Real-World Data About Treatment Outcomes for Patients with EGFR-Mutated NSCLC Resistance to Osimertinib and Platinum-Based Chemotherapy

IntroductionDocetaxel is an established standard therapy after osimertinib and platinum-based doublet chemotherapy (Pt-doublet) for locally advanced or metastatic non-small cell lung cancer (NSCLC) with an epidermal growth factor receptor gene (EGFR) mutation. To facilitate future therapeutic developments in these patients after treatment with osimertinib and Pt-doublet, we estimated the outcomes of currently used post-treatment therapies.MethodsData of patients with NSCLC who received at least one medication after osimertinib and Pt-doublet between April 2008 and August 2021 were extracted from the Medical Data Vision claims database. The duration of treatment (DoT) (first treatment after osimertinib and Pt-doublet) and overall survival (OS) were estimated. The index date was the first day on which the medication was prescribed.ResultsIn total, 731 patients (mean age 64 years) were screened. The most frequent post-treatments were docetaxel-based chemotherapy (30.2%), immune checkpoint inhibitor (ICI) alone or in combination (17.2%), first-/second-generation EGFR-tyrosine kinase inhibitors (16.7%), osimertinib (16.3%), and Pt-doublet (5.2%). The median DoT and OS (95% confidence interval) of all post-treatments were 3.5 (3.27, 3.77) and 10.3 (9.3, 12.1) months, respectively, reflecting the median DoT (3.8 months) and OS (10.0 months) of docetaxel-based chemotherapy. Among all post-treatment regimens, ICIs resulted numerically the shortest [2.77 (2.33, 3.00) months] and osimertinib the longest [4.40 (3.47, 5.67) months] median DoT. The median OS was shortest in patients post-treated with ICIs [7.07 (5.40, 9.90) months] and longest in patients rechallenged with Pt-doublet (12.27 months), followed by patients post-treated with osimertinib (11.70 months). In a subset analysis of patients who received first-line osimertinib and second-line Pt-doublet as well as Pt-doublet immediately after osimertinib, those post-treated with ICIs had the shortest median DoT.ConclusionGiven the limited real-world efficacy on EGFR-mutant NSCLC resistant to osimertinib and platinum-based chemotherapy, the development of more highly potent post-treatment therapies is warranted.