Patent ID: 12201922

DETAILED DESCRIPTION

The proposed method for operating a chromatography setup1of a bioprocess installation2for performing a chromatography process can be assigned to downstream processing.

The expression “chromatography process” presently represents any kind of biochemical purification process, in particular biopharmaceutical purification processes, employing at least one chromatography column3to10for the separation of chemical compounds. The operation of a chromatography setup1with multiple chromatography columns3to10for performing a multi-column SMB process represents such a chromatography process.

The term “downstream processing” involves all the steps related to the recovery and the purification of biosynthetic products, particularly biopharmaceuticals, from natural sources such as animal or plant tissue or cell broth, including the recycling of salvageable components and the proper treatment and disposal of waste. Such steps can be liquid/solid separations, capturing, purification and/or polishing steps.

In general, the cultivation of cells is currently used for the production of biopharmaceuticals, in particular proteins, such as human insulin, growth factors, hormones, vaccines, or antibodies, antibody derivatives, or viral vectors such as lentiviral vectors and adeno-associated viral vectors and the like. The products may as well be non-biopharmaceuticals, such as enzymes for food processing, laundry detergent enzymes, biodegradable plastics or biofuels. The focus of the present disclosure is on biopharmaceutical products, such as antibodies, viral vectors, nucleic acids such as DNA and RNA or the like.

As shown inFIGS.1to4, the proposed method for operating a chromatography setup1of a bioprocess installation2for performing a chromatography process employs a plurality of chromatography columns3to10. In some embodiments, the proposed method employs at least four, at least six, or here eight, chromatography columns, each with a column inlet11and a column outlet12. Moreover, the chromatography setup comprises a valve switching cassette13. It is especially noteworthy, that the proposed method is easily adaptable for employing even more than eight chromatography columns3to10simultaneously, due to the complex valve manifold provided by the valve switching cassette13. According to some embodiments (not shown), the valve switching cassette13can employ up to 16 chromatography columns3to10simultaneously.

The chromatography setup1with a plurality of chromatography columns3to10is being operated in a chromatography cycle comprising chromatography steps, such as equilibration-, loading-, washing-, elution-, regeneration- and storage steps.

The equilibration step describes the step by which a system enters its state of equilibrium. In a chromatography setup1, this refers to a filling of the respective chromatography column3to10with the respective buffer to be used for the subsequent bioproduct purification, until its entire volume is occupied by the respective buffer.

The loading step refers to a step of loading the respective chromatography column3to10with product-containing supernatant in order to bind the product to the at least one chromatography column3to10initiating the purification of the bioproduct.

The washing step refers to a step of washing the respective chromatography column3to10with buffer. This washing step typically serves for flushing the respective chromatography column3to10to remove unspecifically bound compounds and separate them from the target product.

The elution step describes the step of extracting one material from another, e.g. by eluting with a solvent, such as water, buffer, imidazole or the like. Here, it refers to the extraction of the bioproduct from the respective chromatography column3to10using an aqueous solution, such as with pH- and/or ion gradients, representing different salt concentrations and conductivities.

The regeneration step describes the step of recovering the separation material in order to recover the separation performance of the at least one chromatography column3to10. In this particular context, it refers to a re-equilibration and/or cleaning of the respective chromatography column3to10, e.g. with sodium hydroxide (NaOH) solution.

The storage step describes the step of flushing the at least one chromatography column3to10with e.g. an ethanol solution keeping the separation material sterile. In this particular context, it refers to storage of the respective separation material of the chromatography column3to10, such as in a 10% ethanol (EtOH) solution.

According toFIG.1, the valve switching cassette13comprises a group of inlet ports PI, a group of outlet ports PO, a group of column-in ports CPIand a group of column-out ports CPO, wherein each port CPI, CPOis communicating with an assigned internal liquid line14within the valve switching cassette13.

The term “internal liquid line” means here the entirety of all internal liquid lines14within the valve switching cassette13.

The expression “port” represents the interface for interconnecting components of the bioprocess installation2to the respective internal liquid line14.

The expression “line” represents any longitudinal volume that may hold and guide liquid between two locations. A line in this sense may also include an inflatable and collapsible conduit structure.

The term “column-in port” represents the interface of the valve switching cassette13for interconnecting components of the bioprocess installation2, to create an outflow of liquids out of the valve switching cassette13into at least one chromatography column3to10.

The term “column-out port” represents the interface of the valve switching cassette13for interconnecting components of the bioprocess installation2, to create an outflow of liquids out of the chromatography column3to10into the valve switching cassette13.

