Federal authorities on Friday approved the expanded use of Xalkori (crizotinib) manufactured by pharma giant Pfizer to treat patients with advanced non-small cell lung cancer.

The Food and Drug Administration said in a statement that the medicine will be given to the 1 percent of lung cancer patients with a rare mutation, or whose tumors have an ROS-1 gene alteration, which lead to abnormal cells.

It is interesting to note that Xalkori is the first and only therapy for the condition which has received the FDA approval. A companion diagnostic test is currently being developed for the benefit of the patients with ROS-1 mutated lung cancer.

Xalkori was first authorized in 2011 and this Pfizer drug is said to be effective in decreasing the size of tumors in ROS-1 mutated lung cancer patients. In 2014, a clinical trial had revealed that the drug had a 72 percent success rate, reducing the size of tumors in 36 out of 50 patients.

According to Dr. Richard Pazdur of FDA, the lung cancer is difficult to treat, partly because patients have different mutations and in some cases the mutations are quite rare.

"The expanded use of Xalkori will provide a valuable treatment option for patients with the rare and difficult-to-treat ROS-1 gene mutation," said Pazdur.

Dr. Alice Shaw of Massachusetts General Hospital, welcomed the FDA's approval of Xalkori, saying it represents another significant step forward in biomarker-driven cancer care. Meanwhile, a Pfizer spokesperson said Xalkori's price list is $14,336 a month.