In an amazing discovery for Pfizer, the American drug company disclosed that it’s celebrated drug for lung cancer, Xalkori actually shrunk cancer tumors in people with a rare genetic mutation.

This data comes from a study where the drug was targeted toward people with this genetic makeup specifically.

According to the data, the drug shrunk the tumors in 36 of 50 patients and halted the growth in nine other patients. It was at the ESMO or European Society for Medical Oncology meeting held in Madrid, Spain that the announcement was made. The findings were also published in the New England Journal of Medicine.

To fine tune things, the discover revolves around an abnormality of the ROS1 gene. This makes up around 1.5 million yearly cases of non small cell lung cancer. The drug Xalkori showed effectiveness for around 18 months in the patients which is longer than the 12 months noticed by other treatments that are targeted according to Pfizer.

The data shows that Xalkori assists in shutting down the ROS1 gene that causes the cancers to grow. The drug was approved in 2011 for the treatment of non small cell lung cancer for patients who showed mutations of the ALK gene that is similar in configuration to ROS1. So effective is the drug that the National Comprehensive Cancer Network which is made up of 25 cancer centers is already recommending that physicians use Xalkori in those patients who possess this genetic defect.

This study is a continuation of the clinical trials of Xalkori and patients possessing the ALK gene mutation. Some fifty patients were then enrolled who testes positive for the ROS1 genetic defect from late in the year 2010 to August 2013. The drug was administered twice a day. Just about at the end of the trial it’s reported that around half of the patients still received Xalkori and showed no signs of tumor growth.

This is good news for Pfizer as their last bid to take over AstraZeneca met with rejection and now AstraZeneca is playing better with their own successful drug experiments. As both companies battle it out for lung cancer treatment surprising results in both stock prices and corporate dealings will be presented no doubt to the amazement of the public and investor analysts.