Vertex CF Drug Shines in Late-Stage Study in Children
Vertex Pharmaceuticals (NASDAQ:VRTX) reported today positive results from an ongoing late-stage study of its cystic fibrosis drug, VX-770, that show that the drug is working about as well in children as it did in older patients with the genetic disorder.
The Cambridge, MA-based company said that the Phase III study of the drug, which aims to improve the function of a defective protein with a specific mutation called G551D, met its primary goal among patients ages 6 to 11 of improving lung function through 24 weeks. The 48-week study involving 52 patients is ongoing. At 24 weeks, children on the drug showed a mean absolute improvement from baseline in lung function of 12.5 percent, slightly better than the still-impressive 10.6 percent improvement after 24 weeks among CF patients ages 12 and up who participated in a separate Phase III study described on February 23. The lung function test used in the study measures how much air a patient can exhale in a second.
The latest study also showed improvements in weight gain and reductions in sweat chloride levels in patients who took VX-770. People with the disease, which leads to the production of thick, sticky mucus and chronic lung infections that can be fatal, often lose weight in part because of the lung infections and nutritional problems that result from the disorder. And high levels of sweat chloride in patients with the disease are a key indicator of the defective CF protein, which fails to properly transport chloride ions through cell membranes. Vertex said that adverse events during the study included respiratory issues that were observed in both patients on its drug and those who took a placebo.
The positive results from the study of children on the drug and those from the trial involving older patients bode well for Vertex as it plans to submit applications including the data for U.S. and European approval of the VX-770 in the second half of 2011. The drug could become a game-changing therapy for certain patients with CF. There are about 30,000 patients in the U.S. and 70,000 patients worldwide with the genetic disorder; about 4 percent of them in the U.S. have at least one copy of the G551D mutation.
“The data announced today are highly encouraging because children with CF tend to be healthier than adults and significant improvements in lung function may be harder to demonstrate in a clinical study,” Robert Beall, president and CEO of the Cystic Fibrosis Foundation, which has supported the development of VX-770, said in a statement. “Data from Phase 3 studies of VX-770 in people with the G551D mutation provide strong support for the concept that addressing the defective protein that leads to CF may significantly improve outcomes for patients and give hope for the future of other CF treatments that repair the basic defect of the disease.”