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