Last week experts told BioPharma-Reporter.com that, despite its $12,000 price tag and efforts to develop alternatives, Protein A will continue to be favoured by the monoclonal antibody (mAb) manufacturing sector.
One, Jonathan RF Robinson from the UK National Biologics Manufacturing Centre, told us that continued demand for Protein A will be good news for GE Healthcare which, in collaboration with partner Repligen, is the major Protein A supplier to the biopharmaceutical industry.
We put this to GE, which told us that: “Protein A-based affinity chromatography technology is currently the most robust and economic approach available for the commercial purification of monoclonal antibodies.
The firm also suggested that while efforts to develop alternatives to are ongoing – expanded bed adsorption, crystallization and precipitation among others – for the time being Protein A is likely to continue to be the go-to mAb capture technology.
“At the moment, in terms of yield, capacity, ease-of-scale up, ease-of-operation and ease-of-process development, Protein A offers significant advantages, leading to overall better process economy and shorter development times for new molecules.
GE also said that it is investing to improve the efficacy of Protein A-based resins, with the current focus being increasing their binding capacity and re-usability citing MabSelect SuRe LX as an example.
“The enhanced capacity and stability of MabSelect SuRe LX helps improve process economy and product quality, and allows cleaning to be performed with cost-effective reagents such as sodium hydroxide thus eliminating the need for expensive and hazardous cleaning agents such as Gua-HCl.”
Protein L resins
Another area of investment for GE is Protein L, which is a molecule found on the surface of the bacterial species Peptostreptococcus magnus that like Protein A and G also binds immunoglobulins.
However, unlike Proteins A or G which bind antibody Fc regions, Protein L interacts with immunoglobulin light chains which makes them useful for producers of fragment-based biopharmaceutical products according to GE.
“We are investing in the development of newer affinity resins for the purification of a next-generation of biotherapeutics such as antibody fragments – for example affinity resins based on Protein L.”