TroVax Phase II Trials

Oxford Biomedica PLC
01 September 2004


FOR IMMEDIATE RELEASE                                         1 SEPTEMBER 2004


OXFORD BIOMEDICA ANNOUNCES POSITIVE INTERIM PHASE II RESULTS WITH TROVAX IN
COLORECTAL CANCER

Oxford, UK - 1 September 2004: Oxford BioMedica (LSE: OXB) announced today that
the primary endpoints have been achieved at the interim stage of two Phase II
trials in patients with Stage IV colorectal cancer receiving TroVax alongside
chemotherapy. TroVax is the Company's novel cancer immunotherapy product against
the tumour associated antigen 5T4. The primary endpoints are safety and
demonstrable anti-tumour immune responses against the 5T4 tumour antigen.

The results from an interim analysis of both trials, initiated in 2003, showed
that the combination of TroVax and standard of care chemotherapy is safe and
that patients mount specific immune responses to the 5T4 antigen. Full
recruitment is imminent across both trials with 36 of 37 projected patients
enrolled. The objective is to have ten evaluable patients in each setting. The
interim results are based on 13 patients in total, who have reached an interim
analysis point defined as four TroVax immunisations and more than eight cycles
of chemotherapy. There have been no serious adverse events associated with
TroVax treatment and the product was well tolerated. 11 of the 13 patients (85%)
mounted antibody and/or cellular immune responses to the 5T4 tumour antigen
following four immunisations with TroVax.

The Company expects to report full safety and immunological data in mid-2005
when all patients will have received 12 cycles of chemotherapy and 6 doses of
TroVax. At this time, tumour response rates will also be determined.

TroVax plus IFL chemotherapy

The protocol of the first Phase II trial is six immunisations of TroVax
alongside chemotherapy cycles of irinotecan, 5-fluorouracil (5FU) and leucovorin
(a combination referred to as IFL). A total of 19 patients have been enrolled.
Ten patients have reached the interim analysis point. Nine out of ten patients
(or 90%) have mounted specific anti-tumour immunological responses to the 5T4
antigen.

TroVax plus FOLFOX chemotherapy

The second Phase II trial protocol is similarly six immunisations of TroVax
alongside cycles of oxaliplatin, 5FU and leucovorin (referred to as FOLFOX). The
trial is fully recruited at 17 patients. Three patients have reached the interim
analysis point and two of these (or 67%) have shown anti-5T4 immune responses to
date.

Commenting on the Phase II results, Prof. Alan Kingsman, Chief Executive of
Oxford BioMedica, said, 'We are very pleased with the progress of our first
Phase II trials with TroVax. The high number of anti-5T4 responses at this
interim stage suggests that patients are able to mount an anti-tumour immune
response even in the context of chemotherapy treatment. In our earlier Phase I/
II trials, it was clear that anti-5T4 immune responses correlated with improved
patient survival. We now feel confident that TroVax has a role to play in the
treatment of colorectal cancer.'


                                     -Ends-


For further information, please contact:
Oxford BioMedica plc:
---------------------
Professor Alan Kingsman, Chief Executive               Tel: [phone]

Nick Woolf, SVP Corporate Strategy
City/Financial Enquiries:
-------------------------
Lisa Baderoon/ Mark Court: Buchanan Communications     Tel: [phone]
Scientific/Trade Press Enquiries:
---------------------------------
Sue Charles, Katja Stout: Northbank Communications      Tel: [phone]

An analyst briefing will be held at 10:00am today in relation to the interim
financial results followed by a press briefing which will commence at 11:30am.
The venue for both meetings is Buchanan Communications, 107 Cheapside, London
EC2V 6DN. The analyst presentation will be accessible live via a web cast and a
recording will be available after the meeting on the Company's website at
www.oxfordbiomedica.co.uk.

Notes to editors

1. Oxford BioMedica

Oxford BioMedica (LSE: OXB) is a biopharmaceutical company specialising in the
development of novel gene-based therapeutics with a focus on the areas of
oncology and neurotherapy. The Company was established in 1995 as a spin out
from Oxford University, and is listed on the London Stock Exchange.

