Sustained Clinical Benefit of Pyrotinib Combined with Capecitabine Rescue Therapy After Trastuzumab Resistance in HER2-Positive Advanced Gastric Cancer: A Case Report

Abstract

Background HER2-positive patients with advanced gastric cancer have a poor prognosis, and trastuzumab-resistant patients lack effective treatment. Case Presentation We report a 72-year-old male with HER2-positive gastric cancer. The patient had metastatic tumor during adjuvant chemotherapy after surgery, followed by second-line chemotherapy, and achieved a progression-free survival (PFS) of 4.5 months. Subsequent third-line chemotherapy treatment also failed. Fortunately, the patient had a significant tumor response and 8.5 months of PFS on trastuzumab combined with chemotherapy. After trastuzumab resistance, the patient was treated with programmed cell death protein-1 inhibitor combined with apatinib, which selectively inhibited VEGFR2, but the effect was not satisfactory. Finally, the patient was treated with capecitabine combined with pyrotinib, an irreversible TKI, acting on HER2. The tumor shrank significantly after this treatment. Conclusion The mechanism and countermeasures of trastuzumab resistance were discussed in this case. For patients with HER2-positive advanced gastric cancer, pyrotinib can achieve good results after trastuzumab resistance.

HER2+ advanced gastric cancer: Current state and opportunities (Review)

“…Additionally, the combination of pyrotinib and SHR6390, a CDK4/6 inhibitor, showed good efficacy and safety in treating patients with refractory HER2 + AGC and solid tumors ( 126 ). In one case report ( 127 ), a 72-year-old male patient with HER2 + AGC developed resistance to trastuzumab and camrelizumab (a PD-1 inhibitor) combined with apatinib. When the patient was treated with capecitabine combined with pyrotinib, the tumor size was markedly reduced, which prolonged the patient's survival.…”

Dual targeted therapy with pyrotinib and trastuzumab forHER2‐positive advanced colorectal cancer: A phase 2 trial

“…Pyrotinib, a novel irreversible pan‐HER tyrosine kinase inhibitor agent targeting HER2, EGFR, and HER4, was approved for breast cancer treatment in China in 2018 12 . The antitumor effect of pyrotinib also has been reflected in other solid tumors, such as lung cancer and gastric cancer 13–16 . In addition, pyrotinib combined with trastuzumab and docetaxel as neoadjuvant treatment presented clinical efficacy in HER2‐positive early or local breast cancer with an acceptable manageable safety profile in a phase 3 trial 17 .…”

“… 12 The antitumor effect of pyrotinib also has been reflected in other solid tumors, such as lung cancer and gastric cancer. 13 , 14 , 15 , 16 In addition, pyrotinib combined with trastuzumab and docetaxel as neoadjuvant treatment presented clinical efficacy in HER2‐positive early or local breast cancer with an acceptable manageable safety profile in a phase 3 trial. 17 This study was designed to explore the efficacy and safety of pyrotinib plus trastuzumab in patients with HER2‐positive advanced CRC.…”