Biopurification Process Reaches Patent Milestone

A Notice of Approval from the US Patent and Trademark Office moves GTC Biotherapeutics (Framingham, MA) one step closer to receiving a patent for its biopurification process based on tangential flow filtration (TFF). Specifically, the company’s approach would speed the recovery of recombinant therapeutic proteins, endogenous proteins, fusion proteins, protein fragments, and antibodies from feedstreams of transgenic mammalian milk.

In the patent application titled “Methods of tangential flow filtration and an apparatus therefore,” GTC researchers implement TFF technology “to clarify, concentrate, and fractionate the desired recombinant protein or other molecule of interest from the native components of milk or contaminants thereof. The resulting clarified bulk intermediate is a suitable feed material for traditional purification techniques such as chromatography which are used downstream from the TFF process to bring the product to its final formulation and purity.”

Company researchers produce therapeutic proteins in animal milk using transgenic technology, in which a gene that expresses a specific protein is coupled with a particular milk-protein promoter gene. The system is then incorporated into an animal's genome, and the protein is expressed during the animal's lactation. GTC claims this approach “enables the production of therapeutic proteins that are difficult to express in traditional production methods.”

–Maribel Rios