Introduction

Monoclonal antibodies (mABs) are the last frontier of modern medicine for the cure of diseases such as cancer, cardiovascular, autoimmune and inflammation; they are also strong contenders in the fight against Covid-19. Despite the advancement in cell culture bioreactors and recombinant technologies, the efficiency in mAbs production is severely limited by the purification process, based on expensive separation methods and traditionally operated in discontinuous mode (resulting limited productivity). The current mAbs purification platforms – absorb about 65% of production costs – and are based on chromatographic methods, whose limiting factor is the resin’s high cost (Protein A). Currently, no known process adopts crystallisation as purification method. This technology allows the purification of  (mAbs) and their fragments from impure mixtures (e.g. a cell culture broth) by crystallisation and/or precipitation assisted by artificial membranes. This technology can be extended to the purification of further biologics such as serums and vaccines, hemo-derivatives, hormones etc.

Technical features

In this invention, the mixture containing the biological drug to be purified is placed in contact with a membrane able to promote its selective crystallisation. The yield and purity of the solid product recovered are comparable to those obtained with chromatographic technologies. The invention has been successfully implemented and tested in the laboratory for the crystallization of anticancer Rituximab (or Rituxan). A prototype with 150 mL capacity of feed solution was operated with performance comparable to tests carried out at lower volumes. The purity of the solid product (> 90%) recovered from culture broth in a single step is comparable to that typically obtained by chromatography. The current TRL is 4.

Possible Applications

• Purification of monoclonal, polyclonal, conjugated antibodies, serums and vaccines, allergens, fusion proteins, polypeptides, hormones, hemo-derivatives and enzymes.

Advantages

• Low CAPEX and OPEX;
• Continuous manufacturing;
• Higher flexibility due to intrinsic modularity of membrane technology, ease scale-up and automation;
• Enhanced sustainability due to reduced use of organic solvents and toxic chemicals;
• Excellent control of process parameters (supersaturation, induction time, nucleation rate etc.);
• Possibility of multi-stage operations for high product purity.