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Press Release
AmpliMed™ Drug Amplimexon™ Exhibits Unique Mechanisms of Synergy with Gemcitabine in Human Pancreatic Cancer Cells
Tucson, Ariz., May 10, 2005 - Researchers from the Arizona Cancer Center have made an important breakthrough in the understanding of the mechanism by which AmpliMed's lead drug, Amplimexon (imexon inj.), may synergize with gemcitabine against human pancreatic cancer cells in vitro and in vivo. These findings may help guide the future clinical development of Amplimexon, which recently entered a Phase I/II study in combination with gemcitabine in the treatment of patients with previously untreated pancreatic adenocarcinoma. These new data, which were presented at the American Association for Cancer Research (AACR) annual meeting on April 18, suggest that the drug may have broader utility than previously thought.
The active ingredient in Amplimexon is imexon, a compound which previously has shown activity against a variety of human cancer types in cell based and animal studies, including melanoma, myeloma and pancreatic adenocarcinoma. Previous work had suggested that imexon might augment the effectiveness of other cancer drugs by causing the accumulation of toxic free radicals inside rapidly dividing cells such as cancer cells. However this mechanism does not adequately explain the significant synergies observed between imexon and a certain class of cancer drugs known as antimetabolites.
One such drug is gemcitabine, which is used as first line therapy in pancreatic cancer which cannot be treated surgically. Unfortunately advanced pancreatic cancer is often resistant to gemcitabine and response rates are relatively low. Experiments in animals implanted with human pancreas tumor cells had suggested that the combined use of imexon and gemcitabine was much more effective at slowing tumor growth and causing tumor shrinkage than either drug alone, even causing regression in tumors resistant to each individual drug.
During a poster presentation
on April 18th, 2005 at the AACR annual meeting, an Arizona Cancer Center researcher,
Dr. Nick Roman, reported that imexon possesses additional biological and biochemical
properties that may explain these unexpected positive findings. He reported
that the imexon is an inhibitor of the processes by which a cell divides,
causing cells to accumulate in a particular phase of the cell cycle during
which they are highly susceptible to gemcitabine therapy. Furthermore, imexon
appears to directly target an enzyme called ribonucleotide reductase (RNR)
which is a necessary component of the pathway to DNA synthesis. RNR is also
a target for gemcitabine itself and the combination of the two drugs is more
effective than either drug alone at inhibiting this key enzyme.
"The results of this study demonstrate that Amplimexon is uniquely synergistic with gemcitabine in vitro and in vivo, and support the rationale for clinical trials, not only in pancreatic cancer but also in other types of cancer in which antimetabolites in the same class as gemcitabine are routinely administered," said Dr. Robert Dorr, Chief Scientific Officer for AmpliMed, in whose laboratory at the Arizona Cancer Center Dr. Roman carried out his studies. "We plan to follow our pilot clinical studies with a program of clinical trials designed to prove the clinical utility of the Amplimexon/gemcitabine combination in pancreatic cancer. Based on these new findings, we remain optimistic that our clinical development program will result in a positive outcome for these patients. We will be exploring other drug combinations with Amplimexon, and other types of cancer which may be particularly susceptible to the unique combination of attributes that Amplimexon may offer."
About Amplimexon
Amplimexon is AmpliMed's trademarked name for imexon injection, a cyanoaziridine
compound which showed tantalizing evidence of activity in limited studies
in lung cancer, melanoma and breast cancer that were documented in publications
in the 1980s. The potential of imexon as a cancer drug was never fully explored,
until 1994, when AmpliMed co-founding scientists Drs. Evan Hersh, David Alberts,
Robert Dorr and William Remers initiated a program to decipher Amplimexon's
novel mechanism of action. This led to the initiation in 2003 of an ongoing
Phase I clinical study of the drug as a stand-alone therapy in late-stage
cancer patients. Further preclinical research revealed that the combined use
of Amplimexon and certain other chemotherapeutics resulted in a significant
increase in efficacy compared to either drug alone. These findings are now
being translated into a series of Phase I/II clinical studies of combination
therapy in patients with various types of cancer.
About AmpliMed Corporation
AmpliMed Corporation was founded in 1989 with the support of the University
of Arizona Technology Development Corporation and is focused on the clinical
development of chemotherapeutic agents for cancer. AmpliMed's strategy is
to develop anti-cancer drugs with novel mechanisms of action designed to overcome
some of the limitations, such as myelosuppression (suppression of blood cell
counts), multi-drug resistance (treatment-induced resistance to many cancer
drugs) and cardiac toxicity, frequently associated with current cancer therapy.
The company's lead product, Amplimexon (imexon inj.), is undergoing
NDA-directed clinical development. Other products in the company's portfolio
include Amplizone™, which is anticipated to enter the clinic early in
2006, and a portfolio of derivatives of both lead compounds for future development.
AmpliMed Corporation is based in Tucson, Arizona and is on the Web at http://www.amplimed.com.
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For additional information about AmpliMed Corporation, please contact Mr. Wayne Morrison at (520) 529-1000.
AmpliMed®, Amplimexon® and Amplizone™, are United States trademarks of AmpliMed Corporation.
