(524f) The Use of Affinity Fibro Chromatography in Bind and Elute Mode for the Capture of Monoclonal Antibodies

The COVID-19 pandemic has underscored the importance of fast production of safe and efficacious biotherapeutic products. Current downstream bioprocessing within the pharmaceutical industry is still heavily driven by resin chromatography, which is restricted by low productivity and high costs. Fibro chromatography has been recently introduced as an alternative technique in bio-separations. This uses devices formed from electrospun fibers with considerably greater pore sizes than resins, resulting in enhanced convective mass transfer and reduced diffusion mass transfer resistance.

To our knowledge, there is currently insufficient data to justify a transition from affinity resins to affinity fibro chromatography in capturing antibodies in an industrial application. In this study, we compared the performance of a Fibro device with a resin device functionalized with the same PrismA ligand operating in a bind and elute mode. By using five different antibodies (an IgG1, 3x IgG4’s and a Multimeric Fc) provided by CSL^TM, our results show that the key challenge with bind and elute fibro device is low binding capacity resulting in a threefold increase in eluate pool, especially for IgG1 monoclonal antibody (mAb) and Multimeric Fc molecule. By modelling binding profiles between each antibody and PrismA ligands generated from surface plasmon resonance, the low binding capacity for IgG1 mAb was related to slower mass transfer kinetics, while Multimeric Fc molecule appeared to have a lower equilibrium binding capacity due to more binding sites on this protein. Nevertheless, the residence time for the Fibro device was 30 times shorter, exhibiting similar protein recovery and comparable impurity (aggregates and host cell proteins) clearance.

A lifetime study also confirmed the consistent performance of the Fibro device over 200 cycles. Helium ion microscopy (Figure 1) showed minimal protein fouling of the device over this period. A ninefold scale-up study was performed to investigate the effect of different flow paths on the eluate pool volume. This study showed that the larger device had a proportionately lower void volume, resulting in a reduced eluate volume. However, even at this scale, the eluate pool was still significantly larger than the one collected from the comparable resin process. Despite the resulting increase in buffer consumption, a cost analysis based on in-house trials showed that fibro chromatography could potentially save 73% of the processing costs for a 2000-L batch compared with a resin approach. However, when processing multiple batches, the resin process becomes more economical when the number of batches is greater than 4. These results provide important insights for a successful transition from resin to fibro chromatography for antibody capture using bind and elute processes where required.