brachysil cancer therapy achieves primary endpoint

ASX/MEDIA RELEASE 21st June 2005
BrachySil™ Cancer Therapy Achieves Primary Endpoint
in Phase IIa Clinical Trials
Final Report Confirms BrachySil™ Safe and Well Tolerated
Global nanotechnology company pSivida Limited (ASX:PSD, NASDAQ:PSDV, XETRA:PSI)
and the Singapore General Hospital (“SGH”), are very pleased to announce key findings
from the final report on its Phase IIa clinical trials with BrachySil™ as a potential new
brachytherapy treatment for inoperable primary liver cancer.
The report confirms that the primary endpoint of the trial was achieved in its key first
indication in that BrachySil™ (32-P BioSilicon™) was found to be both safe and well
tolerated. The trial was conducted at the SGH on eight patients with advanced liver cancer
who were evaluated after three and six months following treatment.
Among other key findings of the trial was the finding that BrachySil™ also reduced
significantly the size of tumors treated as determined by CT scanning. These combined
results pave the way for a multi-centre Phase IIb dose-profiling study for BrachySil™ in this
indication, which is scheduled to begin later in 2005. This study is expected to provide data
to support the registration of BrachySil™ as an approved treatment for liver cancer.
Gavin Rezos, Managing Director of pSivida, said, “This report confirms the excellent results
for BrachySil™ that we previously announced at the 12-week interim study time point, and
will provide not only a robust foundation for future clinical development and regulatory filing,
but also a springboard for our ongoing licensing activities with partners looking to enhance
their own portfolios of specialist cancer therapies.”
Dr Pierce Chow, Senior Consultant, Hepatobiliary and General Surgery at Singapore
General Hospital, said, “From the perspective of patients suffering with advanced cancer of
this kind, BrachySil™ promises to offer the possibility of an effective, safe and relatively
pain-free treatment, which can potentially improve both the duration and quality of life. We,
at the SGH, are very encouraged by the promising data seen to date with BrachySil™ and
are optimistic that subsequent clinical trials will continue to show positive results in this and
other serious cancer indications.”
BrachySil™ is a micron-sized nanostructured silicon particle in which radioactive 32-
phosphorus (32-P) is immobilized. It is administered as a liquid suspension through a finegauge
needle directly into tumors. The procedure takes place under local anaesthetic and
without the need for shielded rooms or robotic injectors, and patients can be discharged the
next day.
Key Findings
The final report of the Phase IIa clinical trial has confirmed four key findings:
• Safety – No product-related adverse events
BrachySil™ was found to be well tolerated by all eight patients in the trial group. No
significant product-related adverse events were reported either immediately following
implantation or during the six month follow–up period. Adverse events tended to be mild
and transient.
• Efficacy – Treated tumors demonstrate significant tumor regression
Implanting BrachySil™ directly into tumors results in significant tumoricidal activity.
Although the primary objective of the study was to determine the safety profile of
BrachySil™, CT scan analysis of tumors at the time of treatment and three and six months
later demonstrates significant tumor regression in targeted lesions with a maximum
regression of 100% in some small tumors from the dose used in the trial.
• Specificity – Retention of radioactivity in the tumor
A key finding is that BrachySil™ microparticles remain in the tumor with no or insignificant
detectable radioactive leakage. This observation is a very significant outcome for the trial.
Unlike other liver brachytherapy approaches that involve delivery via the hepatic artery
which, in some cases, results in radioactivity becoming associated with healthy tissue,
BrachySil™ is administered directly into tumors restricting radioactivity to the tumor itself.
• Ease Of Application – Practical and rapid treatment of tumors with ultrasound and
CT guidance
The procedure has been shown to be straightforward and accurate for the treatment of
tumors in a routine and conventional clinical setting. From a market perspective, this
demonstration is in line with the Company’s strategy to develop a simple procedure for the
nuclear medicine physician and interventional radiologist to selectively treat specific
tumors.
Next Steps
As mentioned above, pSivida is planning to initiate a multi-centre Phase IIb dose-profiling
study for BrachySil™ as a treatment for advanced liver cancer in the second half of 2005.
The Company plans to pursue a ‘device-based’ regulatory strategy, with BrachySil™ filings
scheduled in 2007 initially as a treatment for liver cancer and thereafter for the treatment for
other cancers involving solid tumors.
pSivida has already started a development programme for BrachySil™ in a second key
cancer indication – pancreatic cancer – and plans to commence Phase IIa clinical trials
before the end of 2005 to evaluate and safety and tolerability of the treatment. The trial will
also monitor the efficacy of the treatment based on CT measurements of tumor regression
as a foundation for subsequent Phase IIb dose-profiling studies.
Finally, pSivida will employ a multi-injector/implanter device that will be clinically evaluated in
all subsequent trials using BrachySil™ as a means of ensuring effective distribution of the
implanted dose from a single entry point. This device will, for the first time, enable physicians
to treat larger tumors and could represent a significant advantage of BrachySil™ over
existing brachytherapies. The Company is currently seeking development and marketing
partners for BrachySil™ in the major territories.
