EP2571362A1 - Procédé perfectionné pour un agent folate-ciblé - Google Patents

Procédé perfectionné pour un agent folate-ciblé

Info

Publication number
EP2571362A1
EP2571362A1 EP11784235A EP11784235A EP2571362A1 EP 2571362 A1 EP2571362 A1 EP 2571362A1 EP 11784235 A EP11784235 A EP 11784235A EP 11784235 A EP11784235 A EP 11784235A EP 2571362 A1 EP2571362 A1 EP 2571362A1
Authority
EP
European Patent Office
Prior art keywords
formula
compound
buffer
treating
reaction mixture
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Withdrawn
Application number
EP11784235A
Other languages
German (de)
English (en)
Other versions
EP2571362A4 (fr
Inventor
Daniel S. Reno
Katheryn Marie Stanford
Iontcho Radoslavov Vlahov
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Endocyte Inc
Original Assignee
Endocyte Inc
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Endocyte Inc filed Critical Endocyte Inc
Priority claimed from PCT/US2011/037134 external-priority patent/WO2011146707A1/fr
Publication of EP2571362A1 publication Critical patent/EP2571362A1/fr
Publication of EP2571362A4 publication Critical patent/EP2571362A4/fr
Withdrawn legal-status Critical Current

Links

Classifications

    • C—CHEMISTRY; METALLURGY
    • C07—ORGANIC CHEMISTRY
    • C07K—PEPTIDES
    • C07K7/00—Peptides having 5 to 20 amino acids in a fully defined sequence; Derivatives thereof
    • C07K7/02—Linear peptides containing at least one abnormal peptide link
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61K—PREPARATIONS FOR MEDICAL, DENTAL OR TOILETRY PURPOSES
    • A61K47/00—Medicinal preparations characterised by the non-active ingredients used, e.g. carriers or inert additives; Targeting or modifying agents chemically bound to the active ingredient
    • A61K47/50—Medicinal preparations characterised by the non-active ingredients used, e.g. carriers or inert additives; Targeting or modifying agents chemically bound to the active ingredient the non-active ingredient being chemically bound to the active ingredient, e.g. polymer-drug conjugates
    • A61K47/51—Medicinal preparations characterised by the non-active ingredients used, e.g. carriers or inert additives; Targeting or modifying agents chemically bound to the active ingredient the non-active ingredient being chemically bound to the active ingredient, e.g. polymer-drug conjugates the non-active ingredient being a modifying agent
    • A61K47/54—Medicinal preparations characterised by the non-active ingredients used, e.g. carriers or inert additives; Targeting or modifying agents chemically bound to the active ingredient the non-active ingredient being chemically bound to the active ingredient, e.g. polymer-drug conjugates the non-active ingredient being a modifying agent the modifying agent being an organic compound
    • A61K47/55—Medicinal preparations characterised by the non-active ingredients used, e.g. carriers or inert additives; Targeting or modifying agents chemically bound to the active ingredient the non-active ingredient being chemically bound to the active ingredient, e.g. polymer-drug conjugates the non-active ingredient being a modifying agent the modifying agent being an organic compound the modifying agent being also a pharmacologically or therapeutically active agent, i.e. the entire conjugate being a codrug, i.e. a dimer, oligomer or polymer of pharmacologically or therapeutically active compounds
    • A61K47/551—Medicinal preparations characterised by the non-active ingredients used, e.g. carriers or inert additives; Targeting or modifying agents chemically bound to the active ingredient the non-active ingredient being chemically bound to the active ingredient, e.g. polymer-drug conjugates the non-active ingredient being a modifying agent the modifying agent being an organic compound the modifying agent being also a pharmacologically or therapeutically active agent, i.e. the entire conjugate being a codrug, i.e. a dimer, oligomer or polymer of pharmacologically or therapeutically active compounds one of the codrug's components being a vitamin, e.g. niacinamide, vitamin B3, cobalamin, vitamin B12, folate, vitamin A or retinoic acid

