Two mutations that cause lung cancer resistance to the investigational ALK inhibitor alectinib were identified, and this information may help design new treatment regimens for patients with ALK-positive lung cancer, according to a study published in Clinical Cancer Research, a journal of the American Association for Cancer Research.

In 2014, more than 159,000 men and women are expected to die of lung cancer in the United States. About 84 percent of lung cancers are non-small cell lung cancers (NSCLC), and 3 to 5 percent of NSCLCs have mutations in the gene ALK.

“The goal of our study was to determine why ALK-positive lung cancers become resistant to alectinib, and we looked at this in two different ways,” said Alice T. Shaw, MD, PhD, a thoracic oncologist at the Massachusetts General Hospital Cancer Center. “We studied a resistant cell line model that we generated in the lab, and we also studied a tumor sample from a patient with NSCLC who had been treated with alectinib and then became resistant.