Rationale and protocol design of a phase II study of first-line osimertinib treatment for patients with poor performance status and EGFR mutation-positive non-small cell lung cancer (OPEN/TORG2040)

BACKGROUND: Cancer chemotherapy indications for patients with poor performance status and advanced lung cancer are limited. Molecular targeted drugs, including epidermal growth factor receptor (EGFR)-tyrosine kinase inhibitors, can be used in patients with poor performance status owing to their high efficacy and safety. The third-generation EGFR-tyrosine kinase inhibitor osimertinib has demonstrated effectiveness in the initial treatment of advanced EGFR mutation-positive non-small cell lung cancer in patients with good performance status; however, no evidence exists of the drug’s effectiveness in patients with poor performance status in a prospective study. We designed a study that aims to investigate the efficacy and safety of first-line osimertinib treatment in patients with advanced non-small cell lung cancer harboring sensitive EGFR mutations and with poor performance status. METHODS: The OPEN/TORG2040 study is a multicenter, single-arm, phase II trial for patients with unresectable, advanced EGFR mutation-positive non-small cell lung cancer with a poor performance status (≥ 2). Eligible patients will receive osimertinib until disease progression or unacceptable toxicity. The primary endpoint is the objective response rate of the first-line osimertinib treatment. Considering a threshold value of 45%, expected value of 70% for objective response rate, one-sided significance level of 5%, statistical power of 80%, and ineligible patients, the sample size was set to 30. The secondary endpoints are disease control rate, performance status improvement rate, and safety and patient-reported outcomes using the European Organization for Research and Treatment of Cancer Quality of Life Questionnaire-Core Quality of Life Questionnaire and Lung Cancer 13. Time to treatment failure, progression-free survival, and overall survival will also be assessed. DISCUSSION: Our study can determine the clinical benefits of osimertinib treatment in patients with poor performance status, since the clinical outcomes of patients with EGFR mutation-positive non-small cell lung cancer with poor performance status treated with this drug as a first-line treatment have not been sufficiently evaluated. TRIAL REGISTRATION: Japan Registry of Clinical Trials: jRCTs041200100 (registration date: February 12, 2021).