SAN FRANCISCO (August 1, 2009)—Non-small cell lung cancer patients who have progressed on a cetuximab-containing regimen may respond to erlotinib, Fox Chase Cancer Center researchers reported today at the annual meeting of the International Association for the Study of Lung Cancer.
Both cetuximab (Erbitux) and erlotinib (Tarceva) inhibit the epidermal growth factor receptor (EGFR) and the assumption has been that once a patient progresses on one EGFR inhibitor they will not respond to another EGFR inhibitor. The new data suggests that may not be the case.
"Just because a patient received and progressed on one EGFR inhibitor doesn't necessarily mean they will not derive clinical benefit from another one," says Hossein Borghaei, D.O., medical oncologist at Fox Chase. "And for patients who don't have a lot of treatment options, we think this is a good thing. It gives them one more drug to try when their disease is progressing."
To find out if patients whose disease is no longer controlled by cetuximab can respond to erlotinib, Borghaei and colleagues examined the treatment and clinical outcomes for a subgroup of patients who had participated in a Fox Chase clinical trial that tested a combination of carboplatin, paclitaxel and cetuximab as first-line treatment for advanced non-small cell lung cancer. Out of 53 patients who had participated in that trial, the investigators identified 15 individuals who had received erlotinib during subsequent therapy.
Of those 15 patients who received erlotinib, three remain on erlotinib. For the 12 patients who are no longer on erlotinib, the median duration of erlotinib therapy was 63 days, with a range from 36 to 222 days. The three patients remaining on therapy have been on the drug for 41, 238, and 459 days. The median progression-free survival time on erlotinib was 2.5 months for all 15 patients.
"It appears that some patients can enjoy durable disease control on erlotinib after progressing on cetuximab," Borghaei says. He cautions, however, that these data come from a subset analysis and are retrospective, so they are not conclusive, but are only hypothesis generating.
Although erlotinib is approved for use in patients with non-small cell lung cancer and cetuximab has been studied in this setting for several years, this is the first formal analysis to show that the drugs can be used in sequence. The tumor characteristics that predict clinical benefit from erlotinib after progression on a cetuximab-containing regimen is yet to be elucidated, but that is an area Dr. Borghaei would like to address in future studies.
Source: Fox Chase Cancer Center