INTRODUCTION:We present the treatment rationale and study design for the RELAY study (NCT02411448 ). This phase Ib/III study will assess safety, tolerability, and efficacy of the combination of ramucirumab with erlotinib in previously untreated stage IV non-small-cell lung cancer patients with an activating epidermal growth factor receptor (EGFR) mutation. PATIENTS AND METHODS:The study is being conducted in approximately 120 sites in North America, Europe, and Asia and is currently open for enrollment. In part A (phase Ib), approximately 12 patients will receive ramucirumab (10 mg/kg) every 2 weeks with erlotinib (150 mg) every day. Dose-limiting toxicity will be assessed during 2 cycles (4 weeks) of treatment. In part B (phase III), approximately 450 patients will be randomized in a 1:1 ratio to receive ramucirumab or placebo every 2 weeks with erlotinib daily until disease progression, unacceptable toxicity, or other withdrawal criteria are met. The primary end point is progression-free survival, on the basis of investigator assessment. Secondary end points include overall survival, objective response rate, disease control rate, duration of response, safety, and quality of life. CONCLUSION:Erlotinib with ramucirumab combination was chosen because the addition of an antiangiogenic agent, such as ramucirumab, would further improve the efficacy of erlotinib, which is a standard of care in the first-line treatment of patients with activating EGFR mutations.