Erbitux adds 5 weeks to lung cancer survival
By Deena Beasley
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.
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)