In colon cancer drug study, more wasn't better
By STEPHANIE NANO, Associated Press Writer Stephanie Nano, Associated
Press Writer – 20 mins ago

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NEW YORK – Doctors thought that combining two newer drugs that more
precisely attack cancer would help people with advanced colon cancer.
Instead, it made the cancer worse and made the patients more miserable,
a study found. The surprising findings underscore the importance of
doing rigorous studies before rushing to mix these pricey,
new-generation drugs, the Dutch researchers and other experts said.
The doctors tried combining Erbitux and Avastin because lab tests and an
earlier small study had shown promising results.
"This will stand out as a warning," said Dr. Cornelis Punt, the study's
leader. "You have to do the randomized studies to see what really
happens."
For the study, Eli Lilly & Co.'s Erbitux was added to standard
treatment, which includes Genentech Inc.'s Avastin. Since both are
"targeted" drugs and attack tumors in different ways, the thinking was
that the combo would do a better job of keeping the cancer from growing.
But the results show "more is not always better," said Dr. Robert Mayer,
of Dana-Farber Cancer Institute in Boston. He wrote an editorial
published with the study in Thursday's New England Journal of Medicine.
What makes the results even more compelling, Mayer said, is that another
similar study reached the same conclusion. That study, released in
December, tested another targeted drug that works the same way as
Erbitux.
"This is the first time we've seen harm by combining targeted therapies
and it tells us we need to be cautious," said Dr. Jordan Berlin, a
gastrointestinal cancer specialist at Vanderbilt-Ingram Cancer Center in
Nashville, Tenn.
Berlin, who had no role in the research, stressed that the drugs do help
patients, just not when given together.
Colorectal cancer is the nation's second leading cancer killer. The
disease was expected to kill almost 50,000 Americans last year although
death rates are dropping because of screening and better treatment.
The research was done at hospitals throughout the Netherlands and led by
Punt at Radboud University Nijmegen Medical Center. The 755 study
patients had colon cancer that had spread. They all received Avastin,
also known as bevacizumab, and two chemotherapy drugs. Half of them also
got Erbitux, also called cetuximab. They were followed for nearly two
years.
The group that got Erbitux saw their cancer get worse sooner, the
researchers found. On average, their cancer progressed after 9.4 months
compared to 10.7 months for those who didn't get Erbitux. The Erbitux
group also had lower quality-of-life scores.
The overall survival in both groups was about the same.

Punt said they are now trying to figure out why the combo didn't work;
it could be an interaction between these two specific drugs, Erbitux and
Avastin.

After the study began in 2006, it was shown that Erbitux didn't help
colon cancer patients who had a specific gene mutation. The Dutch
researchers said their study confirmed that — the worst results were
in those with the mutation who got Erbitux.

Vanderbilt's Berlin said the results also show doctors need to be
careful when using drugs "off-label." Drugs are approved for specific
uses but doctors can prescribe them for other purposes. Medicare has
recently expanded its coverage for such use of some cancer drugs, which
can cost thousands a month.
Off-label use "needs to be cautious and this proves it," said Berlin.

The study was supported by a network of Dutch researchers which receives
grants from a cancer foundation and drug companies. The two targeted
drugs were provided by the companies that market them in Europe. Several
of the researchers have consulted for cancer drug companies, as has the
editorial writer and Berlin.