Definitions

  • the invention described herein pertains to an improved process for preparing the folate-targeted conjugate EC 145 and to the conjugate EC 145 prepared using the improved process, as well as to a pharmaceutical composition comprising the conjugate EC 145 prepared using the improved process.
  • EC145 comprises a highly potent vinca alkaloid cytotoxic compound, desacetylvinblastine hydrazide (DAVLBH), conjugated to folate.
  • DAVLBH desacetylvinblastine hydrazide
  • the EC145 molecule targets the folate receptor found at high levels on the surface of epithelial tumors, including non-small cell lung carcinomas (NSCLC), ovarian, endometrial and renal cancers, and others, including fallopian tube and primary peritoneal carcinomas. It is believed that EC145 binds to tumors that express the folate receptor delivering the vinca moiety directly to cancer cells while avoiding normal tissue. Thus, upon binding, EC 145 enters the cancer cell via endocytosis, releases DAVLBH and causes cell death or inhibits cell function.
  • EC 145 has the following formula
  • EC 145 means the compound, or a pharmaceutically acceptable salt thereof; and the compound may be present in a solid, solution or suspension in an ionized form, including a protonated form.
  • EC145 is disclosed in U.S. Patent No. 7,601,332, as well as in
  • EC145 is prepared by forming a disulfide bond using the thiol of formula
  • CDSI carbamo l disulfide intermediate
  • Chromatographic fractions having greater than 90% peak area of EC 145 were combined, diluted with water, and lyophilized. Typically, purified yields were in the 30 - 40% range with purities in the 90 - 93% range. The volumes associated with the lyophilizations made preparation of more than gram quantities very cumbersome.
  • X is alkylsulfonyl, arylsulfonyl, arylthio or heteroarylthio, in the presence of an aqueous buffer of pH less than 8.
  • X is 2-thiopyridinyl or 3-nitro-2-thiopyridinyl.
  • X is 2-thiopyridinyl.
  • the buffer has a pH of less than about 7. In another embodiment, the buffer has a pH of less than 6.5. In another embodiment, the buffer has a pH of 5.9 to 6.3. In another embodiment, the buffer has a pH of 5.9 to 6.1.
  • the buffer is a phosphate buffer.
  • the buffer is a sodium phosphate buffer.
  • the use of a buffer, as disclosed herein affords better control of the pH and the problem of degradation than the use of sodium bicarbonate.
  • one embodiment is the process wherein the treatment occurs in a liquid medium comprising acetonitrile.
  • a further aspect is a process further comprising the step of treating desacetylvinblastine hydrazide with an acylating agent of formula
  • the leaving group Y may be any of a number of leaving groups appropriate for the acylation of the hydrazide.
  • Y is the residue of an alcohol which forms an active ester with a carboxylic acid or with the monoester of a carbonic acid, for example a 4-nitrophenoxy residue, a 1-benzotriazolyloxy residue or a 7-azabenzotriazol-l-yloxy residue.
  • the acylating agent is of the formula
  • acylating agent is of the formula
  • acylating agent is introduced in the form of an acid addition salt, a base such as triethylamine or diisopropylethylamine is used to free the base.
  • acylating agent is of the formula
  • one embodiment is the process wherein the desacetylvinblastine hydrazide is treated with the acylating agent in a solvent comprising acetonitrile.
  • one embodiment is the process wherein the desacetylvinblastine hydrazide is provided in a highly purified form.
  • desacetylvinblastine hydrazide may be obtained as a highly purified solid using a procedure involving dissolution/precipitation (denoted as crystallization) from ethyl acetate and toluene.
  • ECl 19 is provided in a highly purified form.
  • ECl 19 is synthesized using Fmoc-based solid phase chemistry.
  • First Fmoc-Cys(Trt)-OH is loaded onto the resin through esterification with
  • 2-chlorotrityl chloride resin in the presence of diisopropylethylamine (DIPEA).
  • DIPEA diisopropylethylamine
  • the Fmoc protecting group on the resin-bound Cys(Trt) is then removed by treating the resin with 6% piperazine in 0.1 M HOBt in dimethylformamide (DMF).
  • DMF dimethylformamide
  • the resin is washed with DMF and methyl t-butyl ether (MTBE).
  • Fmoc-Asp(OtBu)-OH is coupled to the resin with
  • the coupling reaction is monitored by a Kaiser test.
  • the deprotection and coupling are repeated with Fmoc- Asp(OtBu)-OH, Fmoc-Arg(Pbf)-OH, Fmoc-Asp(OtBu)-OH and Fmoc-Glu-OtBu.
  • the coupling of N 10 -TFA-Pte-OH uses 1.2 equivalents of N 10 -TFA-Pte, 1.2 equivalents of PyBOP, 1.2 equivalents of HOBt and 2.4 equivalents of DIPEA.
  • the trifluoroacetyl group is removed with 2% hydrazine in DMF.
  • the peptide is cleaved from the resin with a cleaving reagent containing approximately 85% trifhioroacetic acid, 10% ethanedithiol, 2.5% triisopropylsilane, and 2.5% deionized water.
