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Photo by Reed Hutchinson UCLA
Photographic Services
Researcher Dennis Slamon has been studying HER-2, a gene
that drives breast-cancer growth, for nearly two decades.
His work led to the development of Herceptin.
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the hero of the herceptin story
He led pursuit of
breast-cancer villain
BY AJAY SINGH
UCLA Today Staff
Dennis Slamon, head of clinical/transitional research at UCLA’s
Jonsson Cancer Center, has spent most of his career trying to beat
HER. That’s short for human epidermal growth factor receptor,
a gene that regulates cell growth and sometimes causes cancer. For
nearly two decades, Slamon has been studying HER-2, one of the four
siblings in the HER family, whose altered form is present in about
25% to 30% of women suffering from advanced breast cancer. Slamon’s
work was honored Feb. 28 by the American Cancer Society, which awarded
him the Medal of Honor, its most prestigious prize.
The award is in recognition of the research that led Slamon and
his UCLA colleagues to develop Herceptin, a breast-cancer drug that
was approved by the FDA in 1998. It is the first comprehensive breast-cancer
therapy to arise from the cutting-edge world of molecular biology.
In a sense, the “Herceptin story,” as Slamon calls
the drug’s development, began back in 1972 when he decided
to devote his life to cancer research. It was a field at which,
he recalled, a lot of people were looking at a time when “people
were just learning about genes carrying oncogenic agents more potent
than chemical agents or even radiation.”
In 1979, Slamon came to UCLA to complete a fellowship in medical
oncology. By the time he began working with HER-2 in 1985, it was
still not known that the gene is abnormally altered in about a quarter
of breast-cancer cases. Slamon examined breast-cancer samples, hoping
to isolate any gene even remotely responsible for regulating abnormal
cell growth.
He discovered that HER-2 was indeed altered in one-third of the
samples and that the women from whom the samples were taken had
three things in common: They were free of cancer for relatively
shorter periods, were less responsive to mainstream therapies and
died more rapidly once they got sick.
But Slamon still needed to show that HER-2 was the cancer-causing
villain he suspected, and that it could be therapeutically targeted.
With the help of generous donors, he expanded his research and demonstrated
that HER-2 does drive breast-cancer growth.
After testing antibodies aimed at checking the growth, Slamon
and his team conducted eight clinical trials, which, together with
12 years of research, cost more than $100 million.
Slamon, who’s as famously tireless as he is affable, recently
began an ambitious new trial to see if Herceptin is effective in
3,200 women worldwide who have recently been diagnosed with breast
cancer. “That is where we think we’ll be able to impact
the disease most and potentially cure patients,” he said.
Indeed, if survivors from his Herceptin story are any indication,
Slamon might already have achieved his goal — some patients
from the last trial have been disease-free for up to 11 years.
“We’ve improved survival by 30%, and they may well
be cured,” Slamon said. “But we’d like to do that
for a much larger percentage of patients. So there is still a lot
to be done.”
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