- FDA agrees with the company’s assessment that doxepin does not appear to have genotoxic potential
- Standard, long-term carcinogenicity studies may be a Phase 4 commitment pending evaluation of all preclinical data
- NDA timeline on track; third quarter 2007 submission anticipated
Somaxon Pharmaceuticals, Inc. (NASDAQ:
SOMX) today is providing an update on its preclinical testing program for SILENOR™
(doxepin HCl), its lead product candidate that has completed a successful Phase 3 clinical
program for the treatment of insomnia. The company is confirming that it expects to file
a New Drug Application (NDA) with the U.S. Food and Drug Administration (FDA) for
SILENOR™ in the third quarter of 2007.
In recent correspondence, the FDA agreed with Somaxon’s assessment that SILENOR™
does not appear to have genotoxic potential. The FDA indicated that, unless other
preclinical data raise a concern, a complete assessment of the carcinogenic potential of
SILENOR™ may not be needed prior to NDA approval. The FDA also indicated that it
may accept the results of a shorter-term carcinogenicity study for approval of the NDA and allow the standard two-year carcinogenicity study to be completed as a Phase 4
commitment. While the company intends to discuss the subject of a shorter-term
carcinogenicity study with the FDA, it believes such a study can be completed by the first
half of 2008.
Ken Cohen, Somaxon’s President and CEO, said, “We believe that this FDA
communication means that we can file our NDA without carcinogenicity data and that
two year carcinogenicity studies are unlikely to be needed for approval. Our NDA
preparation activities continue as planned, and we look forward to submitting it to the
FDA in the third quarter of 2007.”
As the company previously disclosed, in connection with a planned pre-NDA meeting for
SILENOR™ in May 2006, the FDA requested that Somaxon conduct additional
preclinical work regarding SILENOR™. Somaxon then initiated a preclinical program
consisting of standard genotoxicity, reproductive toxicology and carcinogenicity studies.
With respect to the timing of these studies, the FDA indicated that the data from the
genotoxicity studies and reproductive toxicology studies should be included in the
original NDA for SILENOR™. The FDA also indicated to Somaxon that depending on
the outcome of the genotoxicity studies, it may be flexible as to the timing of the conduct
of the carcinogenicity studies, including the potential that the data from those studies may
be submitted as a post-NDA approval commitment.
The company completed the genotoxicity studies and, in its assessment of the results, did
not observe a signal indicative of genotoxicity in any of the assays. The company
submitted the data from the genotoxicity studies to the FDA and, based on the company’s
assessment, requested that the agency clarify the required timing of submission of the
data from the requested carcinogenicity studies of SILENOR™. Today’s announcement
reflects the FDA’s response to Somaxon’s request.
The company is currently conducting the reproductive toxicology studies of SILENOR™
requested by the FDA and plans to complete those studies in the first half of 2007.
Somaxon has previously reported the results of all of its four Phase 3 clinical trials
evaluating SILENOR™ for the treatment of insomnia. The company reported the results
from the first of these clinical trials, which evaluated SILENOR™ in the treatment of
adults with chronic insomnia, in April 2006. SILENOR™ demonstrated a statistically
significant improvement compared to placebo on the primary endpoint of Wake After
Sleep Onset (WASO), as well as a range of secondary endpoints including Latency to
Persistent Sleep (LPS).
Somaxon reported results from its second Phase 3 clinical trial, which evaluated
SILENOR™ in healthy adults experiencing transient insomnia in a sleep laboratory
setting, in October 2006. SILENOR™ demonstrated a statistically significant
improvement compared to placebo on the primary endpoint of LPS, as well as a range of
secondary endpoints including WASO, Total Sleep Time (TST) and Latency to Sleep
Onset (LSO).
The company reported results from its third Phase 3 clinical trial, which evaluated
SILENOR™ in elderly patients with primary sleep maintenance insomnia in an
outpatient setting, in November 2006. SILENOR™ demonstrated a statistically
significant improvement compared to placebo in the primary endpoint of subjective Total
Sleep Time (sTST), as well as a range of secondary endpoints including subjective Wake
After Sleep Onset and Sleep Quality.
The company reported results from its fourth and final Phase 3 clinical trial, which
evaluated long-term use of SILENOR™ in elderly patients with primary sleep
maintenance insomnia, in December 2006. SILENOR™ demonstrated a statistically
significant improvement compared to placebo in the primary endpoint of WASO, as well
as a range of secondary endpoints including TST, Sleep Efficiency, sTST, and LSO.
In each of these trials, SILENOR™ was well tolerated and adverse events were
comparable to placebo.
