A PROCESS FOR THE PURIFICATION OF VITAMIN K DEPENDENT COAGULATION FACTORS BY CHROMATOGRAPHY

Abstract: A process for the purification of vitamin K dependent coagulation factors by affinity chromatography wherein fractions of a source containing said vitamin K dependent factors are a) subjected to chromatography on a material modified with 2-hydroxyaminopropyl groups bonded to spacers having more than 3 carbon atoms, said source being applied from a solution whose ionic strength is chosen such that said vitamin K dependent coagulation factors are adsorbed on the above anion-exchange material, washing is optionally performed with an appropriate buffer solution, then, after separation of the eluate, b) a buffer solution of higher ionic strength than that used in step a) is contacted with the affinity chromatographic material such that said vitamin K dependent factors are eluted, then this fraction is either processed further to give a PPSB preparation, or these fractions containing the factors are pooled and then said fractions c) are subjected to a second chromatographic step in the form of a heparin affinity chromatography.

Description: A Process for the Purification of Vitamin K Dependent Coagulation Factors by Chromatography The present invention pertains to a process for the purification of vitamin K dependent coagulation factors by anion-exchange chromatography and to a PPSB fraction or a proteins C and S as well as factor IX fraction obtainable by the process according to the invention, as well as a chromatographic material. EP 0 396 022 describes the preparation of a factor IX concentrate from plasma by chromatography, namely affinity chromatography by means of a carrier material in which 2-hydroxyaminopropyl (HAP) groups are bonded to a relatively short chain of 3 carbon atoms (spacer) . Following a heparin affinity chromatographic step, a factor IX concentrate can be prepared by the method described therein which is said to contain a specific factor IX activity of above 200 U/mg. The overall yield of the factor, based on plasma, is said to be near 30% when washing is performed with aqueous solutions containing only NaCl as a salt (for increasing conductivity) . l-Amino-2-propanol serves as the eluent . This is a drawback for drug safety reasons. In addition, the yield will decrease according to the procedure described in EP 0 396 022 when virus inactivation steps are performed. This is absolutely required, however, when pooled plasma is used in order to prevent viral transmission with the vitamin K dependent factors (e.g. hepatitis A and B, HIV, etc.) . Although the presently known anion exchange or affinity chromato¬ graphic materials are suitable to ensure chromatographic separa¬ tion of the vitamin K dependent coagulation factors, it is desirable to provide chromatographic materials which enable further improvement of the separation of vitamin K dependent coagulation factors from blood plasma. Thus, the object of the present invention is, on one hand, to provide a process which enables an improved yield of vitamin K dependent coagulation factors, such as PPSB concentrates, pro¬ teins C and S/factor IX fractions, and to provide a chromato¬ graphic material which is particularly useful for preparing vitamin K dependent coagulation factors from appropriate sources . The object of the present invention is achieved by a process according to claim 1. Claims 2 to 10 pertain to preferred embodiments of the process according to the invention. Claims 11 and 12 are directed to products containing vitamin K dependent coagulation factors which are characterized by a high purity and high specific activity and obtainable by the process according to the invention. Claim 13 is concerned with a protein C and S containing fraction obtainable by step c) of claim 1. Claim 14 pertains to the chromatographic material which may be used in the process according to the invention. According to the invention, there is added to the source con¬ taining the vitamin K dependent factors a material to which HAP ligands are bonded through so-called tentacles. The term "tentacles" refers to certain spacers with which chromatographic material is modified as described in EP 0 337 144. The chromato¬ graphic material modified with HAP ligands to which the ligand is bonded through tentacles exhibits novel properties resulting in the object of the invention's being achieved. The HAP ligands covalently bonded to the chromatographic material through the tentacles are bonded to the matrix in a freely movable manner through the tentacles. By using this material, it is possible to perform chromatography of the vitamin K dependent coagulation factors from undiluted plasma and to