Xalkori (crizotinib) has been approved by the US Food and Drug Administration (FDA) for the treatment of patients with late-stage, non-small cell lung cancers (NSCLC) who express the abnormal anaplastic lymphoma kinase (ALK) gene.
The European Medicines Agency has accepted the drug for review and a decision is expected by the end of the year.
Xalkori is being approved in the US with a companion diagnostic test that will help determine if a patient has the abnormal ALK gene, a first-of-a-kind genetic test called the Vysis ALK Break Apart FISH Probe Kit.
About 1% to 7% of those with NSCLC have the ALK gene abnormality. Patients with this form of lung cancer are typically non-smokers.
Xalkori works by blocking certain proteins called kinases, including the protein produced by the abnormal ALK gene. It is a pill taken twice a day as a single-agent treatment.
“The approval of Xalkori with a specific test allows the selection of patients who are more likely to respond to the drug,” said Richard Pazdur, Director of the Office of Oncology Drug Products in the FDA’s Centre for Drug Evaluation and Research.
“Targeted therapies such as Xalkori are important options for treating patients with this disease and may ultimately result in fewer side effects.”
Xalkori’s safety and effectiveness were established in two multi-center, single-arm studies, enrolling a total of 255 patients with late-stage, ALK-positive NSCLC.
A sample of a patient’s lung cancer tissue was collected and tested for the ALK gene abnormality prior to study enrolment.
The studies were designed to measure objective response rate, the percentage of patients who experienced complete or partial cancer shrinkage. Most patients in the studies had received prior chemotherapy.
In one study, the objective response rate was 50%, with median response duration of 42 weeks. In another, the objective response rate was 61%, with median response duration of 48 weeks.
The most common side effects reported in patients receiving Xalkori included vision disorders, nausea, diarrhea, vomiting, swelling (edema), and constipation.
Vision disorders included visual impairment, flashes of light, blurred vision, floaters, double vision, sensitivity to light, and visual field defects.
Xalkori use has also been associated with inflammation of the lung tissue (pneumonitis), which can be life-threatening.
Patients with treatment-related pneumonitis are recommended permanently to stop treatment with Xalkori, while the drug should not be used in pregnant women.