Phase 2 study of osimertinib in combination with platinum and pemetrexed in patients with previously untreated EGFR-mutated advanced non-squamous non-small cell lung cancer: The OPAL Study

BackgroundThis multicenter phase 2 trial evaluated the safety and efficacy of osimertinib and platinum-based chemotherapy (OPP) in patients with previously untreated EGFR-mutated advanced non-squamous non-small cell lung cancer (NSCLC).Patients and methodsPatients received osimertinib 80 mg once daily (QD), with either cisplatin 75 mg/m2 (arm A) or carboplatin (area under the curve [AUC] = 5; arm B), plus pemetrexed 500 mg/m2 for four cycles and maintenance therapy of osimertinib 80 mg QD with pemetrexed 500 mg/m2 every 3 weeks. The primary end-points were safety and objective response rate (ORR), and the secondary end-points were complete response rate (CRR), disease control rate (DCR), and progression-free survival (PFS).ResultsIn total, 67 patients (34 in arm A and 33 in arm B) were enrolled between July 2019 and February 2020. At the data cutoff (28th February 2022), 35 (52.2%) patients had discontinued the protocol treatment, including 10 (14.9%) due to adverse events. No treatment-related deaths occurred. In the full analysis set, the ORR, CRR, and DCR were 90.9% (95% confidence interval [CI], 84.0–97.8), 3.0% (0.0–7.2), and 97.0% (92.8–100.0), respectively. Based on updated survival data (data cutoff on August 31, 2022, median follow-up time: 33.4 months), the median PFS was 31.0 months (95% CI, 26.8 months–not reached) and median overall survival was not reached.ConclusionsThis is the first study to show that OPP has excellent efficacy with acceptable toxicity in previously untreated EGFR-mutated advanced non-squamous NSCLC patients.