Experimental Drug Makes the Immune System Revolt Against Cancer

http://blog.wired.com/wiredscience/2...mental-dr.html
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Experimental Drug Makes the Immune System Revolt Against Cancer
June 07, 2008

A biotech company, founded by researchers from the University of Munich,
has developed a fascinating way to make the immune system fight cancer.

On Thursday, Micromet Inc. announced that its experimental drug, MT103,
had impressive results in a test upon seven Non-Hodgkin's Lymphoma
patients. All of them had failed at least three conventional treatments,
but showed signs of recovery after receiving doses of a two-headed
antibody.

BiTE antibodies, or bispecific T cell engagers, are highly-engineered
biological molecules with sticky ends. One side can cling to CD19, a
protein found on cancerous B cells, and the other half can grab onto CD3,
which is found on cytotoxic T cells. By momentarily drawing those cells
together, the drug can coax the cytotoxic T cells into fighting the
disease.

Training the immune system to fight cancer may be one of the best ways to
keep it from coming back after several rounds of standard treatment. In
most cases, surgery and radiation cannot get rid of every last cancer
cell. Traditional chemotherapy may halt the growth of tumors, but it will
not finish them off. Even after the best treatments, clusters of cancerous
or pre-cancerous cells, called micrometastases, often drift around in the
body and lodge themselves into vital organs.

To eliminate those lingering killers, many researchers have turned to
cancer vaccines, which can convince the body to hunt down stray cancer
cells and destroy them when they flare up. BiTE antibodies are another way
to harness the defensive power of our immune systems.

When I spoke to Christian Itlin, CEO of Micromet, he said that many
blockbuster cancer drugs are made from antibodies, and there is some
evidence that they work by stirring up the immune system -- even though
that is not how they were meant to operate. His company does intentionally
what others have done accidentally -- making drugs that train the body to
viciously attack cancer. In theory, their strategy could be used to combat
many varieties of the deadly disease, but their treatment for lymphoma
happens to be furthest along in the pipeline.

Since this was a very early trial, which was meant to assess the safety
rather than effectiveness of the new drug, the good news should be a
source of cautious optimism. Three more clinical trials of the BiTE
antibody are starting in Germany. Two are for lymphoma. The newest one is
meant to attack colorectal, gastrointestinal, and lung cancer.

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Remember it's early and there can be bias in small cohorts.
Just so you know, though, research is ongoing.
J