Oxford BioMedica Announces Presentation of New Clinical Data From ProSavin(R) Phase I/II Study in Parkinson's Disease

OXFORD, England, May 23, 2011 -

- Six-Month Data From Third Cohort Presented at ASGCT 14th Annual
Meeting -

- Highest Efficacy Results to Date With 43% Average Motor Function
Improvement -

Oxford BioMedica plc ("Oxford BioMedica" or "the Company") (LSE: OXB), a
leading gene therapy company, announces that new data from the on-going Phase
I/II trial of ProSavin(R) for the treatment of Parkinson's disease (PD) were
presented at the American Society of Gene & Cell Therapy (ASGCT) 14th Annual
Meeting held in Seattle, USA by Professor Stephane Palfi, Principal
Investigator at the Henri Mondor Hospital in Paris, on Saturday 21 May 2011.

Highlights of third cohort at six months (2x dose, enhanced
administration)

- Average motor function1 improvement of 43%, with a maximum
of 61% in one patient;

- Patient diary data2 show an increase in functional "ON" time
(when PD symptoms are not present) of approximately 3 hours;

- Patient diary data2 show a decrease in "OFF" time (after
withdrawal of PD medication) of approximately 4 hours;

- Daily dose of L-DOPA "equivalent" therapy has either reduced
or remained stable;

- Quality of life has either improved or remained stable on
the PDQ-39 questionnaire3 and these findings are consistent with the UPDRS
activities of daily living (ADL) subscore4; and

- Continued favourable safety profile with no serious adverse
events related to ProSavin(R) or the enhanced administration procedure
developed by the Company.

1. Motor function is assessed according to the Unified
Parkinson's Disease Rating Scale (UPDRS) in patients' "OFF" state (i.e. after
withdrawal of PD medication).

2. Patient diary data only available for n=2 patients at six
months.

3. Quality of life is assessed based on a standard measure of
clinical benefit using a patient questionnaire known as PDQ-39.

4. The activities of daily living (ADL) subscore of the UPDRS
captures the impact of PD on daily function.

Commenting on the six-month third cohort results, Professor
Stephane Palfi, Principal Investigator at the Henri Mondor Hospital in Paris,
said: "Cohort 3 results at six months confirmed the safety profile of
ProSavin(R) and the enhanced delivery method which permits a significant
reduction of the surgical time. The encouraging efficacy data on Parkinsonian
motor symptoms obtained in cohort 3 patients show that we are definitely
approaching the right dose for the randomised Phase II study."

Stuart Naylor, Chief Scientific Officer of Oxford BioMedica,
said: "The ProSavin(R) data set is extremely promising in terms of the
improvements we are seeing across multiple endpoints. With patient diary
measures further supporting the positive impact on patients' lives, these
data underline the potential for this novel approach to address the motor
symptoms of Parkinson's disease. Our LentiVector(R) platform technology is
designed to treat chronic, degenerative diseases and the ProSavin(R) results
to date demonstrate the long-term benefits associated with a single
administration."

Tom Isaacs, President and Co-Founder of The Cure Parkinson's
Trust and person with Parkinson's disease, said: "ProSavin(R) is one of the
more advanced of the prospective gene therapy products in development for
Parkinson's and is unique in its aim to achieve dopamine replacement. These
results demonstrate it also has the potential to make a huge difference to
those of us living with this terrible condition. For 40 years, people with
Parkinson's have struggled with the complexities and side-effects of oral
L-DOPA. These statistics indicate that, at last, there might be an effective
and enduring alternative means of re-asserting control over the movement of
your own body. People with Parkinson's everywhere should take heart."

The on-going Phase I/II study is designed to assess the
safety, efficacy and dose evaluation of ProSavin(R) in patients with
mid-stage PD who are experiencing reduced benefit on L-DOPA "equivalent"
therapy. The trial is being conducted at two centres of excellence for
neurosurgery; the Henri Mondor Hospital in Paris with Professor Stephane
Palfi as Principal and Coordinating Investigator, and at Addenbrookes
Hospital in Cambridge, UK, with Dr Roger Barker as Principal Investigator.

Two dose levels (1x and 2x) have been evaluated in nine
patients to date. Six patients received the 2x dose, the latter three of
which were treated using an enhanced administration procedure that has been
shown to reduce the surgical delivery time by 50%; facilitates higher dosing;
and has the potential to provide better reproducibility of administration as
study centres expand. Pre-clinical evidence suggests that the enhanced
procedure may also improve the distribution and, consequently, may improve
efficacy of ProSavin(R), which is further supported by the new data reported
today.

