WESTMINSTER, Colo., Feb. 14 /PRNewswire-FirstCall/ -- Allos Therapeutics,
Inc. (Nasdaq: ALTH) today announced the publication of results from an
Allos-sponsored pre-clinical study, designed to compare the activity of a
pralatrexate (PDX)/gemcitabine combination relative to a commonly used
combination of methotrexate/cytarabine (ara-C) in treating lymphoma. Results
of the study, which were reported in the February 1st edition of Clinical
Cancer Research, indicate that the combination of pralatrexate followed by
gemcitabine was superior to the combination of methotrexate/ara-C in vitro and
in vivo models of lymphoma, and was more potent in inducing apoptosis in
certain lymphoma cell lines.
The study, which was performed in the laboratory of Owen A. O'Connor,
M.D., Ph.D. at Memorial Sloan Kettering Cancer Center, assessed the effects of
single agent treatments and the pralatrexate and methotrexate combinations in
parallel in a large B-cell lymphoma cell line. Results of the analysis
indicated that in vitro, the scheduled combination of pralatrexate/gemcitabine
possessed greater cytotoxicity compared to the methotrexate/ara-C combination,
as well as significantly increased apoptosis in a cell line specifically
selected for its resistance to pralatrexate. In vivo studies demonstrated a
significant reduction of tumor burden in mice treated with
pralatrexate/gemcitabine compared to those treated with methotrexate/ara-C.
Importantly, both in vivo and in vitro experiments indicate a
schedule-dependent interaction between pralatrexate and gemcitabine. The
sequence of pralatrexate followed by gemcitabine was five times more effective
in reducing tumor burden and inducing apoptosis than the simultaneous exposure
of the two drugs.
"This is an exciting observation," said Owen O'Connor, M.D., Ph.D.,
Assistant Attending Physician, Lymphoma Service Memorial Sloan-Kettering
Cancer Center. "Given the activity of pralatrexate in T-cell lymphomas, and
the wide use of gemcitabine in this particular setting, the combination of
pralatrexate and gemcitabine may also represent a novel treatment platform for
patients with these challenging diseases."
These data established the superior therapeutic activity of pralatrexate
in models of human non-Hodgkin's lymphoma and provide further support for the
Phase 1/2 study of pralatrexate in patients with non-Hodgkin's lymphoma which
is currently on-going at Memorial Sloan Kettering Cancer Center.
About Pralatrexate (PDX)
Pralatrexate is a small molecule chemotherapeutic agent that inhibits
dihdrofolate reductase, or DHFR, a folic acid (folate) dependent enzyme
involved in the building of DNA and other processes. Preclinical data suggests
that PDX has an enhanced potency and toxicity profile relative to methotrexate
and other related DHFR inhibitors because of a greater affinity for the
reduced folate carrier (RFC-1) and foly-polyglutamyl synthase leading to
enhanced intracellular accumulation and polyglutamylation in tumor cells.
Drugs that inhibit DHFR, such as methotrexate, were among the first
chemotherapeutic agents discovered. Methotrexate remains one of the most
widely applied antifolate chemotherapeutics and has been used to treat
leukemia, breast, bladder, gastric, esophageal, head and neck cancers.
About Allos Therapeutics, Inc.
Allos Therapeutics, Inc. (Nasdaq: ALTH) is a biopharmaceutical company
focused on developing and commercializing innovative small molecule
therapeutics for the treatment of cancer. The Company's lead product
candidate, EFAPROXYN, is a synthetic small molecule designed to sensitize
hypoxic, or oxygen-deprived, tumor tissue during radiation therapy. EFAPROXYN
is currently being evaluated as an adjunct to whole brain radiation therapy in
a pivotal Phase 3 trial in women with brain metastases originating from breast
cancer. The Company's other product candidates are: PDX (pralatrexate), a
small molecule chemotherapeutic agent (DHFR inhibitor) currently under
investigation as both a single agent and in combination therapy regimens in
patients with non-small cell lung cancer and Non-Hodgkin's lymphoma; and RH1,
a small molecule chemotherapeutic agent bioactivated by the enzyme
DT-diaphorase currently under evaluation in patients with advanced solid
tumors. For more information, visit the Company's web site at http://www.allos.com.
Safe Harbor Statement
This press release contains forward-looking statements that are made
pursuant to the safe harbor provisions of the Private Securities Litigation
Reform Act of 1995. Such forward-looking statements include statements
relating to the potential safety and efficacy profile of pralatrexate; the
potential utility of pralatrexate and gemcitabine in the treatment of lymphoma
and other statements that are other than statements of historical facts. In
some cases, you can identify forward-looking statements by terminology such as
"may," "will," "should," "expects," "intends," "plans," anticipates,"
"believes," "estimates," "predicts," "projects," "potential," "continue," and
other similar terminology or the negative of these terms, but their absence
does not mean that a particular statement is not forward-looking. Such
forward-looking statements are not guarantees of future performance and are
subject to risks and uncertainties that may cause actual results to differ
materially from those anticipated by the forward-looking statements. These
risks and uncertainties include, among others: that future clinical trials may
not demonstrate that pralatrexate plus gemcitabine is both safe and more
effective than current standards of care; that data from preclinical studies
and clinical trials may not necessarily be indicative of future clinical trial
results; and the risk that the Company may lack the financial resources and
access to capital to fund future clinical trials for PDX or any of its other
product candidates. Additional information concerning these and other factors
that may cause actual results to differ materially from those anticipated in
the forward-looking statements is contained in the "Risk Factors" section of
the Company's Annual Report on Form 10-K for the year ended December 31, 2004
and in the Company's other periodic reports and filings with the Securities
and Exchange Commission. The Company cautions investors not to place undue
reliance on the forward-looking statements contained in this press release.
All forward-looking statements are based on information currently available to
the Company on the date hereof, and the Company undertakes no obligation to
revise or update these forward-looking statements to reflect events or
circumstances after the date of this presentation, except as required by law.
Note: EFAPROXYN(TM) and the Allos logo are trademarks of Allos
Therapeutics, Inc.
SOURCE Allos Therapeutics, Inc.
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Related links:
http://www.allos.com
CONTACT:
Jennifer Neiman, Manager, Corporate
Communications of Allos Therapeutics, Inc., +1-720-540-5227,
jneiman@allos.com
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