Effective Treatment of Lung Adenocarcinoma Harboring EGFR-Activating Mutation, T790M, and cis-C797S Triple Mutations by Brigatinib and Cetuximab Combination Therapy.

Acquired resistance to osimertinib mediated by EGFR cis-C797S is now a growing challenge. No effective treatment strategy is currently available to overcome cis-C797S-mediated resistance. In this retrospective cohort study, 15 patients with advanced lung adenocarcinoma and EGFR-activating mutation, T790M, and cis-C797S after osimertinib progression were identified by targeted next-generation sequencing. Five of these patients received a combined therapy of brigatinib and cetuximab, and 10 patients received cisplatin-based doublet chemotherapy. Among the five patients who were positive for EGFR 19del-T790M-cis-C797S mutations, and who received brigatinib and cetuximab combination therapy, three patients achieved partial response, and two had stable disease, resulting in an overall objective response rate of 60% and disease control rate of 100%. Among the 10 patients who were positive for EGFR 19del or L858R-T790M-cis-C797S mutations and received chemotherapy, only one patient achieved partial response, five had stable disease, and the other four did not benefit from chemotherapy, resulting in an overall objective response rate and disease control rate of 10% and 60%, respectively. The median progression-free survival of patients who received combined targeted therapy was 14 months, and 3 months for those treated with chemotherapy. No grade III to IV adverse events were observed in any patient. Our retrospective study provides clinical evidence that a combined targeted therapy of brigatinib and cetuximab could be of benefit and may potentially be an effective treatment strategy to improve survival outcomes in patients who acquire EGFR T790M-cis-C797S-mediated resistance to osimertinib.

Wang Y ，Yang N ，Zhang Y ，Li Li ，Han R ，Zhu M ，Feng M ，Chen H ，Lizaso A ，Qin T ，Liu X ，He Y ... -  《-》

Possibility of brigatinib-based therapy, or chemotherapy plus anti-angiogenic treatment after resistance of osimertinib harboring EGFR T790M-cis-C797S mutations in lung adenocarcinoma patients.

There was no standard treatment for patients who acquired resistance to osimertinib mediated by epidermal growth factor receptor (EGFR) T790M-cis-C797S. The aim of this study was to investigate the association between different therapeutic strategies and survival outcomes among these patients. This retrospective cohort study analyzed 46 patients with metastatic lung adenocarcinoma and EGFR T790M-cis-C797S after osimertinib progression from January 1, 2017 to October 31, 2020. Among them, 13 patients received brigatinib-based therapy, 23 patients received chemotherapy in combination of anti-angiogenics or not, and 10 patients received other targeted treatments like dacomtinib, bevacizumab, or a combined therapy of osimertinib and other targeted drugs. Compared to other targeted therapy, brigatinib-based therapy (median progression-free survival [mPFS]: 4.40 vs. 1.63 months, hazard ratio [HR] = 0.39, 95% confidence interval [CI]: 0.21-0.73, p = 0.001) and chemotherapy-based treatment (mPFS: 4.70 vs. 1.63 months, HR = 0.18, 95% CI: 0.06-0.50, p < 0.001) presented a better survival outcome and there was no significant difference between brigatinib-based therapy and chemotherapy-based treatment (mPFS: 4.40 vs. 4.70 months, HR = 1.24, 95% CI: 0.57-2.67, p = 0.58). Chemotherapy combined with anti-angiogenics achieved a better efficacy than only chemotherapy (mPFS: 5.50 vs. 1.03 months, HR = 0.30, 95% CI: 0.11-0.83, p = 0.02). Patients carrying EGFR exon 19 deletion mutation had a longer PFS than those who harboring EGFR exon 21 p.L858R mutation (4.57 vs. 1.03 months, HR = 0.18, 95% CI: 0.06-0.54, p = 0.001), no matter they received brigatinib-based therapy (mPFS: 5.00 vs. 3.23 months, HR = 0.19, 95% CI: 0.01-0.96, p = 0.05) or chemotherapy-based treatment (mPFS: 7.23 vs. 1.03 months, HR = 0.05, 95% CI 0.01-0.49, p < 0.001). Brigatinib-based therapy and chemotherapy plus anti-angiogenics could be considered beyond progression from osimertinib therapy. For patients harboring EGFR exon 19 deletion/T790M/cis-C797S mutation, the clinical efficacy was superior to patients harboring EGFR exon 21 p.L858R/T790M/cis-C797S mutation.

Yang Y ，Xu H ，Ma L ，Yang L ，Yang G ，Zhang S ，Ai X ，Zhang S ，Wang Y ... -  《Cancer Medicine》

Response to Brigatinib Targeted Therapy in Non-Small Cell Lung Cancer Harboring Epidermal Growth Factor Receptor Exon 19 Deletion, T790M, and cis-C797S Triple Mutations: A Case Report.

Chen ZW ，Lin G ，Shih HJ ，Wu CE ... -  《INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES》

Sequential use of EGFR-tyrosine kinase inhibitors based upon EGFR mutation evolution achieves long-term control in a non-small cell lung cancer patient: a case report.

Jiang Y ，Zhang J ，Jiang X ，Cheng L ，Liao X ，Li Y ，Zhang M ，Chen R ，Yin T ... -  《-》

Effective treatment of pulmonary adenocarcinoma harboring triple EGFR mutations of L858R, T790M, and cis-C797S by osimertinib, bevacizumab, and brigatinib combination therapy: a case report.

Zhao J ，Zou M ，Lv J ，Han Y ，Wang G ，Wang G ... -  《OncoTargets and Therapy》