Rapafusyn Pharmaceuticals

What Rapafusyn Pharmaceuticals does

Rapafusyn Pharmaceuticals is a private, discovery-to-preclinical-stage biotechnology company pioneering RapaGlues™ — a novel modality of non-degrading molecular glues designed to address disease targets previously considered intractable. Founded by Professor Jun O. Liu of Johns Hopkins University School of Medicine (the discoverer of the FK506/cyclosporin A molecular glue mechanism in 1991), the company is headquartered in Baltimore, MD, with a Shanghai subsidiary established through its Roche Accelerator participation. Its core platform combines an FKBP12-binding macrocyclic peptide scaffold inspired by natural products (rapamycin, FK506) with a proprietary DNA-encoded library of more than 8 billion non-degrading molecular glues, complemented by arrayed libraries, 3D rapafucin microarrays, and AI/ML-enabled target selection and SAR optimization. The mechanism forms neo-protein-protein interactions with disease targets via the abundant intracellular chaperone FKBP12, inhibiting function without protein degradation — distinguishing it from the degrader-based induced-proximity space.

The company's internal pipeline focuses on oncology, immunology and inflammation, renal disease, and pain. The lead asset, RAP-0001, is a first-in-class ENT1 inhibitor for the prevention of acute kidney injury (AKI) in cardiac surgery patients, advancing toward IND-enabling studies. Additional programs include ONC-003 (SLC7A11), ONC-005 (GSTP1), ONC-006 (transcription factor), ONC-001 (immune-regulatory ligase), IMM-001 (transcription factor), and IMM-002/IMM-003 (TNFR1-selective PPIs). The company has published in Nature Chemistry, Angewandte Chemie, and Cell, anchoring the scientific credibility of the platform.

Rapafusyn's business model is sales-led and partnership-driven, pursuing co-discovery collaborations, platform licensing, and pipeline asset out-licensing with global pharmaceutical partners. The company is currently pre-revenue, with a Roche Accelerator collaboration (announced May 2025) and an active global pharma partner leveraging its DEL library — both B2B revenue mechanics in early stages. Approximately $44 million has been raised in cumulative Series A financing (oversubscribed round closed September 2025), led by BioTrack Capital and Yonjin Capital with continued participation from 3E Bioventures, Proxima Ventures, and Lapam Capital.

Name

Rapafusyn Pharmaceuticals

Legal name

Rapafusyn Pharmaceuticals Inc.

Website

https://rapafusyn.com

Company type

Private

Founded year

2020

Operating status

Operating

Headcount range

11–50 employees

Short description

Rapafusyn Pharmaceuticals is a private Baltimore-based biotech pioneering RapaGlues™, a novel class of non-degrading molecular glues built on FKBP12-binding macrocyclic peptides and an 8+ billion compound DNA-encoded library, targeting previously undruggable proteins in oncology, immunology, renal, and pain indications.

Ownership category

akta.pro rank

Product category

Drug Discovery Platform (Biotechnology)

NAICS

Research and Development in Biotechnology (except Nanobiotechnology) (541714), Biological Product (except Diagnostic) Manufacturing (325414), Pharmaceutical and Medicine Manufacturing (3254), Scientific Research and Development Services (5417)

SIC

Pharmaceutical Preparations (2834), Biological Products, (No Disgnostic Substances) (2836)

akta.pro primary industry

Drug Discovery (Target ID/Validation & Hit Discovery) (HLAIALAA)

akta.pro secondary industries

Library & Diversity Generation Platforms (display libraries, DNA-encoded libraries for biologics, variant libraries) (HLAAAIAL), Therapeutic Peptides & Protein/Peptide Biologics (HLAAAAAH), Engineered Protein Therapeutics (de novo/AI-designed proteins, novel scaffolds) (HLAAAAAJ)

Keywords

• Non-degrading molecular glues
• DNA-encoded library screening
• Macrocyclic peptide therapeutics
• Induced proximity drug discovery
• FKBP12 binding platforms

Headquarters

HQ city

Baltimore

HQ country

United States

HQ region

North America

Offices3 records

Markets served

GTM type

B2B

Offering type

Services

Cost components

Personnel, Technology or R&D, Operations, Supply Chain, Marketing or Sales

Revenue model

1. Pharmaceutical Licensing and Partnership Deals: Rapafusyn generates revenue through licensing its RapaGlue platform technology and pipeline assets to pharmaceutical partners, including co-discovery collaborations (e.g., drug co-discovery collaborations with Roche) and potential out-licensing of development-stage programs. The company also collaborates with global pharmaceutical partners leveraging its DNA-encoded library of more than 8 billion non-degrading molecular glues.
2. Drug Development and Commercialization: Advancing an internal pipeline of macrocyclic peptide-based non-degrading molecular glue therapeutics targeting oncology, immunology, renal, and pain disease areas. Revenue would be generated through eventual product sales upon regulatory approval.

