Gilead Announces Sustained Virologic Response Rates from Two Phase 3 Studies
of Sofosbuvir for Hepatitis C
-- FISSION and NEUTRINO Studies Both Meet Primary Endpoints and Will Support
Regulatory Filing for Sofosbuvir --
FOSTER CITY, Calif. -- February 4, 2013
Gilead Sciences (Nasdaq:GILD) today announced topline results from two Phase 3
studies, FISSION and NEUTRINO, evaluating a 12-week course of the once-daily
nucleotide sofosbuvir in combination with ribavirin (FISSION) and in
combination with ribavirin and pegylated interferon (NEUTRINO) among
treatment-naïve patients with chronic hepatitis C virus (HCV) infection.
In the FISSION study, patients with genotype 2 or 3 HCV infection were
randomized to receive either a 12-week course of sofosbuvir plus ribavirin
(RBV) or standard of care with 24 weeks of pegylated interferon alfa-2a
(peg-IFN) plus RBV. The study met its primary efficacy endpoint of
non-inferiority of sofosbuvir plus RBV to peg-IFN plus RBV, with 67 percent
(170/253) of patients achieving a sustained virologic response (SVR) in the
sofosbuvir plus RBV treatment group versus 67 percent (162/243) in the peg-IFN
plus RBV treatment group (95 percent CI for the difference: -7.5 to +8.0
percent for sofosbuvir plus RBV versus peg-IFN plus RBV; predefined criterion
for non-inferiority was a lower bound of a two sided 95 percent CI of -15
percent). All common adverse events (≥10 percent in any group) occurred more
frequently in subjects receiving peg-IFN and RBV as compared to sofosbuvir and
RBV. The most common adverse events in the sofosbuvir plus RBV arm occurring
in ≥10 percent of the patients were fatigue, headache, nausea, insomnia and
In the NEUTRINO study, patients with genotype 1, 4, 5 or 6 HCV infection were
treated with a 12-week course of sofosbuvir, RBV and peg-IFN. This study met
its primary efficacy endpoint of superiority compared to a predefined historic
control SVR rate of 60 percent with 90 percent (295/327) of patients achieving
SVR12 after completing therapy (P<0.001).
In the NEUTRINO study the most common adverse events that occurred in ≥20
percent of patients were fatigue, headache, nausea, insomnia and anemia.
“These data support the favorable clinical profile of sofosbuvir as the
backbone of a potent, safe and well-tolerated treatment regimen that is
effective across a broad range of HCV patient genotypes,” said Norbert
Bischofberger, PhD, Executive Vice President of Research and Development and
Chief Scientific Officer, Gilead Sciences. “The sofosbuvir regimens in these
trials allowed us to shorten the duration of effective hepatitis C therapy to
just 12 weeks for treatment-naïve patients with genotypes 1 through 6.”
In FISSION, treatment-naïve HCV genotype 2 and 3 patients were randomized
(1:1) to receive either 12 weeks of sofosbuvir 400 mg once daily plus RBV
(1,000 or 1,200 mg/day) (n=256) or 24 weeks of peg-IFN (180 μg/week) plus RBV
(800 mg/day) (n=243). Overall, 20 percent of patients had compensated
cirrhosis (advanced liver disease) and 72 percent had genotype 3 infection.
The SVR12 rates in patients receiving sofosbuvir plus RBV were 97 percent for
genotype 2 patients and 56 percent for genotype 3 patients. The SVR12 rates in
patients receiving peg-IFN plus RBV in this study were 78 percent for genotype
2 patients and 63 percent for genotype 3 patients. Among patients with
cirrhosis at baseline who received sofosbuvir/RBV, 47 percent achieved SVR12;
38 percent of cirrhotics who received peg-IFN plus RBV achieved SVR12.
With the exception of one patient who was non-compliant, all patients in the
sofosbuvir/RBV arm became HCV negative on treatment and relapse accounted for
the virologic failures.
Three patients (1 percent) receiving sofosbuvir discontinued treatment due to
adverse events compared to 26 patients (11 percent) receiving peg-IFN/RBV.
In NEUTRINO, 327 treatment-naïve HCV genotype 1, 4, 5 and 6 patients were
treated for 12 weeks with sofosbuvir 400 mg once daily in combination with RBV
(1,000 or 1,200 mg/day) and peg-IFN (180 μg/week). Seventeen percent of
patients had compensated cirrhosis and 89 percent were infected with genotype
1. Among genotype 1 patients, 89 percent achieved SVR12. Of the 35 patients
with genotypes 4, 5 or 6, 97 percent achieved SVR12. Among patients with
cirrhosis at baseline, 80 percent achieved SVR12. All patients in this study
became HCV RNA negative on treatment and relapse accounted for all virologic
Five patients (2 percent) receiving sofosbuvir in combination with peg-IFN and
RBV discontinued treatment due to adverse events.
FISSION, NEUTRINO, POSITRON and FUSION are the pivotal Phase 3 studies
designed to support an initial regulatory filing for sofosbuvir as part of
all-oral therapy with RBV for genotype 2 and 3 treatment-naïve,
treatment-experienced and interferon-intolerant HCV patients, and for
sofosbuvir in combination with RBV and peg-IFN for genotype 1, 4, 5 and 6
treatment-naïve patients. Topline results from the POSITRON study were
announced inNovember 2012, and topline results from the last Phase 3 study,
FUSION, are anticipated later this quarter. Full results from all four studies
will be presented at a future scientific conference.
Additional information about these and other ongoing clinical studies can be
found at www.clinicaltrials.gov. Sofosbuvir is an investigational product and
its safety and efficacy have not yet been established.
About Gilead Sciences
Gilead Sciences is a biopharmaceutical company that discovers, develops and
commercializes innovative therapeutics in areas of unmet medical need. The
company’s mission is to advance the care of patients suffering from
life-threatening diseases worldwide. Headquartered in Foster City, California,
Gilead has operations in North America, Europe and Asia Pacific.
This press release includes forward-looking statements within the meaning of
the Private Securities Litigation Reform Act of 1995 that are subject to
risks, uncertainties and other factors, including the possibility that the
proportion of patients in the FISSION and NEUTRINO trials will not maintain
SVR with longer follow up as favorable as the SVR12 rates reported in this
press release. In addition, there is the possibility of unfavorable results
from additional clinical trials involving sofosbuvir, including the FUSION
trial. Further, we may not release topline results from the FUSION study or
file for regulatory approval of sofosbuvir in the timelines currently
contemplated. As a result, sofosbuvir may never be successfully
commercialized. Further, Gilead may make a strategic decision to discontinue
development of the compound if, for example, Gilead believes commercialization
will be difficult relative to other opportunities in its pipeline. These
risks, uncertainties and other factors could cause actual results to differ
materially from those referred to in the forward-looking statements. The
reader is cautioned not to rely on these forward-looking statements. These and
other risks are described in detail in Gilead’s Quarterly Report on Form 10-Q
for the quarter ended September 30, 2012, as filed with the U.S. Securities
and Exchange Commission. All forward-looking statements are based on
information currently available to Gilead, and Gilead assumes no obligation to
update any such forward-looking statements.
For more information on Gilead Sciences, please visit the company’s website at
www.gilead.com, follow Gilead on Twitter (@GileadSciences) or call Gilead
Public Affairs at 1-800-GILEAD-5 or 1-650-574-3000.
Gilead Sciences, Inc.
Patrick O’Brien, 650-522-1936 (Investors)
Cara Miller, 650-522-1616 (Media)
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