Cystic Fibrosis Foundation Therapeutics (CFFT) is expanding its alliance with Vertex Pharmaceuticals, agreeing to provide $75 million. The new partnership will concentrate on drugs known as correctors, which aim to treat the underlying cause of cystic fibrosis (CF). CFFT is entitled to receive a royalty on future net sales of these correctors.
The collaboration will now support VX-661, Vertex’ second corrector to enter clinical development. It will also back the discovery and development of next-generation correctors. Vertex expects to begin a Phase II study with VX-661 by the end of this year in people with CF who have the F508del mutation.
CF is caused by defective or missing CF transmembrane conductance regulator (CFTR) proteins, which results in poor ion flow across cell membranes including in the lungs, causing the accumulation of abnormally thick, sticky mucus that leads to chronic lung infections and progressive lung damage. In people with the F508del mutation, which is the most common CFTR mutation, CFTR proteins do not reach the cell surface in normal amounts.
Vertex and CFFT began their R&D efforts in 1998. To date three CFTR modulators have resulted from the collaboration: potentiator VX-770 and correctors VX-809 and VX-661. Vertex retains worldwide rights to develop and commercialize, and CFFT is eligible to royalties on these three drug candidates under the organizations’ previous arrangement.
VX-661, VX-809, and VX-661 all aim to increase CFTR function by increasing the movement of CFTR to the cell surface. In people with the G551D mutation in the CFTR gene, CFTR proteins are present at the cell surface but do not function properly. VX-770, known as a CFTR potentiator, aims to increase the function of defective CFTR proteins by increasing their ability to transport ions across the cell membrane of CFTR at the cell surface.
Vertex recently reported positive results from two Phase III studies of VX-770: the STRIVE trial in adolescents and adults and the ENVISION trial in children ages 6 to 11. Vertex expects to submit marketing applications in the U.S. and Europe in the second half of this year.
Vertex is also conducting a Phase II trial with VX-809 and VX-770 in people with two copies of the F508del mutation. The first part of the study is designed to evaluate VX-809 or placebo dosed alone for 14 days and in combination with VX-770 or placebo for seven days. Vertex expects to obtain data from part one of the trial in the first half of this year. In in vitro studies, a combination of VX-661 and VX-770 resulted in greater CFTR activity as compared to treatment with VX-661 alone.