Immunoadsorption for rAAV Vector Delivery in Gene Therapy
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Solution Overview
Problem
The administration of recombinant adeno-associated virus (rAAV) vectors in gene therapy is hindered by pre-existing neutralizing antibodies, which reduce the efficiency of gene transfer and require cumbersome strategies like plasma exchange and immunosuppressive regimens, offering limited success.
Innovation Solution
Immunoadsorption is used to deplete immunoglobulins from the blood extracorporeally, creating a therapeutic window for rAAV delivery by reducing neutralizing antibody levels, allowing for efficient transduction with lower vector doses and potentially avoiding cellular immune responses.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If plasma exchange is used to remove neutralizing antibodies, then neutralizing antibody levels are reduced, but the procedure is cumbersome and has limited success
Solution Approach 1:
The patent extracts and removes neutralizing antibodies from the patient's blood plasma through plasma exchange procedures. The harmful antibodies are separated from the plasma and discarded, while the remaining plasma components are returned to the patient or replaced with fresh frozen plasma containing no neutralizing antibodies.
Solution Approach 2:
Fresh frozen plasma or plasma from donors serves as an intermediary substance that replaces the patient's antibody-containing plasma. This intermediary plasma provides the necessary clotting factors and plasma proteins without containing neutralizing antibodies against the AAV capsid.
2Object-affected harmful factors
If immunosuppressive regimens are used to reduce neutralizing antibody formation, then antibody formation is reduced, but the regimens are complex and have limited efficacy
Solution Approach 1:
The patent applies immunosuppressive medications before and during AAV vector administration to prevent the formation of neutralizing antibodies. This preliminary immunosuppression creates a window of opportunity for successful gene transfer by suppressing the immune system's ability to recognize and neutralize the viral capsid.
Solution Approach 2:
The patent changes the immunological parameters of the patient by administering immunosuppressive drugs that alter immune cell function and antibody production. This modifies the immune system's response characteristics to allow successful AAV transduction.
3Productivity
If high rAAV vector doses are used to overcome pre-existing antibodies, then transduction efficiency is improved, but the required dose increases tenfold
Solution Approach 1:
The patent applies preliminary plasma exchange and/or immunosuppressive therapy to counteract the presence of neutralizing antibodies before AAV vector administration. This preliminary anti-action removes or suppresses the harmful antibodies that would otherwise neutralize the vector, allowing effective transduction at standard doses.
4Reliability
If patient screening is performed to exclude those with neutralizing antibodies, then treatment safety is improved, but patient accessibility is reduced
Solution Approach 1:
The patent converts the previously disqualifying presence of neutralizing antibodies into a manageable condition through plasma exchange and immunosuppression. Patients who would have been excluded due to antibody presence can now receive treatment after these preparatory procedures remove or suppress the harmful antibodies.
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 enables effective rAAV vector administration in subjects with high neutralizing antibody levels, providing a safer and more efficient treatment approach by reducing immunoglobulin concentrations and potentially lowering the dose required for successful transduction.
Implementation Method 1
separating the blood provided in a) in plasma components and cellular components
Implementation Method 2
subjecting the plasma components obtained in c) to immunoadsorption by using the device provided in b)
Data Source
AI summary
Upon administration of rAAV vectors the humoral immune response (neutralizing antibodies) is the first barrier that needs to be overcome. Surprisingly it was found that by using immunoadsorption for depletion of immunoglobulins from the blood (plasma), subjects can be highly efficiently treated with rAAV vectors, i.e. obtain highly efficient transduction after rAAV vector administration, in spite of the presence of high levels of nAb.