Vertex Marching Ahead With Cystic Fibrosis Program

Xconomy Boston — 

All eyes aimed at Vertex Pharmaceuticals tend to focus, understandably, on its experimental drug for hepatitis C. The Cambridge, MA-based company showed in mid-stage clinical trials that the drug, called telaprevir, could eliminate the liver-damaging virus from the blood for about twice as many patients as do standard treatments; the firm is now on a quest to prove it to regulators in an ongoing clinical trial of 1,050 patients called Advance.

Yet lost amid the hepatitis C buzz in yesterday’s second-quarter earnings call was Vertex’s (NASDAQ: VRTX) news that it is making headway with another product, an experimental drug for cystic fibrosis. An estimated 30,000 children and young adults in the U.S. have the genetic disease, which largely affects the lungs and reduces patients’ life expectancy to an average of 37 years.

Vertex said it has completed enrollment in the second part of a mid-stage clinical trial that will look at how patients perform on the drug compared with a placebo for 28 days. By the end of the year, Vertex said, the company should have data which, if positive, will position the firm to start a pivotal clinical trial program in 2009 that could pave the way for approval in the U.S. and Europe.

Back in March, Vertex released data showing that VX-770 was able to improve lung function by 10 percent for patients who took a high dose of the drug for 14 days, compared with less than 1 percent improvement for those on a placebo. The pill is designed for a subset of cystic fibrosis patients who have one of several mutations that cause the disease by producing malfunctioning versions of a protein called CFTR. That protein normally transports chloride ions out of certain types of cells; when it’s faulty, chloride ions get stuck inside the cells, leading to a buildup of mucus in the lungs, infections, and lung damage, Frank Accurso, director of the Cystic Fibrosis Center at Children’s Hospital in Denver, explained in an interview I did while I was at Bloomberg News.

If it works, the Vertex treatment will be the first to treat cystic fibrosis by directly targeting this underlying mechanism, stimulating the faulty protein to let chloride ions pass through the cells’ membranes more normally, said Accurso, the lead investigator of the study. In contrast, other cystic fibrosis drugs on the market treat symptoms of the disease (for instance, Novartis’ inhalable antibiotic Tobi, which kills bacteria that build up in the lungs). One patient in the Vertex study had a serious adverse event when lung function worsened, but it wasn’t considered drug-related, Accurso said at the time.

One other notable aspect of this cystic fibrosis program is that more than just Vertex shareholders have skin in the game. The Cystic Fibrosis Foundation, one of the better-financed and organized patient advocacy groups out there, co-sponsored the VX-770 trial with Vertex and has invested $79 million in the project since it began. Apparently, the foundation likes the returns it sees so far. “The emerging data for VX-770 represents the most exciting results we’ve seen from a Phase 2 trial and increase our confidence that we’re on the right track,” said Robert Beall, CEO of the foundation, in a statement in March.

That’s all the more reason to stay tuned for the 28-day study results later this year. Even if everybody in the market remains laser-focused on telaprevir.