The analysis and trial, led by Roy S. Herbst, M.D., Ph.D., of The University of Texas
M. D. Anderson Cancer Center, found that patients who used gefitinib (Iressa
"These early results from a subset of patients in our clinical study suggest that gefitinib might keep cancer cells dormant for a period of time," says Herbst, chief of thoracic medical oncology. "Using gefitinib as a maintenance therapy is a very nice concept, and may offer some advantage in our goal to make lung cancer a chronic, manageable disease."
Herbst cautions, however, that the initial studies which combined the drug in upfront therapy with chemotherapy in lung cancer, were clearly disappointing and negative. "In a sense, this might be a silver lining in that some patients appear to have gained benefit but only after they first responded to the standard therapy," he said. "Much work still needs to be done to help the 50-plus percent patients who never respond to their first chemotherapy for lung cancer."
Herbst presented the study results at the annual meeting of the American Society of Clinical Oncology.
The investigators re-examined results from the INTACT pair of clinical trials, which tested whether adding gefitinib to standard chemotherapy regimens offered a clinical benefit in patients with advanced lung cancer. Findings from the two randomized, double-blind, placebo-controlled trials, which enrolled more than 2,000 patients, were negative; gefitinib did not provide an improvement in survival when added to platinum-based chemotherapy versus chemotherapy alone.
But in examining data from the INTACT 2 trial, which was led by M. D. Anderson researchers and where the largest accrual occurred, Herbst and colleagues found a trend toward improved survival in 250 patients who received gefitinib for 90 or more days. "Gefitinib may be effective as a cytostatic agent, maintaining tumor regression following chemotherapy," says Herbst. Several studies are now in development in an attempt to validate this finding, he says.
Gefitinib, a once daily, oral tablet, is the first in a new class of anti-cancer drugs known as epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors, to become commercially available. Gefitinib tablets received FDA approval May 5 as a single agent treatment for patients whose advanced lung cancer has continued to progress despite treatment with platinum-based and docetaxel chemotherapy, two drugs that are currently the standard of care in this disease. "We are already seeing the benefit of this agent in the clinic in the refractory setting," Herbst says.
Contact: Laura Sussman or Stephanie Dedeaux, (713) 792-0655