealed. The time required for the freezing / annealing step will vary depending on several parameters, including the size of the sample, the exact composition of the sample, and the efficiency of the equipment used. In certain embodiments, the time ranges from 3 hours or less to 10 hours or more. However, the optimal time for a particular set of parameters can be determined by one of ordinary skill in the art using routine experimentation.

[0045] The first drying step is typically performed at about -5°C to about -50°C and a pressure of about 75 to about 150 mTorr. Preferably, such a step is performed at about -20°C to about -40°C and a pressure of about 100 to about 145 mTorr. The time required to perform the first drying step will vary depending on several parameters, including the size of the sample, the exact composition of the sample, the specific temperature and pressure selected, and the efficiency of the equipment used. In certain embodiments, the time lasts from 10 hours or less to 72 hours or more. However, the optimal time for a particular set of parameters can be determined by one of ordinary skill in the art using routine experimentation.

[0046] The second drying step can be carried out at about 5°C to about 50°C and a pressure of less than about 25 mTorr. Preferably, such a step is carried out at about 10°C to about 40°C and a pressure of less than about 15 mTorr. This second drying step is carried out until the moisture content of the composition is less than about 1.0% by weight, preferably less than about 0.75% by weight, and most preferably less than about 0.6% by weight. While essentially dry compositions can be prepared by extending the duration of the lyophilization cycle, compositions that retain very little moisture (greater than about 0.1% by weight or greater than about 0.2% by weight) exhibit desirable long-term storage stability.

[0047] The time required to perform the second drying step will vary depending on several parameters, including the size of the sample, the exact composition of the sample, the specific temperature and pressure selected, and the efficiency of the equipment used. In certain embodiments, the time period lasts from 10 hours or less to 60 hours or more, although the optimal time period for a particular set of parameters can be determined by one of ordinary skill in the art using routine experimentation.

[0048] Yet another aspect described herein is a method of treating a cancer patient comprising administering to the cancer patient an effective amount of a composition described herein reconstituted from a lyophilized composition described herein comprising bendamustine and sulfobutyl ether beta-cyclodextrin, wherein the composition contains a molar excess of sulfobutyl ether beta-cyclodextrin relative to the amount of bendamustine present; is free of mannitol; and has a moisture content of less than about 1.0% by weight.

[0049] In one embodiment, 25 mL vials containing the lyophilized composition described herein can be prepared by complexing 104.56 mg of bendamustine hydrochloride monohydrate with 3.33 g of SBECD in an aqueous solution, each vial containing 90.76 mg of bendamustine moieties in complex form (an amount equivalent to the amount of bendamustine moieties present in 100 mg of bendamustine hydrochloride); and then lyophilizing the solution according to the method described above.

[0050] The lyophilized powder is then reconstituted with 8.0 mL of a pharmaceutically acceptable diluent. It is noteworthy that, in addition to the diluents currently used in commercially available bendamustine formulations (i.e., 0.9% sodium chloride injection; 2.5% dextrose / 0.45% sodium chloride injection; and 5% dextrose injection), as demonstrated in Example 3, the inclusion complex formulation exhibits sufficient stability in water, allowing the use of water for injection as a diluent. This provides additional benefits to patients with sugar and / or sodium intolerances.

[0051] In certain embodiments, the recommended dose of the described composition for CLL is 100 mg / m administered intravenously over 10 minutes on days 1 and 2 of a 28-day cycle. 2 The recommended dose for iNHL is 120 mg / m administered intravenously over 10 minutes on days 1 and 2 of a 21-day cycle. 2The compound is bendamustine hydrochloride, which is administered for up to eight cycles.

[0052] The amount of reconstituted solution needed to achieve the desired dose is typically added to a 150 mL partial addition bag (PAB) containing 50 mL of the same diluent used for reconstitution. Prior to administration, mix the PAB contents by gently inverting the bag back and forth 20 times.

[0053] In certain embodiments, for CLL indications, the volume of dosing solution in PAB is 1 ml 2 60mL to 3m for patients 2 For patients with ≥100 mg / kg, the range is 80 mL, and the corresponding bendamustine concentration is 1 m 2 1.51 mg / mL to 3 m 2 and 3.4 mg / mL for patients with ≥ 100 mg / mL of bendamustine hydrochloride; this corresponds to 1.67 mg / mL to 3.75 mg / mL of bendamustine hydrochloride, respectively.

[0054] In certain embodiments, for iNHL indications, the mixture comprises 1 ml 2 62mL to 3m for patients 2 The corresponding bendamustine concentration ranged from 1 m to 86 mL for patients with 2 1.76 mg / mL to 3 m 2 and 3.80 mg / mL for patients; which corresponds to 1.94 mg / mL to 4.19 mg / mL of bendamustine hydrochloride, respectively.

