Vertex Pharmaceuticals Inc on Thursday
said a combination of its cystic fibrosis drug Kalydeco and an
experimental compound was shown to improve lung function in a
mid-stage trial, sending its shares up nearly 8 percent.
The study found that treatment with Kalydeco and the
experimental drug VX-661 for 28 days resulted in a 4.6 percentage
point improvement in mean lung function for patients with two
specific genetic mutations.
If eventually approved by regulators, VX-661 would be the second
drug from Vertex that works by treating the underlying cause of
cystic fibrosis, a rare genetic disease that impairs the lungs and
The disease is caused by defective or missing CF transmembrane
conductane regulator (CFTR) proteins. Kalydeco is designed for
patients with certain CFTR mutation. VX-661 is being tested in
combination with Kalydeco, as in this Phase 2 trial, and in patients
with different genetic mutations.
"It is good data and some believe it does have an incremental
positive read-through to the all-important Phase 3 data later this
summer," said RBC Capital Markets analyst Michael Yee.
That trial will answer the question of whether a combination of
Vertex drugs is effective in patients with two copies of the gene
mutation not currently addressed by Kalydeco — a market representing
about half of the 30,000 cystic fibrosis patients in the United
A positive result "would be transformative to the cystic fibrosis
community," Yee said.
The most common side effects seen during the Phase 2 trial included
cough, headache and upper respiratory tract infection.
But ISI Group analyst Mark Schoenebaum cautioned that Vertex has not
disclosed results from the mid-stage trial for patients treated with
Vertex also announced that first-quarter sales of Kalydeco totaled
$100 million, which fell short of the average analyst estimate of
$107 million, according to Wells Fargo Securities.
Separately, the company reported an adjusted first-quarter loss
of $1.00 per share, also below the average analyst per-share loss
estimate of 67 cents, according to Thomson Reuters I/B/E/S.
Vertex said it would discontinue research into treatments for
hepatitis C, a market now dominated by sales of Gilead Sciences
Inc's Sovaldi. Vertex late last year sold off its non-North America
royalty rights to hepatitis C drug Incivek.
Shares of Vertex, which closed at $68.95 in regular Nasdaq trading,
were up $5.30 at $74.25 after hours.
(Reporting By Deena Beasley; editing by David Gregorio and Alden