Efficacy and safety of first-line osimertinib treatment and postprogression patterns of care in patients with epidermal growth factor receptor activating mutation-positive advanced non-small cell lung cancer (Reiwa study): study protocol of a multicentre, real-world observational study

IntroductionOsimertinib, a third-generation epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor (TKI), is widely used as the first-line treatment for EGFR mutation-positive non-small cell lung cancer (NSCLC). Nevertheless, most cases ultimately acquire resistance to osimertinib, and no effective treatment has been currently established for cases having progressive disease (PD) with osimertinib. In clinical practice, EGFR-TKI therapy could be continued beyond response evaluation criteria in solid tumours (RECIST)-defined PD cases when they are clinically stable. Currently, the progression pattern of osimertinib and criteria for identifying patients who might benefit from osimertinib beyond PD are unknown. In addition, the efficacy and safety of osimertinib as the first-line treatment in real-world clinical practice remain unclear in Japan. This multicentre study was designed to evaluate the real-world data on first-line osimertinib and its post-treatment.Methods and analysisThe study enrols patients with EGFR mutation-positive, advanced or recurrent NSCLC who received EGFR-TKI as the first-line therapy after 1 September 2018, from October 2019 to August 2020, and those started on osimertinib will be followed up until August 2022. We will evaluate the efficacy and safety of the first-line osimertinib treatment, adherence to it, progression patterns on RECIST PD and subsequent treatment.Ethics and disseminationAll participating patients will provide written informed consent before entering the study. The protocol, amendments and patients’ informed consent forms will be approved before study commencement by the institutional review board or independent ethics committee at each participation site (Lead Ethics Committee; Japan Red Cross Medical Center (26 April 2019, order number 976)). Patients will be anonymised before registration into the study and their anonymised data will be collected from the case report form. The results of this study will be presented at the national and international conferences and submitted for publication.Trial registration numberUMIN000038683.

ERK inhibitor ASN007 effectively overcomes acquired resistance to EGFR inhibitor in non‐small cell lung cancer

SummaryThe emergence of acquired resistance limits the long-term efficacy of EGFR tyrosine kinase inhibitors (EGFR TKIs). Thus, development of effective strategies to overcome resistance to EGFR TKI is urgently needed. Multiple mechanisms to reactivate ERK signaling have been successfully demonstrated in acquired resistance models. We found that in EGFR mutant non-small cell lung cancer (NSCLC) patients, acquired resistance to EGFR TKIs was accompanied by increased activation of ERK. Increased ERK activation was also found in in vitro models of acquired EGFR TKI resistance. ASN007 is a potent selective ERK1/2 inhibitor with promising antitumor activity in cancers with BRAF and RAS mutations. ASN007 treatment impeded tumor cell growth and the cell cycle in EGFR TKI-resistant cells. In addition, combination treatment with ASN007 and EGFR TKIs significantly decreased the survival of resistant cells, enhanced induction of apoptosis, and effectively inhibited the growth of erlotinib-resistant xenografts, providing the preclinical rationale for testing combinations of ASN007 and EGFR TKIs in EGFR-mutated NSCLC patients. This study emphasizes the importance of targeting ERK signaling in maintaining the long-term benefits of EGFR TKIs by overcoming acquired resistance.

Osimertinib in advanced EGFR-mutant Lung Adenocarcinoma with asymptomatic brain metastases: an open-label, three-arm, phase II pilot study

Background Osimertinib is selective for both EGFR-TKI sensitizing and Thr790Met mutations. While intracranial activity of osimertinib is documented in larger trials, a prospective study focusing exclusively on patients with asymptomatic brain metastases has not been reported. Methods In this nonrandomized, phase II, open label, 3-arm prospective proof-of-concept pilot study, 48 patients with metastatic EGFR-mutant lung adenocarcinoma (LUAD) received osimertinib 80 mg daily. Patients were either treatment naïve (arm A=20) or previously treated with an EGFR-TKI and Thr790Met-positive (arm B=18) or negative (arm C=10). In cases of isolated intracranial progression, osimertinib dose was escalated (160 mg). The primary endpoints were intracranial objective response rate (iORR) and intracranial disease control rate (iDCR). The secondary endpoint was intracranial progression free survival (iPFS). This study is registered at Clinicaltrials.gov, NCT02736513. Results The iORR’s were 84.2%, 66.7% and 50% and the iDCR’s were 94.7%, 94.4% and 80% in arms A, B and C, respectively. The median iPFS was 11.8 months (95% CI 7.7-NA), 7.6 (95% CI 5.3-NA) and 6.3 months (95% CI 3.9-NA) in arms A, B and C, respectively. Following dose escalation, pooled iORR was 54% (arm A=5, arm B=4, arm C=2). Adverse events were similar to those in previously published literature. Conclusion Osimertinib demonstrated high efficacy on brain metastases. All trial arms displayed a significant decrease in the number and diameter of target lesions. These findings indicate that osimertinib is effective for Thr790Met-positive and negative LUAD patients with asymptomatic brain metastases. Therefore, osimertinib should be considered a viable option for EGFR-mutant patients with brain involvement regardless of their Thr790Met mutation status.

The Optimal Therapeutic Strategy for Patients with EGFR-Mutated Non–Small Cell Lung Cancer with Brain Metastasis: A Real-World Study from Taiwan

ObjectiveThe treatment options for epidermal growth factor receptor (EGFR)-mutated non-small-cell lung cancer (NSCLC) with brain metastases (BMs) include EGFR-tyrosine kinase inhibitors (TKIs), stereotactic radiosurgery (SRS), whole-brain radiotherapy (WBRT), brain surgery (BS), and anti-angiogenesis therapy. As treatment options evolve, the redefinition of optimal treatment strategies for improving survival is crucial.Methods150 EGFR-mutant NSCLC patients with BMs who received first- or second-generation EGFR-TKIs as first-line treatment between January 2012 and October 2019 were included in this analysis.ResultsAfter multivariate analysis, patients with graded prognostic assessments for lung cancer based on molecular markers (Lung-mol GPA) ≥ 3 (Hazard ratio (HR): 0.538, 95% Confidence Interval (CI): 0.35-0.83); who received afatinib or erlotinib as first-line treatment (HR:0.521, 95%CI: 0.33-0.82); underwent SRS therapy (HR:0.531, 95%CI: 0.32-0.87); or were sequentially treated with osimertinib (HR:0.400, 95%CI: 0.23-0.71) were associated with improved overall survival (OS). Furthermore, SRS plus EGFR-TKI provided more OS benefits in patients with Lung-mol GPA ≥ 3 compared with EGFR-TKI alone in our patient cohort (44.9 vs. 26.7 months, p = 0.005). The OS among patients who received sequential osimertinib therapy was significantly longer than those without osimertinib treatment (43.5 vs. 24.3 months, p < 0.001), regardless of T790 mutation status (positive vs. negative/unknown: 40.4 vs. 54.6 months, p = 0.093).ConclusionsThe study demonstrated that EGFR-mutant NSCLC patients with BMs could be precisely treated with SRS according to Lung-mol GPA ≥ 3. Sequential osimertinib was associated with prolonged survival, regardless of T790M status.