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Exh. 99.1
Contact:
<Table>
Investors: Media:
Ann Tanabe Daniel Budwick
Director, Investor Relations and Corporate Communications BMC Communications
Encysive Pharmaceuticals (212) 477-9007 ext. 14
(713) 796-8822
</Table>
Hershel Berry
The Trout Group
(415) 392-3385
FOR IMMEDIATE RELEASE
ENCYSIVE ANNOUNCES RESULTS FROM STRIDE-4
CONFERENCE CALL SCHEDULED FOR TODAY AT 4:45 P.M. ET
HOUSTON- DECEMBER 20, 2004- Encysive Pharmaceuticals (Nasdaq: ENCY) today
announced top line results from STRIDE-4, a Phase III, randomized, double-blind,
placebo-controlled safety and efficacy study of Thelin(TM) treatment in patients
with pulmonary arterial hypertension (PAH).
STRIDE-4 was designed to determine whether a lower, 50 mg dose of Thelin could
be as effective as the 100 mg dose. The study enrolled 98 patients in Latin
America, Poland and Spain; 34 patients in a placebo arm, and 32 each in the 100
and 50 mg arms. For the primary endpoint of six minute walk, patients treated
with 100 mg of Thelin improved 58 meters versus 22 meters for the 50 mg dose
(p=0.014) and 34 meters with placebo (p=0.2). All other efficacy parameters, for
which the trial was not powered, trended toward significance at the 100 mg dose
versus placebo: WHO class (p=0.038), time to clinical worsening (p=0.09) and
Borg dyspnea scale (p=0.016). No patient receiving 100 mg of Thelin deteriorated
in WHO class versus 12% on placebo. There were three clinical worsening events
with placebo versus none on 100 mg of Thelin. The 50 mg dose showed no
meaningful efficacy trends on any parameter.
Thelin continued to demonstrate a favorable safety profile. Drug therapy
discontinuations and serious adverse events occurred with similar frequency in
all groups. One patient in each group (3%) experienced liver transaminase
increases above three times the upper limit of normal. All three were
discontinued from the study and both Thelin patients fully recovered without
developing symptoms. Bleeding adverse events were similar in all three groups
with the lowest incidence occurring in the 100 mg Thelin dose group. The most
frequently observed adverse events in the study occurring more frequently than
placebo were fatigue, edema, headache, dizziness, nasopharyngitis, dyspnea and
extremity pain.
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Exh. 99.1
"The lack of a significant placebo response has been a constant observation in
PAH placebo-controlled trials. However, prior registration studies have been
conducted in countries where patients have had easier access to advanced medical
care," noted program principal investigator Dr. Robyn Barst, Professor of
Pediatrics at Columbia University College of Physicians and Surgeons, and
Director, New York Presbyterian Hospital Pulmonary Hypertension Center. "In
STRIDE-4, the roughly 30% of patients from Europe performed as expected, with a
61 meter placebo-subtracted improvement in six minute walk for the 100 mg dose.
I would hypothesize that the placebo effect seen in STRIDE-4 may reflect an
improvement in the overall medical care of the patients from Latin America while
enrolled in a placebo-controlled trial."
"This was an insurance study to support the 50 mg dose of Thelin if it turned
out to be effective in the STRIDE-2 study. With the 50 mg dose proving
ineffective, STRIDE-4 becomes unnecessary from a registration perspective," said
Dr. Bruce D. Given, President and CEO of Encysive Pharmaceuticals, Inc. "While
the placebo response on six minute walk is unwelcome, the overall performance of
the 100 mg dose of Thelin was as expected and leaves us feeling encouraged going
into the pivotal STRIDE-2 results in February."
CONFERENCE CALL INFORMATION
You may access the conference call scheduled for Monday, December 20, 2004, at
4:45 p.m. ET either through the call-in number or an audio webcast. The access
number for the call is (612) 332-0335.
Or, you may participate live online via Encysive's web site at www.encysive.com.
The webcast replay will be available until January 29, 2005. In addition, a call
replay will be available beginning December 20, 2004, at 8:15 p.m. ET through
December 24, 2004. The telephone replay can be accessed by calling (320)
365-3844 and entering passcode 763279.
ABOUT THELIN AND PAH
Thelin is a small molecule that blocks the action of endothelin, a potent
mediator of blood vessel constriction and growth of smooth muscle in vascular
walls. Endothelin receptor antagonists may prove to be effective in the
treatment of a variety of diseases where the regulation of vascular constriction
is important. Thelin is 6,500-fold selective in the targeting of the endothelin
A receptor versus the endothelin B receptor.
Pulmonary arterial hypertension (PAH) is a condition that involves high blood
pressure and structural changes in the walls of the pulmonary arteries, which
are the blood vessels that connect the right side of the heart to the lungs. PAH
causes shortness of breath, limits activity, and is eventually fatal unless
treated successfully with heart/lung or lung transplantation. PAH is estimated
to afflict approximately 80,000 to 100,000 people worldwide, many of whom are
children and young women.
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Exh. 99.1
Side effects of Thelin seen in the program to date, and which occurred more
frequently than in placebo, include liver dysfunction (increased ALT and AST),
headache, edema, constipation, nasal congestion and flushing. Because Thelin
inhibits the metabolism of warfarin, the dose of warfarin should be adjusted
downward when co-administered with Thelin.
ABOUT ENCYSIVE PHARMACEUTICALS
Encysive Pharmaceuticals Inc., a biopharmaceutical company focused on the
discovery, development and commercialization of novel drugs, is recognized for
our expertise in small molecule drug development and vascular biology.
Argatroban, our first FDA-approved product, is being marketed by GlaxoSmithKline
for heparin-induced thrombocytopenia. Encysive Pharmaceuticals is in Phase III
development of the endothelin antagonist, Thelin, for pulmonary arterial
hypertension. Our majority-owned affiliate, Revotar Biopharmaceuticals AG, is in
Phase II development with the selectin antagonist bimosiamose in asthma,
psoriasis and atopic dermatitis. Encysive Pharmaceuticals has several other
research and development programs ongoing for a range of cardiovascular and
inflammatory diseases. To learn more about Encysive Pharmaceuticals please visit
our web site: www.encysive.com.
This press release contains "forward-looking statements" within the meaning of
Section 27A of the Securities Act of 1933, as amended, and Section 21E of the
Securities Exchange Act of 1934, as amended. These forward-looking statements
are subject to certain risks, trends and uncertainties that could cause actual
results to differ materially from those projected. Among those risks, trends and
uncertainties are timing and cost of our clinical trials, attainment of research
and clinical goals and milestones of product candidates, attainment of required
government approvals, sales levels of our products and availability of financing
and revenues sufficient to fund development of product candidates and
operations. In particular, careful consideration should be given to cautionary
statements made in the various reports Encysive Pharmaceuticals, including as
Texas Biotechnology Corporation, has filed with the Securities and Exchange
Commission. The Company undertakes no duty to update or revise these
forward-looking statements.
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