recover the vitamin K dependent coagulation factors in high yield and purity. The fractions of the coagulation factors recovered according to the invention together will then give highly pure coagulation factor concentrates following the purification steps of the process according to the invention. The figure shows a flow-chart of the procedure of the process according to the invention with preferred embodiments for preparing a PPSB concentrate and a factor IX concentrate. According to the invention, a source containing vitamin K dependent factors is separated into the desired fractions by means of affinity chromatography. This is done on a material modified with 2-hydroxyaminopropyl groups. Particularly preferred is a material obtainable by coupling 2-hydroxyaminopropyl groups to a matrix resulting in the so-called tentacle chromatographic materials (Merck) . The modification of the material and the material itself will be characterized below. The source containing vitamin K dependent factors is contacted with the affinity material from a solution, this solution having a relatively low ionic strength, corresponding to from 10 to 150 mOsm. This is achieved in a particularly simple way by charging the chromatographic material, preferably as a slurry, into a chromatographic column and charging the solution with the source containing vitamin K dependent factors on the column. The ionic strength is adjusted such that the vitamin K dependent coagulation factors remain adsorbed to the chromatographic material whereas other components are washed from the chromato¬ graphic column. Optionally, following application of the solution containing the vitamin K dependent coagulation factors, washing may be performed with a solution of similar ionic strength as that used in the application. Then, according to step b) of the process according to the invention, a solution with higher ionic strength is contacted with the chromatographic material. This will result in desorption of the vitamin K dependent coagulation factors adsorbed to the chromatographic material according to the invention from the surface of the chromatographic material and elution from the chromatographic column. This fraction contains the PPSB factors IX, II, X, and VII, and the proteins C and S. Then, this fraction can be further processed into a commercial PPSB preparation in a per se known manner. For isolation of factor IX, the fraction eluting according to step b) is collected and subjected to a second chromatography in the form of a heparin affinity chromatography. Heparin affinity chromatography is known as such and described in more detail in D. Josic, F. Bal and H. Schwinn, Journal of Chromatography, 632 (1993) , 1-10. Finally, in order to obtain a preparation which is unobjection¬ able by current standards, a virus inactivation step is per¬ formed, preferably between steps b) and c) of the process according to the invention. Preferably, virus inactivation is carried out by chemical treatment with detergents and/or heat treatment. As detergents, non-ionic detergents may be used. These are combined with dialkyl/trialkyl substituted phosphates, such as TNBP (tri-n-butylphosphate) , for instance. The detergents employed for virus inactivation can be used at up to 20%. The heat treatment step corresponds to a pasteurizing step, prefera¬ bly in a temperature range of from 60 to 65°C for 5 to 30 hours, especially for 8 to 14 hours (WO 94/17834) . In a further embodiment of the process according to the inven¬ tion, step c) may be followed by a second virus inactivation step. This is advisable especially when only one virus inactiva¬ tion is performed between steps b) and c) . Particularly preferred is chemical virus inactivation between steps b) and c) , and physical virus inactivation, for example, heat treatment, following step c) of the process according to the invention. If a second virus inactivation step is performed following step c) of the process according to the invention, a third chromato¬ graphic purification operation is recommended which is one of a second heparin affinity chromatography, anion-exchange chromato¬ graphy, or chromatography on the carrier material used in step a) of the process according to the invention. In another embodiment of the process according to the invention, physical virus inactivation, for example, heat treatment, may be performed following step b) . Preferably, this is followed by an intermediate purification which is either anion-exchange chromatography or another chromatography on the carrier material according to the invention used in step a) of the process according to the invention. This may be followed by solvent/de¬ tergent inactivation (EP 131 