Human Epidermal Growth Factor Receptor 2 Positive Advanced Gastric or Esophagogastric Adenocarcinoma: Reflecting on the Past to Gain a New Insights.

Purpose Of Review: Human epidermal growth factor receptor 2 (HER2) is a critical target in advanced gastric cancer (AGC). This review highlights the current treatment landscape, lessons learned from past clinical trials, and prospects for future treatment strategies for HER2-positive AGC.

Recent Findings: Trastuzumab had been the standard treatment for HER2-positive AGC for a decade, and subsequently, trastuzumab deruxtecan, an antibody-drug conjugate (ADC), emerged with an impressive response.

The tumor immune microenvironment and therapeutic efficacy of trastuzumab deruxtecan in gastric cancer.

Trastuzumab deruxtecan (T-DXd), an anti-HER2 antibody-drug conjugate with a topoisomerase I inhibitor connected by a cleavable linker, has been approved for patients with HER2-positive gastric or gastroesophageal junction tumors. This biomarker study assessed HER2 expression and immune cell infiltration in relation to the therapeutic response to T-DXd. This retrospective analysis included samples from patients treated with T-DXd in three clinical trials.

[A New Molecular Targeted Agent for Gastric Cancer-The Anti-Claudin 18.2 Antibody, Zolbetuximab].

The standard first-line treatment for unresectable advanced or recurrent gastric cancer(GC)and gastroesophageal junction cancer(GEJC)has been a platinum doublet chemotherapy. Trastuzumab with chemotherapy is the standard regimen for HER2-positive GC/GEJC. While, for HER2-negative cases, chemotherapy with or without immune checkpoint inhibitors (ICIs)such as nivolumab or pembrolizumab are regarded as the standard therapy.

The HSP90 Inhibitor Pimitespib Targets Regulatory T Cells in the Tumor Microenvironment.

Regulatory T (Treg) cells play key roles in cancer immunity by suppressing a range of antitumor immune responses and contributing to resistance to programmed death (PD)-1 blockade therapy. Given their critical roles in self-tolerance, local control of immunosuppression by Treg cells, such as in the tumor microenvironment (TME), has been intensively studied. Inhibition of heat shock protein 90 (HSP90), a chaperone with vital roles in regulating proteostasis in cancer cells, impedes cancer progression by interrupting oncogenic signaling pathways and potentially modulating antitumor immunity, but we have very little mechanistic insight into these immune modulatory effects.