Download New Data Shows Lack of Drug Tolerance or Dependence With

New Data Shows Lack of Drug Tolerance or Dependence With Novel Opioid Painkillers
SOUTH SAN FRANCISCO, Calif., Mar 15, 2002 -- Pain Therapeutics, Inc. (Nasdaq: PTIE), a medical research company, today
presented new data on its two novel opioid painkillers, OxyTrex(TM) and MorViva(TM), at the 21st Annual Scientific Meeting of
the American Pain Society in Baltimore, Maryland.
"The Company's new data present an intriguing challenge to the conventional view that opioid therapy is necessarily tied to
drug dependence and tolerance," said Grant Schoenhard, Ph.D., Pain Therapeutics' chief scientific officer. "In conjunction with
our academic collaborators, today we presented comprehensive animal data showing that chronic doses of oxycodone and
morphine need not necessarily be associated with opioid tolerance, dependence or withdrawal."
The Company presented two technical posters today at The American Pain Society meeting:
"OxyTrex(TM), a Novel Formulation of Oxycodone, Shows Absence of Tolerance, Physical Dependence and NaloxonePrecipitated Withdrawal Effects in Mice," and "MorViva(TM) Reverses and Prevents Morphine-Induced Tolerance and
Naloxone-Precipitated Withdrawal In Mice Chronically Treated with Morphine."
Study Abstracts
Oxycodone is a widely used opioid painkiller chemically related to morphine. With repeat use, the development of tolerance and
physical dependence is an often-observed feature of all opioid drugs. Pain Therapeutics is developing an alternative drug to
oxycodone called OxyTrex(TM), and an alternative drug to morphine called MorViva(TM). The Company believes these two
proprietary drugs offer minimal opioid tolerance and physical dependence following chronic administration. Investigators
recently conducted two pre-clinical experiments to test this hypothesis.
In the first experiment, two groups of healthy mice were given chronic doses of either morphine or MorViva(TM) over ten days.
As expected, mice that received morphine quickly became tolerant to the drug and no longer responded to a standard assay of
analgesia by day three. Mice that received MorViva(TM), however, did not show drug tolerance; these mice showed a
continuous analgesic response during the entire seven day study (p<0.01). Furthermore, when morphine tolerant mice were
switched over to MorViva(TM), these mice showed an analgesic response without subsequent redevelopment of tolerance
(p<0.01). These results demonstrate the ability of MorViva(TM) to prevent and to reverse opioid tolerance in laboratory animals
after chronic treatment.
In the second experiment, two groups of healthy mice were given chronic doses of either oxycodone or OxyTrex(TM) over
seven days. Mice that received oxycodone quickly developed drug tolerance. In contrast, mice that received OxyTrex(TM)
showed an absence of opioid tolerance. In addition, OxyTrex(TM) was more potent than oxycodone over the entire duration of
the study.
At the end each study mice were given naloxone to reverse the effects of both oxycodone and morphine. Mice that had been
receiving oxycodone or morphine went into a classic opioid withdrawal behavior, indicating the presence of physical
dependence. Mice that had been receiving OxyTrex(TM) or MorViva(TM) did not do so, indicating the absence of physical
dependence (p<0.01).
The results of these pre-clinical experiments indicate the Company's OxyTrex(TM) and MorViva(TM) drugs:
●
●
●
●
Do not result in analgesic tolerance (p<0.01)
Are more potent than oxycodone and morphine, respectively (p<0.01)
Remain efficacious longer than oxycodone and morphine, respectively (p<0.01)
Prevent withdrawal behavior, indicating the lack of physical dependence (p<0.01)
The Company's scientific posters will be available on its website, www.paintrials.com.
About Opioid Painkillers
Opioid ("narcotic") painkillers are drugs derived from opium and the poppy plant. The clinical use of opioid drugs to treat
severe pain is widely accepted throughout the world. In the United States, opioid drugs exceed $3 billion in annual sales and
account for over five percent of all prescription drug sales. Despite widespread use, opioid painkillers have debilitating effects
that limit their usefulness at all doses. Chronic use may lead to tolerance, dependence, abuse, or, more rarely, addiction. As a
result, some patients prefer to suffer through pain rather than endure the ill effects of opioid drugs. The under-treatment of
pain is a serious and growing problem in the U.S. For example, according to the National Institutes of Health, over 40 million
Americans are unable to find relief from their pain.
About Pain Therapeutics, Inc.
We are a medical research company specializing in the discovery and development of novel proprietary painkillers. We believe
our lead drug candidates, MorViva(TM) and OxyTrex(TM), may offer more pain relief (with no increase in side-effects) and
lower tolerance/dependence, withdrawal effects or addiction potential compared to conventional forms of oxycodone and
morphine. The target market for our drugs exceeds $3 billion in the United States. Our proprietary painkillers are currently in
various phases of clinical testing, including Phase II trials. Pain Therapeutics is traded on Nasdaq under the symbol PTIE.
Note Regarding Forward-Looking Statements: This press release contains forward-looking statements for purposes of the
Private Securities Litigation Reform Act of 1995 and it is Pain Therapeutics' intent that such statements be protected by the
safe harbor created thereby. Examples of such statements include, but are not limited to, statements about the minimal
tolerance and physical dependence effects of the Company's drug candidates, the timing, breadth or anticipated results of the
Company's clinical development of its drug candidates, the potential benefits of the Company's drug candidates and the size of
the potential market for the Company's products. Such statements are based on management's current expectations, but
actual results may differ materially due to various factors. Such statements involve risks and uncertainties, including, but not
limited to, those risks and uncertainties relating to difficulties or delays in development, testing, regulatory approval, production
and marketing of the Company's drug candidates, unexpected adverse side effects or inadequate therapeutic efficacy of the
Company's drug candidates that could slow or prevent product approval or market acceptance (including the risk that current
and past results of clinical trials are not necessarily indicative of future results of clinical trials), the uncertainty of patent
protection for the Company's intellectual property or trade secrets, the Company's ability to obtain additional financing if
necessary and unanticipated research and development and other costs. For further information regarding these and other
risks related to the Company's business, investors should consult the Company's filings with the Securities and Exchange
Commission, including its Form 10-K for the year ended December 31, 2000 and its subsequent quarterly filings.
NOTE: The BUTTERFLY DESIGN/LOGO is a registered trademark of Pain Therapeutics, Inc.
SOURCE Pain Therapeutics, Inc.
CONTACT: Christi Waarich, Manager, Investor Relations of Pain Therapeutics, Inc., +1-650-825-3324, or
[email protected]