The US FDA has approved Xalkori (crizotinib) for the treatment of late-stage NSCLC (non-small cell lung cancer) in patients who have the abnormal ALK (anaplastic lymphoma kinase) gene. Patients undergo a genetic test, known as the Vysis ALK Break Apart FISH Probe Kit which detects the abnormal gene. The FDA has also approved this test.

The abnormal ALK gene causes cancer to develop and grow. Approximately 1% to 7% of patients with non-small cell lung cancer have this genetic abnormality. They are usually non-smokers. Xalkori blocks kinases, types of proteins, including a protein that the abnormal ALK gene produces.

Ian Read, president and chief executive officer of Pfizer, said:

“Overall, lung cancer is responsible for more deaths each year worldwide than any other type of cancer. XALKORI is an advance in the treatment of this devastating illness, providing a new therapeutic option for a subset of patients with the disease. The acceleration, collaboration and critical focus of the XALKORI clinical development program reflect Pfizer’s Precision Medicine approach to advancing our pipeline and strengthening our innovative core to deliver medicines that matter most.”

Patients take Xalkori in pill form twice daily.

Richard Pazdur, M.D., director of the Office of Oncology Drug Products, Center for Drug Evaluation and Research, FDA, said:

“The approval of Xalkori with a specific test allows the selection of patients who are more likely to respond to the drug. Targeted therapies such as Xalkori are important options for treating patients with this disease and may ultimately result in fewer side effects.”

The FDA (Food and Drug Administration) assessed two single-arm studies involving 255 patients with late-stage NSCLC, they were all ALK positive. Before enrollment, a sample of each patient’s lung cancer tissue was collected and tested to determine whether the abnormal ALK gene was present. The aim of the study was to measure objective response rate and how many patients experienced partial or complete shrinkage of cancer. The majority of them had already undergone chemotherapy.

In the two studies:

  • Study 1
    Objective response rate – 50%.
    Median response duration – 42 weeks.

    • Study 1
    Objective response rate – 61%.
    Median response duration – 48 weeks.

Data from other studies was used to assess and approve the Vysis ALK Break Apart FISH Probe Kit.

Xalkori underwent a priority review program by the FDA, meaning the review of the drug was expedited over six months. Drugs designated priority review status are those that can offer important advances in the treatment, or that provide a treatment when there is no current one.

Both Xalkori and the companion Vysis ALK Break Apart FISH Probe Kit were approved approximately four weeks earlier than the expected goal date.

Alberto Gutierrez, Ph.D., director of the Office of In Vitro Diagnostic Device Evaluation and Safety in the FDA’s Center for Devices and Radiological Health., said:

“The trend in oncology research continues towards targeted therapies. This test is an example of the important role companion diagnostics play in determining that the safest and most effective treatments are promptly delivered to patients living with serious and life-threatening diseases.”

Xalkori’s reported side effects include constipation, edema, vomiting, diarrhea, nausea, and vision disorders. Vision disorders may include double vision, photophobia, visual field defects, floaters, and blurred vision.

Dr. Paul Bunn, professor of medicine and the James Dudley chair in cancer research at the University of Colorado, Denver, said:

“By truly understanding the underlying genetic drivers of NSCLC, such as ALK, we can select patients who are more likely to respond to treatment. Xalkori provides a model for how to approach future drug development and cancer care. Xalkori, the first new drug approved for lung cancer by the FDA in more than six years, represents a paradigm shift in NSCLC treatment, where we’re moving away from a one-size-fits-all approach to biomarker-based treatment decisions.”

Pfizer Inc., the makers and marketers of Xalkori, say the drug is available immediately through some specialized pharmacies. If you are prescribed Xalkori, you can call 1-877-744-5675 for help in getting hold of the drug. For more data on the ALK test, call (855) TEST-ALK (837-8255).

Written by Christian Nordqvist