(Corrects third paragraph to show hold on U.S. trial, not
By Bill Berkrot
July 25 Vertex Pharmaceuticals Inc said
U.S. health regulators placed a partial clinical hold on a
mid-stage study of an experimental oral hepatitis C treatment
because of potential liver problems, sending its shares sharply
lower on Thursday.
Vertex said the U.S. Food and Drug Administration took the
action after the Phase II study in Europe of its VX-135 in
combination with the standard hepatitis drug ribavirin showed
elevated liver enzymes in three patients taking the 400
milligram dose of its drug.
As a result of the hold on the U.S. clinical trial, the
Massachusetts-based biotechnology company said it was unable to
begin dosing patients in a planned U.S. study aimed at testing
VX-135 at 200 mg.
"We are committed to continuing to work closely with the FDA
to provide the data needed to support evaluation of a 200 mg
dose of VX-135 in the U.S.," Robert Kauffman, Vertex's chief
medical officer, said in a statement.
The 400 mg arm of the European study was discontinued and
the patients' liver enzymes returned to what they had been prior
to entering the trial, Vertex said.
A U.S. study evaluating 100 mgs of VX-135 was not affected,
the company said.
VX-135 is also being studied at 100 mg and 200 mg in
combination with Bristol-Myers Squibb Co's daclatasvir,
a highly promising hepatitis drug from a different class of oral
Vertex has the market leading hepatitis C treatment with
Incivek. But that drug must be taken with the difficult to
tolerate injected drug interferon to provide high cure rates.
Incivek sales have been declining sharply as patients wait
for new all oral treatment regimens that promise very high cure
rates without the need for interferon and the miserable flu-like
symptoms that come with it.
The first of those are expected to become available in 2014
from other companies and Vertex has been playing catch-up.
"With our ongoing studies in the U.S., Europe and now New
Zealand with VX-135 and daclatasvir, our strategy in hepatitis C
is unchanged - to develop an all-oral therapy that provides a
high cure rate across multiple hepatitis C genotypes," Kauffman
Vertex shares were down more than 9 percent at $80 in after
hours trading after closing at $87.62 on Nasdaq.
(Reporting by Bill Berkrot; Editing by Grant McCool and Andre