[0055] Because the reconstituted formulation is not completely saturated, the composition can be administered in less than about 15 minutes, preferably less than about 10 minutes.

[0056] It is understood that each component, compound, substituent, or parameter disclosed herein is interpreted as disclosed for use alone or in combination with one or more of all other components, compounds, substituents, or parameters disclosed herein.

[0057] As used herein, the terms "composition" and "formulation" are used interchangeably.

[0058] Also, each amount / value or amount / value range for each component, compound, substituent, or parameter disclosed herein should be construed as being disclosed in combination with each amount / value or amount / value range disclosed for the other component(s), compound(s), substituent(s), or parameter(s) disclosed herein; and thus, any combination of amounts / values ​​or amount / value ranges for two or more component(s), compound(s), substituent(s), or parameters disclosed herein should also be understood to be disclosed in combination with each other for purposes of this description.

[0059] Furthermore, it is understood that each lower limit of each range disclosed herein should be interpreted as a disclosure in combination with each upper limit of each range disclosed herein for the same component, compound, substituent, or parameter. Thus, a disclosure of two ranges should be interpreted as a disclosure of four ranges derived by combining each lower limit with each upper limit of each range. A disclosure of three ranges should be interpreted as a disclosure of nine ranges derived by combining each lower limit with each upper limit of each range, etc. Furthermore, a specific amount / value of a component, compound, substituent, or parameter disclosed in the description or examples should be construed as disclosing either the lower or upper limit of a range and, therefore, can be combined with the lower or upper limit of any other range or specific amount / value of the same component, compound, substituent, or parameter disclosed elsewhere in this application to form a range of that component, compound, substituent, or parameter.

[0060] (Example)

[0061] The following examples are offered to illustrate the described compositions and methods and should not be construed as limiting in any respect, except as indicated in the appended claims.

[0062] Examples 1 and 2; and Comparative Experiments A-G

[0063] Freeze drying method

[0064] In each of Examples 1 and 2 and Comparative Experiments A to F, the following method was employed:

[0065] A 100 mL bulk solution of bendamustine / SBECD complex was prepared as follows:

[0066] (a) Add 70 mL of water for injection to a 100 mL volumetric flask;

[0067] (b) slowly add 35.38 grams of SBECD and stir for 5 minutes at 5°C until a clear solution is obtained;

[0068] (c) slowly adding 1.04 grams of bendamustine hydrochloride monohydrate and stirring for 30 minutes at 5°C until a clear solution is obtained; and

[0069] (d) Add additional water for injection until the total volume reaches 100 mL.

[0070] Ten mL of the bulk solution was transferred to a 25 mL glass, Type 1, flint vial and partially sealed with a 20 mm butyl rubber stopper. The vial was placed in a laboratory-scale Millrock REVO Series Freeze Dryer lyophilizer and subjected to the lyophilization cycle described in Table 1 below.

[0071] The moisture content of the resulting lyophilisates was measured (average of 10 samples) and the results of such tests are also shown in Table 1 below.

[0072] Table 1. [Table 1] *Water content could not be determined because the sample was not soluble in non-polar media. **Average of three replicates.

[0073] The above data indicate that by employing a freeze-drying cycle that includes a low-temperature primary drying step followed by a very low-pressure secondary drying step, the moisture content of the freeze-dried cake can be reduced to less than 1%.

[0074] The lyophilized cake of Example 1 exhibited some cracking, which was a cosmetic defect, but no significant defects or imperfections. Upon addition of 8 mL of water for injection, the cake dissolved in less than 1 minute (average of 3 samples).

[0075] The freeze-dried cake of Example 2 was hard and dense with a uniform internal structure. Upon addition of 8 mL of 0.9% saline, the cake dissolved in approximately 2 minutes (average of three samples).

[0076] Storage stability

[0077] The storage stability of the samples of Comparative Experiments B and D, and Example 1, was determined by storing the samples upright for six months at 40°C (+ / - 2°C) and 75% relative humidity (+ / - 5% relative humidity). The average loss of total bendamustine content (three samples) was measured and the useful storage life of the samples (when stored under the above conditions) was calculated based on the estimated time until the HP1 content exceeded 1.5% by weight, and the results are shown in Table 2 below:

[0078] Table 2. [Table 2]

[0079] Lyophilized bendamustine compositions that retain less than about 1% water by weight experience a significantly reduced degree of degradation.

[0080] The above results show that reducing the initial moisture content of the lyophilisate significantly improves the storage stability of the composition.