Go-to-market motion1 record

Distribution channels1 record

Marketing channels6 records

Core offering

Rapafusyn operates a proprietary non-degrading molecular glue drug discovery platform (RapaGlues) that uses FKBP12-binding macrocyclic peptides and a DNA-encoded library of more than 8 billion compounds to identify orally bioavailable small molecules for previously undruggable targets. The company commercializes this discovery engine through co-discovery collaborations, platform licensing, and pipeline out-licensing deals with global pharmaceutical partners, while internally advancing a pipeline led by the ENT1 inhibitor RAP-0001 for acute kidney injury.

Product overview

Rapafusyn Pharmaceuticals is an innovative biotech pioneering RapaGlues, a novel modality of non-degrading molecular glues for previously undruggable disease targets. The company operates the RapaGlue Platform as its core technology, which consists of large DNA-encoded libraries (DELs) and arrayed libraries of FKBP12-binding macrocyclic peptides. The platform enables rapid discovery of cell-permeable small molecules that form neo-protein-protein interactions to block target function. Lead program RAP-0001 is an ENT1 inhibitor for Acute Kidney Injury advancing toward IND-enabling studies, with additional pipeline programs in oncology (GSTP1, SLC7A11) and immunology/inflammation (TNFR1-selective, STAT6). The company applies AI/ML methods for target selection and drug candidate optimization.

Differentiator

Problem solved

Functional benefit

Brands

• RapaGlues™: Non-degrading molecular glue drug discovery platform that leverages FKBP12-binding macrocyclic peptides to modulate protein-protein interactions for drug discovery
• RAP-0001

Products and services

• RapaGlue Platform A proprietary non-degrading molecular glue drug discovery platform that leverages FKBP12-binding macrocyclic peptides to modulate protein-protein interactions, transcription factors, transmembrane proteins (SLCs/transporters, ion channels), enzymes, and ligases. Sold and accessed through drug co-discovery collaborations, platform licensing, and pipeline asset out-licensing for global pharmaceutical partners.
• DNA-Encoded Library (DEL) of 8+ Billion Non-Degrading Molecular Glues One of the largest reported DNA-encoded libraries of non-degrading molecular glues in the industry, enabling rapid identification of novel chemical starting points for hard-to-drug targets. Used by Rapafusyn's platform scientists and made available to global pharmaceutical partners through co-discovery collaborations.
• RAP-0001 (ENT1 Inhibitor) First-in-class, potent and selective ENT1 inhibitor discovered through the RapaGlue platform for the prevention of Acute Kidney Injury (AKI) in cardiac surgery patients. Currently advancing toward IND-enabling studies as Rapafusyn's most advanced internal asset.

Quantifiable outcome

• Lead ENT1 inhibitor program (RAP-0001) demonstrated compelling preclinical efficacy in renal disease models and is advancing toward IND-enabling studies for the prevention of AKI in cardiac surgery patients.
• +3 more outcomes

Segments2 records

Ideal customer profiles2 records

Technology focussed Yes

API detail

Has API

No

API docs

API detail

Core technology

AI maturity

App detail

AI capability1 record

Feature6 records

Partnerships

Four partnerships are on record, tiered core and minor.

