Pfizer Inc., an American multinational pharmaceutical corporation, announced that the US Food and Drug Administration (FDA) has accepted and granted Priority Review for a supplemental New Drug Application (sNDA) for Xalkori (crizotinib) for the treatment of patients with metastatic non-small cell lung cancer (NSCLC) whose tumours are ROS1-positive.

In April 2015, Xalkori received Breakthrough Therapy designation by the FDA for this potential indication. If approved, Xalkori would be the first FDA-approved biomarker-driven therapy for the treatment of ROS1-positive metastatic NSCLC. Xalkori is currently indicated for patients with metastatic NSCLC whose tumors are anaplastic lymphoma kinase (ALK)-positive as detected by an FDA-approved test. The projected FDA action date is April 2016.

Priority Review status accelerates FDA review time from 10 months to a goal of six months from the day of acceptance of filing and is given to drugs that may offer major advances in treatment or may provide a treatment for which no adequate therapy exists.

“ROS1 represents the second molecular subgroup of NSCLC in which Xalkori has demonstrated a level of anti-tumour activity that can potentially make a meaningful difference for patients,” said Dr. Mace Rothenberg, senior vice president of clinical development and medical affairs and chief medical officer for Pfizer Oncology.

“The development of Xalkori in this subgroup of patients is an example of the capability of precision medicine to identify treatments for patients whose tumors contain rare genetic mutations, such as ROS1-positive metastatic NSCLC.”

ROS1 rearrangement occurs when the ROS1 gene attaches to another gene and changes the way each gene normally functions, which can contribute to cancer-cell growth. Epidemiology data suggest that ROS1 rearrangements occur in approximately one percent of NSCLC cases. Of the estimated 1.5 million new cases of NSCLC worldwide each year, roughly 15,000 may be driven by oncogenic ROS1 fusions.

The submission to the FDA is based on data from a multicenter, single-arm phase 1 study (Study 1001) that evaluated Xalkori in 53 patients with ROS1-positive metastatic NSCLC.3 Data from 50 of these patients were published in the November 20, 2014 issue of The New England Journal of Medicine and showed that Xalkori exhibited marked anti-tumour activity in patients with ROS1-positive metastatic NSCLC. Additionally, the safety profile of Xalkori in ROS1-positive metastatic NSCLC was consistent with that observed in patients with ALK-positive metastatic NSCLC.

Xalkori is a kinase inhibitor indicated in the US for the treatment of patients with metastatic non-small cell lung cancer whose tumors are anaplastic lymphoma kinase-positive as detected by an FDA-approved test. Xalkori has received approval in more than 85 countries including Australia, Canada, China, Japan, South Korea and the European Union.