740 A2) and heparin affinity chromatography. As the source containing vitamin K dependent coagulation factors, there may be used, in particular, blood plasma or cryopoor plasma or cell culture supernatants or other solutions containing vitamin K dependent coagulation factors. Depending on the condition of the source containing vitamin K dependent coagulation factors, filtration through biocompatible materials may be recommended. As filters, there may be used, in particular, filters having pore sizes of between 0.5 and 2.0 μm. By means of the process according to the invention, concentrates may be prepared containing vitamin K dependent coagulation factors. The factor IX and PPSB concentrates have higher purity as compared to the prior art concentrates and are therefore novel substances. Further, the proteins C and S have a specific activity of from 8 to 10 U/mg in the PPSB concentrate. Thus, a useful starting material is obtained for the preparation of a new high purity concentrate of proteins C and S. The chromatographic material which may be employed in the process according to the invention can be obtained by modification of so- called tentacle materials with 2-hydroxyaminopropyl groups (HAP) as ligands. The chromatographic material according to the inven¬ tion has a hydrophilic moveable arm (spacer) on the base matrix, or carrier material. To this arm the HAP group is bonded. Sur¬ prisingly, it is shown that by using the chromatographic material according to the invention, purification of the vitamin K dependent coagulation factors from appropriate sources is possible with high purity and yield. The invention will be illustrated in more detail by the following examples . Examples 1 and 2 include a comparison between the chromatographic material described in EP 0 396 022 and the chromatographic material according to the invention under otherwise authentic conditions mimicking those used in EP 0 396 022. Example 1 includes the use of the material according to the invention while Example 2 includes the use of the material described in EP 0 396 022. Example 1 A 10 ml column filled with a matrix having 2-hydroxyaminopropyl ligand bonded thereto through a tentacle arm is equilibrated with 60 ml of buffer A (10 mM citrate, 10 mM NaHP0 4 , 100 mM NaCl , pH 7.5) . Two hundred ml of cryopoor plasma is applied at a linear flow rate of 100 cm/h and then washed with 50 ml of buffer A. Sub¬ sequently, factor IX is eluted with buffer A containing 0.8 M NaCl . 30% of factor IX is found in the eluate while 50% is eluted with 0.8 M NaCl. The specific activity of factor IX is 6.5 U/mg. The enrichment in the 0.8 M NaCl eluate of protein C is 30% and of protein S 20% of the initial amount. Example 2 A 10 ml column filled with a matrix bearing 2-hydroxyaminopropyl ligand consisting of a copolymer of glycidyl methacrylate, pentaerythritol dimethacrylate, and poly(vinyl alcohol) (Toyopearl TSK-Amino, TosoHaas) is equilibrated with 60 ml of buffer A (10 mM citrate, 10 mM NaHP0 4 , 100 mM NaCl, pH 7.5) . Two hundred ml of cryopoor plasma is applied at a linear flow rate of 100 cm/h and then washed with 50 ml of buffer A. Sub¬ sequently, factor IX is eluted with buffer A containing 0.5 M NaCl. Seventy-five % of factor IX is found in the eluate while 13% is eluted with 0.5 M NaCl. The specific activity of factor IX is 7 U/mg. The enrichment of protein C in the 0.5 M NaCl eluate is only 2% of the initial amount while protein S is not detectable. Example 3 shows the result obtained by using the material accord¬ ing to the invention in the process according to the invention under different buffer and elution conditions, Example 3 showing an optimization according to the invention, and Example 4 showing the result which can be achieved with the conventional material using the optimized conditions according to the invention. Example 3 A 10 ml column filled with a matrix having 2-hydroxyaminopropyl ligand bonded thereto through a tentacle arm is equilibrated with 60 ml of buffer A (20 mM citrate, pH 7.5) . Two hundred ml of cryopoor plasma is applied at a linear flow rate of 100 cm/h and then washed with 50 ml of buffer A contain¬ ing 0.15 M NaCl. Subsequently, factor IX is eluted with buffer A containing 0.8 M NaCl. Eighteen % of factor IX is found in the eluate while 75% is eluted with 0.8 M NaCl. The specific activity of factor IX is 7 U/mg. The enrichment in the 0.8 M NaCl eluate of protein C is 50% and of protein S 30% of the initial amount. Example 4 A 10 ml column filled with a matrix bearing 2-hydroxyaminopropyl ligand consisting of a copolymer of glycidyl ethacrylate, pentaerythritol dimethacrylate, and poly(vinyl alcohol) (Toyopearl TSK-Amino, TosoHaas) is equilibrated