MK-4621

MK-4621 (formerly known as RGT 100, RGT100-PEI, and ImOl 100) is a synthetic RNA oligonucleotide that acts as an agonist of the retinoic acid-inducible gene I protein (RIG-I; also known as DDX58). It was developed for intratumoral or intralesional injection in patients with advanced or recurrent solid tumors. The drug activates the RIG-I pathway, inducing a type I interferon response and stimulating immune activity within the tumor microenvironment. Preclinical studies demonstrated potent antitumor activity in mouse models, while early-phase clinical trials showed increased expression of interferon signaling genes and chemokines such as CXCL11 in treated patients. The development program included both monotherapy and combination therapy with pembrolizumab. Clinical development was discontinued after phase 1/2 trials due to limited efficacy[1][2][3][4][6].

Other names

RIG-I selective ligand RGT100