A Phase II Study of Osimertinib Combined With Platinum Plus Pemetrexed in Patients With EGFR-Mutated Advanced Non–Small-cell Lung Cancer: The OPAL Study (NEJ032C/LOGIK1801)

Background: Osimertinib, a third-generation epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor, is now a standard treatment of previously untreated EGFR-mutated advanced non–small-cell lung cancer (NSCLC). However, disease progression occurs within 19 months of treatment. In the NEJ009 study, gefitinib plus carboplatin plus pemetrexed demonstrated significantly better progression-free and overall survival compared with gefitinib monotherapy. Furthermore, the Lung Oncology Group in Kyushu and North East Japan Study Group, major clinical trial groups in Japan, conducted a randomized phase II study to evaluate the efficacy and safety of second-line osimertinib plus carboplatin plus pemetrexed versus osimertinib monotherapy for patients with disease progression during first-line EGFR tyrosine kinase inhibitor therapy and the EGFR T790M resistance mutation (TAKUMI trial; trial registration no., jRCTs071180062). In the first treatment course for the initial 24 patients, no safety issues were reported in the combination arm. Thus, we have planned this phase II study to evaluate the safety and preliminary efficacy of osimertinib plus cisplatin/carboplatin plus pemetrexed therapy for patients with previously untreated EGFR-mutated NSCLC. Patients and Methods: A total of 66 patients will be enrolled, because this sample size will be adequate for assessing treatment safety and efficacy. The co-primary endpoints include safety and the objective response rate, and the secondary endpoints include the complete response rate, disease control rate, and progression-free survival. Conclusions: This is the first study to explore the efficacy and safety of osimertinib combined with platinum-based chemotherapy in previously untreated NSCLC patients with EGFR-sensitizing mutations. Our findings could provide valuable information for phase III studies such as FLAURA2 and for developing treatment strategies for EGFR-mutated NSCLC.