The ALK inhibitor crizotinib (Xalkori) has shown effectiveness in patients with non-small cell lung cancer (NSCLC) who have changes in the ALK gene that make the gene overactive (so-called ‘ALK-positive’ patients). A recent clinical trial compared Xalkori to chemotherapy as a second-line treatment in these patients. Over 300 patients with ALK-positive advanced NSCLC who had undergone one previous round of chemotherapy were treated either with Xalkori or one of the chemotherapy drugs pemetrexed (Alimta) or docetaxel (Taxotere). Tumors shrank in 65% of Xalkori-treated patients, compared to 20% of those receiving chemotherapy. The Xalkori-treated patients also went longer without their cancer worsening, experienced fewer symptoms, and reported higher quality of life.