Merck (NYSE:MRK), known as MSD outside the United States and Canada, today announced the presentation of interim data from a Phase 1B trial (PN001) evaluating MK-3475, an investigational anti-PD-1 immunotherapy, in patients with previously-treated non-small cell lung cancer (NSCLC). The data were presented today by Dr. Edward Garon, Director of Thoracic Oncology, Jonsson Comprehensive Cancer Center, University of California, Los Angeles, at the 15th World Conference on Lung Cancer in Sydney, Australia (Abstract # MO18.02). Detailed interim data were presented for response rates and safety from a cohort of 38 previously-treated NSCLC patients who received MK-3475 10mg/kg every three weeks as well as initial findings from an analysis of the relationship between response rates and PD-L1 expression. “We are encouraged by these initial responses in NSCLC patients,” said Dr. Eric H. Rubin, vice president, Oncology, Merck Research Laboratories. “Based on these preliminary data and other research, we believe that PD-L1 expression has the potential to be a useful predictor of response to MK-3475 in certain cancers. We look forward to further data from this and other studies to help us to understand the potential role of MK-3475 in lung cancer, and of PD-L1 as a biomarker.” Based on data from this Phase IB study, Merck initiated a Phase II/III trial comparing two doses of MK-3475, 10mg/kg every three weeks and 2mg/kg every three weeks (10mg/kg Q3W and 2mg/kg Q3W), versus docetaxel in previously-treated patients with NSCLC who have received at least one prior treatment regimen (see clinicaltrials.gov). Merck plans to present data from ongoing studies evaluating 10mg/kgQ2W and 10mg/kgQ3W dosing regimens for MK-3475 in patients with NSCLC in 2014. Interim results presented at International Association for Study of Lung Cancer 2013 Tumor responses were assessed by investigator-assessed, immune-related response (irRC) criteria as well as independent, central, blinded radiographic review per Response Evaluation Criteria in Solid Tumors (RECIST 1.1) criteria.