The European Commission has widened the scope of Pfizer's Xalkori to include the treatment of adults with ROS1-positive advanced non-small-cell lung cancer (NSCLC).

The drug is already available for the treatment of adults with anaplastic lymphoma kinase (ALK)-positive advanced NSCLC, and was the first ALK inhibitor to win clearance from regulatory authorities in the US, EU, China and Japan.

Approval of the new indication follows a positive opinion issued by the European Medicines Agency's Committee for Medicinal Products for Human Use earlier this year, and comes after what the firm describes as "compelling results" from a multicenter, single-arm Phase I study (Study 1001) in which patients were given 250mg of Xalkori (crizotinib) orally twice daily.

Data from the study showed that Xalkori exhibited marked anti-tumour activity in patients with ROS1-positive advanced NSCLC, and met its primary endpoint of improved objective response rate. Also, on the safety side, the side-effect profile was "generally consistent" with that seen in patients with ALK-positive advanced NSCLC, according to Pfizer.

Andreas Penk, regional president, International Developed Markets at Pfizer Oncology, said the expanded approval represents "an important milestone" for with limited treatment options.

"We now know that NSCLC is not a single disease, but includes a number of molecularly defined tumors with different clinical characteristics and treatment options. With EU approvals in two distinct molecular targets in advanced NSCLC, ROS1 and ALK, Xalkori continues to break new ground and exemplify our commitment to precision drug development and patients."

The drug is also approved for both patient subsets in the US.