News Brief: Targeting the Basic Defect
Research to discover and develop new therapies for cystic fibrosis continues to produce exciting results. The Cystic Fibrosis Foundation and Vertex Pharmaceuticals, Inc., are working in collaboration on several promising potential drugs that could treat the defective protein that causes cystic fibrosis — not just the symptoms.
Here’s an update on one potential therapy that is set for FDA review, VX-770, and the progress of clinical trials for other Vertex drugs in development.
Potential CF Therapy, VX-770, Set for FDA Review
Vertex plans to submit a new drug application for VX-770 to the U.S. Food and Drug Administration (FDA) in October. The company is seeking approval for the drug in people age 6 and older who carry at least one copy of the G551D mutation of CF.
It generally takes between 6 and 12 months for the FDA to review and decide on a drug application, putting VX-770 on track for possible approval in 2012.
In Phase 3 clinical trials of VX-770 in people with the G551D mutation, those who took the drug demonstrated remarkable improvements in lung function, weight gain and sweat chloride levels.
If VX-770 is approved, it will be the first drug on the market that targets the defective CFTR protein that causes CF and improves key symptoms of the disease.
Vertex also expects to begin clinical trials of VX-770 in other CF population groups in the first half of 2012. These will include a study of the therapy in children age 2 to 5 with the G551D mutation, and studies of VX-770 in people with other “gating” mutations of CF besides G551D.
In gating mutations like G551D, the defective CFTR protein moves to its proper place at the surface of the cell but does not function correctly. It acts instead like a locked gate, interfering with the proper flow of salt and fluid into the airways. VX-770 aims to unlock that gate and restore CFTR function.
Vertex has said that the new studies of VX-770 may also include people with CF mutations other than gating mutations.
As FDA review of VX-770 gets underway, Vertex has set up a program to provide the drug to people with the G551D mutation who are in critical medical need and could benefit from the treatment prior to potential approval.
The expanded access program is designed for people with CF who have highly limited lung function and meet other criteria.
To learn more, speak with your CF doctor or call the VX-770 Expanded Access Call Center at 1-800-745-4484.
The Bottom Line: With VX-770 on track for possible FDA approval, more studies will evaluate whether greater numbers of people with CF could benefit from the drug.
Read more in these FAQs and keep up to date on the status of VX-770 clinical trials.
More Studies Planned for Combination Treatments Aimed at Most Common CF Mutation
This month, Vertex plans to begin the second part of an ongoing Phase 2 clinical trial of VX-770 in combination with another oral drug in development, VX-809, targeting the basic defect in CF.
The study will enroll people with at least one copy of the Delta F508 mutation, the most common mutation of CF.
In July, the CF Foundation and Vertex announced results from the first part of the trial, which examined the combination treatment in people with two copies of the Delta F508 mutation. Participants who received the two drugs together showed reduced sweat chloride levels.
Because excessive sweat chloride is a key symptom of CF, the results suggest that VX-770 and VX-809 in combination may help the defective CFTR protein work the way it should.
The second part of the combination trial is expected to evaluate the two drugs over a longer period of time than the earlier study and will test VX-809 at higher dosing levels. The main goals of the upcoming study are to measure the effect of the combination treatment on sweat chloride levels and evaluate their safety and tolerability in people with CF.
Vertex is also planning to start a clinical trial by the end of this year that will study VX-770 in combination with a third potential therapy, VX-661. The study will enroll people with two copies of the Delta F508 mutation.
VX-661, like VX-809, is designed to help move the CFTR protein to the surface of the cell. Once the protein is in its proper place, VX-770 aims to help the protein function more normally.
The CF Foundation worked with Vertex to discover VX-770, VX-809 and VX-661 and has provided substantial scientific, financial and clinical support throughout the development process. Earlier this year, it expanded its collaboration with Vertex to speed up the development of new therapies, including VX-661 and other potential drugs to treat people with the Delta F508 mutation.
The Bottom Line: Studies of multiple combination therapies could accelerate the development of additional drugs addressing the basic defect to help all people with CF.
Learn more about the ongoing clinical trial of VX-770 and VX-809.
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