Ryzard Kole gets many requests for his oligo tracking technology, which he is using to develop therapies for diseases caused by aberrant splicing.

In 2002, Ryzard Kole described in our pages a mouse assay for testing antisense oligonucleotides1. The assay provides incontrovertible evidence, Kole says, that a particular oligonucleotide works by an antisense mechanism, something that has not always been so clear with antisense. In addition, it allows investigators to track the location and function of oligos injected into whole animals. In his Nature Biotechnology paper, Kole and his team designed an oligonucleotide to target a splice variant of green fluorescent protein (GFP). When this oligonucleotide was injected intraperitoneally into mice transgenic for the GFP splice variant, restoration of proper protein splicing and function could be confirmed by the detection of fluorescence in mice tissues, such as colon, small intestine and liver. This elegant assay provided the starting point for Kole to move therapeutic programs forward. But it hasn't been an easy path.

For one thing, although the biology might have been ready back then, the chemistry of the oligos was not. In the intervening years, nucleic acid chemistry has advanced to the point that one can make molecules that are stable in vivo. But Kole didn't have that at the time. And now that he does, the world both of researchers and the money men who back them have moved onto sexier therapeutic nucleic acid formats of higher potency, like RNA interference and microRNA.

But Kole remains undeterred, believing that targeting splicing is “a new frontier” and the company he founded back in 2001, Ercole Biotech (Research Triangle Park, NC, USA), is holding its own, according to Scott Forrest, the technology manager at the University of North Carolina, where all this has been playing out. It has space, a staff of three researchers, and a set of collaborations with companies, which is giving it a foothold in the commercial sector. From Forrest's vantage point, the company is independent, sound and secure. “It's a pleasure to see,” he says. And without a dime of venture capital, which can be both good and bad, says Forrest. The university's shares in Ercole have not been diluted, but the company doesn't get what venture capitalists bring to the table, in terms of expertise in forming and managing a startup.

Getting there required the university taking the risk in providing early venture money, which has paid off in Ercole's case. “We don't always get it back, but if every once in awhile it leads to a living, breathing company, that's consistent with our larger mission of economic development, an attitude that has helped Research Triangle Park and the region make headway in becoming a biotech hotspot,” says Forrest.

Ercole's raison d'être is to apply antisense technology to modulating alternative splicing and correcting splicing defects. Some 70% of genes undergo alternative splicing, and a number of serious diseases are caused by errors in splicing. Kole wants to target these diseases, and he's using the assay described back in 2002 to try to get there. To choose what diseases to target, he lets the chemistry be his guide. He says “[you can] see where oligos with a certain chemistry go—which tissues, which cells—and because of that, can chose what is a target gene and a target disease that we know we can treat because that's where the oligo goes.”

Earlier this year, Ercole announced a collaboration with the antisense company AVI Biopharma (Portland, OR, USA) for developing therapies for Duchenne's muscular dystrophy and beta-thalassemia. Ercole also has a long-standing deal with Isis (Carlsbad, CA, USA) and a recent agreement with Santarus (San Diego), which affords them access to various oligonucleotide chemistries. Kole says he gets frequent requests from companies and individual investigators to test their oligos and delivery systems.

The idea of using antisense to correct splice variants may soon be validated in humans. After the demonstration that systemically delivered oligonucleotides that target splicing have therapeutic effects in a mouse model of Duchenne's muscular dystrophy2, a Dutch biotech company, Prosensa (Leiden), received permission from the Netherlands Central Committee on Research to initiate a trial in humans using locally administered antisense oligos.