The FDA has approved crizotinib (Xalkori; Pfizer) to treat patients with locally advanced or metastatic non–small-cell lung cancer (NSCLC) who express the abnormal anaplastic lymphoma kinase (ALK) gene. Crizotinib has been approved with a companion diagnostic test that will help determine if a patient has the abnormal ALK gene, Vysis ALK Break Apart FISH Probe Kit (Abbott Molecular).
Crizotinib blocks protein kinases, including the protein produced by abnormal ALK. This oral agent is designed to be taken twice daily as a single-agent treatment.
Approval was based on 2 multicenter, single-arm studies enrolling a total of 255 patients with late-stage ALKpositive NSCLC. In one study, the objective response rate (ORR) was 50%, with a median response duration of 42 weeks. In the other, the ORR was 61%, with a median response duration of 48 weeks. The Vysis ALK Break Apart FISH Probe Kit was approved on data from one of the studies. The most common side effects reported with crizotinib include vision disorders, nausea, diarrhea, vomiting, edema, and constipation. Vision disorders included visual impairment, flashes of light, blurred vision, floaters, double vision, sensitivity to light, and visual field defects.
Crizotinib use was associated with pneumonitis; patients with treatment-related pneumonitis should permanently stop treatment. In addition, the drug should not be used in pregnant women. Crizotinib also was approved under the FDA’s accelerated approval program.