- Vion to Advance Additional Phase I Schedules in Preparation for Phase II
Studies and Combinations with other Anticancer Agents -
NEW HAVEN, Conn., March 2 /PRNewswire/ -- Vion Pharmaceuticals, Inc.
(Nasdaq: VION) today announced it has completed a Phase I single dose study of
Triapine(R), a potent ribonucleotide reductase inhibitor that blocks a
critical step in the synthesis of DNA, thereby preventing the replication of
tumor cells. The Phase I study was designed to assess Triapine's safety
profile and pharmacokinetics when administered intravenously as a two-hour
infusion every four weeks. Patients were treated on nine dose levels of
Triapine and tolerated the treatment well. Furthermore, at the highest dose
level, there were no clinically significant toxicities, and peak serum levels
of Triapine exceeded the concentrations required to show activity against
tumor cells, as demonstrated in preclinical studies. The trial was conducted
at the University of Miami and the Arizona Cancer Research Center.
The favorable safety profile and pharmacokinetics support the continued
evaluation of Triapine in schedules optimized for antitumor activity.
Preclinical studies have shown that Triapine has the greatest effect on tumors
when administered consecutively for several days. Vion is continuing to
enroll patients into a second Phase I trial of Triapine administered daily for
five days every four weeks and will initiate a Phase I study of 96-hour
continuous intravenous infusion in the near future. Subsequent Phase I trials
are planned based on preclinical data, generated by the company and its
collaborators at Yale University, which showed promising antitumor activity
when Triapine was combined with three well-known and highly potent
DNA-damaging anticancer agents, etoposide, cisplatinum and cyclophosphamide.
Mario Sznol, M.D., vice president of clinical affairs of Vion
Pharmaceuticals, stated, "The extensive preclinical studies conducted by Vion
and Yale University to date, combined with these initial clinical results
support our strong belief that Triapine has substantial potential to benefit
cancer patients. Both the ongoing and planned Phase I studies will allow us
to evaluate dose regimens and combinations we believe may be most effective in
treating solid tumors and hematologic malignancies."
There are many enzymes involved in DNA synthesis, and those that arrest
tumor growth are difficult to selectively manipulate. The reductive
conversion of ribonucleotide to deoxyribonucleotides by ribonucleotide
reductase is a particularly critical step in the synthesis of DNA, since
deoxyribonucleotides are present in extremely low levels in mammalian cells.
The development of Triapine is based on the concept that a strong inhibitor of
ribonucleotide reductase, which is essential for cellular replication, would
be a useful weapon in the therapeutic arsenal against cancer.
Vion is developing Triapine(R), a Ribonucleotide Reductase Inhibitor
(RRI), as a potential treatment for solid tumors and acute myelogenous
leukemia. In preclinical studies, Triapine exhibited significant in vitro and
in vivo activity against human ovarian cancer grafted onto mice and in mouse
tumors for leukemia and lung cancer. Testing its efficacy on L1210 leukemia
in an in vivo murine model, Triapine, administered at low doses, cured 40% of
the mice and extended their lives by an average of 2.46 times. On M109 lung
carcinoma in an in vivo murine model, Triapine, compared with Taxol, had
nearly comparable results.
Vion Pharmaceuticals, Inc. is a biopharmaceutical company engaged in the
research, development and commercialization of cancer treatment technologies.
Vion's product portfolio consists of TAPET(R), a drug delivery platform, and
three cancer therapeutics (Promycin(R), Triapine and Sulfonyl Hydrazine
Prodrugs). TAPET has been shown in preclinical models to effectively deliver
anticancer agents while having a minimal toxic effect on healthy normal
tissues. TAPET uses genetically altered strains of Salmonella as a bacterial
vector, or vehicle, for delivering cancer fighting drugs preferentially to
solid tumors. Promycin, which attacks oxygen depleted cancer cells, is
currently being evaluated with radiation in a multicenter Phase III clinical
trial for the treatment of head and neck cancer. Triapine, which is designed
to prevent the replication of tumor cells by blocking a critical step in the
synthesis of DNA, is currently being evaluated for its safety in a Phase I
clinical trial. Sulfonyl Hydrazine Prodrugs, compounds that are designed to
be converted to unique potent, alkylating agents, are currently being
evaluated in preclinical studies. For additional information on Vion and its
research and product development programs, visit the company's Internet web
site at http://www.vionpharm.com.
Statements included in this press release which are not historical in
nature are forward-looking statements made pursuant to the safe-harbor
provisions of the Private Securities Litigation Reform Act of 1995. Forward-
looking statements regarding the company's future business prospects, plans,
objectives, expectations and intentions are subject to certain risks,
uncertainties and other factors that could cause actual results to differ
materially from those projected or suggested in the forward-looking
statements, including, but not limited to those contained in the company's
Registration Statement filed on Form S-3/A (file no. 333-95671). The shares
of Common Stock, described above, have not been registered under the
Securities Act of 1933, as amended, and may not be offered and sold in the
United States absent registration under such Act or an applicable exemption
from registration. This press release shall not constitute an offer to sell or
the solicitation of an offer to buy its securities nor shall there be any sale
of these securities in any state in which such offer, solicitation or sale
would be unlawful prior to registration or qualification under the securities
laws of any such state.
CONTACT: Alan Kessman, President and CEO, Thomas E. Klein, VP Finance &
CFO, both of Vion Pharmaceuticals, 203-498-4210; Financial Communications: Sue
L. Yeoh, investors, 201-641-2408, or Lisa Bradlow, media, 212-579-7428, both
of CPR Financial Communications, LLC, for Vion
SOURCE Vion Pharmaceuticals, Inc.
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Related links:
http://www.vionpharm.com
CONTACT:
Alan Kessman, President and CEO, Thomas E.
Klein, VP Finance & CFO, both of Vion Pharmaceuticals,
203-498-4210; Financial Communications: Sue L. Yeoh, investors,
201-641-2408, or Lisa Bradlow, media, 212-579-7428, both of CPR
Financial Communications, LLC, for Vion
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