University Of Michigan Researchers Zero-In
CD55 Is Over Expressed On Prostate Cancer,
Promotes Cancer Cell Survival And Contributes To Metastatic Potential,
According To New Data
London, UK, 27 March 2006: Onyvax Limited, the biotechnology
company developing novel cancer therapies, today announced the
publication of two key research papers by a group led by Professor
Kenneth Pienta and Dr Robert Loberg at the University of Michigan,
that validate the target of the Onyvax-105 vaccine in prostate
cancer. The researchers report that CD55 is over-expressed in
prostate cancer and that it is an important mediator of prostate
cancer development, in particular by protecting tumour cells
from immune attack. Furthermore, they showed that inhibition
of CD55 expression in an in vivo model of prostate cancer resulted
in a 76% decrease in overall tumor burden. Key findings from
the research are summarized below.
CD55 is significantly over-expressed in prostate cancer
The first paper, published in December 2005, demonstrated that
CD55 is consistently elevated in cancerous versus normal prostate
tissue (Urology (2005)66:1321-1326). Furthermore, the molecule
was shown to be functionally active and protected cells from
Targeting CD55 reduces metastatic burden in prostate cancer
In the second paper published in January 2006 (Neoplasia (2006)
8:69-70), the researchers used siRNA to compare the growth of
prostate cancer cells that expressed CD55 versus those that did
not in an in vivo mouse model of prostate cancer metastasis.
The total tumor burden in mice injected with CD55 negative tumors
was 76% lower than mice with CD55 positive tumors. This result
provides further validation that an anti-CD55 therapy should
be a valuable tool for the treatment of prostate cancer patients.
Dr Kenneth Pienta said “This laboratory research shows
great promise for an anti-CD55 therapy, and we are looking forward
to moving this therapy into the urology clinics under a clinical
trial. There is a lack of effective therapies for metastatic
prostate cancer and it is the metastases that kill patients.
Any treatment that can help prevent the disease spreading would
be very valuable.”
Onyvax’s anti-CD55 antibody
Onyvax-105 is a fully human monoclonal antibody that has been
tested in clinical trials for colorectal cancer and osteosarcoma
and has shown encouraging results to date. The company is planning
new clinical trials of Onyvax-105, both as a monotherapy in
a range of cancer types including prostate cancer and in combination
with other treatment modalities, especially other immunotherapies.
In particular Onyvax is planning clinical trials of Onyvax-105
in combination with the company’s lead product, Onyvax-P,
a cell-based vaccine in late stages of development and due to
enter Phase IIb/III clinical trials in 2006. It is hoped that
administration of Onyvax-105 will disrupt the metastasis of prostate
cancer cells, unmask the tumor’s defensive shield and thus
enhance the effectiveness of the broad immune responses generated
For further information, please contact:
Dr Anthony Walker / Robert Johnson
+44 (0)208 682 9494
+44 (0)20 7831 3113
Notes to Editors:
Onyvax Ltd is a biotechnology company developing novel cancer
therapies that harness the selective power of the immune system
to seek and destroy tumor cells.
Founded in 1998, Onyvax is developing products that use the
power of the immune system to treat of prostate and other cancers.
Onyvax’s lead products are based on combinations of inactivated
cell lines that induce immune responses to a broad spectrum of
tumor targets. Onyvax-P, a Cell Vaccine for prostate cancer,
is due to enter Phase IIb/III clinical trials in early 2006.
For each cancer type, Onyvax generates banks of proprietary cell
lines representative of different stages of the disease. The
vaccines are manufactured in bulk under standardized conditions.
The Phase IIa trial for Onyvax-P demonstrated the product was
safe and showed signs of efficacy with 40% patients showing statistically
significant reductions of PSA velocity (a blood marker for prostate
cancer) and median progression free survival of 58 weeks versus
historical controls of 29-30 weeks.
Onyvax is also developing Onyvax-105, an antibody based therapy
designed to target CD55. The product has shown promising results
in early clinical trials in colorectal cancer and osteosarcoma.
The company is intending to develop the antibody further, initially
in prostate cancer.
Onyvax is committed to the commercialization of new therapies
that significantly prolong survival while maintaining a high
quality of life for cancer patients. The Company is based in
London and has collaborations with leading institutions in Europe
and the US. Further information on Onyvax can be found at www.onyvax.com