Frizzled class receptor 8–immunoglobulin G1 Fc fusion protein (ipafricept) (OMP-54F28)

OMP-54F28 (ipafricept) is a first-in-class, recombinant fusion protein comprising the cysteine-rich ligand-binding domain of the human Frizzled class receptor 8 (Fzd8) fused to the Fc portion of human IgG1. It acts as a soluble decoy receptor for Wnt ligands, thereby competitively blocking activation of the Wnt/β-catenin signaling pathway, which is essential for cancer stem cell maintenance, tumor cell proliferation, and tumor progression in various malignancies. Clinical trials have shown that OMP-54F28 has a manageable safety profile, most notably inducing reversible increased bone turnover and some mild-to-moderate constitutional symptoms. It is being investigated primarily in combination with standard chemotherapeutic agents in multiple solid tumor indications, where it demonstrates reduction of cancer stem cell frequency, tumor growth inhibition, and synergy with cytotoxic drugs.

Other names

FZD8-FcipafriceptFrizzled 8–Fc fusion protein

Functions as a soluble decoy receptor by combining the extracellular ligand-binding domain of Fzd8 with an IgG1 Fc domain, sequestering Wnt ligands and antagonizing canonical Wnt/β-catenin signaling. Reduces cancer stem cell renewal and tumorigenic potential, especially when used together with chemotherapy.