  • This reaction also results in simultaneous removal of the t-Bu, Pbf, and trityl protecting groups.
  • Crude product is precipitated with MTBE and isolated by filtration. The purity of crude ECl 19 is approximately 90%. The preparation is described in more detail in the examples.
  • one embodiment is the process wherein the step of treating desacetylvinblastine hydrazide with an acylating agent to form a reaction mixture comprising the compound of formula
  • one embodiment is the process further comprising the step wherein the reaction mixture containing EC 145 is diluted with citrate buffered, aqueous sodium chloride solution and loaded onto a polystyrene-divinylbenzene polymeric resin column or cartridge for purification.
  • This process makes the dilute and load sequence possible.
  • the dilute and load approach involves diluting the reaction mixture with buffered saline (targeting a 10% acetonitrile content for the diluted solution) and loading this solution onto the chromatography column. This eliminates the need for one ultra-filtration sequence and saves about 12 to 24 hours in processing time.
  • Another embodiment further comprises eluting the EC 145 product from the column or cartridge using a mobile phase comprising acetonitrile and citrate buffered, aqueous sodium chloride solution.
  • a mobile phase comprising acetonitrile and citrate buffered, aqueous sodium chloride solution.
  • the use of buffered saline mobile phases improves the chromatographic process in several ways.
  • the increased ionic strength of the buffered saline mobile phase influences the partitioning of the product between the mobile and stationary phases.
  • the affinity of the product for the stationary phase is increased to the point that the column's capacity for crude EC 145 is more than doubled.
  • the increased affinity of the stationary phase also eliminates the occurrence of product break-through (a portion of the product passing through the column during the loading operation) while loading the crude EC145 onto the column.
  • the higher ionic strength also improves the kinetics of the
  • one embodiment is the process further comprising the step of using ultra- filtration to afford EC 145 as a purified product in aqueous solution.
  • This process avoids the time and product purity loss (about 1%) associated with large scale lyophilization.
  • it provides the purified product in aqueous solution in a condition appropriate for the further embodiment of filtering through a 0.2 micron absolute filter, which reduces the microbial count and endotoxin levels relative to the process without the filtration.
  • one embodiment is the process wherein the water used in any step contains dissolved oxygen at a concentration that does not exceed about 0.9 parts per million (ppm).
  • conjugate EC145 prepared by a process described hereinabove.
  • conjugate EC145 prepared by a process comprising the step of treating a compound of formula
  • X is alkylsulfonyl, arylsulfonyl, arylthio or heteroarylthio, in the presence of an aqueous buffer wherein the buffer has a pH of 5.9 to 6.3.
  • X is 2-thiopyridinyl.
  • the process further comprises the step of treating desacetylvinblastine hydrazide with an acylating agent of formula
  • a further embodiment of the above is the conjugate 24 wherein the acylating agent is of the formula
  • a pharmaceutical composition comprising the conjugate EC 145 as described in any of the above embodiments together with a diluent, excipient or carrier.
  • X is alkylsulfonyl, arylsulfonyl, arylthio or heteroarylthio, in the presence of an aqueous buffer of pH less than 8.
  • X is alkylsulfonyl, arylsulfonyl, arylthio or heteroarylthio, in the presence of an aqueous buffer wherein the buffer has a pH of 5.9 to 6.3.
  • a pharmaceutical composition comprising the conjugate EC145 described in any of clauses 21-25 together with a diluent, excipient or carrier.
  • alkyl includes a chain of carbon atoms, which is optionally branched or cyclic, and which is optionally substituted or may contain an oxygen, sulfur or nitrogen atom, as a heteroalkyl. It is to be further understood that in certain embodiments, alkyl is advantageously of limited length, including CrC 6 , and CrC 4 .
  • Illustrative alkyl groups are, but not limited to, methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, cyclohexyl and the like.
  • aryl includes monocyclic and polycyclic aromatic carbocyclic groups, each of which may be optionally substituted.
  • Illustrative aromatic carbocyclic groups described herein include, but are not limited to, phenyl, naphthyl, and the like.
  • heteroaryl includes aromatic heterocyclic groups, each of which may be optionally substituted.
  • Illustrative aromatic heterocyclic groups include, but are not limited to, 2-pyridinyl, 3-nitro-2-pyridinyl, and the like.
  • optionally substituted includes the replacement of hydrogen atoms with other functional groups on the radical that is optionally substituted.
