Research Update

Allergy Therapeutics PLC
18 April 2007

Wednesday 18 April 2007



                            Allergy Therapeutics plc



           Announces Conclusive Results Of Oral Allergy Vaccine Study



      Promising Preliminary Results Reinforced In High Allergen Dose Group



Allergy Therapeutics plc (AIM: AGY), the specialist pharmaceutical company
focussed on allergy vaccination announces the successful conclusion of its Phase
IIA oral allergy vaccine study following on a December announcement of promising
initial data.  That earlier announcement was based on the preliminary data from
three study groups and today's announcement gives further details plus the data
from a fourth study group that received a higher dose of grass pollen allergen.




Allergy Therapeutics' new generation of allergy vaccines use MPL(R) an
innovative TLR4-agonist as an adjuvant to boost and accelerate the immune
response of an allergy vaccine.  This study (Study 103) recorded a number of
firsts.  It was the first ever examination of oral delivery of MPL in humans and
it was the first time that any adjuvant has ever been clinically tested in an
oral allergy vaccine.



The study showed that:



  • The vaccine was safe and well tolerated



  • Clinical symptoms improved following an eight week treatment period



  • Immunological response was noted following an eight week treatment period



  • Efficacy results follow a MPL dose dependant pattern



Fuller analysis of the data has given Allergy Therapeutics further confidence
that it can develop an effective, rapid-onset, orally delivered allergy vaccine.
  As a next step, the Company is discussing the study results with leading
allergy specialists to define the potential clinical benefit of MPL in orally
administered allergy vaccines and is completing an evaluation of the formulation
of a commercial product in preparation for further Phase II development.



What does it mean for allergy sufferers?



Allergic rhinitis or hay fever affects 35.9 million people in the United States
alone according to the AAAAI and is a large and growing problem.  Worldwide over
150 million people are estimated to suffer from allergic rhinitis.



The development of a convenient, effective, short course, oral allergy vaccine
would have significant implications for allergy therapy and redefine the market
for allergy products.  Currently available oral allergy vaccines require
prolonged treatment periods leading to poor patient compliance and low efficacy.
 There is an existing substantial unmet medical need and substantial costs to
society including US$12 billion of spending on pharmaceuticals each year.



Full Details of Study 103



The purpose of Study 103 was to investigate the potential benefit of MPL when
administered orally for the first time as part of a sublingual vaccine.



Study 103 was a double-blind placebo-controlled safety study evaluating
different doses of MPL and grass pollen allergen involving 4 groups of 20 grass
pollen sensitive subjects (16 active plus 4 placebo per group). Subjects self
administered the liquid sublingual vaccines daily for 8 weeks and assessments
were made during and 2 weeks after the dosing period.  Group 1 received Allergy
Therapeutics' Oralvac Plus grass pollen vaccine; Group 2 received a similar
vaccine incorporating a low dose of MPL and Group 3 likewise but with a higher
dose of MPL.  Group 4 received the higher dose of MPL but with a higher grass
pollen allergen dose.  Comparisons were made with the overall number of patients
on placebo (n=16).



The primary objective of the study was safety and tolerability.  Throughout the
study, all vaccines were well tolerated with no patients withdrawn due to
adverse events and no reports of serious or severe adverse reactions.  The
nature of adverse events was as expected with slightly more patients reporting
transient mild itching in the mouth during the first couple of days on active
treatment compared to placebo.  There was no evidence of any adverse effect
associated with the use of MPL.



The secondary objective of the study was to investigate the contribution of MPL
to the activity of the vaccines as measured by clinical (nasal challenge) and
immunological (IgG, IgG1, IgG4 and IgE) parameters.



The nasal challenge test involves the objective measurement of nasal airflow,
together with assessment of nasal secretions and irritation and other non-nasal
symptoms, at 10, 20 and 30 minutes after allergen is sprayed into the nose.  A
negative test indicates minimum reaction to the allergen challenge throughout.
Groups 3 and 4 show a notably greater proportion of patients with a negative
nasal challenge compared to placebo (44% vs 19%) following treatment (ITT).  A
further analysis indicates that Groups 3 and 4 (high dose MPL) show a
statistically significant improvement in nasal challenge over placebo combined
with Groups 1 and 2 (low dose MPL) (p<0.05).



In terms of immune response, all the active treatment groups showed an increase
in median IgG following treatment, yet with Groups 3 and 4 this rise was evident
earlier, after 3 to 5 weeks of treatment.  Regarding the IgG subclasses, an
increase in IgG4 in particular seemed to be associated with the addition of MPL.
 As would be expected with allergy vaccination, a rise in IgE was also
associated with active treatment; however, the rise in IgE was lowest with the
higher MPL dose Groups 3 and 4.



In summary, the results from Study 103 indicate a pattern of response with the
oral administration of MPL that matches with that already experienced with
subcutaneous administration - a stimulation of immune response accompanied by
clinical benefit (increase in negative nasal challenge after 8 weeks therapy).
Further detailed analyses of the nasal challenge component scores and of
secretory immunoglobulins, cytokines and other inflammatory markers is underway.




Keith Carter, Chief Executive of Allergy Therapeutics, said:



"Allergy Therapeutics' objective is to transform allergy treatment.  We have two
pivotal phase III allergy vaccine trials underway for Pollinex Quattro, with
MPL, using subcutaneous administration.  MPL assists in allowing Pollinex
Quattro to be dosed in four injections rather than the sixteen to fifty
injections that are currently standard practise in many parts of the world.
Study 103 demonstrates that MPL may have a similar potential of effect in oral
administration.  Currently available oral allergy vaccines require prolonged
treatment periods involving more than one thousand doses over a three and a half
year period.  We are now confident that MPL will allow us to do better than
this."



Professor Ludger Klimek, University of Mannheim, said:



"These results are very exciting.  The nasal challenge is a robust model
demonstrating clinical efficacy and we have not seen similar results before with
an oral vaccine after just 8 weeks treatment.  I look forward to presenting
these results at the EACCI meeting in Goteborg in June 2007"



For further information


Allergy Therapeutics                                      [phone]
Keith Carter, Chief Executive

Financial Dynamics                                        [phone]
David Yates
Ben Brewerton






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