A Phase II Study to Assess the Efficacy of Osimertinib in Patients With EGFR Mutation-positive NSCLC Who Developed Isolated CNS Progression (T790M-negative or Unknown) During First- or Second-generation EGFR-TKI or Systemic Disease Progression (T790M-negative) After Treatment With First- or Second-generation EGFR-TKI and Platinum-based Chemotherapy (WJOG12819L)

Efficacy of epidermal growth factor receptor tyrosine kinase inhibitor in the treatment of patients with nonsmall cell lung cancer

This study aimed to examine the effectiveness of epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor (TKI) in treating patients with nonsmall cell lung cancer (NSCLC), and the association between clinical characteristics and effectiveness. This retrospective study included 140 patients with NSCLC admitted to our hospital between July 2020 and July 2022. The patients were categorized into 2 groups according to the treatment that they received: a comparison group (67 patients) and a research group (73 patients). The comparison group received conventional chemotherapy, and the research group received conventional chemotherapy and EGFR-TKI-targeted therapy. The immune and tumor marker levels, clinical response, and relationship between clinical characteristics and response to therapy were compared between the 2 groups before and after treatment. After treatment, the levels of neuron-specific enolase and carcinoembryonic antigen (CEA) and CD8+ count were significantly lower, and forced vital capacity, forced expiratory volume in 1 second, and CD4+ count were significantly higher in the research group than in the comparison group. After treatment, the clinical effectiveness in the 2 groups significantly improved, and the disease control rate in the research group was significantly higher than that in the comparison group (89% vs 69%, P = .014). The bivariate analysis revealed that smoking history, ECOG Performance Status score, and CEA level were significantly associated with clinical effectiveness. Conventional chemotherapy combined with EGFR-TKI-targeted therapy is effective in patients with NSCLC and has a clinically significant effect on improving patients' immune function and lung function.

A phase II study (WJOG12819L) to assess the efficacy of osimertinib in patients with EGFR mutation-positive NSCLC in whom systemic disease (T790M-negative) progressed after treatment with first- or second-generation EGFR TKIs and platinum-based chemotherapy

BACKGROUND

Osimertinib is a third-generation epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor (TKI) that is an established standard treatment option for chemotherapy-naive patients with EGFR mutation-positive non-small cell lung cancer (NSCLC). However, of such patients who have received prior treatment with a first- or second-generation EGFR TKI, only approximately half are eligible for osimertinib therapy because its indication as second-line treatment and beyond is limited to metastatic NSCLC that is positive for the T790M resistance mutation of the EGFR gene. This study was initiated at the request of a dedicated network for patients with lung cancer in Japan.

METHODS

We conducted a phase II study to assess the efficacy of osimertinib in patients with EGFR mutation-positive NSCLC in whom systemic disease (T790M-negative) progressed after treatment with first- or second-generation EGFR TKIs and platinum-based chemotherapy. The primary end point was response rate (assessed by a central imaging reviewer).

RESULTS

From August 2020 to February 2021, 55 patients from 15 institutions were enrolled in the study. The overall response for primary analysis was achieved in 16 patients (29.1 %; 95 % CI, 17.6-42.9), which exceeded the threshold response rate necessary for analysis. Stable disease was found in 16 patients (29.1 %), and progressive disease, in 18 (32.7 %). The median length of progression-free survival (PFS) was 4.07 months (95 % CI 2.10-4.30), and the rate of 12-month PFS was 17.3 %.

CONCLUSIONS

Osimertinib demonstrated modest antitumor activity against progressive EGFR T790M-negative disease.

Efficacy of Osimertinib After Progression of First-Generation Epidermal Growth Factor Receptor-Tyrosine Kinase Inhibitor (EGFR-TKI) in EGFR-Mutated Lung Adenocarcinoma: A Real-World Study in Chinese Patients

Objective

Osimertinib is the standard targeted strategy for lung adenocarcinoma patients harboring epidermal growth factor receptor (EGFR)-activating mutation who have achieved acquired mutation T790M beyond progression of first-line EGFR-tyrosine kinase inhibitor (TKI). In a real world setting, the efficacy for osimertinib as a subsequent treatment beyond first-generation EGFR-TKI progression under complex circumstances such as different T790M mutation status is still worth exploring.

Methods

Records of 84 lung adenocarcinoma patients with an EGFR sensitive mutation who received first-generation EGFR-TKI as first-line therapy and sequenced by osimertinib after progression were retrospectively reviewed in this study. The assessment of efficacy of subsequent osimertinib treatment was evaluated by progression free survival (PFS), objective response rate (ORR), complete response (CR), partial response (PR), disease control rate (DCR) and stable disease (SD) rates. Relationship between PFS and clinicopathological characteristics was analyzed using univariate analysis.

Results

Until the median follow-up time of 23.7 months (IQR 10.8–29.0 months), the median PFS (mPFS) of subsequent osimertinib was 17.0 months (HR 1.744, 95% CI, 13.547–20.382). Among 60 patients who had at least one measurable lesion, 35.0% of patients (21/60) had PR to osimertinib, and 63.3% patients (38/60) had SD during osimertinib treatment. The ORR was 35.0%, and the DCR was 98.3%. Patients with acquired T790M mutation which was detected by NGS or ddPCR assay had an mPFS of 17.0 months (HR = 1.032, 95% CI, 14.941–18.987), while the remaining 17 patients who had negative or unknown T790M mutation status had an mPFS of 23.5 months (HR = 9.404, 95% CI, 5.068–41.932). No significant difference was observed in those with and without T790M mutation (P = 0.704).

Conclusion

Osimertinib may serve as an alternative subsequent choice after progression of first-generation EGFR-TKI in EGFR-mutated lung adenocarcinoma and may represent a potential treatment option for selected T790M-negative patients.

Efficacy of osimertinib for preventing leptomeningeal metastasis derived from advanced EGFR-mutated non-small cell lung cancer: a propensity-matched retrospective study

Background

Leptomeningeal metastasis (LM) is a severe complication of advanced non-small cell lung cancer (NSCLC). This retrospective study aimed to investigate the potential use of osimertinib for preventing LM in patients with advanced epidermal growth factor receptor (EGFR)-mutated NSCLC.

Methods

Patients with advanced NSCLC harboring EGFR mutations who underwent tyrosine kinase inhibitors (TKIs) therapy for at least 8 weeks between September 2016 and September 2019 were eligible for this study. All included patients were divided into two groups based on whether they received osimertinib, the osimertinib group (patients treated with osimertinib) and the control group (patients not treated with osimertinib). Propensity score matching (PSM, ratio of 1:1) was used to account for differences in baseline characteristics. The cumulative incidence of LM and the overall survival (OS) were evaluated.

Results

A total of 304 patients were included in the study population. Among them, 116 patients received osimertinib, and 188 did not. A total of 112 patients remained in each group after PSM, and the baseline characteristics were not significantly different between the two cohorts. LM developed in 11 patients (9.82%) in the osimertinib group and 24 patients (21.42%) in the control group (hazard ratio [HR] 0.38, 95% confidence interval [CI] 0.19–0.79, p = 0.009). Multivariate analysis indicated that osimertinib was an independent, statistically significant predictor for determining the risk for LM, with an HR of 0.33 (p = 0.042). At present, the OS rate data are too immature for statistical analysis.

Conclusion

Real-world data demonstrate that osimertinib can significantly reduce the incidence of LM in patients with advanced NSCLC harboring common EGFR mutations. Given this result, osimertinib should be encouraged in clinical practice for specific patient populations.