Efficacy of third-line pemetrexed monotherapy versus pemetrexed combination with bevacizumab in patients with advanced EGFR mutation-positive lung adenocarcinoma

Excellent platinum dependent response to chemotherapy after relapse under TKI treatment in NSCLC with sensitizing EGFR mutations and no detectable resistance mutations: three case studies

First-line tyrosine-kinase inhibitor (TKI) treatment is the current standard for patients with metastasized non-small cell lung cancer (NSCLC) and sensitizing epidermal growth factor receptor (EGFR) mutations. Despite good initial responses, patients treated with TKIs relapse after an average of 12 months. About half of them develop known resistance mechanisms and therefore are qualified for further targeted therapies. However, many patients still have to be treated with standard chemotherapeutic regimens. In this case series we describe three patients with similar progression patterns under TKI treatment in the absence of treatable resistance mechanisms and excellent platinum dependent response to chemotherapy and review the current literature focusing on effectiveness of standard chemotherapy in this cohort.

Efficacy of pemetrexed and carboplatin with or without bevacizumab in lung adenocarcinoma patients with EGFR non-T790M mutations after progression on first-line EGFR-tyrosine kinase inhibitors

Background

The purpose of this study was to compare the effects of pemetrexed and carboplatin plus bevacizumab (PC + B) versus pemetrexed and carboplatin (PC) in lung adenocarcinoma patients with EGFR non‐T790M mutations after progression on first‐line EGFR‐tyrosine kinase inhibitors (TKIs).

Methods

Patients with EGFR‐positive lung adenocarcinoma who had received second‐line PC with or without bevacizumab harboring EGFR non‐T790M mutations after progression on first‐line EGFR‐TKIs between April 2015 and 2017 at Tianjin Medical University Cancer Institute and Hospital were enrolled in the study. The primary endpoint was progression‐free survival and secondary endpoints were overall survival, objective response rate, disease control rate, and safety.

Results

A total of 85 patients were eligible for the study: 55 and 30 cases were enrolled in the PC and PC + B groups, respectively. The median progression‐free survival was prolonged with PC + B compared to PC (median 8.2 vs. 5.1 months; P = 0.037). The objective response rate was improved with PC + B compared to PC (46.7% vs. 25.5%; P = 0.047) and overall survival prolonged with PC + B compared to PC (median 26.3 vs. 19.2 months; P = 0.012). Safety was similar to previous studies of bevacizumab in non‐small cell lung cancer: one patient experienced grade 3 hypertension and proteinuria but did not require the discontinuation of therapy.

Conclusion

The addition of bevacizumab to PC was superior to PC alone as second‐line therapy in patients with advanced non‐T90M EGFR‐positive lung adenocarcinoma. However, this result needs to be confirmed by prospective clinical trials.