Benitec snaps up sixth licence, aims for $5m per year

Brisbane RNAi gene therapy company Benitec (ASX:BLT) has granted a global, non-exclusive licence for its gene-silencing technology to a German company that develops genetically modified mice for research.

The licence is Benitec's sixth for the year, and the first granted to a European company. Benitec's revenue stream from licensing now exceeds $1 million a year, according to CEO John McKinley, and the company is on target to achieve a figure of $5 million by June next year.

Artemis Pharmaceuticals of Cologne develops knock-out and knock-in mice for its customers to do basic research into gene function, and for drug-discovery, and is moving to develop transgenic rats for similar purposes.

Artemis has licensed in Benitec's proprietary DNA-directed RNAi interference (ddRNAi) technology, for the life of the Benitec patents.

Artemis' managing director for business development, Dr Paul Rounding, said the licence enables his company to offer customers a rapid and efficient way to knock down gene expression in all mouse tissues, in vivo.

Unlike the 'knockout' mice produced by current techniques, RNAi 'hairpin' gene constructs rarely produce 100 per cent silencing of the target gene.

At the recent Horizons in Livestock Science on RNAi-gene silencing in Surfer's Paradise, Dr Frank Koentgen, CEO of Perth-based transgenic mouse company OzGene, said his company had developed an RNAi-knockdown mouse for Benitec, named "Betty".

Koentgen said current ddRNAi gene constructs were relatively inefficient, typically reducing gene-expression levels to about 30 to 40 per cent of original - not enough to produce full-knockout mice or rats. But Koentgen said that in some circumstances, researchers might want on to reduce rather than knock out a target gene's expression.

Benitec CEO John McKinley said the company's researchers are working to develop efficient ddRNAi knockout systems, as well as to develop conditional-knockout constructs with externally inducible promoters for studying the effects of gene knockdown in juvenile or adult rodents, rather than in embryonic phase.

McKinley said these would be commercialised as they were validated, but could not say when. Benitec is also developing constructs to simultaneously knock down expression of up to five genes.

Dr John Morrison, CEO of CopyRat -- a Monash University-based company that develops transgenic rats for research -- said neither CopyRat nor its subsidiary, transgenic mouse-maker InGenko, was yet using RNAi-knockdown in vivo, because of the "total mess" surrounding patent ownership for RNAi technologies.

However, Morrison said his company was currently in talks with an RNAi company that has freedom to operate.

CopyRat researchers have been experimenting with short-interfering RNAi technology in in vitro, cellular systems, because it allows large numbers of gene knockdowns to be performed; interesting gene targets identified in this way can then be transferred to animal models.

Morrison said it is potentially much easier to create transgenic rodents with RNAi technology than with conventional knockout-knock-in systems that rely on homologous recombination.

The gene-knockout construct can be injected into a fertilised egg, producing in a transgenic animal in a single step, without the need to go through an intermediate step of creating chimeric hybrid mice.