Gefitinib, also known as Iressa, the once-promising targeted therapy for the treatment of non-small cell lung cancer, has proven as effective as chemotherapy as a second-line therapy for the disease with far fewer side effects, according to an international Phase III clinical trial, led by researchers at The University of Texas M. D. Anderson Cancer Center.

However, in contrast to earlier Iressa findings, the study showed that there was no additional survival benefit for patients who expressed an elevated level of the epidermal growth factor receptor (EGFR) mutation.

The Iressa in Non-small cell lung cancer Trial Evaluating REsponse and Survival versus Taxotere (INTERST) study, published today in The Lancet, represents a paradigm shift for the treatment of the disease, according to lead author Edward S. Kim, M.D., assistant professor in M. D. Anderson’s Department of Thoracic Head and Neck Medical Oncology. It marks the first time in lung cancer that an oral pill has proven as effective as chemotherapy in a head-to-head trial.