EDISON, N.J., Oct. 13, 2016 /PRNewswire/ -- ContraVir
Pharmaceuticals, Inc. (NASDAQ: CTRV), a biopharmaceutical company
focused on the development and commercialization of targeted
antiviral therapies, today reported positive interim data for
CMX157, the Company's highly potent prodrug of tenofovir, from its
ongoing Phase 2a multiple ascending dose clinical study. The
head-to-head study is the first evaluation of CMX157 in HBV
patients, and directly compares CMX157 to tenofovir disoproxil
fumarate (TDF, Gilead's Viread®) in chronically infected
hepatitis B (HBV) patients.
Patients successfully completed both 5 mg and 10 mg cohorts, and
interim data reported below are from 10 HBV-infected patients who
completed 14 days of once-a-day oral dosing of 25 mg of CMX157, and
two HBV patients treated for 14 days of oral dosing with 300 mg
TDF. The CMX157 treated patients showed an average 99%
reduction in HBV viral load compared to baseline.
Significantly, the observed antiviral activity for CMX157 is
comparable to that observed in TDF-treated patients, but at
1/12th the dose (25 mg CMX157 vs. standard 300 mg
TDF).
A key goal of this study was to monitor levels of active
tenofovir in the blood, exposure to which is a key predictor of
off-target side effects. Following oral dosing, levels of CMX157
and active tenofovir in the bloodstream are approximately dose
proportional and similar both in chronic HBV patients as well as in
an earlier healthy volunteer study. Notably, CMX157 does not
appear to break down readily into active tenofovir in the blood
(tenofovir: Cmax = 2.8 ng/mL; AUC = 34 ng*h/mL) in contrast to
patients taking Viread® (tenofovir: Cmax 340 ng/mL, AUC
1910 ng*h/mL). The high levels of circulating tenofovir in subjects
taking Viread® are consistent with results from
earlier published clinical studies of Viread® in
HIV and HBV patients. These results are significant
considering that CMX157 achieved similar antiviral activity
compared to Viread® while significantly reducing
systemic tenofovir exposure.
Active tenofovir levels observed in blood following oral dosing
of CMX157 are significantly below levels seen for
Viread®-treated patients, regardless of dose used, which
is consistent with CMX157 targeting the liver followed by
activation of CMX157 specifically within the liver. This is
further supported by the observation that viral load reductions
with CMX157 are comparable to Viread® despite a
significantly lower dose.
"We are pleased and excited with these clinical results, as they
demonstrate CMX157's great potential in our ongoing effort to
develop a cure for HBV," said James
Sapirstein, CEO of ContraVir. "The significant viral
load reduction and favorable safety at this low dose of CMX157
speaks to the unique liver-targeting mechanism of our drug, which
concentrates the antiviral activity of tenofovir in the liver,
enabling anti-HBV efficacy at lower doses and minimal drug exposure
to other tissues. We believe, based on the data that are
being generated, that CMX157 has great potential as a safe and
highly potent backbone of combination therapy against HBV."
Pharmacokinetic data observed for CMX157 to date in healthy and
HBV-infected subjects are similar across the completed Phase 1b and
ongoing Phase 2a studies, consistent with the prodrug's site of
action and anticipated improved safety profile. CMX157 was
earlier found to be safe and well tolerated at daily oral doses of
up to 100 mg in healthy volunteers and is presently demonstrating
an excellent safety profile at 25 mg dose in the ongoing Phase 2a
study in HBV patients. Upon completion of the 4-week dosing
regimen and independent safety review, dose escalation is planned
to continue at the 50 mg and 100 mg levels, respectively.
Similarity of pharmacokinetic profiles observed for CMX157 in
healthy and HBV-infected subjects strongly suggests that the
remaining 50 mg and 100 mg doses of CMX157 in the ongoing Phase 2a
study will also be safe and potentially even more active against
HBV.
