Oxford
BioMedica's TROVAX® Poised to enter Phase II
Trials
Positive
Results for Therapeutic Cancer Vaccine
Oxford
BioMedica plc (LSE:OXB) will today release additional data
from its Phase I/II clinical trial of TroVax®
at the Society for Cancer Gene Therapy Conference in London.
The data,
being presented by Dr Miles Carroll, Vice President of Immunotherapy
at Oxford Biomedica, is from colorectal cancer patients at
the Christie Hospital in Manchester receiving medium and high
doses and shows that they tolerated the product well with
no adverse reactions being observed. In addition, the results
demonstrate that TroVax is extremely efficient at inducing
the appropriate immune response with all of the ten immunocompetent
patients analysed to date in the trial mounting a specific
response against the tumour antigen OBA1, the active component
of TroVax, and some patients showing reductions in levels
of circulating tumour marker proteins that are used as indicators
of tumour load. The new data reinforces the observations previously
reported for the low dose group. The trial has been a complete
success and TroVax will proceed to the next stage of clinical
development.
TroVax
is a gene-based therapeutic vaccine that is designed to stimulate
the patient’s immune system to recognise and destroy
cancer cells. The product is based on a gene that encodes
a protein, OBA1, that exists on the surface of tumour cells
and not on normal cells - such proteins are known as Tumour
Associated Antigens (TAAs). When the OBA1 gene is expressed
by Oxford BioMedica’s highly engineered virus-based
delivery system, it induces an anti-tumour response. OBA1
is present on a wide range of tumours, thus whilst the first
clinical trials of TroVax have been conducted in colorectal
cancer patients, TroVax is also expected to be applicable
to many other solid tumours.
The Phase
I/II study described today was designed primarily to assess
safety and immunogenicity of TroVax in 12 patients. As is
the case with all early stage cancer trials, the patients
were at a relatively advanced stage in the disease. All 12
patients have been recruited and treated with TroVax. As reported
previously, one of the patients in the low dose group was
unable to mount an immune response to any test antigen during
the study and so was not included in the immunological evaluation
of TroVax. One other patient is part-way through their treatment
and their immune responses have not been analysed fully to
date. The remaining 10 patients all responded to TroVax by
mounting an immune response to the tumour protein OBA1. It
is this response that is anticipated to have a beneficial
effect. In several patients the induction of the immune response
was correlated with reductions in circulating markers of tumour
load.
In the
current trial patients were recruited after they had completed
chemotherapy treatment. In the next trial it is likely that
the product will be tested on patients who are at a somewhat
earlier stage in the disease process. Although still in the
planning stage, it is likely that the next trial will be a
phase II study, in which TroVax will be assessed in colorectal
cancer patients while they are undergoing chemotherapy. This
patient group would be the first target market for TroVax.
Subsequently the therapy may be used in other tumours and
at an earlier stage.
The market
potential for TroVax is substantial as an addition to existing
cancer treatment regimens. Approved drugs such as irinotecan,
which have been shown to extend survival by a few months,
have achieved global sales in excess of $500 million as an
addition to standard 5-FU chemotherapy.
Commenting
on the results presented today Oxford BioMedica’s Chief
Executive, Professor Alan Kingsman said: “We are
delighted that the TroVax trials have been so successful with
such encouraging results. It is unusual for a vaccine, particularly
a cancer vaccine, to elicit an immune response in all patients.
We believe that we have achieved a significant step towards
TroVax progressing successfully to the market”.
-Ends- |
