Xalkori, the Pfizser Inc’s drug to treat lung cancer patients with specific gene mutation has been effective in shrinking tumors in even rarer form of the disease which resists treatment. The data was presented at a medical meeting on Saturday.
The study involved 50 non small cell lung cancer patients with a gene mutation of the ROS1 gene. Xalkori treatment led to noteworthy tumor shrinkage in 72% of the tumors. 36 patients showed significant reduction in the tumor size and the tumor growth was completely halted in 9 patients.
The ALK gene mutation accounts for 4% of the non small cell lung cancers. 1 to 2% of the NSCLC patients are ROS1 positive. Such cases are caused by the fusion of two genes which are usually separate. Xalkori which is also known chemically as Crizotinib has been approved for treating patients who have ALK gene mutation in conjunction with a companion diagnostic test to identify those with mutation.
Dr. Alice Shaw, the study’s lead investigator from the Massachusetts General Hospital Cancer Center in Boston, said in a statement, “This is the first definitive study to establish crizotinib’s activity in a large group of patients with ROS1-positive lung cancer and confirms that ROS1 is a bona fide therapeutic target in those patients.”
In normal process, the duration of the response to the drug was 17 months in a BD dosage. 50% of the patients were still receiving the treatment with no signs of any progression in the tumor size.
Shaw added,”The remissions induced by crizotinib in ROS1-positive patients are quite prolonged, and (treatment) resistance appears to emerge much later, on average, than what we have seen with other targeted therapies for lung cancer and melanoma.”
The study was published in the New England Journal of Medicine and was presented at the European Society for Medical Oncology (ESMO) meeting in Madrid.