Stimulator of interferon genes (STING) agonist
STING:
STING is a 379-amino-acid protein which is expressed in various endothelial and epithelial cell types, hematopoietic cells (T cells, macrophages and DC).
STING plays a vital role in controlling the transcription of numerous host defence genes, such as type I Interferons and pro-inflammatory cytokines.
STING is part of the innate immune response
STING agonist: In Cancer therapy
STING Agonist Kick starts immune system against tumour,
The STING agonist is delivered directly into the tumour-associated immune cell => activating the c-GAS STING DNA sensing pathway and creates immune response by producing IFNβ by tumor-associated stromal cells.
Type 1 interferon activates immune cell =>dendritic cells migrates to lymph node =>presents antigen=>activation of Cytotoxic T cell by teaching them =>destroys tumor.
however the action of T cell on tumor destruction is deformed by tumor by expression of proteins such as PD-L1
PD-L1 binds to the PD 1 receptor on T cell =>Suppress tumor killing function
Combining STING agonist with PD 1 inhibitor=>prevents binding of PD-L1 to PD 1 receptor on T cell =>Tumor killing function
Availability ,safety and efficacy:
currently this drug is under phase 1 clinical study ,as a monotherapy and in combination with ezabenlimab in patients with advanced solid tumors.
The clinical studies are expected to end by end of 2023