Final Phase II Data Shows That Onyvax-P
May Significantly Extend Progression Free Survival For Men
With Advanced Prostate Cancer
London, UK – 17 June, 2004: Onyvax Limited, the biotechnology
company developing novel cancer therapies, today announced
final Phase II clinical data showing that treatment with Onyvax-P,
the company’s investigational immunotherapy, may provide
a clinical benefit to men with advanced (hormone-resistant)
prostate cancer (HRPC).
The data show that in 26 men whose disease has not metastasised
to the bones (Cohort One), the median progression free survival
(PFS) was 58 weeks which compares favourably with recently
published data of 26-29 weeks (Journal of Clinical Oncology
(2000) 18:3894-3903; Atlas of Clinical Urology (2002), Ed.
Peter T. Scardino MD). All patients also received standard
of care, which is a continuation of hormone therapy plus supportive
care, when appropriate.
In addition to this PFS benefit, patients also showed biochemical
and immunological responses to the treatment. 11 patients (42%)
experienced a prolonged, statistically significant reduction
in prostate specific antigen (PSA) velocity. PSA is a blood
marker for prostate cancer and at this stage of the disease
generally increases exponentially until death. According to
studies presented at this year’s ASCO meeting, a prolonged
reduction in PSA velocity correlates with and is a predictor
of prostate cancer disease progression and survival in HRPC
(2004 ASCO Annual Meeting abstracts 4506 and 4554). Furthermore,
vaccinated patients who showed a clinical slowdown in disease
exhibited evidence of immunological activation, including proliferation
of patient T cells and enhancement of cytokine responses. The
treatment was very well tolerated and side effects were limited
to mild fatigue and local injection-site reactions.
“These findings add to the growing body of evidence
that immunotherapies may be effective in treating cancer. Onyvax-P
may provide a new option for men who have limited treatment
alternatives when their PSA level is rising but are otherwise
asymptomatic,” said Dr Hardev Pandha, MD, Consultant
in Medical Oncology at St George’s Hospital Medical School,
London and principal investigator for the study. “This
is a novel approach to treat prostate cancer that appears to
be safe and feasible. We hope that immunotherapies such as
Onyvax-P alter the natural history of the disease and the data
from this trial provide a clear basis for the initiation of
larger Phase III randomised studies in this group of patients.”
“This study was designed to assess whether to conduct
further trials of this product. Based on the clinical, PSA
and immune response data generated, the case for further investigation
is overwhelming,” said Anthony Walker, PhD, Chief Executive
at Onyvax Limited. “Manufacturing of material for pivotal
trials is underway and we hope to start patient recruitment
in early 2005.”
The trial recruited 48 patients in two prospectively defined
cohorts. The first cohort recruited 28 patients with HRPC with
no bone metastases. The second cohort recruited patients with
HRPC with bone metastases but no clinical symptoms. Two patients
in Cohort One did not receive treatment due to protocol violation.
Data from Cohort Two, which recruited men with asymptomatic
metastatic HRPC is still being collected and will be presented
later in the year. Survival data is being collected for both
cohorts.
The trial enrolled patients with all levels of Gleason scores
(a measure of the aggressiveness of prostate cancer) including
the highest risk patients. The median Gleason score in Cohort
One was 7.7.
Disease progression in the trial was defined by the development
of new lesions in the bone or soft tissue; the requirement
of palliative treatment with an opioid analgesic for new disease-related
pain; the occurrence of new disease-related symptoms that required
intervention such as treatment with chemotherapy, radiation
or surgery; the occurrence of a clinical event determined by
the investigator to represent disease progression; or death.
For further information, please contact:
Onyvax Financial Dynamics
Dr Anthony Walker / Robert Johnson Francetta Carr / Lucy Briggs
+44 (0)208 682 9494 +44 (0)20 7831 3113
