Improved downstream process for the production of plasmid DNA for gene therapy.

Gene therapy and genetic vaccines promise to revolutionize the treatment of inherited and acquired diseases. Since viral vectors are generally associated with numerous disadvantages when applied to humans, the administration of naked DNA, or DNA packed into lipo- or polyplexes emerge as viable alternatives. To satisfy the increasing demand for pharmaceutical grade plasmids we developed a novel economic downstream process which overcomes the bottlenecks of common lab-scale techniques and meets all regulatory requirements. After cell lysis by an in-house developed gentle, automated continuous system the sequence of hydrophobic interaction, anion exchange and size exclusion chromatography guarantees the separation of impurities as well as undesired plasmid isoforms. After the consecutive chromatography steps, adjustment of concentration and final filtration are carried out. The final process was proven to be generally applicable and can be used from early clinical phases to market-supply. It is scaleable and free of animal-derived substances, detergents (except lysis) and organic solvents. The process delivers high-purity plasmid DNA of homogeneities up to 98% supercoiled form at a high yield in any desired final buffer.