mAb Purification Process Development Using Mixed-Mode Resins — The DOE Approach

Monoclonal antibody (mAb) purification is a multistep process, typically using three chromatography resins. These three purification steps are referred to as capture, intermediate, and polish. The workflow is based on multiple criteria to maximize product quality and output, including process efficiencies. One focus area of process intensification is reducing the downstream processing (DSP) steps to improve the mAb purification workflow.

Mixed-mode resins are being increasingly integrated into DSP due to their unique properties and wide design space, which deliver high purity and yield. These resins consist of multiple modes of interaction, enhancing selectivity and separation power.

This case study presents a two-step mAb purification workflow and compares two multimodal resin alternatives used for the polishing step post–protein A capture. Data demonstrating the behavior of multiple mAbs with these two different mixed-mode resins and the design of experiments (DOE) are shown. The importance of scale, prior knowledge, and the development stage will also be discussed. Both mixed-mode resin studies and their different DOE approaches to development are shown to achieve high-purity products.

Key topics covered:

• Understanding of DOE strategies in process development — three phase strategy includes screening, modeling, and optimization
• Assessment of DOE models and tools to select (96 well plates, robocolumns, and columns), depending on development stage
• Evaluation of the data using mixed-mode resins in a 2-step mAb purification workflow