* Tested in genotype 2/3 patients who failed prior therapy
* Cure rate 73 pct for 16 weeks, 50 pct for 12 weeks
* Gilead seen seeking US, European approval in 2nd quarter
* Shares up 1.7 percent
Feb 19 Gilead Sciences Inc said its
experimental hepatitis C drug sofosbuvir, in a late-stage
clinical study, was clearly superior to historical cure rates at
both 12 and 16 weeks of treatment in patients who were not
helped by prior therapy.
The cure rate for those with genotype 2 and 3 of the serious
liver disease was significantly higher for patients who received
16 weeks of treatment: 73 percent versus 50 percent for those
treated for 12 weeks, according to study results released on
Both rates were far higher than the comparable 25 percent
historic cure rate - or sustained virologic response (SVR) - for
these types of patients.
"Fusion is the fourth Phase III trial of sofosbuvir that has
met its primary endpoint with no significant adverse events,"
Sanford Bernstein analyst Geoffrey Porges said in a research
"We believe these results represent the final piece of
de-risking for the asset, and approval is as close to certainty
as it can be," he added.
In the latest trial, genotype 2 patients fared better than
those with genotype 3, which is more difficult to treat. Rates
of SVR, which is considered tantamount to a cure, were also
lower in patients suffering from cirrhosis, typically among the
sickest of hepatitis patients.
The study tested sofosbuvir in combination with the older
oral hepatitis treatment ribavirin in patients who did not
respond to prior treatments with ribavirin and injectable
No patients in the study discontinued treatment due to
adverse side effects.
Fatigue, headache, insomnia and nausea were the most common
adverse effects, reported in less than 15 percent of patients,
"With positive results from all four Phase 3 trials now in
hand, Gilead is on track to meet its goal of filing regulatory
applications in the United States and Europe in the second
quarter," Gilead Chief Scientific Officer Norbert Bischofberger
said in a statement.
Earlier this month, Gilead said the drug combination also
achieved the main goals set in two other late-stage trials of
patients who had not received prior treatment.
Sofosbuvir also showed promise in a late-stage study called
Positron in patients who were unable or unwilling to take
interferon, a standard hepatitis C drug known for its unpleasant
side effects that lead many patients to delay or discontinue
With analysts estimating a multibillion-dollar annual
market, new interferon-free treatment options for hepatitis C
are among the hottest areas of pharmaceutical research.
Several other companies, including Abbvie Inc,
Bristol-Myers Squibb Co and Vertex Pharmaceuticals Inc
, are developing interferon-free treatment combinations
for hepatitis C, with most focusing on by far the most common
strain of the virus, genotype 1.
ISI Group analyst Mark Schoenebaum said Gilead needs to find
ways to improve cure rates in Genotype 3 patients, possibly by
combining sofosbuvir with other experimental drugs in its
"Competition in the Genotype 2/3 space is sparse, so even
with these data, Gilead probably has many years to optimize
before they will face a serious threat," he said.
The SVR rates for genotype 3 was 30 percent with 12 weeks of
treatment and 62 percent after 16 weeks of therapy. That
compared with SVR rates of 86 percent and 94 percent for
Gilead said it will present full data from the four Phase
III studies at a future scientific conference.
Shares of the company were up 70 cents, or 1.7 percent, at
$42.30 in midday trading on the Nasdaq on Tuesday.