Pfizer's Lung Cancer Drug Xalkori Effective In Rare Gene Trial
September 29, 2014
By Riley McDermid, BioSpace.com Breaking News Staff
Drug giant Pfizer Inc. announced Sunday that its new lung cancer drug Xalkori has proved effective in shrinking tumors in those with an even a rare genetic mutation, according to data the firm presented at the European Society for Medical Oncology meeting in Madrid.
New York-based Pfizer simultaneously announced the results in the New England Journal of Medicine’s website.
The company studied 50 non-small cell lung cancer patients with a rearrangement of the ROS1 gene and found that Xalkori (crizotinib) significantly shrank tumors in 36 of them, or 72 percent, and halted tumor growth in an additional 9 patients.
The drug was effective for about 18 months in patients, longer than the average eight to 12 months seen for some other targeted treatments
“We’re seeing much longer durations of remissions,” Alice Shaw, a lead author on the study and an associate professor of medicine at Harvard Medical School and Massachusetts General Hospital in Boston, told Bloomberg. “This points to being a very good target in lung cancer and this drug being a very effective targeted therapy for these patients.”
About 15,000 people, or 1 percent of the estimated 1.5 million annual new cases of non-small-cell lung cancer, have an abnormality to the ROS1 gene, according to Pfizer.
Xalkori generated $282 million in 2013 sales, according to data compiled by Bloomberg, and could earn more than $812 million in 2017.
Criizotinib is already approved to treat patients with a mutation of the ALK gene, along with a companion diagnostic test to identify those with the mutation, which accounts for about 4 percent of non-small cell lung cancers (NSCLC). However, crizotinib appeared to last longer in ROS1-positive patients than in patients with ALK-positive tumors.
"Almost all patients treated with targeted therapies eventually develop resistance,"said Shaw, in a statement. "Fortunately, the remissions induced by crizotinib in ROS1-positive patients are quite prolonged, and resistance appears to emerge much later, on average, than what we have seen with other targeted therapies for lung cancer and melanoma."
While crizotinib's FDA approval currently covers only ALK-positive NSCLC, Shaw notes that National Comprehensive Cancer Network guidelines recommend that patients with advanced lung cancer be considered for ROS1 testing and that crizotinib should be used to treat ROS1-positive patients.