About Us

Who We Are

Rapafusyn was founded on discoveries from the laboratory of Dr. Jun O. Liu, Professor of Pharmacology and Molecular Sciences at Johns Hopkins University, with a singular mission: to create a transformational molecular glue modality for disease areas high unmet medical needs. Our RapaGlues™ platform is comprised of highly selective, non-degrading macrocyclic molecular glues that precisely modulate hard-to-drug intracellular and transmembrane targets to unlock new therapeutic possibilities. Based within the Johns Hopkins School of Medicine campus in Baltimore, our teams draw on a world-class clinical and scientific ecosystem to accelerate the translation of breakthrough science into meaningful therapies.

Our Platform and Science

Rapafusyn discovers and develops next-generation molecular glues engineered to selectively modulate cytosolic and transmembrane proteins. Our proprietary RapaGlue modality is non-degrading and purpose-built for hard-to-drug targets, drawing on the favorable properties of natural products rapamycin and FK506 and leveraging the endogenous cytosolic protein FKBP12. Powered by our AI-enabled machine learning capability and proprietary DEL library of 8+ billion non-degrading glues—among the largest reported in the industry—we have repeatedly identified innovative chemical starting points across diverse target classes, including protein–protein interactions (PPIs), transcription factors, transmembrane proteins (such as SLCs), ligases, and other enzymes (including GSTases). RapaGlues have demonstrated exquisite selectivity, high potency, intrinsic cell permeability, and the potential for durable clinical benefit supported by long residence time and slow off-rate kinetics.

Our Platform and Science

A Disruptive Pipeline

Rapafusyn’s strong screening productivity has generated a promising early-stage pipeline of potentially first- and best-in-class programs spanning oncology (including GSTP1 and SLC7A11), immunology & inflammation (TNFα R1–selective, STAT6), and renal disease (ENT1 for acute kidney injury). Our programs are differentiated by the distinctive attributes of RapaGlues, including high selectivity, unique binding modes, and the ability to engage hard-to-drug targets that have remained challenging for other modalities.

Our most advanced program targets ENT1, an SLC transporter implicated in acute kidney injury (AKI). AKI remains an area of substantial unmet need, with no approved therapies for the large subset of patients—approximately 30%—who undergo CABG (heart) surgery and subsequently experience some degree of AKI associated renal damage.