Notes on BrachySil™ and competitive advantages in brachytherapy
BrachySil™ (32-P-BioSilicon™) is being manufactured to regulatory guidelines by supply
chain contract partners including Atomising Systems Ltd and High Force Ltd in the UK and
Auriga Medical in Germany. Importantly the manufacturing process has already been scaled
up successfully to supply materials for clinical trial programmes and early product launch.
Brachytherapy treatment utilising BrachySil™ includes the following potential advantages:
• Short range – 32-P isotope has a short active range resulting in controlled exposure
to radioactivity and less damage to healthy tissue.
• Immobilization – 32-P device is immobilized in the tumor, significantly reducing risk
of leakage or systemic side effects.
• Ease of application - BrachySil™ is delivered under local anaesthetic and patients
can be discharged the next day.
• Direct delivery – BrachySil™ is delivered via fine-gauge needle, minimizing side
effects and tissue trauma without the need for shielded rooms or robotic injectors
allowing treatment in hospitals without the need for investment in specialised
facilities.
• Range of tumors – fine-gauge needle delivery allows potential application to many
solid tumors, unlike current brachytherapy products.
• Distribution – 32-P half-life of 14 days allows convenient distribution to hospitals
and application in the patient.
• Manufacture – BioSilicon™ is “radiation hard” allowing ease of manufacture of
BrachySil™ from phosphorus-doped silicon used in the electronics industry without
the need to build costly manufacturing facilities.
-ENDSFor
further information, please contact:
pSivida Limited Tel: + 61 (8) 9226 5099
Gavin Rezos, Managing Director
Joshua Mann, CFA, Investor Relations
Singapore General Hospital Tel: + 65 6321 4325
Ms Angela Ng,
Assistant Manager, Corporate Communications
US Public Relations
Beverly Jedynak, Martin E. Janis & Co. Tel: +1 (312) 943 1100
UK & Europe Public Relations
Mark Swallow, Ph.D, Citigate Dewe Rogerson Tel: +44 (0)20 7638 9571
NOTES TO EDITORS:
pSivida Limited
pSivida is a global nanotechnology company committed to the biomedical sector and the development
of products in healthcare. The company’s focus is the development and commercialisation of a
modified form of silicon (porosified or nano-structured silicon) known as BioSilicon™. As a new and
exciting biocompatible material, BioSilicon™ offers multiple potential applications across the high
growth healthcare sector, including controlled release drug delivery, targeted cancer therapies
(including brachytherapy and localized chemotherapy), tissue engineering and orthopedics. Potential
diagnostics applications are being developed through its subsidiary AION Diagnostics Limited.
pSivida owns the intellectual property rights to BioSilicon™ for use in or on humans and animals. The
IP portfolio consists of 26 patent families, 30 granted patents and over 80 patent applications. The
core patent, which recognises BioSilicon™ as a biomaterial was granted in the UK in 2000 and in the
US in 2001.
pSivida is listed on NASDAQ (PSDV), the Australian Stock Exchange (PSD) and in Germany on the
Frankfurt Stock Exchange on the XETRA system (German Symbol: PSI. Securities Code (WKN)
358705). pSivida’s shares also trade in the United Kingdom on the OFEX International Market Service
(IMS) under the ticker symbol PSD.
The Company’s strategic partner and largest shareholder is the QinetiQ group, the largest science
and technology company in Europe. QinetiQ is the former UK government Defence Evaluation
Research Agency and was instrumental in discovering BioSilicon™. pSivida enjoys a strong
relationship with QinetiQ having access to its cutting edge research and development facilities. For
more information on QinetiQ visit www.qinetiq.com.
For more information visit www.psivida.com
Singapore General Hospital
Singapore General Hospital (SGH) is Singapore’s oldest and largest tertiary acute care hospital and
national referral centre. It offers a comprehensive range of clinical specialties and support services
for the South-East Asia region. Annually, 70,000 patients are admitted to the hospital and 600,000
attend its specialist outpatient clinics. SGH also recognizes research and education as essential
pillars of healthcare. Drawing upon its wealth of resources (clinical expertise, modern research
facilities, and patient data and specimens), the Hospital’s researchers are pursuing, in an integrated
and holistic manner, the full range of ‘molecules-to-communities’ studies. Extensive teaching and
educational services are also offered.
For more information visit www.sgh.com.sg
This document contains forward-looking statements that involve risks and uncertainties. Although we believe that the expectations
reflected in such forward-looking statements are reasonable at this time, we can give no assurance that such expectations will prove to
be correct. Given these uncertainties, readers are cautioned not to place undue reliance on such forward-looking statements. Actual
results could differ materially from those anticipated in these forward-looking statements due to many important factors including: our
failure to develop applications for BioSiliconTM due to regulatory, scientific or other issues. Other reasons are contained in cautionary
statements in the Registration Statement on Form 20-F filed with the U.S. Securities and Exchange Commission, including, without
limitation, under Item 3.D, "Risk Factors" therein. We do not undertake to update any oral or written forward-looking statements that
may be made by or on behalf of pSivida.