675. High Quality Plasmid DNA Manufacturing for Ex-Vivo Protein Synthesis and Viral Vector Production for Gene Therapy

Abstract

High quality plasmid DNA is required for a variety of therapeutic purposes. Although use as a DNA vaccine is the most popular, a high quality plasmid DNA product is also required as the raw material for processes like viral vector production for gene therapy, ex-vivo protein synthesis, etc. Contrary to a DNA vaccine, plasmid products used as raw materials have varied requirements in terms of purity and presence of contaminant levels in the final product. It is essential to have a large scale plasmid production method which can be tailored for the specific plasmid product based on its potential use. Our company has designed a plasmid production strategy, consisting of 5 purification steps, for removal of specific contaminants. It can be tailored to manufacture plasmid for specific uses at both research and large cGMP scale. Plasmid pVGXIa, a raw material for Ex-vivo protein synthesis, was produced using a modified purification approach. Since the plasmid was the raw material for protein synthesis and not a drug product, removal of only host cell protein (HCP) as a contaminant was critical during purification. Plasmid paste from the fermentation process was purified using a modified 3 step method designed for the removal of HCP. The 3 step method consisted of our company's patented Airmix® technology, Ion Exchange separation and Buffer-exchange. The final purified plasmid contained £0.2% of HCP. Total circular form of plasmid DNA was 100%. A 25% reduction in production cost and 10% increase in yield at the 10L scale were achieved by customizing the purification strategy. This same approach can be utilized for cost effective production of high quality plasmid DNA for viral vector generation for gene therapy at large scale.