• Roche (Roche Accelerator)coreStrategic or Co-development Partner · 27 May 2025Rapafusyn was selected to join the Roche Accelerator, Roche's innovation hub that connects pioneering biotechs with Roche's world-class expertise. This provides external validation of the RapaGlue platform and enables drug co-discovery collaborations with Roche in areas with high unmet need such as cancer and immunology. The Roche Accelerator is Roche's first in-house accelerator globally, based in Shanghai, strengthening collaboration with local partners in the innovation ecosystem. Rapafusyn's Shanghai subsidiary is an integral part of this ecosystem.
• Global Pharmaceutical Partner (DEL Collaboration)minorStrategic or Co-development PartnerRapafusyn is leveraging its DNA-encoded library of more than 8 billion non-degrading molecular glues in a collaboration with a global pharmaceutical partner. The collaboration uses the company's proprietary DEL library for drug discovery against challenging targets.
• Johns Hopkins University School of MedicinecoreStrategic or Co-development PartnerRapafusyn emerged from the laboratory of Dr. Jun O. Liu at Johns Hopkins University. The company is based within the Johns Hopkins School of Medicine campus in Baltimore. Rapafusyn collaborates with leading nephrologists at Johns Hopkins University for its ENT1/AKI program. The company's Scientific Advisory Board includes members affiliated with Johns Hopkins.
• R&D Steering Committee and Scientific Advisory BoardcoreOthersRapafusyn has assembled a Scientific Advisory Board (SAB) and R&D Steering Committee comprising experienced pharma and biotech veterans including: Dr. Garry Neil (R&D Steering), Dr. Scott Reines (R&D Steering), Dr. Howard Hutchinson (R&D Steering), Dr. Frank Walsh (Sr Strategic Advisor), Dr. Magid Abou-Gharbia (R&D strategy + Med Chem), Dr. Hamid Rabb (Acute Kidney Injury + Cardiovascular), Dr. George Vlasuk (Cardiovascular), Dr. Dan Marquess (Oncology), Dr. Lyn Jones, Dr. Winston Wu, Dr. Howard Schulman (Neuroscience), Dr. Steven Projan (Infectious Disease + Immunology), Dr. Robert Besthof (Drug Commercialization), Dr. Derek Maclean, Dr. Steven Bender, Dr. Wayne Childers (Acting Co-Head of Medicinal Chemistry), and Dr. Scott Dax (Head of Preclinical Development).

Scale indicators6 records

Recent moves7 records

Expansion highlights6 records

Direct peers

• Kymera Therapeutics: Clinical-stage biotech developing targeted protein degraders using a proprietary discovery platform. Directly comparable as an induced-proximity platform company pursuing previously undruggable targets.
• Monte Rosa Therapeutics: Develops molecular glue degraders to modulate previously undruggable disease targets. Closely comparable as a molecular glue-focused biotech targeting intractable proteins with rationally designed small molecules.
• C4 Therapeutics: Developer of degronimid-based degraders and other targeted protein degradation approaches. Comparable as a small-molecule induced-proximity platform company addressing intractable oncology and I&I targets.
• Arvinas: Clinical-stage leader in targeted protein degradation using PROTAC and molecular glue platforms. Comparable as an induced-proximity drug discovery company pursuing challenging intracellular targets via novel chemical modalities.

Emerging players

• Plexium: Develops novel induced-proximity medicines, including molecular glues and targeted degraders, using a proprietary cell-based screening platform. Comparable as an emerging induced-proximity platform company.
• Amphista Therapeutics: Develops next-generation targeted protein degradation approaches using a proprietary mechanism. Comparable as a platform-based induced-proximity company targeting challenging disease proteins.
• Foghorn Therapeutics: Focused on chromatin biology and developing drugs against previously undruggable targets in the chromatin regulatory system. Comparable in its pursuit of intractable targets through a proprietary platform approach.
• Neomorph: Pioneers molecular glue degraders for previously undruggable targets, with backing from Blackstone. Comparable as an emerging induced-proximity/molecular glue discovery company.
• Proxygen: Focused on discovering molecular glue degraders for hard-to-drug targets using a yeast-based screening platform. Comparable as an early-stage molecular glue discovery company targeting similar undruggable proteins.

Others

• HitGen Inc. Large DNA-encoded library (DEL) provider and drug discovery CRO with extensive DEL-based screening capabilities. Comparable as a DEL-driven drug discovery platform — a related but supporting infrastructure provider to Rapafusyn's internal DEL capabilities.

Market position

Strengths5 records

Weaknesses5 records

Competitive moat4 records

Key risks6 records

Key highlights7 records

Customer concentration

Revenue estimate

Valuation estimate

Number of profiles

Profiles11 records

Subsidiaries1 record

Funding overview

Funding rounds2 records

Investors5 records

Funding detail is available on the Subscription and Enterprise plan.Contact sales →

M&A

Investments

M&A and investment is available on the Subscription and Enterprise plan.Contact sales →

Frequently asked questions about Rapafusyn Pharmaceuticals