  • Such other functional groups illustratively include, but are not limited to, halo, nitro, and the like.
  • a pharmaceutical composition as described herein means a pharmaceutical composition adapted for the parenteral administration of EC145.
  • HPLC Methods used for fraction and sample evaluation in the examples include the following:
  • Sample preparation dilute material to approximately 0.5 mg/mL with 8 M guanidine HC1.
  • Sample preparation dilute material to approximately 1 mg/mL with phosphate buffered saline or 1: 1 acetonitrile- water (v/v).
  • ECl 19 is synthesized using Fmoc-based solid phase chemistry as follows:
  • cleaving reagent (lOmL/g resin) containing 85% TFA, 2.5% triisopropylsilane, 2.5% water and 10% ethanedithiol to a flask. Cool the mixture in an ice- bath. Add the resin and allow to react for 2-3 hours at room temperature. Filter and collect the filtrate. Add the filtrate to cold MTBE (lOmL of MTBE per 1 mL of filtrate) . Stir at 0-5 °C for 30 ⁇ 10 min. Filter the precipitated product through a medium porosity glass filter. Wash the precipitate with cold MTBE 3 times. Dry the product under vacuum at room temperature. Store under nitrogen at -20 °C.
  • Crude ECl 19 is purified by preparative HPLC using a reverse phase CI 8 column (6-inch column, 2.8kg, 10 ⁇ , 100A).
  • the mobile phases are 0.5% NH 4 OAc (A) and 0.5% NH 4 OAc/ACN(l:4) (B).
  • 40g of the crude ECl 19 is dissolved in 1-5% TFA, filtered through a 1 ⁇ glass fiber filter and load on the 6-inch column. Fractions are collected and sampled for HPLC analysis. The pH of each fraction is adjusted to 3-4 immediately after collection using 50% AcOH under nitrogen to precipitate the product.
  • the precipitated product is centrifuged, washed with 0.1% AcOH and stored at 2-8 °C until further processing.
  • the containers are blanked with nitrogen during centrifugation operation to reduce the potential for oxidation.
  • the pool criteria are purity > 98%, isomers of D-Arg ⁇ , D-Glu ⁇ and D-Asp3 ⁇
  • reaction, extractive work-up and isolation are run under a nitrogen or argon atmosphere.
  • Pressure filters are used to remove the sodium sulfate and capture the product.
  • the sodium chloride solutions used in the quench and wash are sparged with nitrogen or argon until the dissolved oxygen level is not more than 0.9 ppm.
  • Vinblastine sulfate and anhydrous methanol are charged to an argon purged reactor.
  • 5-Norbornene-2-carboxylic acid and anhydrous hydrazine are added to the reactor.
  • the mixture is stirred, and after the solids dissolve, heat the mixture to around 60 °C.
  • HPLC analysis when the reaction is complete, it is cooled, quenched and extracted into ethyl acetate. After drying, the product is crystallized from ethyl acetate and toluene. The solids are dried under vacuum overnight at room temperature.
  • the buffered NaCl contains: 10.0 g NaCl, 7.10 - 7.30 g NaH 2 P0 4 , 4.40 - 4.60 g of Na 2 HP0 4 and 90 mL of water.
  • the solution is sparged with argon or nitrogen (dissolved oxygen content ⁇ 0.9 ppm).
  • a typical isolated yield is 50 - 60% of the theoretical maximum.
  • WFI water for injection
  • the column can be reused once. If the column will be used for a second run, perform ii - iv.
  • the ultra-filtration endpoint must be determined by analyzing a sample of the retentate via GC and concentration. The specification is ⁇ 50 micrograms of acetonitrile per milligram of EC145. If not achieved, perform another cycle of the ultra-filtration.
  • the API solution's concentration must be adjusted so that the packaged material is 6 to 12 mg/mL.
  • the apparatus will be rinsed with 1 liter of water. Therefore, continue ultra-filtration or add water as necessary. Once the product solution is out of the ultra-filtration apparatus, rinse the ultra-filtration apparatus with 1 L of deoxygenated water and combine with the product solution.
  • this solution After the rinse is combined with the product solution, this solution must be filtered through a 0.2 micron absolute filter, and this filtrate is packaged (performed under an inert atmosphere).
  • the ultra-filtration endpoint must be determined by analyzing a sample of the retentate via GC and concentration. The specification is ⁇ 50 micrograms of acetonitrile per milligram of EC 145. If not achieved, perform another cycle of the ultra-filtration. The API solution's concentration must be adjusted so that the packaged material is about 12 mg/mL.
  • the apparatus will be rinsed with water. Therefore, continue ultra-filtration or add water as necessary. Once the product solution is out of the ultra-filtration apparatus, rinse the ultra-filtration apparatus with deoxygenated water and combine with the product solution.
  • this solution After the rinse is combined with the product solution, this solution must be filtered through a 0.2 micron absolute filter, and this filtrate is packaged (performed under an inert atmosphere).
  • a typical yield of isolated product is 50 - 60% of the theoretical maximum.