Summary of independently verified improvements in motor
function to date:

    Cohort Dose Administration 3 months        6 months 1 year     2 years
                method         (UPDRS)
                                               (UPDRS)  (UPDRS)    (UPDRS)
    1, n=3 1x   Original       Mean 27%        Mean 30% Mean 29%   Mean 20%
                               Max. up to 30%  Max. up  Max. up to Max. up to
                                               to 48%   44%        30%

    2, n=3 2x   Original       Mean 28%        Mean 34% Mean 29%   -
                               Max. up to 53%  Max. up  Max. up to
                                               to 53%   56%

    3, n=3 2x   Enhanced       Mean 26%        Mean 43% -          -
                               Max. up to 52%  Max. up
                                               to 61%

A further higher (5x) dose of ProSavin(R) is being assessed in
the current six-patient cohort; the scaled equivalent to the optimal dose in
pre-clinical studies. Three-month results from the first three patients in
the 5x dose cohort are expected mid-2011 and will be announced in H2 2011
following a review by the study's independent Data Monitoring Committee
(DMC). Planning is on-going for a sham-controlled Phase II study that will
recruit up to 50 patients. Depending on the results from the 5x dose cohort
and the independent opinion from the study's DMC, a randomised Phase II trial
of ProSavin(R) could be initiated in the EU/US in 2012.

Notes to editors

1. Oxford BioMedica(R)

Oxford BioMedica plc (LSE: OXB) is a biopharmaceutical company
developing innovative gene-based medicines and therapeutic vaccines that aim
to improve the lives of patients with high unmet medical needs. The Company's
technology platform includes a highly efficient LentiVector(R) gene delivery
system, which has specific advantages for targeting diseases of the central
nervous system and the eye; and a unique tumour antigen (5T4), which is an
ideal target for anti-cancer therapy. Through in-house and collaborative
research, Oxford BioMedica has a broad pipeline and its partners include
sanofi-aventis, Sigma-Aldrich and Pfizer. Further information is available at
www.oxfordbiomedica.co.uk.

2. LentiVector(R) gene delivery technology

Oxford BioMedica's LentiVector(R) gene delivery technology is
one of the most advanced gene delivery systems currently available, which has
many applications in product development and discovery research. It is the
system of choice for gene-based treatments addressing chronic and inherited
diseases. Oxford BioMedica has established a dominant intellectual property
estate in the field of lentiviral-vector mediated gene delivery through its
in-house research and from work conducted by the Company's co-founders at
Oxford University.

3. Parkinson's disease

Parkinson's disease affects approximately 1.5 million patients
in the seven major markets (US, Japan, UK, France, Germany, Italy and Spain)
which is projected to rise to 1.7 million by 2019. None of the current
treatments provide long-term relief from symptoms, yet, by 2019, sales of
these treatments could exceed US$2.8 billion in the seven major markets
(source: Datamonitor, Dec-2010). ProSavin(R) has the potential to address a
major unmet medical need in Parkinson's disease, offering long-lasting
benefit from a single administration with an excellent safety profile. The
product could therefore also significantly reduce the social care burden that
is associated with the mid to late-stage of disease.

4. ProSavin(R)

ProSavin(R) uses the Company's LentiVector(R) gene delivery
technology to deliver the genes for three enzymes - AADC (aromatic amino acid
decarboxylase), TH (tyrosine hydroxylase) and CH1 (GTP-cyclohydrolase 1) -
that are required for the synthesis of dopamine. These genes re-programme
transduced cells to manufacture and secrete dopamine. The product is
administered locally to the region of the brain called the striatum,
converting cells into a replacement dopamine factory within the brain, thus
replacing the patient's own lost source of the neurotransmitter. ProSavin(R)
has the potential to address an unmet medical need in Parkinson's disease,
offering long-lasting benefit from a single administration with an excellent
safety profile.

5. The Cure Parkinson's Trust

The Cure Parkinson's Trust funds innovative science and
inspirational scientists. It supports and galvanises pilot studies of novel
therapies. It believes that the key ingredients to achieving its only goal -
"a cure" - are teamwork, communication and urgency. People with Parkinson's
were integral to its formation and continue to be the focal point for every
decision made. www.cureparkinsons.org.uk

The Cure Parkinson's Trust, The Vestry, 1, St Clement's Court,
London, EC4N 7HB Tel: +44(0)20-7929-7656 Email: cptinfo@cureparkinsons.org.uk
Registered charity number: 1111816

    For further information, please contact:
    Oxford BioMedica plc:
    Lara Mott, Head of Corporate Communications  Tel: +44(0)1865-783-000

    Media/Financial Enquiries:                  Tel: +44(0)20-7920-2342
    Emma Thompson/Katja Toon/Amber Bielecka
    M:Communications

.