Oxford BioMedica Announces Positive DSMB Review of Ongoing RetinoStat® and StarGen(TM) Clinical Studies

OXFORD, England, August 8, 2012 /PRNewswire/ –

— Treatment of final RetinoStat(R)patient cohort underway –

Oxford BioMedica plc (“Oxford BioMedica” or “the Company”) (LSE: OXB), the leading
gene-based biopharmaceutical company, and its partner Sanofi (EURONEXT: SAN and NYSE: SNY)
today announce a positive interim review of the RetinoStat(R) Phase I study in neovascular
“wet” age-related macular degeneration (AMD) and the StarGen(TM) Phase I/IIa study in
Stargardt disease by the Data Safety Monitoring Board (DSMB); an independent panel of
specialists in the fields of ophthalmology, virology and vectorology. RetinoStat(R) and
StarGen(TM) were designed and developed by Oxford BioMedica using the Company’s
proprietary LentiVector(R) gene delivery technology.

DSMB highlights of ongoing RetinoStat(R) Phase I study

        - Nine patients treated to date (n=3 at each of dose levels 1, 2 and 3)
        - No serious adverse events related to RetinoStat(R) or its method of
          administration
        - Long-term safety profile now up to 18 months post-treatment (dose level 1)
        - Successful retinal transduction, as shown by substantial increase in
          expression and secretion of endostatin and angiostatin proteins measured in the
          anterior chamber of the eye following a single administration of RetinoStat(R). So
          far, expression is sustained for up to 12 months post-treatment at dose level 1 (n=3)
          and up to six months post-treatment at dose level 2 (n=3)
        - DSMB support received to proceed to final patient cohort (n=9, confirmatory
          dose level)

DSMB highlights of ongoing StarGen(TM) Phase I/IIa study

        - Eight patients treated at dose level 1 to date (n=4 severe level of
          disease, n=4 less severe)
        - No serious adverse events related to StarGen(TM) or its method of
          administration
        - Long-term safety profile now up to 12 months post-treatment (dose level 1)
        - DSMB support received to proceed to third patient cohort (n=4, dose level 2)

John Dawson, Chief Executive Officer of Oxford BioMedica, said: “The continued
progress of our ophthalmology portfolio, supported by another positive DSMB review, is
encouraging – particularly given that early RetinoStat(R) data demonstrate sustained
therapeutic protein expression in the eye following a single administration. The
favourable safety profile of our novel ocular gene therapies further supports the wider
LentiVector(R) platform safety package with over 33 patients treated to date across the
ocular and Parkinson’s disease programmes.”

The RetinoStat(R) open label, dose escalation Phase I study will enrol 18 patients
with “wet” AMD and will evaluate three dose levels to assess safety and aspects of ocular
physiology. The study is led by Professor Peter Campochiaro at the Wilmer Eye Institute at
Johns Hopkins, Baltimore (USA) and Oxford BioMedica has opened a second clinical site at
the Oregon Health and Science University, Portland with Dr Andy Lauer as principal
investigator. Further results from this study are expected in Q4 2012.

The StarGen(TM) open label, dose escalation Phase I/IIa study will enrol up to 28
patients and will evaluate three dose levels for safety, tolerability and aspects of
biological activity. In the US, the study is led by Professor David Wilson at the Oregon
Health and Science University, Portland, Oregon. In France, Professor Jose-Alain Sahel
leads the study at Centre Hospitalier National d’Ophtalmologie des Quinze-Vingts, Paris.
StarGen(TM) has received European and US Orphan Drug Designation which brings development,
regulatory and commercial benefits. Further results from this study are expected in Q4
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 with current partners and licensees
including Sanofi, Pfizer, GlaxoSmithKline, MolMed, Sigma-Aldrich, Biogen Idec, Emergent
BioSolutions and ImaginAb. Further information is available at

http://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. Oxford BioMedica’s agreement with Sanofi

Under the terms of the agreement signed with Sanofi in April 2009, Oxford BioMedica is
responsible for the pre-clinical and initial Phase I/II studies of four lentiviral
vector-based product candidates in the field of ophthalmology: RetinoStat(R) for “wet”
age-related macular degeneration, StarGen(TM) for Stargardt disease, UshStat(R) for Usher
syndrome 1B and EncorStat(R) for corneal graft rejection. Oxford BioMedica will receive
committed funding of up to US$24 million over the initial phase of development. Oxford
BioMedica granted Sanofi a license to develop the products and an option for further
development, manufacture and commercialisation on a worldwide basis. At any time prior to
or within a defined period after completion of each Phase I/II study, Sanofi can exercise
its option to license the products. On 29 June 2012, Sanofi elected to exercise its
options to acquire two exclusive worldwide licences for further development, manufacture
and commercialisation of StarGen(TM) and UshStat(R). Oxford BioMedica is currently
conducting the two ongoing Phase I/IIa trials for StarGen(TM) and UshStat(R). The
companies will continue to work together to plan the next stages of development and
finalise the terms of the worldwide licence agreements.

4. Age-Related Macular Degeneration and RetinoStat(R)

Age-related macular degeneration (AMD) is a major cause of blindness affecting an
estimated 25 to 30 million people worldwide and the incidence of AMD is expected to triple
by the year 2025 (source: AMD Alliance International). Neovascular “wet” AMD accounts for
the majority of all severe vision loss from the disease. RetinoStat(R) delivers two
anti-angiogenic genes, endostatin and angiostatin, directly to the retina and aims to
preserve and improve the vision of patients through anti-angiogenesis which blocks the
formation of new blood vessels. On the basis of pre-clinical data, it is anticipated that
RetinoStat(R) may require only a single administration which would give the product a
significant advantage in the market over currently available treatments that often require
frequent, repeated administration.

5. Stargardt disease and StarGen(TM)

Stargardt disease is the most common juvenile degenerative retinal disease which
affects approximately 80-100,000 patients in the US and Europe. The disease is caused by a
mutation of the ABCR gene which leads to the degeneration of photoreceptors in the retina
and vision loss. StarGen(TM) uses the Company’s LentiVector(R) platform technology to
deliver a corrected version of the ABCR gene. On the basis of pre-clinical data, it is
anticipated that a single application of StarGen(TM) to the retina could potentially
either provide long-term or permanent correction. There are currently no approved
treatments available for Stargardt disease.

        For further information, please contact:

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

        Media Enquiries:
        Mary Clark/Sarah Macleod/Claire Dickinson M:Communications
        Tel: +44(0)20-7920-2360

SOURCE Oxford BioMedica plc