OncoTargets and Therapy (Oct 2020)
Efficacy of Pyrotinib in a Heavily Pretreated Patient with Lung Adenocarcinoma Harboring HER2 Amplification and Exon 20 Insertions: A Case Report
Abstract
Jianzhen Shan,1,* Jian Ruan,1,* Yanbin Tan,2 Li Yan,3 Songan Chen,3 Miaoyan Du,1 Lingjie Wang1 1Department of Medical Oncology, The First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, People’s Republic of China; 2Department of Radiology, The Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, People’s Republic of China; 3Department of Medicine, Burning Rock Biotech, Guangzhou, People’s Republic of China*These authors contributed equally to this workCorrespondence: Jianzhen ShanThe First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou 310003, People’s Republic of ChinaTel +86 571-87235409Email [email protected]: The clinical benefits of HER2 inhibitors in patients with non-small cell lung cancer (NSCLC) have been limited. There is a paucity of effective therapies in NSCLC after developing resistance to initial anti-HER2 therapy. Herein, we presented the clinical benefit of pyrotinib in a 53-year-old patient with advanced lung adenocarcinoma whose circulating tumor DNA (ctDNA) analysis of pleural effusion revealed the coexistence of HER2 exon 20 p.Y772_A775dup (mutation ratio: 38.86%) and HER2 amplification (copy number: 4.5) following failures of multiple therapies including afatinib and ado-trastuzumab emtansine (T-DM1). Notably, pyrotinib treatment induced rapid and marked improvement of clinical symptoms, and partial response was observed after 8 weeks. CtDNA monitoring during the treatment showed that the mutation ratio of HER2 decreased to 7.99%, and the amplification disappeared. The patient achieved a progression-free survival of 7.5 months after treatment with pyrotinib. Thus, pyrotinib may be a new treatment strategy for the subgroup of lung adenocarcinoma patients, with coexistence of HER2 exon 20 p.Y772_A775dup and HER2 amplification even after failures of multiple anti-HER2 therapies. It also indicated the value of capture-based next-generation sequencing to monitor and guide therapy.Keywords: pyrotinib, HER2 mutation, HER2 amplification, non-small cell lung cancer, next-generation sequencing
