Mixed Mode Chromatography for Etanercept Separation
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Solution Overview
Problem
Current methods fail to effectively separate correctly folded etanercept from incorrectly folded etanercept produced in CHO cells, resulting in impure pharmaceutical preparations with reduced therapeutic efficacy and potential harm to patients.
Innovation Solution
The use of mixed mode chromatography, specifically with resins like Capto™ MMC and Capto™ Adhere, which exploit both ion exchange and hydrophobic interactions to bind and elute correctly folded etanercept, achieving high purity and yield by selectively separating correctly folded protein from incorrectly folded protein.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional chromatography methods are used to purify etanercept, then the purification process can be performed, but the separation of correctly folded etanercept from incorrectly folded etanercept is insufficient, resulting in low purity
Solution Approach 1:
The patent employs mixed-mode chromatography that combines ion-exchange and hydrophobic interaction mechanisms, utilizing changes in pH and salt concentration parameters to achieve selective separation. The method uses a gradient elution approach where the pH is lowered from 7.5 to 3.0 while increasing salt concentration, allowing correctly folded etanercept to elute at specific conditions while incorrectly folded protein remains bound or elutes at different conditions, thereby achieving greater than 95% purity
Solution Approach 2:
The patent uses mixed-mode chromatography media that combines multiple functional groups (ion-exchange groups and hydrophobic interaction groups) in a single matrix. This composite approach allows simultaneous exploitation of both electrostatic and hydrophobic interactions to achieve superior separation of correctly folded from incorrectly folded etanercept, resolving the technical contradiction between achieving high purity and maintaining ease of manufacture
2Manufacturing precision
If reverse-phase chromatography is used to separate misfolded proteins, then separation resolution is improved, but protein denaturation and aggregation occur due to low pH and organic solvent
Solution Approach 1:
The patent uses a pH gradient approach where the pH is gradually lowered from 7.5 to 3.0 during elution, combined with increasing salt concentration. This controlled parameter change allows selective elution of correctly folded etanercept at milder conditions while maintaining protein stability, avoiding the extreme conditions that cause denaturation
Solution Approach 2:
The patent introduces salt (sodium chloride or sodium sulfate) as an intermediary agent that competes for ionic interactions between the protein and chromatography media. This intermediary approach allows elution of proteins without requiring extreme pH changes or organic solvents, thereby preventing denaturation while maintaining separation resolution
3Stability of the object's composition
If ion exchange chromatography is used under non-denaturing conditions, then protein stability is maintained, but separation of correctly folded from incorrectly folded etanercept is insufficient
Solution Approach 1:
The patent uses mixed-mode chromatography media that combines ion-exchange groups with hydrophobic interaction groups in a single matrix. This composite approach maintains the benefits of non-denaturing conditions (protein stability) while adding hydrophobic interaction capability that enhances separation efficiency between correctly folded and incorrectly folded etanercept
Solution Approach 2:
The patent merges two chromatographic mechanisms (ion-exchange and hydrophobic interaction) into a single unified process. The ion-exchange component maintains protein stability through non-denaturing conditions, while the hydrophobic interaction component provides enhanced separation efficiency, resolving the contradiction between stability and separation efficiency
4Manufacturing precision
If hydrophobic interaction chromatography is used to separate aggregated proteins, then separation capability is improved, but protein aggregation may be induced under harsh conditions
Solution Approach 1:
The patent uses controlled salt concentration gradients (increasing from 0 to 1.0 M NaCl or Na2SO4) combined with pH changes to modulate hydrophobic interactions. This controlled parameter change allows selective elution of correctly folded etanercept while preventing uncontrolled aggregation that might occur under harsh hydrophobic interaction conditions
Solution Approach 2:
The patent employs gradient elution where conditions change progressively over time rather than abruptly. The pH is gradually lowered and salt concentration is gradually increased in a controlled manner, allowing proteins to elute in sequence based on their binding strength, thereby preventing sudden conformational changes that could induce aggregation
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This method achieves a highly pure etanercept preparation with greater than 95% correctly folded protein, minimizing incorrectly folded protein to less than 5%, thereby enhancing therapeutic efficacy and safety.
Implementation Method 1
mixed mode chromatography, specifically with resins like Capto™ MMC and Capto™ Adhere, which exploit both ion exchange and hydrophobic interactions
Implementation Method 2
mixed mode chromatography, specifically with resins like Capto™ MMC and Capto™ Adhere, which exploit both ion exchange and hydrophobic interactions
Data Source
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AI summary
A mixed mode chromatography method for separating correctly folded from incorrectly folded conformations of a given protein is provided. The method is highly effective in separating correctly folded etanercept from incorrectly folded etanercept and aggregates in commercially attractive yields capable of affording etanercept preparations having very high purity in terms of correctly folded etanercept versus incorrectly folded etanercept. The invention is further directed to protein preparations and formulations comprising correctly folded proteins obtained using the present methods, and methods of treatment using the high purity preparations obtained from the mixed mode method.