Pfizer’s Lung Cancer Drug Helps Patients With Gene Defect

Pfizer Inc.’s Xalkori for advanced lung cancer shrunk tumors in those with a rare genetic mutation, according to a study that may provide the first targeted treatment for these patients.

Xalkori reduced the size of tumors in 36 of 50 patients in the study while halting tumor growth in another nine, according to company-funded research released today at the European Society for Medical Oncology meeting in Madrid and online in the New England Journal of Medicine.

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 New York-based Pfizer. Today’s findings also showed that Xalkori was effective for about 18 months in patients, longer than the average eight to 12 months seen for some other targeted treatments, said Alice Shaw, a lead study author.

“We’re seeing much longer durations of remissions,” Shaw, an associate professor of medicine at Harvard Medical School and Massachusetts General Hospital in Boston, said in a telephone interview. “This points to being a very good target in lung cancer and this drug being a very effective targeted therapy for these patients.”

Xalkori helps shut off the ROS1 gene that is causing cancer tumors to grow, she said. It was approved in 2011 to treat non-small-cell lung cancers in patients with mutations to the ALK gene, which has structural similarities to the ROS1 gene. The National Comprehensive Cancer Network, an alliance of 25 cancer centers, already recommends that doctors use Xalkori in patients who have this gene defect.

More Testing

“Pfizer continues to support clinical research of Xalkori in patients with ROS1 rearrangements to better understand the compound’s activity in this population,” Sally Beatty, a company spokeswoman, said in an e-mail.

The cancer drug generated $282 million in 2013 sales, according to data compiled by Bloomberg. The drug may produce revenue of more than $812 million in 2017, according to the average of five analysts’ estimates.

Patients with a mutation to the ROS1 gene are often younger and usually aren’t smokers, Shaw said.

Today’s study is an expansion of the original Phase 1 clinical trial of Xalkori in patients with the ALK gene mutation. Researchers enrolled 50 patients who were ROS1 positive starting in late 2010 through August 2013. Those in the study received Xalkori two times daily.

By the end of the trial, half of the patients were still getting Xalkori and had no signs of their tumors growing, the authors said.

“We’re hopeful that because of showing how well this drug works in ROS1 patients, this will let pathologists know they need to screen their patients for this genetic abnormality,” Shaw said. “In lung cancer there’s been a lot of progress made in targeted therapies.”

Before it's here, it's on the Bloomberg Terminal.