with 60 ml of buffer A (20 mM citrate, pH 7.5) . Two hundred ml of cryopoor plasma is applied at a linear flow rate of 100 cm/h and then washed with 50 ml of buffer A. Sub¬ sequently, factor IX is eluted with buffer A containing 0.5 M NaCl. Sixty-one % of factor IX is found in the eluate while 32% is eluted with 0.5 M NaCl. The specific activity of factor IX is 6 U/mg. The enrichment in the 0.5 M NaCl eluate of protein C is 5% and of protein S 1% of the initial amount. A comparison of Examples 3 and 4 shows that surprisingly a double recovery of factor IX can be achieved by using the material according to the invention. At the same time, and in contrast to the prior art process, proteins C and S are also enriched in this fraction. In Example 5, another optimization with the material according to the invention is shown. In Example 6, the process has been performed under the application and washing conditions according to the invention but using a prior art carrier material . Example 5 A 250 ml column filled with a matrix having 2-hydroxyaminopropyl ligand bonded thereto through a tentacle arm is equilibrated with 2000 ml of buffer A (20 mM citrate, pH 7.5) . Five thousand ml of cryopoor plasma is applied and washed with 750 ml of buffer A. Then, washing is performed with 2000 ml of buffer A containing 0.15 M NaCl. Subsequently, factor IX is eluted with buffer A containing 0.8 M NaCl, 0.1% of a ino acids, such as iysine, 0.1% of arginine. Factor IX of this fraction has a specific activity of 8 U/mg. The recovery of factor IX is 85% of the initial activity in the cryopoor plasma. In this fraction, protein C is contained at 55% and protein S at 40% of the initial amount . The eluate is diafiltrated against 20 mM citrate buffer, pH 7.0, until an osmolality of 200 mOsmol is achieved. To the solution is added 1% of Tween and 0.3% of TNBP followed by incubation at 25°C for 7 hours. A 500 ml Heparin-Sepharose (Pharmacia) is equilibrated with 1500 ml of buffer A. The factor IX eluate is applied and washed with 1000 ml of buffer A. Subsequently, factor IX is eluted with a linear gradient of 0-1 M aCl in buffer A. The fractions with a specific activity of factor IX of more than 200 are pooled, stabilizers are added, and pasteurization is performed. Then, the diluted solution is subjected to a second heparin chromatography. A doubly virus inactivated factor IX concentrate is obtained with a specific activity of >200 U/mg with a recovery of 40% from plasma. Example 6 A 10 ml column filled with a matrix bearing 2-hydroxyaminopropyl ligand consisting of a copolymer of glycidyl methacrylate, pentaerythritol dimethacrylate, and poly(vinyl alcohol) (Toyopearl TSK-Amino, TosoHaas) is equilibrated with 60 ml of buffer A (20 mM citrate, pH 7.5) . Two hundred ml of cryopoor plasma is applied at a linear flow rate of 100 cm/h and then washed with 50 ml of buffer A contain¬ ing 0.15 M ΝaCl . Subsequently, factor IX is eluted with buffer A containing 0.5 M ΝaCl. Fifty % of the amount of factor IX is found in the eluate. Another 38% are found in the 0.5 M ΝaCl wash. Only 5% recovery of factor IX could be found in the 0.5 M ΝaCl eluate. Example 6 makes clear that the use of the conventional material gives rise to essential drawbacks since the major portion of factor IX is in the eluate and in the washing fraction. Factor IX as well as the other vitamin K dependent coagulation factors will bind but insufficiently to the prior art chromatographic material when to be purified from viscous solutions, such as undiluted plasma, or from solutions with high ionic strength. Example 7 includes the preparation of a PPSB concentrate using the chromatographic material according to the invention. Chromatography of the cryopoor plasma with Q-Sepharose Fast Flow was performed as a so-called capture step. This intermediate product was then subjected to chromatography using the chromato¬ graphic material according to the invention. The capture step can also be performed employing other gel materials highly exhibiting anion-exchange properties. Example 7 A 200 ml column filled with Q Sepharose FF (Pharmacia) is equili¬ brated with buffer A (0.005 M NaHP0 4 , pH 6) . Five thousand ml of cryopoor plasma is applied at a flow rate of 100 cm/h and washed with 500 ml of buffer A. Then, the column is washed with 500 ml of buffer A containing 0.05 M NaCl. Sub¬ sequently, elution is performed with buffer A containing 0.4 M NaCl. This fraction is dialysed against 25 mM citrate, pH 7, until an osmolality of 150 mOsm is achieved. To the solution is added 1% of Tween and 0.3% of TNBP followed by incubation at 25°C for 8 hours . A 50 ml column filled with a matrix having 2-hydroxyaminopropyl ligand