RBX-6610

RBX-6610 is a novel, orally administered small molecule inhibitor of eukaryotic translation initiation factor 4E (eIF4E), developed by Ribometrix. eIF4E is a key regulatory protein in mRNA translation and is implicated in oncogenic signaling pathways downstream of KRAS, including MAPK and PI3K. Overactivity of eIF4E promotes the selective translation of pro-oncogenic and anti-apoptotic proteins such as Cyclin D1/3, BCL2, and MCL1. RBX-6610 has demonstrated potent anti-proliferative effects in preclinical models of non-small cell lung cancer (NSCLC) with KRAS G12C mutations—both in treatment-naïve tumors and those resistant to approved KRAS inhibitors (sotorasib/adagrasib). In vitro and in vivo studies show that RBX-6610 can induce tumor growth inhibition as monotherapy, but more notably it synergizes with KRAS inhibitors to re-sensitize resistant tumors, leading to enhanced apoptosis and significant tumor regression without observed toxicity over extended dosing periods. The drug selectively inhibits cap-dependent translation regulated by eIF4E rather than global protein synthesis, which may improve tolerability compared to other translation inhibitors[1][3][5][6].