The researchers have developed an adsorbent that selectively removes trace amounts of antibody aggregates remaining in an antibody solution. They also proved that the developed adsorbent has the effect of suppressing the emergence of new aggregates.

Suppression of new aggregates by removing the aggregate precursors

With the rapid increase in demand for antibody drugs, there is need for high-quality, high-efficiency manufacturing technology that will guarantee effectiveness and safety. Antibody drugs are proteins and unstable macromolecules (with a molecular weight of about 150,000), so they can easily deteriorate in the manufacturing process, generating various product-related impurities. Among these, aggregates of antibody drugs are considered to cause a decrease in drug effectiveness and an increase in immunogenicity, so that there was demand for a technique to remove antibody aggregates as much as possible, and a technique for significantly suppressing the emergence of aggregates.

The developed adsorbent contains a small artificial protein (AF.2A1) that selectively binds to antibodies with non-native conformation (non-native antibody conformers), so it can remove small aggregates such as aggregates with submicrometer-diameters and monomers with non-native conformation (non-native antibody monomers), regardless of their particle size. The researchers also discovered that treatment with the developed adsorbent reduces new aggregates that appear in the antibody solution during its storage. The developed adsorbent is expected to be applied to not only removal of antibody aggregates, but also to long-term stable storage of antibody drugs.

The researchers will work towards the selection of affordable carrier materials suitable for AF.2A1 immobilization, development of devices to be mounted, and safety evaluation of AF.2A1 aimed at practical use, possibly in collaboration with companies.