bonded thereto through a tentacle arm is equilibrated with 2000 ml of buffer B (20 mM citrate, pH 7.5) . The Q Sepharose eluate is applied on the column and washed with 300 ml of buffer B. Subsequently, washing with 250 ml of buffer B containing 0.1 M NaCl and then elution with buffer B containing 0.8 M NaCl, 0.1% of lysine, 0.1% of arginine is performed. A fraction is obtained containing the PPSB factors IX, II, X, and VII at a specific activity of 7 U/mg. The overall recovery of the PPSB factors is 54%. In addition, this fraction contains proteins C and S with a recovery of 40% and 35%, respectively. Surprisingly, the process according to the invention and the material according to the invention results in isolation of factor IX along with proteins C and S, which may be directly from plasma. With the prior art HAP materials, however, the major fraction of proteins C and S is found in the eluate. Preparation Scheme F IX F IX sp. act. (U/mg) 0.02 plasma purification factor (undiluted) I filtration I a) direct chromatography of the plasma on tentacle σ-hydroxyamino group I b) intermediate product 5-10 factors II, VII, IX, X, proteins C, S x 300-500 1 1 st virus inactivation (solvent/detergent (SD) virus inactivation) 1 c) heparin affinity chromatography 1 2nd virus inactivation (pasteurization) I heparin or HAP chromatography i > 150 F IX concentrate > 7500 F IX Recovery, based on plasma: 60-90% following 1 st chromatography

Claims: C L A I M S : 1. A process for the purification of vitamin K dependent coagulation factors by affinity chromatography wherein fractions of a source containing said vitamin K dependent factors are a) subjected to chromatography on a material modified with 2-hydroxyaminopropyl groups bonded to spacers having more than 3 carbon atoms, said source being applied from a solution whose ionic strength is chosen such that said vitamin K dependent coagulation factors are adsorbed on the above anion-exchange material, washing is optionally performed with an appropriate buffer solution, then, after separation of the eluate, b) a buffer solution of higher ionic strength than that used in step a) in contacted with the affinity chro¬ matographic material such that said vitamin K depen¬ dent factors are eluted, then this fraction is either processed further to give a PPSB preparation, or these fractions containing the factors are pooled and then said fractions c) are subjected to a second chromatographic step in the form of a heparin affinity chromatography. 2. The process according to claim 1, wherein a virus inactiva¬ tion step is performed between steps b) and c) . 3. The process according to claim 2, wherein said virus inactivation is performed by treatment of the fractions containing said vitamin K dependent factors with non-ionic surfactants in the presence of dialkyl or trialkylphos- phates with or without a heat treatment. 4. The process according to at least one of claims 1 to 3 , wherein anion-exchange chromatography or a chromatography according to step a) of claim 1 is performed between steps b) and c) . 5. The process according to at least one of claims 1 to 4, wherein another virus inactivation step is performed following step c) of claim 1. 6. The process according to claim 5, wherein said second virus inactivation step includes a heat treatment. 7. The process according to claim 5 or 6, wherein a third chromatographic purification operation is performed following said second virus inactivation step. 8. The process according to claim 7, wherein said third chromatographic purification operation is a heparin affinity chromatography, an anion-exchange chromatography, or a chromatography according to step a) of claim 1. 9. The process according to any of claims 1 to 8, wherein said source containing vitamin K dependent coagulation factors is blood plasma or cryopoor plasma. 10. The process according to claim 1, wherein said source con¬ taining vitamin K dependent coagulation factors is subject¬ ed to filtration prior to step a) of claim 1. 11. A PPSB fraction, obtainable by collecting the fractions following performance of step b) of claim 1. 12. Factor IX, obtainable by collecting the fractions following performance of step c) of claim 1. 13. Protein C and S containing fraction obtainable by step c) of claim 1. 14. A chromatographic material according to step a) of claim 1 obtainable by modification of tentacle material having a hydrophilic spacer bound on the base matrix, with 2-hydroxy aminopropyl groups.

Inventors: JOSIC DJURO, MORFELD FRANK, JOSIC, DJURO, MORFELD, FRANK
Applicants: JOSIC DJURO, MORFELD FRANK, OCTAPHARMA AG, JOSIC, DJURO, MORFELD, FRANK
Application year: 1996
Main classification: C12N9
IPC codes: C12N9