SOURCE: Protherics PLC

January 11, 2008 02:01 ET

Protherics PLC announces Research Update

Cheshire, UK--(Marketwire - January 11, 2008) -

                             Protherics PLC

             Protherics and Advancell start Acadra(TM) clinical study
                    in B-cell chronic lymphocytic leukaemia

London, UK; Brentwood, TN, US; 11 January 2008 - Protherics PLC ("Protherics" or
the "Company"), the international biopharmaceutical company focused on critical
care and cancer, and its co-development partner, Advancell s.l. ("Advancell"),
today announce that the first patient has now been enrolled in a recently
initiated phase 1/2 clinical study of Acadra(TM) (acadesine) in B-cell chronic
lymphocytic leukaemia (B-CLL).

Most drugs currently used to treat B-CLL also kill T-cells, suppressing the
patient's immune system and increasing the risk of serious infection; a common
cause of death in patients with B-CLL.  Acadra(TM) is a potentially selective
treatment for B-CLL which has been shown to cause the death of B-cells whilst
sparing T-cells in blood samples from patients with B-CLL.  Acadra(TM) has also
shown the capacity to kill B-CLL cells that are resistant to current therapies,
such as fludarabine. Protherics and Advancell are jointly developing Acadra(TM)
in this indication following a licensing and co-development agreement announced
in December 2006.

The phase 1/2 study will be conducted at sites in Belgium, France and Spain and
will enroll up to 30 B-CLL patients who have relapsed or are refractory to
existing chemotherapy. The open-label study is designed to assess the safety,
tolerability, pharmacokinetics and the effects on Acadra(TM) on B-cell and T-
cell counts. Part I of the study will investigate escalating single doses of
Acadra(TM) following in part II by an assessment of repeated doses. Results from
part I of the study are expected in the second half of 2008 and the final study
results are expected in the first half of 2009.

Luis Ruiz-Avila, Chief Executive Officer of Advancell, commented:

"We are delighted that Acadra has entered its first clinical study in patients
with B-CLL.  The current study is designed to demonstrate proof of concept in
terms of the selective targeting of B-cells in patients that are resistant or
refractory to fludarabine."

Andrew Heath, Chief Executive of Protherics, commented:

"Acadra is an exciting new therapy being developed to improve the safety and
tolerability of chemotherapy in B-CLL patients.  We expect to get an early
indication of selectivity in this open-label study and we are encouraged by the
strong ex-vivo data generated to date."

                                   |  Ends  |

For further information please contact:

 Andrew Heath, CEO                                          +44 (0) 20 7246 9950
 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, Jonathan Birt                    +1 212 850 5600

 Or visit

Notes for Editors:

About Acadra(TM) (previously acadesine)

Acadra(TM) is a novel nucleoside analogue for the treatment of B-cell chronic
lymphocytic leukaemia (B-CLL), a haematological cancer where there is an excess
of B-cells. Unlike existing chemotherapies for B-CLL, Acadra(TM) has been shown
ex-vivo to selectively kill B-cells, whilst having only minimal toxicity to T-
cells. This selectivity for B-cells means that acadesine therefore has the
potential to reduce the risk of serious infection and other side effects seen
with current chemotherapies. Acadra(TM) may also be effective in patients who
are refractory to fludarabine, which is widely used alone or in combination with
other agents as first line therapy in B-CLL, as it caused the death of B-cells
in blood samples from patients who were resistant to fludarabine.

About B-CLL

B-CLL is the most frequently occurring type of leukaemia in the western world
and accounts for about 40 per cent of all leukaemias in those over 65 years of
age; it is very rare in those below the age of 30 years. It follows an extremely
variable course with overall survival times ranging from months to decades.

About Protherics

Protherics (LSE: PTI, NASDAQ: PTIL) is a leading biopharmaceutical company
focused on the development, manufacture and marketing of specialised products
for critical care and cancer.

Protherics has developed and manufactures two biologics for critical care which
are FDA approved and currently sold in the US: CroFab(TM), a pit viper antivenom
and DigiFab(TM), a digoxin antidote.  Protherics generated GBP31.1 million in
revenues in its financial year ended 31 March 2007, and reported GBP46.9 million
in cash at the half year ending 30 September 2007. 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 critical care
portfolio. CytoFab(TM) is a promising treatment for severe sepsis and
AstraZeneca is about to start an expanded phase 2 programme following a major
GBP195 million licensing deal in December 2005.  In addition, Protherics is
expected to report headline data from a phase 2b "DEEP" study with Digoxin
Immune Fab in the treatment of pre-eclampsia in the first half of 2008.

Protherics has a pipeline of four novel cancer products in clinical development,
and intends to undertake the sales and marketing of these products in the US and
or the EU.  Protherics is preparing to resubmit a BLA for Voraxaze(TM), an
adjunct to high dose methotrexate therapy, in the US under a rolling submission
starting in H2 2008.

With headquarters in London, the Company has approximately 290 employees across
its operations in the UK, US and Australia. For further information visit:

About Advancell

Advancell is a Spanish biotech company that is a European leader in
nanomedicine. The company has two divisions: Pharma, which focuses its activity
on the development of innovative drugs through the search for new applications
for already-known molecules, and Services and Reagents, which uses cell-based in
vitro methods to predict the efficacy, safety and mechanism of action of
developing molecules. Advancell's business model allows it to achieve
substantial reductions in costs, risks and the development time of a drug.
Advancell is a world leader in nanomedicine, the science that uses technologies
at the nanometric (less then a millionth of a millimeter) scale to diagnose,
treat and prevent diseases. The most advanced project is focused on
nanomedicines for the topical treatment of psoriasis and other skin diseases. In
addition, Advancell is developing a new "orphan drug" for Chronic Lymphocytic
Leukaemia and an adjuvant treatment for depression, which is currently in the
clinical phase II.
The Services and Reagents Unit develops and markets in vitro cell models with a
regulatory and/or predictive value. Our R&D efforts are focused on the
development of new in vitro cell-based models and kits targeting skin ADME/Tox
and biology. We are experts in epithelial and mucosal barrier models, as well as
in hepatic metabolism and toxicity. Our ready-to-use reagent line
( is distributed throughout all of Europe.

The company is located in Barcelona's "Parc Cientific" and has research centres
at Santiago de Compostela University and Hospital La Fe, in Valencia.


This document contains forward-looking statements that involve risks and
uncertainties, including with respect to Protherics' product pipeline and
anticipated development and clinical trials for product candidates.  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, including the 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

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