Drug Trials Show Modest Gains Against Lung Cancer
Alimta, Zactima extend survival but cure remains out of reach, studies show
SATURDAY, May 30, 2009 (HealthDay News) -- Certain drugs offer incremental yet significant improvements in pushing back advanced lung cancer.
That's the conclusion of studies presented Saturday at the annual meeting of the American Society of Clinical Oncology (ASCO) in Orlando, Fla.
Lung cancer remains America's leading cancer killer, and "significant" improvements in time-to-disease recurrence and survival are measured in weeks and months, not years, experts stress.
The benefits from any drug also vary from patient to patient. "Some patients are benefiting much more and some much less," noted Dr. Roy Herbst, chief of thoracic medical oncology at the University of Texas M.D. Anderson Cancer Center in Houston and lead author of one of the studies presented at the meeting.
In data presented at an ASCO news conference Saturday, researchers found that the drug Alimta (pemetrexed) prolonged survival by almost three months in patients with advanced non-small cell lung cancer, the deadliest form of the disease. This benefit was almost exclusively confined to people with the nonsquamous forms of the disease, the researchers said.
"This is the first randomized, placebo-controlled trial that showed a benefit to pemetrexed in the 'maintenance' setting, after initial therapy. It was also very well tolerated," said study lead author Dr. Chandra P. Belani, deputy director of the Penn State Cancer Institute in Hershey, Penn.
Maintenance therapy, given after standard chemotherapy, refers to continuing some portion of a patient's treatment to help stave off a recurrence.
While previous research had shown that pemetrexed as maintenance therapy extended disease-free survival, this was the first study to show a benefit to overall survival, the researchers said.
For this study, 663 patients with advanced non-small cell lung cancer who had successfully responded to four rounds of traditional chemotherapy were randomly chosen to receive either pemetrexed or a placebo along with "best supportive care."
The pemetrexed group survived for a median of 13.4 months while those on the placebo survived 10.6 months, the research team reported.
The difference was more pronounced in those patients with the nonsquamous type of cancer: 15.5 months overall survival in those taking pemetrexed versus 10.3 months for those taking a placebo.
Maintenance therapy is a new concept in cancer care. In fact, its initial promise emerged about a year ago, when progression-free survival data for pemetrexed was first presented.
"That was promising but people were wondering if this just delayed the time until we had to use pemetrexed as a second-line treatment," said Dr. Karen Reckamp, assistant professor of medicine at City of Hope Cancer Center in Duarte, Calif.
In general, cancer patients are treated with four to six cycles of "first line" therapy -- about five months -- and are then stopped and monitored. If the cancer returns, they receive "second line" therapy.
Side effects were worse in the pemetrexed group but overall they were not terrible, the researchers stated. "Patients actually tolerated the drug fairly well," Belani said.
Another study, also presented at the ASCO press briefing, looked at patients with advanced non-small cell lung cancer taking the drug Zactima (vandetanib). Researchers found that adding the medication to chemotherapy (including docetaxel) improved progression-free survival.
Unlike other lung cancer drugs, Zactima packs a one-two punch, targeting two separate cellular receptors involved with tumors: epidermal growth factor receptor (EGFR) and vascular endothelial growth factor (VEGF).
Following initial chemotherapy, almost 1,400 patients were randomly selected to receive docetaxel plus Zactima or just docetaxel. After more than a year of follow-up, participants taking Zactima had a median progression-free survival of 17.3 weeks versus 14 weeks for those taking the placebo, a 21 percent reduction in risk.
"There was [also] an improvement in overall survival, a positive trend, but it was not statistically significant: 10.6 months in the Zactima arm versus 10 months in the placebo group," said Herbst, who led the trial.
Patients also felt better on Zactima, the researchers said. The bottom line, according to Herbst, is that "patients [on Zactima] are clearly progressing less quickly. But, unfortunately, all are going to succumb to the disease." Still, "they are reporting they were feeling better," he added. "That's a small step. Do we want more? Absolutely."
Yet a third trial found that combining the targeted therapies Tarceva (erlotinib) with Avastin (bevacizumab) as maintenance therapy in patients with advanced non-small cell lung cancer helped patients live longer before their disease returned -- a median of 4.8 months for the combined group versus 3.7 months in the control group.
Saturday's findings should encourage the use of maintenance treatments, Reckamp said. She noted that the pemetrexed (Alimta) trial is "the first study that shows overall survival is improved with maintenance, so it challenges the initial paradigm. This data, [along] with the data on Avastin and erlotinib, helps to bring the information home that maintenance therapy in lung cancer is something we need to think about and it will be easy [non-toxic] for people to use."
There's more on lung cancer at the U.S. National Cancer Institute.