As shown inFIG.1, the component to be selectively interconnected is an above noted chromatography setup1with multiple chromatography columns3to10for performing multi-column SMB chromatography. Here, the group of inlet ports PIis used as inlets for feed or buffer or the like. These are selectively guided to the respective column-in ports CPI, the respective column inlets11, passing through the respective chromatography columns3to10and leaving the chromatography columns3to10via column outlets12and re-entering the valve switching cassette13via column-out ports CPO.

As shown inFIG.1, the valve switching cassette13comprises an array of switchable valve units nx,y, which are selectively interconnecting the internal liquid lines14for performing the chromatography process, in particular the multi-column SMB process.

The expression “switchable” refers to the possibility of changing the valve unit nx,yfrom the state “valve open” to the state “valve close” or from the state “valve close” to the state “valve open”. The open valve units nx,yare indicated as solid circles, while the closed valve units nx,yare indicated as outlined circles inFIG.3andFIG.4.

The expression “interconnecting” is to be understood in the sense of a fluidic connection.

Moreover, the chromatography setup1comprises a liquid pumping arrangement15assigned to the valve switching cassette13and an electronic process control16for controlling at least the switchable valve units nx,yand the liquid pumping arrangement15.

It can be particularly essential for some embodiments, that a first liquid stream17of concentrated buffer is introduced into a first internal liquid line14via a first inlet port PIand that a second liquid stream18of diluent is introduced into a second internal liquid line14via a second inlet port PI. In a dilution process, the array of valve units nx,yis switched as to create a third liquid stream19by merging the first liquid stream17and the second liquid stream18at a merging location20within the valve switching cassette13.

As shown inFIG.1andFIG.2, here, the switchable valve units nx,yand the liquid pumping arrangement15are being controlled by the electronic process control16. Thereby, a predefined target dilution factor in the third liquid stream19is created, in some embodiments, at least at the end of the third liquid stream19.

Here, as can be seen inFIG.1andFIG.2, the liquid pumping arrangement15comprises a first pump21driving the first liquid stream17and a second pump22driving the second liquid stream18. Both pumps21,22are selectively controlled by the electronic process control16as to create the target dilution factor in the third liquid stream19. In general, a dilution factor, in particular, the target dilution factor, is a consequence of the pumping speeds of the different pumps, driving the liquids to be merged. The individual flow speeds of the first liquid stream17and the second liquid stream18including their ratios, therefore, define the merging ratio in the third liquid stream19.

The third liquid stream19comprises predefined properties, such as at the endpoint of the third liquid stream19. These predefined properties may be a desired final salt concentration (and hence conductivity), a desired final pH, temperature, flow rate or the like. The endpoint of the third liquid stream19is either defined by the respective column inlet11(during a running process) or by the position of the sensor arrangement27(verification process noted below).

Here, according toFIG.1,FIG.3andFIG.4, a first set of the internal liquid lines LFand a second set of the internal liquid lines LSare arranged in two, in some embodiments parallel, planes of the valve switching cassette13. The valve units nx,yof the valve switching cassette13are arranged as to selectively interconnect an internal liquid line of the first set LFand an internal liquid line of the second set LS.

The expression “selectively interconnecting” means, that one or more of the internal liquid lines of the first set LFmay be selected to be interconnected with one or more of the internal liquid lines of the second set LS.

In some embodiments, the valve units nx,yare each communicating with an internal liquid line of the first set LFand with an internal liquid line of the second set LS, such as via transfer lines, as to selectively interconnect those internal liquid lines LF, LS. These transfer lines can be arranged orthogonally with regard to the two, in some embodiments parallel, planes of the first set of internal liquid lines LFand the second set of internal liquid lines LS.

The first liquid stream17and the second liquid stream18each proceed in a separate internal liquid line of the first set LF. Subsequently, the first liquid stream17and the second liquid stream18are introduced into one and the same internal liquid line of the second set LS. The two liquid streams17,18can be sequentially or simultaneously introduced into the same internal liquid line of the second set LS. This is implemented by switching corresponding valve units nx,y, such that this internal liquid line of the second set LSprovides the merging location20. The merging location20defines the starting point of the third liquid stream19.

Hence, and according toFIG.3andFIG.4, the merging location20is inside the valve switching cassette13and can be implemented in any internal liquid line of the second set LS. In some embodiments, the merging location20is implemented in the first internal liquid line of the second set LS, which the first and second liquid streams17,18cross in their separate corresponding internal liquid lines of the first LFset, when entering the valve switching cassette13. The first liquid stream17and the second liquid stream18can be entering the valve switching cassette13via the inlet ports PIand are directed to the outlet ports PO, or, the first liquid stream17and the second liquid stream18can be entering the valve switching cassette13via the outlet ports POand are directed to the inlet ports PI. This means that the valve switching cassette13is fluidically controllable in both possible fluidic flow directions.