About SILENOR™
SILENOR™ is a low-dose (1 mg, 3 mg, 6 mg) oral tablet formulation of doxepin HCl
that is patent protected for its use in insomnia. Doxepin has been prescribed for more
than 35 years for the treatment of depression and anxiety at dosages typically ranging
from 75 mg to 300 mg per day. At the currently prescribed high doses, doxepin is known
to have a range of undesirable side effects. However, at the doses used in SILENOR™ in
controlled clinical trials completed by Somaxon to date, SILENOR™ has been well
tolerated.
Unlike most approved insomnia medications, SILENOR™ is not thought to produce its
sleep-promoting effects via benzodiazepine recognition sites associated with the GABA
neurotransmitter system. Drugs that act on these receptors have been associated with
amnesia, hallucinations, physical dependence and drug-seeking behavior. The U.S. Drug
Enforcement Administration classifies these products as Schedule IV controlled
substances and carefully monitors and controls their prescribing and use. In contrast, it is
believed that the effects of SILENOR™ are mediated through blockade of histamine (H1)
receptors in the central nervous system. Histamine is an important neurotransmitter in
the sleep-wake cycle; histamine blockade has been demonstrated to reduce wakefulness
and to promote the initiation and maintenance of sleep. Further, histamine blockade has
not been associated with recreational abuse or diversion.
Conference Call Information
Somaxon management will host a conference call today at 9:00 a.m. Eastern Time to
review the status of the preclinical program for SILENOR™. Callers may participate in
the conference call by dialing (800) 218-0204 (domestic) or (303) 262-2139
(international). The conference call also will be available to interested parties through a
live audio Internet broadcast at www.somaxon.com and www.opencompany.info.
About Somaxon Pharmaceuticals
Headquartered in San Diego, CA, Somaxon Pharmaceuticals, Inc. is a specialty
pharmaceutical company focused on the in-licensing and development of proprietary
product candidates for the treatment of diseases and disorders in the fields of psychiatry
and neurology. Somaxon has completed four successful Phase 3 clinical trials for its lead
product candidate, SILENOR™ (doxepin HCl) for the treatment of insomnia. Somaxon
expects to file a New Drug Application with the U.S. Food and Drug Administration for
SILENOR™ in the third quarter of 2007, assuming that its ongoing preclinical studies
proceed as currently scheduled. Somaxon has completed a pilot Phase 2 trial for
nalmefene in smoking cessation with positive results and a Phase 2/3 clinical trial for
nalmefene for the treatment of pathological gambling that did not achieve statistical
significance for the primary or secondary endpoints. The company will evaluate the
results from both of these trials before making determinations regarding the future of the
nalmefene program. Acamprosate Ca, a potential treatment for movement disorders, is
currently in formulation development.
For more information, please visit the company’s web site at www.somaxon.com.
Somaxon cautions you that statements included in this press release that are not a
description of historical facts are forward-looking statements. For example, statements
regarding the FDA’s requirements relating to Somaxon’s preclinical studies, planned
filing of an NDA for SILENOR™ and potential for post-approval carcinogenicity studies
are forward looking statements. The inclusion of forward-looking statements should not
be regarded as a representation by Somaxon that any of its plans will be achieved.
Actual results may differ materially from those set forth in this release due to the risks
and uncertainties inherent in Somaxon’s business, including, without limitation, the
potential for the FDA to require additional preclinical work or other clinical
requirements to support submission or approval of an NDA submission for SILENOR™
or to be completed after regulatory approval; the timing of receipt of preclinical study
results and any NDA submission; the results which may be observed in the pending
preclinical studies for SILENOR™; the potential for SILENOR™ to receive regulatory
approval for one or more indications on a timely basis or at all; Somaxon’s ability to
demonstrate to the satisfaction of the FDA that a short-term carcinogenicity study is
appropriate for potential NDA approval of SILENOR™ in the context of completed trials
and pending studies; unexpected findings relating to SILENOR™ that could delay or
prevent regulatory filings, approval or commercialization, or that could result in recalls
or product liability claims; other difficulties or delays in development, testing,
manufacturing or marketing of and obtaining regulatory approval for SILENOR™; the
scope and validity of patent protection for SILENOR™; the market potential for
insomnia, and Somaxon’s ability to compete; Somaxon’s ability to attract and retain key
personnel; and other risks detailed in Somaxon’s prior press releases as well as in
periodic filings with the Securities and Exchange Commission.
You are cautioned not to place undue reliance on these forward-looking statements,
which speak only as of the date hereof. All forward-looking statements are qualified in
their entirety by this cautionary statement and Somaxon undertakes no obligation to
revise or update this news release to reflect events or circumstances after the date hereof.
This caution is made under the safe harbor provisions of Section 21E of the Securities
Exchange Act of 1934.
Contacts:
Meg McGilley
Chief Financial Officer
(858) 480-0402
Rob Whetstone
PondelWilkinson Inc.
(310) 279-5963
