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Cancer’s Trojan Horse
Student
ChE 391
October 3, 2002
Overview
• Cancer
• Folate - a new drug delivery technology
• Experimental evidence that folate works
• Other possible ways to use folate
http://www.endocyte.com/oncology.html
Cancer• Cancer is second leading cause of
death in the U.S.
• 1.2 million Americans diagnosed every year - less than half will survive 5 years
http://medlib.med.utah.edu/WebPath/GIHTML/GI067.html
http://www.endocyte.com/oncology.html
Cancer• Two of the major challenges to increasing survival
are finding:– 1) Diagnostic drugs that can find cancer before it
spreads– 2) Therapeutic drugs that can destroy cancer
cells without harming healthy cells
http://www.endocyte.com/oncology.html
New Drug Delivery Technology
• Purdue University and Endocyte, Inc. developed a drug delivery system that attaches anticancer drugs to vitamins
http://www.endocyte.com/oncology.html
How Folate Works• Folate is a form of water-soluble B vitamin• Cancer cells capture folate more effectively
than normal cells• Dr. Philip S. Low of Purdue University
said, “Basically, we are using vitamins as Trojan Horses to carry virtually any molecule into a cancer cell.”
How Folate Works
http://www.endocyte.com/oncology.html
How Folate Works• Can be applied to many drugs,
including imaging agents, chemotherapy drugs, immuno-modulating agents, liposomes, proteins, and even genes
• Spoonful of sugar helps the medicine go down
http://usembassy.state.gov/tokyo/wwwhgl0388.html
To Diagnose Folate Cancers
• Radioactive imaging agent attached to folate (technetium)
• FolateScan administered intravenously
• When nuclear imaging shows the folate conjugate concentrated in an unknown mass, that mass has folate receptors and is malignant
http://www.endocyte.com/oncology.html
Folate Studies• In U.S. more than 300,000 people per year
diagnosed with a cancer that over-expresses folate receptors
http://www.endocyte.com/oncology.html
Folate Studies
• Immunotherapeutic drugs were linked to folate
• Found that tumors could be eliminated in mice without any evidence of toxicity to normal tissues
http://www.endocyte.com/oncology.html
http://www.endocyte.com/oncology.html
Folate Studies
• A chemotherapy drug called EC72 linked to folate
• Cancer bearing mice that received it lived twice as long as mice treated with the non-targeted drug
• No signs of toxicity to normal tissues
http://www.endocyte.com/oncology.html
Ovarian Cancer Folate Studies• Proof-of-principle study
• Thirty-three women were imaged
• Folate successfully targeted the imaging agent to the tumors of all of the women
• Human trials for treatment begin soon
http://www.endocyte.com/advantages.html
Advantages of Folate Drug Delivery
• Over-expression in cancer cells
• Natural substance
• Many types of drugs
• Folate’s small size (MW 441)
Perspective. Research and Inquiry. Purdue University. Summer 2002. Page 12
Other methods
• Sometimes cancer cells will attach to folate but don’t ingest it rapidly
• A “beacon” is attached to the folate
• The immune system is primed
• Beacon-marked cancer cells attacked
Perspective. Research and Inquiry. Purdue University. Summer 2002. Page 12
Summary
• Folate drug delivery method is “using cancer’s nutritional needs against itself.” (Philip Low)
• This “Trojan horse” therapeutic approach increases destruction of cancer cells while decreasing toxicity to healthy cells
• Human clinical trials for drug treatment method will begin in November