CMX157 Phase 2 Clinical Trial Design
The Phase 2a
multiple ascending dose clinical trial is designed to enroll 60
treatment-naïve patients with chronic HBV infection, and to compare
CMX157 to tenofovir disoproxil fumarate (TDF, Gilead's
Viread®). The sequential dose escalation format
consists of 10 patients per cohort receiving four weeks of a
once-daily dose of 5, 10, 25, 50 and 100 mg, respectively, of
CMX157, plus two patients per cohort receiving 300 mg of TDF, the
standard therapeutic dose of Viread®.
About CMX157
CMX157 is a highly potent analog of the
successful antiviral drug tenofovir. Its novel
liver-targeting structure results in decreased circulating levels
of tenofovir, lowering systemic exposure and thereby reducing the
potential for renal side effects. CMX157 previously completed
a Phase 1b dose escalation clinical study conducted in healthy
volunteers, in which participants were treated at doses up to 100
mg per day for 14 days, displaying an excellent safety,
tolerability, and drug distribution profile. Based on
CMX157's best-in-class potential, ContraVir believes CMX157 can
become the cornerstone of a curative combination therapy for
hepatitis B.
About ContraVir Pharmaceuticals
ContraVir is a biopharmaceutical company focused on the development
and commercialization of targeted antiviral therapies with a
specific focus on developing a potentially curative therapy for
hepatitis B virus (HBV). The Company is developing two novel
anti-HBV compounds with complementary mechanisms of action: CMX157,
a highly potent analog of the successful antiviral drug tenofovir
currently in a Phase 2a clinical trial in HBV patients; and CRV431,
a next generation cyclophilin inhibitor with a unique structure
that increases its potency and selective index against HBV.
ContraVir is also developing FV-100, an orally available nucleoside
analogue prodrug for the treatment of herpes zoster, or shingles,
in a Phase 3 clinical trial. In addition to direct antiviral
activity, FV-100 previously demonstrated the potential to reduce
the incidence of debilitating shingles-associated pain known as
post-herpetic neuralgia (PHN) in a Phase 2 clinical study. For
more information visit www.contravir.com.
Forward Looking Statements
Certain statements in this press release are forward-looking within
the meaning of the Private Securities Litigation Reform Act of
1995. These statements may be identified by the use of
forward-looking words such as "anticipate," "believe," "forecast,"
"estimated" and "intend," among others. These forward-looking
statements are based on ContraVir's current expectations and actual
results could differ materially. There are a number of factors that
could cause actual events to differ materially from those indicated
by such forward-looking statements. These factors include, but are
not limited to, substantial competition; our ability to continue as
a going concern; our need for additional financing; uncertainties
of patent protection and litigation; uncertainties with respect to
lengthy and expensive clinical trials, that results of earlier
studies and trials may not be predictive of future trial results;
uncertainties of government or third party payer reimbursement;
limited sales and marketing efforts and dependence upon third
parties; and risks related to failure to obtain FDA clearances or
approvals and noncompliance with FDA regulations. As with any drug
candidates under development, there are significant risks in the
development, regulatory approval, and commercialization of new
products. There are no guarantees that future clinical trials
discussed in this press release will be completed or successful, or
that any product will receive regulatory approval for any
indication or prove to be commercially successful. ContraVir does
not undertake an obligation to update or revise any forward-looking
statement. Investors should read the risk factors set forth in
ContraVir's Form 10-K for the year ended June 30, 2016, and other periodic reports filed
with the Securities and Exchange Commission.
For further information, please contact:
Sharen Pyatetskaya
Director of Investor Relations
sp@contravir.com; (732) 902-4028
Tiberend Strategic Advisors, Inc.
Joshua Drumm, Ph.D. (investors)
jdrumm@tiberend.com; (212) 375-2664
Claire LaCagnina (media)
clacagnina@tiberend.com; (212) 375-2686
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SOURCE ContraVir Pharmaceuticals, Inc.