Rapafusyn develops non-degrading macrocyclic molecular glues, branded RapaGlues, to address challenging therapeutic targets. Its platform includes DNA-encoded libraries (DELs) and arrayed libraries of RapaGlues that form neo-protein-protein interactions to inhibit target proteins. The compounds are rationally designed to bind FKBP and form ternary complexes with disease target proteins, enabling modulation of intricate protein-protein interactions. The platform’s modular architecture supports SAR and optimization for potency, selectivity, and physicochemical properties to accelerate drug discovery. RapaGlues frequently exhibit cell permeability from the starting point, enhancing their therapeutic potential. The company is led by President and CEO Dr. Sean Hu and intends to use new funding to expand operations and advance its development efforts. Rapafusyn Pharmaceuticals develops non-degrading macrocyclic molecular glues (RapaGlues™) designed to form neo-protein–protein interactions and inhibit target proteins by binding FKBP and creating ternary complexes. The company has built both DNA-encoded libraries (DELs) and arrayed libraries of RapaGlues™ to generate chemical starting points for difficult targets. Its modular architecture enables SAR and optimization for potency, selectivity, and physicochemical properties, and many starting points frequently exhibit cell permeability. Rapafusyn focuses on macrocyclic peptide-based RapaGlues™ as a platform approach to address challenging therapeutic targets. The company plans to use new funding to accelerate progress across its pipeline and to further enhance internal capabilities. Rapafusyn was founded by Jun O. Liu and is headquartered in Baltimore, MD.

Total raised

$72M

Funding rounds

2

Latest round

Series A

Latest activity

Sep 2025