Research Update

Allergy Therapeutics PLC
24 July 2007

24 July 2007

                            Allergy Therapeutics plc
                   ("Allergy Therapeutics" or "the Company")

                          Clinical Development Update


On 11 July 2007 Allergy Therapeutics announced that activity on its clinical
studies had been placed on hold by the United States Food and Drug
Administration ('FDA') whilst the agency fully assesses the report of a rare
adverse event classified at that time by the physician involved as 'possibly
related' to the study drug (the 'Adverse Event').

Allergy Therapeutics continues urgently to investigate the detail of the Adverse
Event, and can notify that the treating physician has stated that, pending
further tests, in her opinion the patient's symptoms resulted from an
alternative diagnosis, of a condition which would be unrelated to the study
vaccine. The Company also continues to collaborate fully with the FDA, to
provide new data as it is accumulated and remains confident that following its
ongoing reviews the FDA will accept the alternative diagnosis.

Owing to the approaching pollen season, Allergy Therapeutics' ongoing Phase III
Ragweed trial (R301) has had to be definitively moved to the observation phase.
Prior to the clinical hold, 992 patients had been recruited onto this study, 92%
of the target of 1074. Of these, approximately 300 have received all four
injections and can therefore be considered to be participating in the study 'per
protocol'. Of the balance, about 300 had received 3 injections, 165 two and 227
one injection. Although the Company anticipates that useful data will be
collected from this study, it is sufficiently compromised that it is highly
unlikely to reach its primary endpoint. Therefore, completion of the Ragweed
programme will require a further study to complete the patient numbers, probably
to be conducted next year.  As a consequence the date for launch of Ragweed in
North America will be 12 months later than previously anticipated.

The Grass efficacy study G301 was already fully recruited and all treatment had
been completed when the FDA clinical hold was applied and will complete its
course as planned; however, the associated safety study cannot be commenced
until the hold is lifted.  As a result, the grass programme may also suffer some
delay in the USA, although this would not necessarily be a full year depending
upon when the clinical hold is lifted.

The Company will continue to give updates as and when new information becomes
available.


For further information

Allergy Therapeutics                                      [phone]
Keith Carter, Chief Executive
Tom Holdich, R&D Director

Bridgewell                                                [phone]
Shaun Dobson

Financial Dynamics                                        [phone]
Ben Brewerton



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