By Bill Berkrot
(Reuters) - Vertex Pharmaceuticals Inc's Kalydeco cystic fibrosis drug failed to meet the main goal of a late-stage study aimed at expanding its use into patients with a specific gene mutation associated with the rare, life-threatening lung disease, the company said on Thursday.
Overall, Kalydeco (ivacaftor) did not significantly improve lung function in CF patients ages 6 and older with the R117H gene mutation. However, among those aged 18 and older in the 69-patient study with more advanced lung disease, Kalydeco led to a statistically significant improvement in lung function and other secondary measures, the company said.
Kalydeco is currently approved to treat patients with a different gene mutation known as G551D that accounts for about 4 percent, or 2,000 people, with the disease.
About 1,100 people in North America, Europe and Australia with cystic fibrosis carry some form of R117H mutation - with about 700 of them 18 and older, Vertex said.
The company said it plans to meet with the U.S. Food and Drug Administration early in 2014 to discuss the new data with the aim of expanding Kalydeco approval to patients with the R117H mutation.
"We believe the company can make a compelling case for label expansion to at least adult R117H patients," Needham & Co analyst Alan Carr said in a research report, noting the unmet need in those patients.
After initially falling in premarket trading, Vertex shares were up 2.5 percent at $70.36 in early afternoon on the Nasdaq.
The older patients in the study began with a far more diminished lung function of about 65 percent, while those between ages 6 and 11 started with an average lung function of 96 percent, the company said.
"While we are disappointed that the study in people with the R117H mutation did not meet its primary endpoint, we are encouraged by the significant improvements in lung function and other measures of CF observed in the subset of patients ages 18 and older who had established lung disease," Robert Kauffman, Vertex's chief medical officer, said in a statement.
Vertex next year is expected to have critically important data from studies that pair Kalydeco with an experimental drug, lumacaftor, in CF patients who have a much more common gene mutation associated with the disease. Success there could drive up the percentage of treatable patients to about 40 percent of the CF population.
The fate of Vertex shares will hinge on those results, ISI Group analyst Mark Schoenebaum said in a research note.
"While I continue to have a hold rating on Vertex, I have a positive view on these trials working and on Vertex long-term," he said.
Kalydeco was the first approved drug to treat the underlying cause of cystic fibrosis rather than just symptoms of the disease, in which a missing or defective protein called CFTR results in poor flow of salt and water into and out of cells in the lungs. That causes a buildup of thick, sticky mucus that can lead to chronic lung infections, progressive lung damage and death at an early age.
(Reporting by Bill Berkrot in New York; additional reporting by Caroline Humer in New York; editing by Matthew Lewis)