SOURCE: Protherics PLC

June 24, 2008 02:00 ET

Protherics PLC announces Research Update

Cheshire, UK--(Marketwire - June 24, 2008) -

Protherics PLC

Start of phase 2a clinical study of Angiotensin Therapeutic Vaccine
in hypertension

London, UK; Brentwood, TN, US; 24 June 2008 - Protherics PLC
("Protherics" or the "Company"), the international biopharmaceutical
company focused on critical care and cancer, today announces that the
first patient has been enrolled in a phase 2a study of its Angiotensin
Therapeutic Vaccine (ATV) for the treatment of hypertension.

Hypertension is a major risk factor for serious and common
cardiovascular diseases such as heart attacks and strokes and the
global market for anti-hypertensive therapies is estimated to be worth
around USUSD30 billion*.  The majority of existing therapies are tablets
which need to be taken on a daily basis, usually for the rest of a
patient's life.  However, many patients with high blood pressure fail
to take their medicines as prescribed, and it is estimated that
approximately 70% of patients with hypertension do not have their blood
pressure adequately controlled*.  Therefore, a vaccine approach, which
may require only three injections and a booster after six months rather
than daily medication, should improve patient compliance with treatment.

The phase 2a, double-blind, placebo-controlled clinical study in
124 patients with mild to moderate hypertension has been initiated in
the UK.  Patients will be given a course of injections over six weeks.
The study will assess the safety and tolerability of the vaccine,
incorporating Protherics' promising novel vaccine adjuvant, CoVaccine
HT™.  In addition both antibody response and effect on blood
pressure will be assessed.  The blood pressure results are expected in
the first half of 2009.

Protherics has shown in a previous phase 2a study that a formulation of
ATV, incorporating the vaccine adjuvant Alhydrogel®, modulated key
hormones involved in regulating blood pressure in hypertensive
patients.  A new formulation of ATV has now been developed,
incorporating the CoVaccine HT™ adjuvant, which has demonstrated a
much stronger immune response in pre-clinical models.

CoVaccine HT™ and ATV are protected by extensive patents and
applications in the US, EU and the rest of the world.  The first US
patent on ATV was granted in May 2008.

Andrew Heath, Chief Executive of Protherics, commented:"We are excited
about the prospects for ATV, a potential value driver
for the company.  A vaccine approach to the treatment of high blood
pressure promises to address the issue of poor patient compliance with
daily medication and thus reduce the incidence of stroke and heart
attacks.  With data expected within a year, this could be a major
outlicensing opportunity."

*Company estimates

/ Ends /

For further information please contact:


Nick Staples, Director of Corporate Affairs +44 (0) 7919 480510

Saul Komisar, President, Protherics Inc     +1 615 327 1027

Financial Dynamics - press enquiries

London: Ben Atwell, Lara Mott               +44 (0) 20 7831 3113

New York: John Capodanno                    +1 212 850 5600

Or visit

Notes for Editors:

About Protherics

Protherics (LSE: PTI, NASDAQ: PTIL) is a leading international
biopharmaceutical company focused on specialist products for critical
care and cancer.

Protherics has produced two FDA approved biologics for critical care
use which are currently sold in the US: CroFabTM, a North American pit
viper antivenom and DigiFabTM, a digoxin antidote. Protherics reported
revenues of GBP26.1 million for its year ended 31 March 2008 and a
strong cash balance of GBP37.7 million.  The Company's strategy is to
use the revenues generated from its marketed and out-licensed products
to help fund the advancement of its broad, late stage pipeline.

Protherics has two major development opportunities in its portfolio.
CytoFab™ is being developed by AstraZeneca, for the treatment of
severe sepsis, following a major licensing deal announced in December
2005.  AstraZeneca is conducting an additional phase 2 programme
following changes to the commercial manufacturing process. A new
formulation of Angiotensin Therapeutic Vaccine, for the treatment of
hypertension, has today commenced a phase 2a study.  Protherics also
has four novel products being developed in a range of cancer
indications where it intends to undertake the sales and marketing in
the US and/or the EU.

With headquarters in London, the Company has approximately 300
employees across its operations in the UK, US and Australia.

For further information visit:

About Angiotensin Therapeutic Vaccine

Angiotensin Therapeutic Vaccine (ATV) is a conjugate vaccine containing
a peptide analogue of the hormone angiotensin I cross linked to the
carrier protein keyhole limpet haemocyanin (KLH).  ATV is designed to
treat hypertension by stimulating the immune system to neutralise
angiotensin I, a peptide hormone that plays a key role in the
regulation of blood pressure.

Protherics has previously shown in hypertensive patients that a first
generation formulation of ATV modulates key hormones involved in
regulating blood pressure.  An improved formulation of ATV has now been
developed, incorporating a novel vaccine adjuvant, CoVaccine HT™,
which has shown evidence of stimulating a much stronger immune response
in pre-clinical models.  CoVaccine HT™ was acquired by in June 2006
by Protherics from CoVaccine BV.

A vaccine approach to the management of hypertension is expected to
improve patient compliance with therapy, which is a major problem in
achieving control of high blood pressure with current therapy.  Because
of its envisaged slow onset and sustained effect, ATV has the potential
to be used on its own, or in combination with existing high blood
pressure medications, to improve the control of hypertension.  For more
information, visit

About Hypertension

Hypertension is one of the most common medical conditions in developed
countries and is a risk factor associated with heart attacks, heart
failure, blood vessel problems and kidney damage.  Current treatments
are tablet based, requiring daily doses, often for life, and patient
compliance is often poor.  The pharmaceutical market for high blood
pressure treatment is the largest single therapeutic sector in the
world, with global sales exceeding USUSD30 billion per annum.


This document contains forward-looking statements that involve risks
and uncertainties including with respect to products under development
and the progress and completion of clinical trials.  Although we
believe that the expectations reflected in such forward-looking
statements are reasonable at this time, we can give no assurance that
such expectations will prove to be correct. Given these uncertainties,
readers are cautioned not to place undue reliance on such
forward-looking statements. Actual results could differ materially from
those anticipated in these forward-looking statements due to many
important factors discussed in Protherics' Annual Report on Form 20-F
and other reports filed from time to time with the U.S. Securities and
Exchange Commission. We do not undertake to update any oral or written
forward-looking statements that may be made by, or on behalf of,

                    This information is provided by RNS
          The company news service from the London Stock Exchange


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