Title: Vical Demonstrates Safety and Tolerability of IL-2 DNA
Delivery with Electroporation Date: 6/3/2007 8:00:00 AM
CHICAGO, June 3 /PRNewswire-FirstCall/ -- Vical Incorporated (Nasdaq: VICL) today
announced that interim data on 19 subjects from an ongoing Phase 1 clinical trial
demonstrated that intratumoral delivery of plasmid DNA (pDNA) encoding interleukin-2
(IL-2) into melanoma tumors, followed by electroporation, was administered safely
following sedative premedication. No serious adverse events related to the study drug or
to the administration procedure were reported and the treatment was well-tolerated. The
majority of related adverse events were localized to the treatment site, with the most
frequent being mild injection site pain.
Individual tumor responses were seen in 12 of 39 (31%) evaluated tumors after injection
of different escalating doses (0.5 to 5 mg per tumor). Treated tumors (7 of 18, or 38%)
showed local responses more frequently than did untreated tumors (5 of 21, or 24%). No
overall clinical responses by standard RECIST criteria were observed among the 19 subjects
evaluated following one or two cycles of treatment. Two subjects (11%) showed activity in
distant, untreated tumors, including one subject showing shrinkage and disappearance of
lung tumors. The data were presented at the annual meeting of the American Society of
Clinical Oncology (Chicago, June 1 - 5) by Jon M. Richards, M.D., Ph.D., Lutheran General
Hospital Division of Hematology/Oncology.
"The primary objective of our ongoing IL-2/electroporation study is to evaluate
the safety and tolerability of electroporation," said Ronald B. Moss, M.D., Vical's
Vice President of Clinical Research, "and the interim results appear to support its
potential value in advanced cancer or other serious diseases. The need for premedication
would limit the use of the current electroporation technology in less serious disease
applications. We will monitor data from additional subjects, some of whom are already
enrolled but have not yet completed therapy, as well as the secondary efficacy endpoints
in this study on a longer-term basis, and evaluate whether further development of the IL-2
product is warranted."
Additional IL-2 pDNA Research
A recent publication by Vical researchers (Cancer Therapy, Vol. 5, 125-132, 2007)
reported that mice bearing melanoma tumors below the skin and receiving electroporation
following intratumoral administration of IL-2 pDNA had significant reductions in tumor
growth compared with mice treated by IL-2 pDNA alone. In addition, 60% of the mice
receiving IL-2 pDNA with electroporation became tumor-free, compared with 20% of the mice
receiving IL-2 pDNA without electroporation. In a separate study reported in the same
publication, mice bearing sarcoma tumors in the skin were evaluated for subsequent
metastatic tumors in the liver. IL-2 pDNA treatment of the primary tumor with
electroporation resulted in a significant reduction in subsequent metastatic tumor growth
compared with IL-2 pDNA treatment alone. Among mice whose primary tumor was treated with
IL-2 pDNA with electroporation, 65% had two or fewer subsequent metastatic tumors in the
liver. Among mice treated with IL-2 pDNA without electroporation, none had two or fewer
subsequent liver metastases, and 55% had liver metastases that were too numerous to count.
Phase 1 Trial Design
The Phase 1 study is evaluating an investigational method of delivering IL-2, a potent
immune system stimulant, to subjects with recurrent metastatic melanoma. Intravenous
delivery of IL-2 protein is approved as a treatment for metastatic melanoma, but
frequently causes severe systemic toxicities. The novel treatment approach being studied
in this Phase 1 trial involves direct injection into a tumor of pDNA encoding IL-2
followed by electroporation, the local application of electrical pulses designed to
enhance the uptake of the pDNA into tumor cells. The pDNA is designed to cause cells
within the tumor to produce high levels of IL-2 protein locally and stimulate the immune
system to attack the tumor without the associated systemic toxicities.
Treatments in the trial are administered once a week in two four-week cycles, with each
cycle followed by an observation period. The initial dose-escalation phase of the trial
enrolled three subjects each at doses of 0.5 mg, 1.5 mg and 5 mg delivered to a single
tumor per subject, with a final group receiving 5 mg in each of three tumors per subject.
Additional subjects are treated at the highest dose of 5 mg per tumor in up to three
injectable tumors.
About Vical
Vical researches and develops biopharmaceutical products based on its patented DNA
delivery technologies for the prevention and treatment of serious or life-threatening
diseases. Potential applications of the company's DNA delivery technology include DNA
vaccines for infectious diseases or cancer, in which the expressed protein is an
immunogen; cancer immunotherapeutics, in which the expressed protein is an immune system
stimulant; and cardiovascular therapies, in which the expressed protein is an angiogenic
growth factor. The company is developing certain infectious disease vaccines and cancer
therapeutics internally. In addition, the company collaborates with major pharmaceutical
companies and biotechnology companies that give it access to complementary technologies or
greater resources. These strategic partnerships provide the company with mutually
beneficial opportunities to expand its product pipeline and address significant unmet
medical needs. Additional information on Vical is available at http://www.vical.com.
This press release contains forward-looking statements subject to risks and
uncertainties that could cause actual results to differ materially from those projected.
Forward-looking statements include statements about the potential advantages of using
Vical's DNA delivery technology followed by electroporation to cause local production of
IL-2 by tumor cells and stimulate the immune system to attack the tumor and the potential
value of this approach in advanced cancer or other serious diseases; as well as the
company's focus, collaborative partners, product candidates, and developmental status.
Risks and uncertainties include whether Vical or others will pursue continued development
of electroporation-enhanced pDNA delivery; whether treatment by electroporation-enhanced
delivery of pDNA encoding IL-2 will be shown to be safe and efficacious in clinical trials
and ultimately be developed and approved; whether results from any further clinical trials
will be consistent with the interim data from this Phase 1 study; whether such treatment
will provide sustained local expression of IL-2 at therapeutic levels without the toxicity
associated with systemic delivery; whether electroporation-enhanced pDNA delivery will be
useful for additional cancer or other serious diseases, or for broader therapeutic or
prophylactic applications; the timing, nature and cost of clinical trials; whether Vical
or others will seek or gain approval to market any product candidates; whether Vical or
others will succeed in marketing any product candidates; and additional risks set forth in
the company's filings with the Securities and Exchange Commission. These forward-looking
statements represent the company's judgment as of the date of this release. The company
disclaims, however, any intent or obligation to update these forward-looking statements.
Contacts: Investors: Media:
Alan R. Engbring Susan Neath
Vical Incorporated Porter Novelli Life Sciences
(858) 646-1127 (619) 849-6007
Website: http://www.vical.com
SOURCE Vical Incorporated
-0- 06/03/2007
/CONTACT: Investors, Alan R. Engbring of Vical Incorporated,
+1-858-646-1127; or Media, Susan Neath of Porter Novelli Life Sciences,
+1-619-849-6007, for Vical Incorporated/
/Web site: http://www.vical.com /
(VICL)
CO: Vical Incorporated
ST: Illinois
IN: HEA MTC BIO
SU: TRI
AS-AA
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3590 06/03/2007 08:00 EDT http://www.prnewswire.com
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