Retroviral Vector Purification via Inverted Filtration Sequence

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Solution Overview

Problem

Current methods for large-scale retroviral vector purification face challenges in preserving high titers and achieving pure product, particularly due to the loss of viral vector titre during filter-sterilization and the inefficiency of traditional concentration steps in clinical-grade formulations.

Innovation Solution

A process where filter-sterilization is performed as a penultimate step followed by concentration, with the concentration step being the final step, using ultrafiltration and maintaining optimal vector particle concentrations below 4.6x10^11 RNA genome copies per ml, and employing a sterilizing filter with a maximum pore size of 0.22µm to improve vector particle yields.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If filter-sterilization is performed prior to concentration, then sterility is achieved, but vector particle yield is considerably lost

Engineering Contradiction:
ImprovesterilityVSAvoidvector particle yield
Core Design Contradiction:
ReliabilityVSQuantity of substance

Solution Approach 1:

The patent inverts the traditional sequence of operations by performing concentration before filter-sterilization rather than after. This reversal resolves the contradiction because concentrating the vector preparation before filtration maintains high vector particle yield, while the subsequent filtration step still achieves the required sterility for clinical-grade formulations.

Inventive Principle:
Principle #13The other way round (Inversion)

2Quantity of substance

If concentration is performed prior to filter-sterilization, then vector particle yield is maximized, but sterility cannot be ensured

Engineering Contradiction:
Improvevector particle yieldVSAvoidsterility
Core Design Contradiction:
Quantity of substanceVSReliability

Solution Approach 1:

The patent applies sequence inversion to resolve this contradiction. By performing concentration first and then filter-sterilization, the method achieves both objectives: maximizing vector particle yield through concentration before loss-prone filtration, while ensuring sterility through the subsequent filtration step using 0.22 µm or 0.1 µm filters.

Inventive Principle:
Principle #13The other way round (Inversion)

3Productivity

If vector particle concentration is maintained at high levels during filter-sterilization, then productivity is improved, but vector particle loss increases

Engineering Contradiction:
Improveproduction efficiencyVSAvoidvector particle loss
Core Design Contradiction:
ProductivityVSQuantity of substance

Solution Approach 1:

The patent resolves this contradiction by inverting the operation sequence. Concentrating the vector preparation before filtration allows the subsequent filtration step to be performed on a smaller volume, which reduces vector particle loss during filtration while maintaining overall productivity through the efficiency of the pre-concentration step.

Inventive Principle:
Principle #13The other way round (Inversion)

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 approach results in increased vector particle yields and improved product recovery, allowing for the production of clinical-grade retroviral and lentiviral vector formulations suitable for human administration with reduced losses during the purification process.

Implementation Method 1

filter-sterilisation step is performed using a sterilising filter with a maximum pore size of up to or equal to 0.22μm

Methodology Applied
Scientific EffectFiltration: Filter (physical)

Implementation Method 2

concentration step (e.g. by ultrafiltration)

Methodology Applied
Scientific EffectUltrafiltration: Semipermeable Membrane

Data Source

PatentEP3192874B1Virus purification
Publication Date: 2019.10.16 OXFORD BIOMEDICA (UK) LTD
  • EP3192874B1 patent drawingFigure 1
  • EP3192874B1 patent drawingFigure 1

AI summary

A process for producing a retroviral or lentiviral vector formulation comprising a filter-sterilisation step wherein the filter-sterilisation step is not the final step in the purification process.