Here, as can be seen inFIG.4, the third liquid stream19comprises an internal stream23through one or more of internal liquid lines14within the valve switching cassette13, and, in some embodiments, an external stream24through one or more of external liquid lines25outside the valve switching cassette13. To clarify and as may be derived fromFIG.3, the third liquid stream19may comprise only an internal stream23through the bypass line30of the second set LSin order to determine the required minimum merging lengths or minimum merging times necessary to determine the lengths and/or diameters for at least one external liquid line, prior to a bioprocess.

In general, external liquid lines25are necessary in order to connect respective column-in ports CPIto the respective column inlets11. Here, the external liquid lines25are double used: The external stream24flows through one or more of external liquid lines25outside the valve switching cassette13and serves additionally for creating a defined minimum merging length and/or merging time, necessary to establish the desired target dilution factor in the third liquid stream19, which will be explained below.

According toFIG.4, the at least one external liquid line25can be provided by a single-use tubing that is interposed in between a column-in port CPIof the valve switching cassette13and the column inlet11of at least one chromatography column3to10. During a running process of at least one of the chromatography columns3to10, the end of the third liquid stream19is defined at the column inlet11of the respective chromatography column3to10. Conclusively, the stream length of the third liquid stream19is defined by its starting point at the merging location20and by its endpoint at the column inlet11of the respective chromatography column3to10.

The term “running process” defines potentially any chromatography step in chromatography processes, wherein a liquid stream is directed via at least one chromatography column3to10, such as equilibration-, loading-, washing-, elution-, regeneration- and/or, storage steps.

Here, as can be seen inFIG.3andFIG.4, the stream length of the third liquid stream19is larger than a minimum merging length.

The terms “minimum merging length” and “minimum merging time” mean here the minimal distance and minimal time respectively that the third liquid stream19requires for a stable creation of the target dilution factor.

In some embodiments, this minimum merging length is being derived from a dilution model26, such as by the electronic process control16or by a user. Additionally or alternatively, the stream length of the third liquid stream19is larger than the length that corresponds to a minimum merging time and the flow rates of the pumps of the liquid pumping arrangement15.

In some embodiments, according toFIG.4, complying with the minimum merging length and/or the minimum merging time ensures the stable creation of the target dilution factor at the end of the third liquid stream19.

The term “stable” means here, that the actual dilution factor is not deviating from the target dilution factor by more than a predefined value, such as deviating less than 10%, less than 5%, or less than 3% from the target dilution factor.

In some embodiments, the dilution model26represents the interdependence between the minimum merging length on the one hand and the flow rates of the pumps and/or the ratio of the flow rates of the pumps and the target dilution factor on the other hand. Additionally or alternatively, the dilution model26represents the interdependence between the minimum merging time on the one hand and the flow rates of the pumps and/or the ratio of the flow rates of the pumps and the target dilution factor on the other hand.

The dilution model26is to be understood as a rule system to derive the minimum merging length and/or minimum merging time necessary to determine the lengths and/or diameters of the respective external liquid lines25. These lengths and/or diameters of the respective external liquid lines25enable a stable creation of the target dilution factor in the external stream24. The minimum merging length and/or minimum merging time are i.a. dependent on the flow rates of the first liquid stream17and second liquid stream18(additionally or alternatively dependent on the resulting flow rate of the third liquid stream19) as well as from the ratios of the flow rates of the first liquid stream17and second liquid stream18. These flow rates and ratios of the flow rates are in turn dependent on the flow rates of the corresponding pumps21,22as well as from the ratios of the flow rates of the corresponding pumps21,22, respectively.

The dilution model26can rely on statistical modelling or machine learning algorithms in order to determine the minimum merging length and/or minimum merging time. The machine-learning mechanism can be based on a supervised or non-supervised neural network, which is, further, a neural convolution network (CNN).

Additionally or alternatively, the minimum merging length and/or minimum merging time can be derived by a series of experiments, such as executed by the user. In the course of such a series of experiments, the individual minimum merging lengths and/or minimum merging times can be empirically determined by testing the interplay between the individual target dilution factors on the one hand, and the individual flow rates of the pumps and/or the ratio of the flow rates of the pumps, as well as viscosities, pressures, densities and temperatures of the liquids to be merged, as a function of space and time, on the other hand. In some embodiments, all the derived minimum merging lengths and/or minimum merging times are stored, such as in a lookup table and/or a cloud service instance.

