UPDATE 1-Erbitux extends life in one study, fails in second
By Ben Hirschler
BERLIN, Sept 23 (Reuters) - Colon cancer drug Erbitux produced conflicting
results in clinical trials on Wednesday, as one study showed it improved
survival in patients with a certain genetic profile while a second found no
difference.
The mixed picture muddies the waters in a battle between Erbitux -- sold
by Merck KGaA, Eli Lilly and Bristol-Myers Squibb -- and Amgen's rival
treatment Vectibix.
British researchers said their study, known as COIN, found no overall
survival benefit in combining Erbitux with chemotherapy as a first-line
treatment for patients with metastatic colorectal cancer.
A few hours earlier, another international trial, called CRYSTAL,
presented at the same ECCO-ESMO cancer congress in Berlin, had found just such
a benefit.
The median overall survival for Erbitux patients with the normal, or
wild-type, version of a gene called KRAS was 23.5 months in CRYSTAL compared
with 20 months for those on chemotherapy alone.
That success was a significant win for Erbitux, which is now the only
targeted colon cancer drug to show an overall survival advantage when combined
with modern chemotherapy.
A year ago, researchers had detected a similar survival gain in the same
CRYSTAL trial, but at that stage the difference was not statistically
significant because the number of patients whose tumours had been tested for
KRAS status was too small.
With COIN also looking in detail at the genetic profile patients, many
experts had been hoping it would show a positive outcome.
In fact, the British team found overall survival was not statistically
significant in their study at 17.0 months in the Erbitux treatment arm compared
to 17.9 months for chemotherapy only.
Wolfgang Wein, head of oncology at German drugmaker Merck, said he was
perplexed by the British trial result, but noted the population group study was
particularly frail and there were also imbalances in chemotherapy given in the
different study arms.
"This is a very surprising result indeed," he told Reuters.
Erbitux currently dominates the market for EGFR drugs, which block a
protein called epidermal growth factor involved in cancer cell growth. Its 2008
sales were $1.6 billion, 10 times more than Vectibix.
Amgen hopes to redress this imbalance by showing its drug is similarly
effective, while offering dosing advantages.
Both drugs have recently been found to work only in the 60 to 65 percent
of patients whose tumours contain wild-type KRAS -- a prime example of the
arrival of personalised medicine, or tailoring treatment according to a
patient's genetic make-up.
By targeting this subset, drug companies are now able to identify which
patients will benefit most from treatment, although it also shrinks the size of
the potential market.
It is a trade-off that Merck's Wein is willing to accept.
"It shows the importance of personalising cancer care, which is more
health economic," he told Reuters. "It's a further endorsement of personalised
medicine and this is clearly where the train is heading."
(Editing by David Cowell and Hans Peters) Keywords: CANCER/ERBITUX
(ben.hirschler@thomsonreuters.com; Tel: +44 7771 575 829; Reuters Messaging:
ben.hirschler.reuters.com@reuters.net; www.twitter.com/reutersBenHir)
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[MERCK KGAA,MRK,DE,,DE0006599905][ELI LILLY AND COMPANY,LLY,US,,US5324571083][BRISTOL-MYERS SQUIBB CO,BMY,US,,US1101221083][AMGEN INC,AMGN,US,,US0311621009]
2009-09-23 11:30:19
3N|GEN|GER USA|HTH CHM PHA|
"Wer gegen den Strom schwimmt, sollte das möglichst in der Nähe des Ufers tun."
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