News Release
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Saturday May 17 11:58 AM EDT
Company Press Release
VICAL CONFIRMS ACTIVITY OF ALLOVECTIN-7 IN MELANOMA
AND HEAD/NECK CANCER
DENVER, CO--(BUSINESS WIRE)--May 17, 1997--
Clinical Trial Results Presented At ASCO Meeting
Vical Incorporated (Nasdaq:VICL) announced today that initial Phase II data for Allovectin-7, the Company's lead oncology
product candidate, indicate potential efficacy in certain patients with advanced melanoma. Preliminary results from a separate
Phase I/II trial indicated potential efficacy in certain patients with inoperable head and neck cancer. Results from both trials
were presented at the annual meeting of the American Society of Clinical Oncology.
Although all melanoma patients enrolled in the multi-center Phase II clinical trial with Allovectin-7 had advanced metastatic
disease, initial results further suggest that the potential treatment may be more effective in patients with advanced regional
disease than in patients with widespread disease affecting multiple internal organs. Alain B. Schreiber, M.D., Vical's President
and CEO, said, ``These results support our decision to perform studies focused on melanoma, and suggest a clear strategy for
development of an initial product indication. We now have information that may allow us to target the melanoma patient
population most likely to benefit from Allovectin-7.''
Allovectin-7
Allovectin-7 is a novel, gene-based product candidate being studied in melanoma and other types of cancer. The active
ingredient in Allovectin-7 is a gene encoding HLA-B7, an antigen responsible for strong immune responses such as organ
transplant rejection. To improve delivery, the gene is complexed with a proprietary lipid and suspended in a water-based
solution. Administration occurs by direct injection into a tumor, leading to uptake by the tumor cells and subsequent expression
of the HLA-B7 antigen. The Company expects the expression of HLA-B7 by cancer cells may trigger the patient's immune
system to recognize these cells as ``foreign'' and selectively destroy the tumor. As a result of Phase I/II clinical testing of
Allovectin-7 in several cancer indications, completed in 1995, Vical concluded that the product candidate was safe and
well-tolerated, successful in delivering the HLA-B7 gene in a majority of patients, and effective in inducing tumor shrinkage in
some patients.
Multi-center Phase II trials of Allovectin-7 began in September 1995, studying five different cancer indications in about 20
patients each. In October 1996, Vical initiated an additional multi-center trial in which approximately 40 patients with
advanced metastatic melanoma are currently being enrolled and treated. Several additional Phase I/II trials are ongoing,
studying Allovectin-7 either alone or in combination with other agents in various cancer indications.
Allovectin-7 in Melanoma
Vical's Allovectin-7 melanoma trials to date have been conducted in Stage IV patients who have failed to respond to
chemotherapy or radiation treatments. Phase I/II Allovectin-7 trials resulted in significant (greater than or equal to 50%) local
tumor shrinkage in 13 of 36 melanoma patients. Seven patients were considered partial clinical responses, and one of the
seven attained a complete response and remains tumor-free more than 33 months later.
Allovectin-7 Phase I/II Results in Melanoma
Disease Patients Local Partial Complete Duration
Progression Response Clinical Clinical
Response Response
Stage IV 36 13 6 1 8-33 months
and continuing
Preliminary Phase II results confirmed the potential efficacy of Allovectin-7 in treating melanoma patients, and suggested a
correlation between disease spread and such potential efficacy. Among 11 melanoma patients with advanced disease involving
the skin or underlying tissue, regional lymph nodes, and no more than one other internal organ, 5 patients exhibited tumor
shrinkage with 3 of those characterized as partial clinical responses. In 16 patients with widespread advanced disease affecting
multiple internal organs, only 1 exhibited tumor shrinkage.
