for emerging biology around Toll-like receptors (TLR’s), key components of the innate immune system that recognizes foreign invaders at their point of entry under the skin, in the mucus linings of the nose, and the lining of the gut, Hershberg says. (This is different from the adaptive immune system, which forms B cells and T cells that develop memory capability to protect against certain pathogens.)
Kamdar had experience cutting a huge deal for Anadys with Swiss pharma giant Novartis, worth as much as $550 million to the smaller company, to co-develop drugs that modify a target called TLR7. So he was seen as the right match on the business side for VentiRx, Hershberg says.
Once they got the seed capital, Hershberg and Kamdar looked around the pharmaceutical industry for diamonds in the rough—potential drugs that could be used against TLRs. One candidate they found appealing was made by chemists at Boulder, CO-based Array Biopharma to stimulate TLR8. This seemed like a good candidate because TLR8 is found in primates and humans, but not in mice, so this was likely to fly below the radar of a lot of researchers, Hershberg says. “A lot of people in immunology think that if you can’t do it in the mouse, it won’t work,” he explains.
Since this target is found on dendritic cells, which recruit immune system T cells to attack foreign invaders, this was seen as a good potential immune-boosting treatment for cancer. VentiRx licensed the drug and chemically transformed it from a small-molecule pill into a form that’s given via a weekly shot just under the skin, which was thought to be more effective. VentiRx cleared all the necessary re-formulation, and animal testing steps, including those in non-human primates, in less than 18 months. The company entered its first clinical trial last month with 20 patients at the Mayo Clinic Arizona and TGen Drug Development Services in Scottsdale, AZ. The drug, code-named VTX-2337, should produce its first set of results this year, Hershberg says.
The drug is made to circulate throughout the body, in low doses, because researchers want to make sure this stimulation doesn’t go too far and provoke an out-of-control whole-body allergic reaction. Essentially, a little bit of immune stimulation can be good, but too much could be dangerous. The most vivid example of this, and something global regulators remember, was a 2006 incident in which six healthy volunteers fell critically ill after taking an experimental antibody drug from German drugmaker TeGenero during a clinical trial in the United Kingdom.
“We made sure we were confident about the pharmacology and toxicology before we moved,” into clinical trials, Hershberg says, of the response to the TeGenero incident.
While that drug marches through the clinic, VentiRx is teeing up a second candidate for allergic rhinitis (stuffy nose.) This candidate is built on emerging evidence behind what’s called the “hygiene hypothesis” that says that allergies, or an over-sensitive immune system, are more common in First World countries like the U.S., but not so much in developing countries, where people’s immune systems are thought to adjust after they have been exposed regularly to microbial invaders.
By giving tiny doses of a TLR stimulator, in a once-weekly nasal spray, VentiRx thinks it might be able to mimic this immune reaction as a sort of diversionary tactic, which could dampen an over-active allergic response or maybe prevent it in the first place, Hershberg says. That drug is in the final stages of paperwork needed to enter clinical trials, and VentiRx hopes to begin that clinical trial in Europe in early 2009, Hershberg says.
As a private company, Hershberg won’t say what kind of financial resources it has to move these programs ahead, but he gave the impression that staying small has enabled it to conserve a lot of its cash. The company already has had some talks with potential partners, although he didn’t promise a deal anytime soon. So at least for now, Hershberg says, VentiRx plans to stay small while building a portfolio it hopes will be big.
