Here's what the Boston Globe had to say about Herceptin:
Biological 'Weapon' Herceptin Shows Promise for
Breast Cancer
By RICHARD SALTUS
c.1998 The Boston Globe
LOS ANGELES -- A new biological weapon that specifically targets
cancer cells has shown such surprising potency in slowing or halting
advanced breast cancers that researchers on Sunday called the
experimental treatment ''a first step into the future.''
The biological agent, called Herceptin, worked best when combined
with standard chemotherapy. The combination was administered to
women whose breast cancer had spread to other organs and failed to
respond to conventional drugs. Together, Herceptin and the
chemotherapy drugs caused even large tumors to stop growing,
shrink, or in some cases disappear, at a significantly higher rate than in
women who got only chemotherapy.
''This is the biggest difference (between an experimental drug and
standard drugs) I have ever seen in a trial of Stage Four (advanced)
breast cancer,'' commented Dr. Larry Norton, a researcher at the
Memorial Sloan-Kettering Cancer Center in New York, who
participated in the testing of Herceptin.
The results were obtained from a trial involving 469 women with
breast cancer that had spread to other organs. Forty-nine percent
(114 of 235) of women who took Herceptin and chemotherapy had a
significant decrease in measurable breast cancer, compared with 32
percent (74 of 234) of those who had only chemotherapy, researchers
said.
These responses lasted for a median of 9.3 months in the
Herceptin-plus-chemotherapy group compared to 5.9 months in the
chemotherapy-alone group, they reported.
A year after treatment, 78 percent of the Herceptin-treated women
were alive compared with 67 percent of the chemo-only group,
though the researchers cautioned it is too early to know whether they
will live longer than those who got the standard regimen. Two of the
women are alive and well five and six years after treatment.
Herceptin is not only potent but relatively nontoxic, thus far causing
none of the loss of hair, extreme nausea, drops in blood cell counts or
other side effects common to powerful chemotherapy drugs.
However, the combination of Herceptin and the sometimes toxic
chemotherapy drug Adriamycin caused heart malfunction in some
patients, though most continued on the combination. Herceptin has
been tested overall in about 700 women with advanced breast cancer.
Dr. Craig Henderson, a veteran breast cancer researcher at the
University of California, San Francisco, Medical Center, said, ''I'm
very excited.''
''The real importance is not Herceptin alone,'' Henderson aid at a
briefing. ''This is a first step into the future: This is not the end of
chemotherapy by any means, but this is the first payoff in a very
common disease of using all the science that came out of the National
Cancer Act,'' with which President Nixon waged the war on cancer in
1971. ''I think the public is starting to get its money back.''
Herceptin, a so-called monoclonal antibody made in the laboratory,
targets a specific genetic alteration that is found in about 30 percent of
breast cancers, and which makes those tumors unusually aggressive
and lethal. The genetic change causes the cells to overproduce a
protein called HER-2/neu, which prods the cells into rapid and virulent
cancerous growth.
But this menacing change also marks the cells as different from normal
breast cells, and Herceptin exploits this change, homing in on the
HER-2/neu protein and disrupting the chain of biological signals that
was causing the malignant cells to proliferate.
''This is proof of principle that we can identify what's broken in a
cancer cell and fix it,'' said Dr. Dennis Slamon, director of the
Revlon/University of California at Los Angeles Women's Cancer
Research Program. ''We're very excited by these results,'' said
Slamon, who developed the biological weapon in collaboration with
scientists at Genentech, Inc., a South San Francisco biotech firm.
The treatment could potentially be used for many of the approximately
60,000 women a year who develop breast cancer with the genetic
change - described as being ''HER2/neu-positive.'' It would not be
used in the 120,000 other women whose breast cancer cells do not
overproduce the protein. However, some other cancers, including
those of the ovary and stomach, appear in some cases to undergo the
genetic change and could eventually be candidates for treatment with
the monoclonal antibody.
The report at Sunday's session of the American Society for Clinical
Oncology meeting here coincides with a recent application by
Genentech to the Food and Drug Administration to market Herceptin.
Until its approval, which the company expects by year's end,
Herceptin is available in limited quantities in clinical trials.
Slamon described the latest results with Herceptin, which has been in
clinical testing for about five years, at a briefing preceding a report to
the society later in the day.
Herceptin is among the first of a new generation of biological cancer
treatments that targets malignant changes in cells that have been
uncovered during the past 10 or 15 years by intensive molecular
research. Because they act so specifically, they are expected to spare
patients much of the toxic and sometimes lethal effects of standard
drugs.
The gene that makes the HER-2/neu protein was first isolated by
Robert Weinberg, a cancer geneticist at the Whitehead Institute for
Biomedical Research, from rodents in 1981. Later, the gene was
found to be too active in a proportion of human breast tumors, causing
overproduction of the HER-2/neu protein that receives biological
signals that prompt the cells to grow uncontrollably.
Women with this genetic change in their breast tumors were found to
have more rapid metastasis to other organs and to die sooner than
those without the gene. Slamon, in collaboration with Genentech
researchers, searched for immune cells called antibodies that could
bind to the HER-2/neu protein on cancer cells and disrupt its growth.
Such antibodies can be made through bioengineering of mice, but need
to be ''humanized'' - have most of their rodent genetic sequences
replaced with human ones - before they can be used in humans.
Manufacturing the Herceptin antibody in large quantities is challenging
Genentech production researchers, said Slamon, but the company is
opening a large new manufacturing facility in California later this year
that's expected to produce enough of the drug for the market,
assuming the FDA approves it later this year or early in 1999. The
FDA has ''fast-tracked'' the drug for rapid approval, he said.
With the American public already keyed up by recent media reports
of other experimental drugs showing great promise in mice, the
company and the researchers expect a wave of requests for the drug,
which at present is available only in limited quantities.
Officials said that patients will be referred to the National Cancer
Institute's hotline, 1-800-FOR CANCER, for information on how to
apply for admission to clinical trials. Genentech is distributing enough
of the drug for about 400 patients a year chosen by a lottery system.
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