# Rapafusyn Pharmaceuticals

Startup profile on Capital Atlas: https://capitalatlas.ai/startups/rapafusyn-pharmaceuticals

- Industry: Biotechnology
- Headquarters: Baltimore, US
- Website: www.rapafusyn.com/
- Total disclosed funding: $44M
- Latest round: Series A (Sep 5, 2025)
- Investors on record: 5

## About

Based in Maryland, US, and founded in 2015 by Jun O. Liu, PhD, Rapafusyn Pharmaceuticals operates as a provider of FKBP-binding macrocyclic peptides for targeting intracellular and transmembrane proteins to drug developers. As of 2024, the company is led by its CEO, Sean X. Hu, PhD, MBA. In September 2025, Rapafusyn Pharmaceuticals raised USD 44 million in series A funding from new investors 3E Bioventures Capital and Proxima Ventures, Lapam Capital, Yongjin Group and BioTrack Capital.

The company provides a wide range of drug discovery products, such as DNA-encoded libraries (DELs), arrayed libraries of non-degrading molecular glues (RapaGlues), large DNA-encoded libraries (DELs), and arrayed libraries of FKBP-binding macrocyclic peptides. Moreover, the firm offers drug discovery solutions targeting intracellular proteins and transmembrane domains like SLCs and GPCRs. Additionally, the company also provides services such as rapid SAR expansion for improving potency, selectivity, and physiochemical properties. 
The company generates revenue through providing its products, such as DNA-encoded libraries (DELs), arrayed libraries of non-degrading molecular glues (RapaGlues), large DNA-encoded libraries (DELs), and arrayed libraries of FKBP-binding macrocyclic peptides. The company will support product innovation and improve business operations.

## Funding rounds

- Series A, Sep 5, 2025, $44M — Yongjin Group, 3E Bioventures Capital, Lapam Capital, Proxima Ventures, BioTrack Capital

## Investors

- Yongjin Group — Series A
- 3E Bioventures Capital (https://capitalatlas.ai/funds/3e-bioventures-capital) — Series A
- Lapam Capital (https://capitalatlas.ai/funds/lapam-capital) — Series A
- Proxima Ventures (https://capitalatlas.ai/funds/proxima-ventures) — Series A
- BioTrack Capital (https://capitalatlas.ai/funds/biotrack-capital) — Series A