In addition to its technical expertise in gene delivery, Oxford BioMedica has
in-house clinical, regulatory and manufacturing know-how. The development
pipeline includes two novel anti-cancer products in clinical trials; and two
neurotherapy products in advanced preclinical development for Parkinson's
disease and retinopathy. The Company is underpinned by an extensive preclinical
and research portfolio and about 70 patent families, which represents one of the
broadest patent estates in the field.

The Company has a staff of approx. 65 split between its main facilities in
Oxford and its wholly owned subsidiary, BioMedica Inc, in San Diego, California.
Oxford BioMedica has corporate collaborations with Wyeth, Intervet, Merck & Co,
Amersham, Viragen and Kiadis.

Further information is available at www.oxfordbiomedica.co.uk.

2. TroVax(R) cancer immunotherapy

TroVax is Oxford BioMedica's leading cancer immunotherapy product. It is
designed specifically to stimulate an anti-cancer immune response and has
potential application in most solid tumour types. TroVax targets the tumour
antigen 5T4, which is broadly distributed throughout a wide range of solid
tumours. The presence of 5T4 is correlated with poor prognosis. The product
consists of a poxvirus (MVA) gene transfer system, which delivers the gene for
5T4 and stimulates a patient's body to produce an anti-5T4 immune response. This
immune response destroys tumour cells carrying the 5T4 protein.

Two Phase I/II trials with TroVax have been completed in the UK in late-stage
colorectal cancer patients. The results showed that the product is safe, that
patients mount an anti-5T4 immune response, and that this immune response
correlates with improved survival.

Four of five planned Phase II trials are underway. The trials are investigating
TroVax in combination with standard of care treatment, post standard of care,
and as an adjuvant to surgery, in colorectal, renal cell and breast cancer. Full
recruitment is imminent in two trials in colorectal cancer patients receiving
standard of care chemotherapy (IFL and FOLFOX). Interim results indicate that
chemotherapy does not affect the frequency of anti-5T4 immune response in
patients. A trial in renal cell cancer is underway in the US under an IND, and
Cancer Research UK is enrolling patients in a trial in colorectal cancer
patients with operable liver metastases.

3. Colorectal cancer

Colorectal cancer is the second leading cause of cancer death in the US and the
third most frequently diagnosed cancer, according to the American Cancer
Society. There were an estimated 57,000 deaths from colorectal cancer in the US
in 2003, which equates to about 10% of all cancer deaths.

Colorectal cancer staging describes how advanced the cancer is. The most severe
is Stage IV, which defines cancers that have spread to other parts of the body
such as the liver or lungs. Therapies range from surgical removal of the cancer
tissue to radiation therapy and chemotherapy agents. Most therapies, however,
are associated with debilitating side effects that affect patients' quality of
life.

In the US, the current standard of care for first line treatment of Stage IV
colorectal cancer is the chemotherapy combination of irinotecan, 5-fluorouracil
(5FU) and leucovorin, a combination known as IFL. In Europe, the most common
treatment is oxaliplatin, 5FU and leucovorin, a combination referred to as
FOLFOX. The leading branded products are Pfizer's Camptosar(R) (irinotecan) in the
US; Aventis' Campto(R) (irinotecan) in Europe, which is being sold to Pfizer; and
Sanofi-Aventis' (formerly Sanofi-Synthelabo) Eloxatin(TM) (oxaliplatin). 
Combined sales of these products exceeded $1.6 billion in 2003.

A new first line treatment option received approval from the US FDA in February
2004. The product, AvastinTM (bevacizumab) from Genentech is a therapeutic
antibody deigned to inhibit VEGF, a protein that plays a role in tumour
angiogenesis and maintenance of existing tumour vessels. Avastin is approved for
use in combination with 5FU based chemotherapy regimens, including both IFL and
FOLFOX. The product has been filed for approval in Europe. In the second quarter
of 2004, Genentech reported Avastin sales of $133 million.

Despite the improvements in treatment, the available options remain
unsatisfactory to colorectal cancer patients, and there is a need for new
therapies offering improved efficacy, tolerability and convenience.

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