XenoPort, Inc. (Nasdaq: XNPT) announced today top-line results from its
pivotal Phase 3 clinical trial of arbaclofen placarbil (AP) for the
treatment of patients with spasticity due to multiple sclerosis (MS).
The trial was unsuccessful in demonstrating that AP provided
statistically significant improvement relative to placebo in the
co-primary endpoints of the study.
Ronald W. Barrett, Ph.D., chief executive officer of XenoPort, stated,
"We are obviously disappointed that the co-primary efficacy endpoints
were not met. Based on the results of the study, we have decided to
terminate further investment in this program. We will be working
diligently to shut down all activities related to AP development, and
plan to provide an update in the future on the impact of these expected
savings on our cash burn guidance. We remain committed to allocating our
resources to build value through the focused commercialization of Horizant
and advancing the development of our novel fumarate product candidate,
About the Trial
The trial was a 13-week, multicenter, randomized, double-blind,
placebo-controlled study that enrolled 228 subjects in 30 sites in the
United States. There was a one-week placebo run-in period, two weeks of
up-titration, eight weeks at the maintenance dose and two weeks of
down-titration. Eligible subjects were randomized to one of four arms:
15 mg, 30 mg or 45 mg of AP or placebo dosed twice a day (BID) with food.
The first of the co-primary endpoints for the study was the time-matched
change from baseline in Maximum Ashworth score (six hours post-dose time
point) at the end of the maintenance dose period. The muscle group in
the lower limbs with the highest Ashworth score at baseline was followed
throughout the trial. Subjects entering the trial were required to have
a Maximum Ashworth score of two or greater prior to entering the study
and at the end of the placebo run-in period, which served as baseline.
The second co-primary endpoint was the score on the 7-point Patient
Global Impression of Change scale at the end of the maintenance period.
The co-primary endpoint analysis plan examined the differences of the 30
and 45 mg BID groups from the placebo group. The co-primary endpoints
and dose groups were analyzed independently. Comparison of the AP groups
to the placebo group did not reach statistical significance on either of
the co-primary endpoints for either of the AP doses.
The most commonly reported adverse event was somnolence (2%, 7%, 16% and
21% for placebo, 15, 30 and 45 mg AP BID, respectively). There were
seven subjects with treatment emergent serious adverse events, none of
which were deemed to be related to treatment.
XenoPort will host a conference call at 8:30 am Eastern Time today to
discuss its AP Phase 3 clinical trial results and business updates. To
access the conference call via the Internet, go to www.XenoPort.com.
To access the live conference call via phone, dial 1-888-275-3514.
International callers may access the live call by dialing 1-706-679-1417.
The replay of the conference call may be accessed after 11:30 am Eastern
Time today via the Internet, at www.XenoPort.com,
or via phone at 1-855-859-2056 for domestic callers or 1-404-537-3406
for international callers. The reference number to enter the call and
the replay of the call is 74912690.
XenoPort, Inc. is a biopharmaceutical company focused on developing and
commercializing a portfolio of internally discovered product candidates
for the potential treatment of neurological disorders. Horizant,
XenoPort's internally discovered drug, is approved and being marketed by
XenoPort in the United States. Regnite® (gabapentin enacarbil)
Extended-Release Tablets is approved and is being marketed in Japan.
Astellas Pharma Inc. holds all development and commercialization rights
for Regnite in Japan and five other Asian countries. XenoPort
holds all other world-wide rights to gabapentin enacarbil. XenoPort's
pipeline of product candidates includes potential treatments for
patients with Parkinson's disease, relapsing-remitting multiple
sclerosis and psoriasis.
This press release contains "forward-looking" statements, including,
without limitation, all statements related to the shutdown of activities
related to AP development, and the timing thereof; future impact on cash
burn guidance and resource allocation; building value through the
focused commercialization of Horizant and advancing the
development of XP23829; and the therapeutic and commercial potential of
XenoPort's product candidates. Any statements contained in this press
release that are not statements of historical fact may be deemed to be
forward-looking statements. Words such as "expected," "plan,"
"potential," "will" and similar expressions are intended to identify
forward-looking statements. These forward-looking statements are based
upon XenoPort's current expectations. Forward-looking statements involve
risks and uncertainties. XenoPort's actual results and the timing of
events could differ materially from those anticipated in such
forward-looking statements as a result of these risks and uncertainties,
which include, without limitation; XenoPort's lack of commercialization
experience and its ability to successfully market and sell Horizant,
including its ability to obtain uninterrupted drug supply and
appropriate pricing and reimbursement for Horizant in an
increasingly challenging environment; XenoPort's ability to comply with
applicable regulatory guidelines and requirements with respect to the
marketing and manufacturing of Horizant or with Horizant
post-marketing commitments or requirements mandated by the U.S. Food and
Drug Administration (FDA); XenoPort's need for additional funding and
the risk that XenoPort could utilize its available capital resources
sooner than it expects; the uncertainty of the FDA approval process and
other regulatory requirements; the uncertain results and timing of
clinical trials and other studies; XenoPort's ability to successfully
initiate, conduct and complete clinical trials in the anticipated
timeframes, or at all; and the uncertain therapeutic and commercial
value of XenoPort's product candidates. These and other risk factors are
discussed under the heading "Risk Factors" in XenoPort's Securities and
Exchange Commission filings and reports, including in its Quarterly
Report on Form 10-Q for the quarter ended March 31, 2013, filed with the
Securities and Exchange Commission on April 24, 2013. XenoPort expressly
disclaims any obligation or undertaking to release publicly any updates
or revisions to any forward-looking statements contained herein to
reflect any change in the company's expectations with regard thereto or
any change in events, conditions or circumstances on which any such
statements are based.
Horizant, Regnite and XENOPORT are trademarks of XenoPort,
Jackie Cossmon, 408-616-7220