The U.S. Food and Drug Administration today approved Xalkori (crizotinib) to treat people with advanced (metastatic) non-small cell lung cancer (NSCLC) whose tumours have an ROS-1 gene alteration. Xalkori is the first and only FDA approved treatment for patients with ROS-1 positive NSCLC.

Lung cancer is the leading cause of cancer-related deaths in the United States, with an estimated 221,200 new diagnoses and 158,040 deaths in 2015, according to the National Cancer Institute. ROS-1 gene alterations, thought to lead to abnormal cells, have been identified in various cancers, including NSCLC. ROS-1 gene alterations are present in approximately 1 percent of patients with NSCLC. The overall patient and disease characteristics of NSCLC with ROS-1 gene alterations appear similar to NSCLC with anaplastic lymphoma kinase (ALK) gene alterations, for which crizotinib use was previously approved. Xalkori was approved to treat certain patients with late-stage NSCLC that expresses an abnormal ALK gene in 2011.

“Lung cancer is difficult to treat, in part, because patients have different mutations, some of which are rare,” said Richard Pazdur, M.D., director of the Office of Hematology and Oncology Products in the FDA’s Center for Drug Evaluation and Research. “The expanded use of Xalkori will provide a valuable treatment option for patients with the rare and difficult to treat ROS-1 gene mutation by giving health care practitioners a more personalized way of targeting ROS-1 positive NSCLC.”

Xalkori is an oral medication that blocks the activity of the ROS-1 protein in tumours that have ROS-1 gene alterations. This effect on ROS-1 may prevent NSCLC from growing and spreading.

The safety and efficacy of Xalkori for the treatment of patients with ROS-1 positive tumours were evaluated in a multi-centre, single-arm study of 50 patients with ROS-1 positive metastatic NSCLC. Patients received Xalkori twice daily to measure the drug’s effect on their lung cancer tumours. The studies were designed to measure overall response rate, the percentage of patients who experienced complete or partial shrinkage of their tumours. Results showed 66 percent of participants experienced a complete or partial shrinkage of their NSCLC tumours, an effect that lasted a median of 18.3 months.

The safety results of this study were generally consistent with the safety profile of Xalkori evaluated in 1,669 patients with ALK-positive metastatic NSCLC.

The most common side effects of Xalkori are vision disorders, nausea, diarrhea, vomiting, swelling (edema), constipation, liver problems (elevated transaminases), fatigue, decreased appetite, upper respiratory infection, and dizziness and numbness or tingling in the hands or feet (neuropathy). Xalkori may cause serious side effects, including liver problems, life-threatening or fatal inflammation of the lungs, abnormal heartbeats and partial or complete loss of vision in one or both eyes.

The FDA granted the Xalkori expanded use application breakthrough therapy designation and priority review status. These are distinct programs intended to facilitate and expedite the development and review of certain new drugs in light of their potential to benefit patients with serious or life-threatening conditions. Xalkori also received orphan drug designation , which provides incentives such as tax credits, user fee waivers and eligibility for exclusivity to assist and encourage the development of drugs for rare diseases.

Xalkori is marketed by Pfizer, based in New York,