Transcript Cancer`s Trojan Horse

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
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://www.endocyte.com/oncology.h
tml
http://medlib.med.utah.edu/WebPath/
GIHTML/GI067.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.h
tml
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.h
tml
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.”
http://www.endocyte.com/oncology.h
tml
How Folate Works
How Folate Works
• Can be applied to many drugs,
including imaging agents,
chemotherapy drugs, immunomodulating agents, liposomes,
proteins, and even genes
• Spoonful of sugar helps the medicine
go down
http://www.endocyte.com/oncology.h
tml
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://usembassy.state.gov/tokyo/ww
whgl0388.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.h
tml
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.h
tml
http://www.endocyte.com/oncology.h
tml
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.h
tml
http://www.endocyte.com/oncology.h
tml
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
Advantages of Folate Drug
Delivery
•
•
•
•
Over-expression in cancer cells
Natural substance
Many types of drugs
Folate’s small size (MW 441)
http://www.endocyte.com/advantages
.html
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.
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
Perspective. Research and Inquiry.
Purdue University. Summer 2002.