[0081] Example 3 - Stability in Water for Injection

[0082] Vials of lyophilized powder containing 90.76 mg of bendamustine complexed with SBECD, prepared according to the methods described herein, were stored at room temperature (25±5° C.) for 13 months.

[0083] The lyophilized material was first reconstituted by adding 8 mL of water for injection (WFI) to each vial to produce 10 mL of reconstituted solution, which was then added to a 150 mL PAB infusion bag containing an additional 50 mL of WFI to prepare the dosing solution.

[0084] Such WFI dosing solutions were stored (a) under refrigerated conditions (5±3°C) or (b) at room temperature (25±5°C), with aliquots removed periodically as shown in the table below. Such aliquots were evaluated using HPLC to determine HP1 concentration. As discussed above, HP1 is the major degradant of bendamustine in aqueous environments, and testing has shown that bendamustine compositions containing less than about 5% HP1 by weight are suitable for human administration.

[0085] The results of such tests can be summarized as follows:

[0086] Table 3. Percentage of HP1 in the dosing solution containing water for injection:

[0087] At 5±3°C: [Table 3]

[0088] At 25±5°C [Table 4]

[0089] The above data demonstrate that the compositions described are stable in WFI and that WFI can be used as a diluent for human patients.

Claims

1. 1. A lyophilized composition comprising bendamustine and sulfobutyl ether beta-cyclodextrin, said composition comprising: a) containing a molar excess of sulfobutyl ether beta-cyclodextrin relative to the amount of bendamustine present; b) mannitol-free; c) the retained moisture has a moisture content of less than about 1% by weight; A composition characterized by:

2. 10. The composition of claim 1, wherein the moisture content of the composition is less than about 0.75% by weight.

3. 3. The composition of claim 1 or claim 2, wherein the moisture content of the composition is less than about 0.6% by weight.

4. 10. The composition of claim 1, wherein the moisture content of the composition is less than about 1.0% and greater than 0.2% by weight.

5. The composition of any one of claims 1 to 3, wherein the moisture content of the composition is less than about 0.6% and more than 0.4% by weight.

6. The composition of any one of claims 1 to 5, wherein the molar ratio of bendamustine to sulfobutyl ether beta-cyclodextrin is from about 1:2 to about 1:

25.

7. The composition of any one of claims 1 to 5, wherein the molar ratio of bendamustine to sulfobutyl ether beta-cyclodextrin is from about 1:3 to about 1:

15.

8. The composition of any one of claims 1 to 5, wherein the molar ratio of bendamustine to sulfobutyl ether beta-cyclodextrin is from about 1:4 to about 1:

10.

9. The composition of any one of claims 1 to 5, wherein the molar ratio of bendamustine to sulfobutyl ether beta-cyclodextrin is from about 1:5 to about 1:

7.

10. The composition of any one of claims 1 to 9, wherein the composition further comprises a cationic stabilizer.

11. 11. The composition of claim 10, wherein the cationic stabilizer is 6-deoxy-6-(3-hydroxy)propylamino beta-cyclodextrin.

12. 1. A method for preparing a lyophilized composition comprising bendamustine and sulfobutyl ether beta-cyclodextrin, said method comprising: a) preparing an aqueous composition comprising water, bendamustine and sulfobutyl ether beta-cyclodextrin, and no mannitol; b) transferring the aqueous composition into a vial; c) freezing and annealing the aqueous composition to form a frozen and annealed composition; d) subjecting the frozen and annealed composition to i) a first drying step carried out at a temperature of about −5° C. to about −50° C. and a pressure of about 75 to 150 mTorr; ii) a second drying step at a temperature of about 5°C to about 50°C and a pressure of less than about 25 mTorr.

13. 13. The method of claim 12, wherein the first drying step is carried out at about −20° C. to about −40° C. and at a pressure of about 100 to about 145 mTorr.

14. 14. The method of claim 12 or claim 13, wherein the second drying step is at about 10° C. to about 40° C. and a pressure of less than about 15 mTorr.

15. 1. A method of treating a patient with cancer, comprising administering to the patient an effective amount of a composition reconstituted from a lyophilized composition comprising bendamustine and sulfobutyl ether beta-cyclodextrin, wherein the lyophilized composition comprises: a) containing a molar excess of sulfobutyl ether beta-cyclodextrin relative to the amount of bendamustine present; b) mannitol-free; c) the retained moisture has a moisture content of less than about 1% by weight; A method characterized by:

16. 16. The method of claim 15, wherein the composition is administered within about 15 minutes.

17. 17. The method of claim 15 or claim 16, wherein water for injection is used as the diluent.

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