Initial Allovectin-7 Phase II Results in Melanoma
Disease Patients Local Partial Complete Duration
Progression Response Clinical Clinical
Response Response
Stage IV
limited to
cutaneous 11 5 3 0 4-10 months
region or and
lymph nodes continuing
Stage IV
affecting
multiple 16 1 0 0 --
internal
organs
Allovectin-7 in Other Indications
Preliminary data from Phase II trials in the other four indications studied showed mixed results. In renal cell carcinoma, 8 of 25
patients had stable disease from 4 to 13 months after treatment, and they continue to be monitored. Patients with breast cancer
and non-Hodgkin's lymphoma remain under study, as preliminary data were insufficient to suggest any conclusions. Among 23
patients with advanced colorectal cancer, no responses were noted.
Allovectin-7 in Head and Neck Cancer
Allovectin-7 is also being evaluated in a separate Phase I/II trial for patients with advanced, inoperable or recurrent
post-surgical head and neck cancers. Of the eight patients treated to date, three have achieved partial clinical responses, two
considered near-complete. Patient accrual and treatment are ongoing.
Initial Allovectin-7 Phase I/II Results in Head & Neck Cancer
Disease Patients Local Partial Near- Duration
Progression Response Clinical Complete
Response Response
Inoperable 4-16 months
Stage III 8 3 1 2 and
or IV continuing
Schreiber said, ``The positive early results with Allovectin-7 in treating advanced head and neck cancers certainly warrant
further study. The emerging pattern of potential product activity in melanoma patients is encouraging.''
Melanoma Background
Melanoma is a skin cancer found predominantly in Caucasians, most often in fair-skinned people susceptible to sunburn.
Exposure to sunlight, particularly UVB rays, is considered the primary cause. The incidence of melanoma is doubling every 6
to 10 years among affected populations, with more than 40,000 new cases annually and 7,000 deaths estimated for 1997 in
the United States.
If detected in Stages I and II, defined as localized disease of varying diameter and thickness, melanoma often can be
successfully treated by surgical removal. The five-year survival rate for localized malignant melanoma, if treated, is about 95
percent.
If untreated, melanoma spreads to tissues beneath the skin and to internal organs, most often the lymph glands, lungs, brain, or
liver. If the disease progresses to Stage III, defined as limited regional metastases, treatment may involve surgical removal of
the tumors and any affected lymph glands, followed by systemic or local chemotherapy with single or multiple agents. The
five-year survival rate for treated Stage III patients is about 60 percent, and quality of life is compromised by both the disease
and the treatment.
If the disease progresses to Stage IV, defined as advanced regional or any distant metastases, treatment may include surgical
removal of tumors and affected lymph glands, systemic or local chemotherapy, radiation therapy, and immunotherapy. The
prognosis is poor, with a five-year survival rate for treated Stage IV patients of about 15 percent and a severely impaired
quality of life.
Head and Neck Cancer Background
Head and neck cancer describes any of several localized tumors affecting the oral cavity, the pharynx or larynx, or the
esophagus. Head and neck cancers are found more frequently in men than in women, and most often in men over age 40. Risk
factors vary with the particular location, but can include use of tobacco and excessive consumption of alcohol. New diagnoses
in the United States for the various head and neck cancers total more than 50,000 new cases annually and more than 20,000
deaths are estimated for 1997.
Most head and neck cancers are treated by surgical removal and/or localized radiation therapy, with widely ranging degrees of
success depending on the number of tumors, their size, and their specific location. In advanced disease, standard treatment
may be preceded by systemic chemotherapy to improve treatability, or followed by systemic chemotherapy to address
remaining cancer cells, most often with a combination of agents. The five-year survival rate for head and neck cancer patients,
if treated, varies from more than 90 percent for localized, accessible disease to less than 5 percent for widespread, inoperable
malignancies.
Vical Incorporated is focused on the development of gene-based pharmaceutical product candidates for human therapy.
Vical's gene-based therapeutic approach may offer safer and more cost-effective alternatives for many diseases, including
cancer, infectious diseases and metabolic disorders.
This press release contains forward-looking statements that are subject to risks and uncertainties that could cause actual results
to differ materially from those set forth in the forward-looking statements, including whether any product candidates will be
shown to be safe and efficacious in clinical trials, the timing of clinical trials, and additional risks set forth in the Company's
filings with the Securities and Exchange Commission. Actual results may differ materially from those projected. 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. |
