CHICAGO (Reuters) -
Lung cancer patients treated in a large
clinical trial with ImClone Systems Inc's Erbitux and
chemotherapy lived about five weeks longer than patients
treated with chemotherapy alone, according to study results
released on Saturday.

“It's a modest improvement in survival,” said Dr. Roy
Herbst, chief of thoracic oncology at MD Anderson Cancer Center
in Houston.

The findings were announced at a meeting here of the
American Society of Clinical Oncology.

The 1,125-patient trial, sponsored by ImClone's European
marketing partner Merck KGaA, showed that overall survival was
11.3 months for patients on the combination therapy, compared
with 10.1 months for the group receiving just chemotherapy.

Lung cancer kills 1.3 million globally a year, according to
the World Health Organization. The American Cancer Society says
the disease was diagnosed in 213,380 people in the United
States last year, killing 160,390.

The Erbitux partners previously said the study was
successful but analysts and clinicians have been eager to see
the full results in order to make comparisons with Genentech
Inc's Avastin, which is so far the only nonchemotherapy drug
approved as an initial treatment for non-small cell lung
cancer, the most common form of the disease.

“I think that is a solid result. Wall Street was looking
for a survival benefit of four to six weeks,” said Cowen & Co
analyst Eric Schmidt. “This is going to drive a lot of use.”

A pivotal trial of Avastin, which excluded certain patient
groups including those with squamous cell cancer, showed it
boosted lung cancer survival by about eight weeks.

“Avastin is approved in a somewhat selective population,”
said Dr. Herbst. But Erbitux “was tested in a population that's
not limited,” he said. “Now we need to dissect out which
patients benefit the most.”

The Erbitux results came in just ahead of the cutoff for
determining whether a trial is statistically significant. “I
would have preferred a more robust number,” Schmidt said.

REGULATORY APPROVAL

Officials at ImClone and Merck said results for certain
patient groups, particularly whites, were more impressive than
those for the overall trial.

“Only one in five (lung cancer) patients get Avastin … .
There is a large group that is going to have a biologic drug
available to them for the first time,” said ImClone Chief
Executive John Johnson.

Erbitux, an antibody designed to block a protein called
epidermal growth factor, is already approved for treating
colorectal as well as head and neck cancers.

Avastin, or bevacizumab, works by a different mechanism –
blocking the blood supply to tumors.

Johnson said ImClone expected to file in the second half of
this year for U.S. regulatory approval in lung cancer and the
new indication could be on the label by mid-2009.

Tumors shrank in 36.3 percent of patients treated with
Erbitux, also known as cetuximab, compared with 29.2 percent of
patients on chemotherapy alone.

Erbitux was shown to increase survival by 1.4 months in
white patients, who made up 84 percent of the trial population,
said Wolfgang Wein, head of oncology at Merck.

Wein said the trial also showed that Erbitux added 1.8
months to survival for patients with adenocarcinoma and 1.3
months to the lives of patients with squamous cell cancer.

The most frequent side effect was an acne-like rash.
Moderate rash was seen in 10.4 percent of patients on the
ImClone drug, compared with 0.2 percent of the
chemotherapy-alone group.

Progression-free survival — a measure of how long patients
live before their tumors grow — was essentially the same at
about 4.8 months for both arms of the trial.

(Reporting by Deena Beasley; Editing by Braden Reddall and
Xavier Briand)