Vertex Selects Drug Combo, a Potential Therapy for 90% of CF Patients

Xconomy Boston — 

[Updated, 12:57 p.m. See below.] Vertex Pharmaceuticals is already a leader in cystic fibrosis therapies. The company is placing its bet on an experimental drug that could strengthen its dominant position.

Vertex said it will file for regulatory approval of VX-445, an experimental drug that the company estimates could treat up to 90 percent of cystic fibrosis (CF) patients. It’s one of two experimental three-drug combination therapies that the Boston company had advanced to late-stage testing.

After reporting earlier this year that both experimental drug combos met Phase 3 goals, Vertex said it would decide in the second quarter which of the two it would submit to regulators. Vertex said Thursday that it determined VX-445 could benefit the greatest number of CF patients.

Shares of Vertex (NASDAQ: VRTX) rose about 1.3 percent in mid-morning trading.

Cystic fibrosis is an inherited disorder caused by mutations to the gene that produces a protein that helps cells pump water in and out. Without that protein, the lungs, pancreas, and other organs develop a thick buildup of mucus that impairs breathing and serves as a breeding ground for bacterial infections.

Vertex’s earlier CF drugs treat patients with specific genetic mutations. But the company has tried to broaden its reach through drug combinations. VX-445 combines the experimental Vertex drug elexacaftor with two of the company’s approved CF therapies, tezacaftor and ivacaftor. The other Vertex three-drug cocktail combines the experimental VX-659 with tezacaftor and ivacaftor.

After four weeks of treatment, Vertex said VX-659 and VX-445 improved lung function by an average of 14 and 13.8 percentage points respectively, compared to a placebo. Showing lung function improvement was the main goal of the Phase 3 studies. With both drugs performing comparably, Vertex said in March that it would further evaluate the two treatments after 24 weeks.

Vertex released 24-week data Thursday showing that patients given VX-445 showed improved lung function by an average 14.3 percentage points. The company did not provide 24-week data for VX-659. Vertex said its selection of VX-445 for regulatory submission was based on a number of factors including safety, tolerability, and how it interacts with other drugs.

[Paragraph added with analyst comment.] In a research note, JMP Securities analyst Liisa Bayko noted that both Vertex drug combos showed similar improvements in lung function and were well tolerated by patients. “In the end, Vertex went with VX-445 due to its ability to be taken with hormonal contraceptives and the lack of photosensitivity, factors that would allow the company to treat a higher number of CF patients,” she wrote.

Vertex said it plans to file for FDA approval of VX-445 in CF patients 12 or older in the third quarter of this year. A submission to the European Medicines Agency is expected in the fourth quarter of this year.

Anatomy of the lungs and heart image by Flickr user University of Liverpool Faculty of Health & Life Sciences via a Creative Commons license