Thereby, the required minimum merging lengths and/or minimum merging times can be easily looked up, such as by the electronic process control16and/or the user. For this reason, the chromatography setup1can be designed without a sensor28providing sensor values29of the third liquid stream19, since an additional verification of the individual minimum merging lengths and/or minimum merging times by the user becomes unnecessary.

Hence, in the dilution model26, the electronic process control16can determine the distance and/or the time necessary for the third liquid stream19to cover the distance between its start and its end, such as, to cover the distance between the merging location20and the column inlet11of the at least one chromatography column3to10.

In some embodiments, and just as an example, by a synopsis of the required time and the respective flow rates, the electronic process control16calculates the required volume of the external liquid line25, which is necessary to provide the minimum merging time required for a stable creation of the target dilution factor in the external stream24.

Alternatively, by a synopsis of the required distance, the respective flow rates and the diameter of the internal liquid lines of the second set LS, the electronic process control16can calculate the required length and the required diameter of the external liquid line25, which is necessary to provide the minimum merging length necessary for a stable creation of the target dilution factor in the external stream24.

In some embodiments, the dilution model26may be exchanged between two different operating instances or even within one and the same operating instance. Moreover, the dilution model26is highly adaptable to different bioprocess settings leading to altered flow paths, dilution factors, tubing lengths, tubing diameters, flow rates, ratios of the flow rates, flow rates of the pumps and ratios of the flow rates of the pumps. This adaptability renders the proposed method exceptionally flexible.

In some embodiments, the electronic process control16comprises a human-machine interface to input the target dilution factor. In some embodiments, the user can pre-set the target dilution factor in the electronic process control16to be measured in the third liquid stream19. According to this pre-set target dilution factor, the electronic process control16adjusts the flow rates of the pumps and/or the ratio of the flow rates of the pumps. Accordingly, a stable creation of the target dilution factor at the end of the third liquid stream19means that the actual target dilution factor is not deviating from the target dilution factor, by more than a predefined value.

Additionally or alternatively, the electronic process control comprises a human-machine interface to output the minimum merging length, in particular the length of the respective external liquid line25for the third liquid stream19. In some embodiments, the user can subsequently prepare the length of the respective external liquid25line accordingly, further such as by installing single-use tubes comprising the proper minimum merging length, or, by cutting single-use tubes under sterile conditions according to the output minimum merging lengths. In case of an emergency event, such as a pump failure, when using the outputted minimum merging length, the stable creation of the target dilution factor can be verified by the user, as will be explained later.

In some embodiments, as can be seen inFIG.1toFIG.4, the chromatography process is a multi-column chromatography (MCC) process, in particular a simulated moving bed chromatography (SMB) process. It can be that during the chromatography process, liquid such as feed liquid or buffer liquid, is being introduced into one of the inlet ports PI.

In some embodiments, as can be seen inFIG.2andFIG.3the chromatography setup1comprises a sensor arrangement27with at least one sensor28providing sensor values29. These sensor values29are being transmitted to the electronic process control16. The sensor28can provide the conductivity of the third liquid stream19as sensor values29, hence representing the actual dilution factor of the third liquid stream19at a measuring position. Additionally, these sensor values29can represent other properties of the third liquid stream19, such as properties such as pH, temperature or optical density.

The sensor arrangement27is not only used to adjust the dilution factor in case of an emergency event but also to determine the required minimum merging lengths or minimum merging times prior to the bioprocess, which are necessary for a stable creation of the target dilution factor in the third liquid stream19. Thereby, the lengths and diameters of the respective required external liquid line25can be derived. In some embodiments, the sensor arrangement27, in particular the measuring position, is located at the end of the bypass line30, which bypass line30is to be discussed later. For determining the required minimum merging lengths or minimum merging times prior to the bioprocess, or, in case of a verification process, the end of the third liquid stream19is defined at the at least one sensor28of the sensor arrangement27.

As mentioned above, in case of an emergency event, a stable creation of the target dilution factor at the end of the third liquid stream19can be verified by the user. Here, the sensor28can be used for verifying the stable creation of the target dilution factor in the third liquid stream19. For a verification, the actual dilution factor of the third liquid stream19represented by the sensor values29, are compared to the target dilution factor. A verification can be achieved when the actual dilution factor, measured by the at least one sensor28in the third liquid stream19, corresponds to the target dilution factor, such as, when the actual dilution factor is deviating less than 10%, less than 5%, or less than 3% from the target dilution factor.

