Regulus, the MicroRNA Child of Isis and Alnylam, Strikes Potential $150M Deal with Glaxo

it has exclusive rights to miR-122 blockers and their use against hepatitis C in the U.S., Europe, and Japan, based on a number of patents and applications which it is citing in a statement today. Xanthopoulos didn’t mince words when he talked who he thinks has the controlling IP.

“GlaxoSmithKline had the benefit of seeing their good preclinical data, but they saw that Regulus completely dominates this intellectual property space, so they decided to go with Regulus,” Xanthopoulos says. “Santaris did a great favor to us by doing that experiment and helping accelerate our work. They played their card, but they played it badly by violating our IP. They are basically dead in the water. We have all the IP. We need nothing from them, and they need everything from us.”

Regulus hasn’t brought any litigation against Santaris to force it to pay for a miR-122 blocker license. But, “they have been put on notice,” Xanthopoulos says.

Art Levin, the president of Santaris’ U.S. operations in San Diego, has a different view of who owns what. “Santaris Pharma believes that it has freedom to operate with its miR-122 targeting compound SPC 3649 for the treatment of hepatitis C,” Levin said in an e-mail.

It’s clear why both companies see a miR-122 blocker as a promising candidate for hepatitis C. The whole field has been rejuvenated in recent years, partly because of the success Cambridge, MA-based Vertex Pharmaceuticals (NASDAQ: [[ticker:VRTX]]) has seen by increasing cure rates of patients with this chronic liver infection with a protease inhibitor drug. The market for this compound, telaprevir, could exceed $2 billion in U.S. sales after just a couple years on the market, analysts say, and the global opportunity is vast with an estimated 170 million people infected. Researchers are keen on creating cocktails of different classes of antivirals, as a way to get rid of the standard regimen of pegylated interferon alpha and ribavirin, which isn’t terribly effective, and causes flu-like symptoms that make patients miserable for months at a time.

One of the weaknesses of telaprevir and other drugs currently in clinical trials is that it only works for a segment of patients with what’s known as genotype 1 infections. A miR-122 blocker ought to work against all the various genotypes of the virus, Xanthopoulos says.

But since microRNA is still a field in its infancy, it’s especially hard to predict how this program will play out. The same target, miR-122, is also thought to have potential as a target for cholesterol-lowering drugs, based on data Regulus recently presented from experiments in monkeys, mice, and rats. Scientists don’t know why it’s able to reduce cholesterol by as much as 40 percent in the bloodstream, although it might work by prevent its transport, according to research presented at a Keystone symposium last month.

Regulus prefers to develop miR-122 as a hepatitis C drug initially, Xanthopoulos says, because it has potential as a differentiated product, it could arrive on the market sooner, and the competitive landscape is less daunting—even though hepatitis C is crowded with a lot of pharmaceuticals currently in the industry pipeline. Xanthopoulos is also deeply familiar with the hepatitis C field, as a former CEO of San Diego-based Anadys Pharmaceuticals (NASDAQ: [[ticker:ANDS]]), the developer of a different type of hepatitis C therapy.

Regulus has a number of programs running simultaneously, and I didn’t really have enough time on the phone to cover them all. It has 40 employees at the moment, and expects to grow to 50 by the end of the year, Xanthopoulos says. Some of them are still working on a miR-21 blocker that scientists have said holds potential as a treatment for congestive heart failure. That program is still going, and Xanthopoulos dropped a hint that other partners may soon belly up to the bar for that or other programs in the pipeline.

“The year is still young,” he says.

Author: Luke Timmerman

Luke is an award-winning journalist specializing in life sciences. He has served as national biotechnology editor for Xconomy and national biotechnology reporter for Bloomberg News. Luke got started covering life sciences at The Seattle Times, where he was the lead reporter on an investigation of doctors who leaked confidential information about clinical trials to investors. The story won the Scripps Howard National Journalism Award and several other national prizes. Luke holds a bachelor’s degree in journalism from the University of Wisconsin-Madison, and during the 2005-2006 academic year, he was a Knight Science Journalism Fellow at MIT.