MK-2118

MK-2118 is a novel small molecule STING (Stimulator of Interferon Genes) agonist developed by Merck for the treatment of advanced or metastatic solid tumors and lymphomas. It functions by binding to and activating the STING pathway in immune cells within the tumor microenvironment, leading to the production of type I interferons and other pro-inflammatory cytokines that promote antitumor immunity. MK-2118 is administered primarily via intratumoral injection, which maximizes local immune activation while minimizing systemic side effects. Clinical trials have evaluated MK-2118 both as monotherapy and in combination with pembrolizumab (an anti-PD-1 antibody), particularly targeting patients who are refractory or intolerant to standard therapies. Early-phase studies indicate manageable toxicity but limited antitumor activity, with evidence that intratumoral administration can induce systemic immune responses[2][3][5][6][7].