Abstract

L'invention concerne un procédé perfectionné de préparation du conjugué EC 145 folate-ciblé et le conjugué EC 145 préparé à l'aide du procédé perfectionné ainsi qu'une composition pharmaceutique comprenant le conjugué EC 145 préparé à l'aide du procédé perfectionné.
EP11784235.1A 2010-05-19 2011-05-19 Procédé perfectionné pour un agent folate-ciblé Withdrawn EP2571362A4 (fr)

Applications Claiming Priority (3)

Application Number Priority Date Filing Date Title
US34644410P 2010-05-19 2010-05-19
US201061351022P 2010-06-03 2010-06-03
PCT/US2011/037134 WO2011146707A1 (fr) 2010-05-19 2011-05-19 Procédé perfectionné pour un agent folate-ciblé

Publications (2)

Publication Number Publication Date
EP2571362A1 true EP2571362A1 (fr) 2013-03-27
EP2571362A4 EP2571362A4 (fr) 2014-01-22

Family

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Family Applications (1)

Application Number Title Priority Date Filing Date
EP11784235.1A Withdrawn EP2571362A4 (fr) 2010-05-19 2011-05-19 Procédé perfectionné pour un agent folate-ciblé

Country Status (1)

Country Link
EP (1) EP2571362A4 (fr)

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2007022493A2 (fr) * 2005-08-19 2007-02-22 Endocyte, Inc. Conjugues de ligand d'alcaloides vinca, analogues et derives
WO2009002993A1 (fr) * 2007-06-25 2008-12-31 Endocyte, Inc. Conjugués contenant des lieurs espaceurs hydrophiles

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2007022493A2 (fr) * 2005-08-19 2007-02-22 Endocyte, Inc. Conjugues de ligand d'alcaloides vinca, analogues et derives
WO2009002993A1 (fr) * 2007-06-25 2008-12-31 Endocyte, Inc. Conjugués contenant des lieurs espaceurs hydrophiles

Non-Patent Citations (2)

* Cited by examiner, † Cited by third party
Title
See also references of WO2011146707A1 *
VLAHOV I R ET AL: "Design and regioselective synthesis of a new generation of targeted chemotherapeutics. Part 1: EC145, a folic acid conjugate of desacetylvinblastine monohydrazide", BIOORGANIC & MEDICINAL CHEMISTRY LETTERS, PERGAMON, GB, vol. 16, no. 19, 1 October 2006 (2006-10-01), pages 5093-5096, XP027966592, ISSN: 0960-894X [retrieved on 2006-10-01] *

Also Published As

Publication number Publication date
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