In the case of such a verification process, the terms “minimum merging length” and “minimum merging time” refer to the distance and time that the third liquid stream19covers to flow from the merging location20to the at least one sensor28providing sensor values29, such as the conductivity of the third liquid stream19. Here, as can be seen inFIG.3, the sensor28is located in close proximity of the outlet port PO. In some embodiments, the distance between the outlet port POand the sensor28is taken into account by the dilution model, when verifying the minimum merging length and minimum merging time in a verification process, or, in a pre-calibration step, to determine the minimum merging lengths or minimum merging times of the third liquid stream19in the first place, prior to the bioprocess.

In case of an emergency event, the actual dilution factor, measured by the at least one sensor28in the third liquid stream19, does not correspond to the target dilution factor. In this case, the electronic process control16can adjust the flow rates of the pumps and/or the ratio of the flow rates of the pumps until the measured sensor values29are corresponding to the target dilution factor, further, until the measured sensor values29are deviating less than 10%, further less than 5%, further less than 3% from the target dilution factor.

In some embodiments, the chromatography setup comprises a bypass line30, set up to provide an internal liquid line14for a liquid stream to circumvent at least one chromatography column3to10. In a prime process, the third liquid stream19is guided through the bypass line30. Thereby, during the chromatography process, a third liquid stream19not comprising the target dilution factor bypasses the at least one chromatography column3to10via one of the internal liquid lines14by switching corresponding valve units (nx,y).

The term “bypass line” means here potentially any internal liquid line14that serves for bypassing at least one chromatography column3to10.

The term “prime process” means here a process by which the internal liquid lines14are filled with liquid, enabling a pump to promote the liquid inside the valve switching cassette13.

In the following, two exemplary modes of operation applying the proposed method are described with reference toFIGS.3and4.

In a first mode of operation, as can be seen inFIG.3, and just as an example, the first liquid stream17, such as a liquid stream of concentrated buffer, and the second liquid stream18, such as a liquid stream of sterile water, are introduced into the valve switching cassette13via corresponding inlet ports PI, here the corresponding inlet ports PIat position three and four. Here, both liquid streams17,18are merged in the eighth internal liquid line of the second set LS, which both liquid streams17,18cross within the valve switching cassette13. Here, the resulting third liquid stream19enters the bypass line30in order to bypass the at least one chromatography column3to10, and is subsequently discarded into waste.

Such mode of operation can, for example, be used in case of an emergency event, such as a pump failure, to verify a stable creation of the target dilution factor with the help of the sensor arrangement27after the emergency event has been resolved. Alternatively, as mentioned above, this can be used to determine the minimum merging times necessary to create the target dilution factor in the third liquid stream19and/or to determine the minimum merging lengths of the external liquid lines25, prior to such a bioprocess.

As soon as the sensor arrangement27detects a stable value for the actual dilution factor at the end of the bypass line30after such an emergency has been resolved, the electronic process control16switches from the bypass line30to the column line31. A stable value is detected, here, by the electronic process control16.

Upon the switching of the corresponding valve units nx,y, in a second mode of operation, as can be seen inFIG.4, the third liquid stream19enters the column line31, leading to the at least one chromatography column3to10.

The term “column line” means here potentially any internal liquid line14or external liquid line25that can lead the third liquid stream19to the respective chromatography column3to10.

According to a second teaching, the chromatography setup1for performing the proposed method is provided as such. In various embodiments, the components of the chromatography setup1that are at least necessary for the intended function, in particular at least including the valve switching cassette13and the liquid pumping arrangement15, form a structural entity. Here, the structural entity is designed as a preassembled unit. Reference is made to all explanations given before.

According to various embodiments, an electronic process control16of the chromatography setup1for performing the proposed method is provided as such. Again, reference is made to all explanations given before.

It can be essential, that the electronic process control16is designed for performing the proposed method by controlling at least the switchable valve units nx,yand the liquid pumping arrangement15.

The electronic process control16may be implemented as a central unit controlling all or at least most of the components of the bioprocess installation2. The electronic process control16may also be implemented in a decentralized structure, comprising a number of decentralized units. In some embodiments, the electronic process control16is individually adjustable and/or programmable and/or comprises at least one microprocessor on which software may be run. All explanations given before are fully applicable to this teaching.

In some embodiments, the electronic process control16comprises a data processing system for the carrying out the above noted method, such as comprising a local data storage and a local processor unit.

Finally, various embodiments are directed to a computer program product for the electronic process control16and to a computer-readable storage media, on which the computer program product is stored, such as in a non-volatile manner. All explanations given before are fully applicable to these teachings.