Vertex's new data on CF drug cocktail doesn't disappoint

Vertex Pharmaceuticals ($VRTX) kept hopes alive for treating cystic fibrosis patients with the most common genetic mutation behind the lung disease, with new data from a mid-stage study showing improved lung function in patients on a combination of its approved drug Kalydeco and the experimental compound VX-809.

The data presented at a CF meeting in Orlando on Thursday were neither dazzling nor disappointing, yet in the end could bolster the company's plan to advance the cocktail into pivotal development next year.  As TheStreet's Adam Feuerstein reported, patients on Kalydeco and 600 mg of VX-809 had 3.4% improvement in lung function over baseline compared with a 3.3% drop in those on placebo from the beginning of the study through the 8th week. And there was reason to speculate that a combo with an even higher dose of VX-809 could provide further improvement.

Kalydeco is the first FDA-approved drug to address the defective protein that causes cystic fibrosis, yet the compound is only licensed for patients with the G551D mutation, which accounts for about 4% of the 70,000 cases of the genetic disorder. Cambridge, MA-based Vertex is now testing its approved drug in other patients with different mutations and with other compounds to expand use of the therapy, which could help the drug become a blockbuster. This will require more time and rigorous trialing, yet Vertex and its collaborators at the Cystic Fibrosis Foundation are strongly committed to the program. 

"We're continuing our efforts to help more people with cystic fibrosis through additional [Kalydeco] studies and the development of more new medicines to treat the underlying cause of the disease," Peter Mueller, Vertex's chief scientific officer, said in a statement.

Investors have swooned over the prospect of broader use of Kalydeco in combination the VX-809 candidate. Vertex's stock has jumped more than 70% this year and had its steepest rise with the release of Phase II results of the combo in early May. (The stock took a hit later in May after the company corrected results from the study because of a data gaffe.) And the company's CF research has revived enthusiasm about Vertex, providing an area of commercial growth beyond treatments for hepatitis C, for which the company markets Incivek/Incivo.

- here's Vertex's release
- check out Feuerstein's article
- and Matthew Herper's analysis