(564a) Adventures in Continuous Downstream Processing

The downstream processes for the manufacture of biologic and recombinant protein-based drugs are where the purity-based critical quality attributes are established and are often where the capacity, cost and raw material bottlenecks lie. We are focused on identifying, developing and demonstrating innovative continuous downstream purification unit operations and processes that can relieve these bottlenecks while meeting the established critical quality attribute targets. Here we will focus on new technologies for the purification of mRNA and monoclonal antibody (mAb) and mAb-related drugs.

In the mRNA space, we are part of a large, multi-institutional program to develop a continuous process for the production of mRNA. We aim to innovate in the mRNA purification space, improving on current processing operations that were developed quickly to support mRNA-based COVID-19 vaccine manufacture via ultrafiltration and oligo(dT)-based affinity chromatography operations. We are focused on the removal of product-related (mRNA fragments, dsRNA) and process-related (enzymes, nucleotides, template DNA) impurities from crude source materials prepared via in vitro transcription. We will describe new affinity-based separations using magnetic beads, chromatographic operations using pairings of H-bonding and affinity columns, and aqueous two-phase extraction-based approaches for mRNA purification.

In the mAb space, we are leading the development of an alternative, precipitation-based downstream process for mAb production as a part of a second multi-institutional team. The alternative downstream operations comprise a precipitation-based capture purification operation and tandem, orthogonal flow-through chromatography-based polishing purification operations. The purification operations operate fully continuously and are drop-in compatible with continuous viral inactivation, viral filtration and final ultrafiltration/diafiltration technologies. We will describe our development and operation of the individual unit operations as well as performance of the integrated purification operations with industrial mAb harvested cell culture fluid feedstocks. With titer-based intensification, the alternative significantly out-performs the current protein-A affinity chromatography-based “platform” process for mAb manufacture in terms of throughput, cost and raw material usage while meeting drug substance purity requirements.