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Biotech / Medical : Alseres Pharmaceuticals -- Ignore unavailable to you. Want to Upgrade?


To: GR who wrote (569)5/4/1998 10:19:00 PM
From: JMarcus  Respond to of 975
 
I'm reprinting below a relevant posting from the CYGS thread at Message 4318619

Monday May 4, 1:55 pm Eastern Time

US doctors warn against euphoria over cancer drugs

By Maggie Fox, Health and Science Correspondent

WASHINGTON, May 4 (Reuters) - Doctors said on Monday they were excited about
a new way to attack cancer but warned against premature euphoria over drugs that may
not work in people.

The two drugs, angiostatin and endostatin, have completely wiped out tumors in mice. A
feature story about the work published in the New York Times on Sunday sent stock in
EntreMed Inc. (ENMD - news), which has rights to the drugs, soaring. Shares in
Bristol-Myers Squibb Co. (BMY - news), which has an agreement with EntreMed, also
shot up in the morning.

''The data are very impressive and compelling. But it is still mouse data. We need clinical
data in humans before we can anoint them as miracle drugs,'' said Dr. Jim Pluda, an
oncologist at the National Cancer Institute (NCI) who is overseeing research in this
area.

''There have been a number of compounds in the past that have cured mice and did not
translate into efficacy in human clinical trials. The field of oncology is littered with the
bodies of agents that were the next cure for cancer.''

Nonetheless the NCI is very excited about the drugs and has made their development a
top priority. The drugs work to stop the growth of blood vessels that tumors need to
grow and flourish. This process of growing arteries is called angiogenesis, so the drugs
are known as angiogenesis inhibitors, or anti-angiogenesis drugs.

Pluda compared the approach to trying to eliminate dandelions from a lawn.

''Normally we keep whacking off the top and the dandelion keeps growing back,'' he
said in a telephone interview. ''But if you kill the roots of the dandelion, the whole plant
dies. We are killing the mechanism by which the tumor cells get nutrition.

In addition, there are few side-effects, unlike the standard treatments that use toxic
drugs or X-rays.

''The hope is that you kill more cancer than normal cells and that the normal cells then
recover first,'' Pluda said. ''But the cancer cells eventually acquire resistance to these
agents while the normal cells don't.''

With angiogenesis inhibitors, there is no resistance because the tumor is not being
directly attacked.

''The remarkable thing about these new agents is the lack of resistance. You could give
the drug over and over again and the tumor continues to respond,'' Pluda said.

Plus they are naturally occurring agents. ''Angiostatin is actually a portion of a normal
circulating blood product called plasminogen. Endostatin is a small fragment of a type of
collagen called collagen 18 that is normally found in the body but localized around blood
vessel cells,'' Pluda said.

The NCI is very excited about this approach, which was first reported in the science
journal Nature in November 1997. It was developed by Dr. Judah Folkman, of
Children's Hospital and Harvard Medical School in Boston, Massachusetts.

''We owe Dr. Folkman an enormous debt of gratitude because he initiated the field, he
kept the field alive when he was being assailed by the slings and arrows of naysayers,''
Pluda said.

But even Folkman remains cautious.

''If you have cancer and you are a mouse, we can take care of you,'' he told the New
York Times. And he said it could be years before the drugs are ready to be tested in
humans.

The drugs may not be suitable for use in children or pregnant women. Angiogenesis is
very important for the growth of unborn babies and children. ''That is an issue,'' Pluda
said.

But even if this approach does not work, there are also hopeful approaches being
worked on with vaccines, with gene therapy and with another form of therapy on the
genetic level known as antisense therapy.

Several other companies are also working on other formulations of angiogenesis
inhibitors.