Phase 3 Study of VX-770 Shows Marked Improvement in Lung Function Among People with Cystic Fibrosis with G551D Mutation

Patients on drug had significant weight gain, reduced sweat chloride and were less likely to experience a pulmonary exacerbation

BETHESDA, Md., Feb. 23, 2011 /PRNewswire-USNewswire/ -- The Cystic Fibrosis Foundation and Vertex Pharmaceuticals announced today that VX-770, an oral medicine in development that targets the defective protein that causes cystic fibrosis, showed promising results in a Phase 3 clinical trial.

The trial was designed to evaluate patients age 12 and up who carry at least one copy of a CF mutation called G551D. The study included 161 patients who received at least one dose of VX-770 or placebo.

Patients who took the drug, compared to those on placebo, showed a marked improvement in lung function at 24 weeks, which was sustained for the duration of the 48-week trial.

Patients also showed improvement across all key secondary endpoints in the study, including reduced likelihood of experiencing a pulmonary exacerbation, decreased respiratory symptoms and improved weight gain. Each of these areas is critically important to the health of people with CF.

In addition, average sweat chloride levels of patients on VX-770 dropped toward normal levels, while those on placebo did not change—indicating the drug is impacting the underlying defect in CF. Excessive sweat chloride (salt) is a key clinical indicator of CF.

VX-770 is being developed by Vertex, and was discovered in collaboration with the CF Foundation, which provided substantial support to Vertex throughout the development process, including an approximately $75 million investment.

About four percent of people with CF carry the G551D mutation. More studies are needed to determine whether other CF mutations may benefit from VX-770.

"These results are highly encouraging. They provide scientific evidence that support our long-standing belief that targeting the underlying defect of CF may have a profound effect on the disease," said Robert J. Beall, Ph.D., president and CEO of the Cystic Fibrosis Foundation. "We have much more to do to end the suffering caused by this disease, but these data are extremely exciting, especially for people with the G551D mutation and their families. The results also offer significant hope that a similar approach to treatment may help the majority of patients living with CF."

The Phase 3 data support Vertex's plan to submit a New Drug Application for VX-770 to the U.S. Food and Drug Administration (FDA) in the second half of 2011. Generally, the FDA takes between 6 and 12 months to review and rule on a drug application.

"The Cystic Fibrosis Foundation has played an instrumental role in our more than 10-year effort to discover and develop potential new CF medicines such as VX-770," said Matthew W. Emmens, chairman, president and CEO of Vertex. "The data announced today reflect a significant investment of time, dollars and scientific expertise from both Vertex and the CF Foundation, and we look forward to working closely with the Foundation as we seek to bring VX-770 to people with CF."

Said Preston W. Campbell III, M.D., executive vice president for medical affairs of the Cystic Fibrosis Foundation: "As a physician who has treated CF patients for many years, the VX-770 results are more than just numbers -- they represent hope." He added, "It's not surprising that patients felt better on the drug because of the magnitude of lung function improvement and weight gain. These are important clinical outcomes, and the fact they were maintained through 48 weeks is very encouraging."

Developing a therapy for individuals with the most common CF mutation, Delta F508, remains a top priority of the CF Foundation. A Phase 2 trial for those with Delta F508 is underway to test VX-770 in combination with a drug known as VX-809. Like VX-770, VX-809 resulted from discovery efforts between Vertex and the CF Foundation. Laboratory studies suggest a combination of the two drugs may be more beneficial than either one alone. Results of this clinical trial are expected later this year.

In addition, the CF Foundation is expanding its medical research program by $100 million over the next five years to focus on developing therapies, known as CFTR modulators, which address the underlying defect.

Vertex's VX-770 Phase 3 program involves three different clinical trials, including the trial for people age 12 and up with the G551D mutation described above. In addition, a VX-770 trial of children ages 6 to 11 with the G551D mutation is ongoing and results are expected in mid-2011. The company also announced results for a trial evaluating VX-770 in patients with two copies of the Delta F508 mutation. Safety was the study's primary focus, and adverse events were similar between the VX-770 and placebo groups in the study. Patients did not show a clinically meaningful improvement in lung function, although sweat chloride improved by a small amount.

Results from all three studies will be part of the drug application Vertex will submit to the FDA.

About the Cystic Fibrosis Foundation

The Cystic Fibrosis Foundation is the world's leader in the search for a cure for cystic fibrosis. The Foundation funds more CF research than any other organization, and nearly every CF drug available today was made possible because of Foundation support. Based in Bethesda, Md., the Foundation also supports and accredits a national care center network that has been recognized by the National Institutes of Health as a model of care for a chronic disease. The CF Foundation is a donor-supported nonprofit organization. For more information, go to www.cff.org.

SOURCE Cystic Fibrosis Foundation