Genentech buys Lonza's GS Gene Expression System

Swiss outsourcing company Lonza has granted biotechnology firm Genentech a non-exclusive, worldwide license to their Glutamine Synthetase (GS) Gene Expression System which offers better yields, speed and stability in cell protein production, thus making Genentech less dependant on external manufacturing capacity.

Both companies are tight-lipped about the details of the agreement but it is understood it involves licence fees and milestone payments and has a research evaluation provision for use of the GS System for research and development purposes.

The deal also includes options for a multi-product license to the GS System for commercial purposes and further options to obtain licences for the use of Lonza's proprietary Protein Free Media System for research and development as well as commercial purposes.

Lonza already has a commercial relationship with Genentech, producing around 50 per cent of the biotech's requirements for its cancer drug Rituxan over the next few years.

But news last summer of Genentech's plans to dramatically increase in-house production capacity in the wake of its $408m (€343m) acquisition of Biogen-Idec's Oceanside facility dampened spirits at Lonza.

This latest deal will therefore increase Genentech's self-reliance in pharmaceutical manufacturing and R&D.

"It is up to every company to look at the benefits of the GS system and decide if they wish to license it," Lonza's spokeswoman Christine Menz told In-Pharmatechnologist.com.

"We are using the technology in all our plants and will continue to make it available to our clients."

Over 70 biotechnology and pharmaceutical companies are using the GS gene expression system worldwide and Lonsa can also create and select GS cell lines as a service for customers and can manufacture cGMP product if required.

Moreover, GS is familiar to the regulatory authorities, having approved four licensed products using this system, including Roche's Zenapax and Medimmune's Synagis.

The high cost of manufacture of protein products, particularly of therapeutic proteins, means that maximising yield per cell is essential if economic processes are to be established.

GS is the enzyme responsible for the biosynthesis of glutamine from glutamate and ammonium in an enzymatic reaction that provides the only pathway for glutamine formation in a mammalian cell.

Thus, in the absence of glutamine in the growth medium, the GS enzyme is essential for the survival of the mammalian cells in culture.

Some mammalian cell lines, such as mouse myeloma lines, do not express sufficient GS to survive without added glutamine, so with these cell lines a transfected GS gene can function as a selectable marker by permitting growth in a glutamine-free medium.

Other cell lines however, such as Chinese Hamster Ovary (CHO) cell lines, do contain sufficient active GS to survive without exogenous glutamine and in these cases the specific GS inhibitor, methionine sulphoximine (MSX), can be used to inhibit endogenous GS activity such that only transfectants with additional GS activity can survive.

Using this method, cell lines have been created that are capable of producing 5.5g/L of recombinant antibody with specific production rates of typically 20 to 50pg/cell/day.

Many investigators use GS, not only to develop a manufacturing process, but as a tool to create recombinant proteins for in vitro screens.