PH-3861

PH-3861 is an investigational **self-delivering RNA interference therapeutic** from Phio Pharmaceuticals built on the company's INTASYL platform. It is a dual-targeting, chemically modified siRNA formulation designed to silence **Programmed cell death protein 1** and **Bromodomain-containing protein 4**, with the goal of reversing tumor immune evasion while also modulating epigenetic programs that support tumor growth. Publicly available company materials describe PH-3861 as a **preclinical** immuno-oncology candidate evaluated by **local intratumoral administration** in hepatocellular carcinoma models, where dual targeting of PD-1 and BRD4 was reported to produce synergistic antitumor activity and durable systemic antitumor immunity in mice.

Other names

INTASYL dual-targeting PD-1 and BRD4