Disitamab vedotin combined with apatinib in gastric cancer: A case report and review of literature.

BACKGROUND

In patients with human epidermal growth factor receptor 2 (HER2)-overexpressing gastric cancer (GC), the combination of HER2 targeting and a standard first-line chemotherapy regimen has been demonstrated to significantly improve their prognosis. However, in a proportion of patients, cancer progresses within a short period of time, and there is currently no standard treatment after disease progression.

CASE SUMMARY

This study presents a case of a 51-year-old male with advanced GC who underwent radical resection (Billroth type II subtotal gastrectomy and gastrojejunostomy) and resection of liver metastases. Immunohistochemical staining revealed a HER2 score of 2+, a dMMR status, and a Ki67 proliferation index of 30% to 40%. The gene test results indicated the presence of ERBB2 amplification and a PD-L1 expression level of less than 5%. Since December 2021, the patient has experienced disease progression during both first-line (two cycles of KN026 combined with KN046) and second-line (five cycles of nivolumab combined with trastuzumab and SOX chemotherapy) treatment regimens. The patient's prognosis following the first and second lines of treatment was unfavorable, with progression occurring in a relatively short time. For third-line therapy, disitamab vedotin (RC48) plus apatinib was used. At the time of this report, the patient had achieved a progression-free survival (PFS) of 25.8 months, which exceeded the median survival time for patients with advanced GC.

CONCLUSION

Despite the unfavorable prognosis associated with advanced GC, the implementation of personalized treatment approaches may still prove beneficial for select patients. In patients with HER2-positive GC with extensive metastatic involvement, the use of the HER2-targeted combination with apatinib has demonstrated the potential to prolong both PFS and overall survival.