Yubo Wang1, Nong Yang2, Yongchang Zhang2, Rui Han1, Mengxiao Zhu1, Mingxia Feng1, Hengyi Chen1, Analyn Lizaso3, Tian Qin3, Xiaoyan Liu4, Yong He5. 1. Department of Respiratory Medicine, Daping Hospital, Army Medical University, Chongqing, People's Republic of China. 2. Department of Medical Oncology, Lung Cancer and Gastrointestinal Unit, Hunan Cancer Hospital/The Affiliated Cancer Hospital of Xiangya School of Medicine, Central South University, Changsha, People's Republic of China. 3. Burning Rock Biotech, Guangzhou, People's Republic of China. 4. Origimed, Shanghai, People's Republic of China. 5. Department of Respiratory Medicine, Daping Hospital, Army Medical University, Chongqing, People's Republic of China. Electronic address: heyong@tmmu.edu.cn.
Abstract
INTRODUCTION: 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. METHODS: 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. RESULTS: 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. CONCLUSIONS: 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.
INTRODUCTION: 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. METHODS: 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. RESULTS: 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. CONCLUSIONS: 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 EGFRT790M-cis-C797S-mediated resistance to osimertinib.
Authors: Yaning Yang; Haiyan Xu; Li Ma; Lu Yang; Guangjian Yang; Shuyang Zhang; Xin Ai; Shucai Zhang; Yan Wang Journal: Cancer Med Date: 2021-10-06 Impact factor: 4.452