Rapafusyn Pharmaceuticals Closes Over-Subscribed $44 Million Series A Financing to Advance Its Non-Degrading Molecular Glue Drug Discovery Platform

BioTrack Capital and Yonjin Capital join Series A round alongside other investors including 3E Bioventures Capital, Proxima Ventures Ltd., and Lapam Capital

Upsized and over-subscribed Series A total funding of $44 million secured

Rapafusyn's RapaGlue™ platform rapidly discovers non-degrading molecular glues, a validated and highly sought-after modality to address challenging disease targets

BALTIMORE, MD, Sept. 04, 2025 (GLOBE NEWSWIRE) --

Rapafusyn Pharmaceuticals, a leader in the discovery and development of non-degrading molecular glue therapeutics, today announced the closing of its over-subscribed Series A financing round with the addition of investors BioTrack Capital and Yonjin Capital. Total funds raised in the Series A round are $44 million, which includes $24 million committed previously. BioTrack Capital and Yonjin Capital join other distinguished investors in the Series A including 3E Bioventures Capital, Proxima Ventures Ltd., and Lapam Capital.

Rapafusyn was co-founded by Professor Jun O. Liu of Johns Hopkins University School of Medicine, a pioneer in the molecular glue field, with initial funding support from Jiangsu Tianqin Investment Ltd.

The financing accelerates the advancement of Rapafusyn's broad drug pipeline addressing many diseases of high unmet medical need in the oncology, immunology, renal and pain disease areas by leveraging RapaGlues™ — a groundbreaking non-degrading molecular platform that can access challenging or previously undruggable disease targets.  

The RapaGlue™ platform has demonstrated the ability to create highly cooperative non-degrading molecular glues with high cell membrane permeability to modulate protein–protein interactions, transcription factors, SLCs/transporters, ion channels, enzymes, and others. Rapafusyn applies innovative machine learning (ML)/AI methods as an integral part of target selection and drug candidate optimization that result in an industry leading success rate at discovering relevant chemical matter for hard-to-drug targets. Rapafusyn's lead program, a selective ENT1 inhibitor, is advancing toward IND-enabling studies after showing compelling activity in renal disease models — a powerful validation of the RapaGlue™ platform's therapeutic potential. Rapafusyn is also leveraging its DNA-encoded library of more than 8 billion non-degrading molecular glues in a collaboration with a global pharmaceutical partner.

"With the successful closing of our Series A financing, we are positioned to propel the RapaGlue™ platform and to accelerate our mission to deliver transformative therapies to patients in need," Dr. Sean Hu, President and CEO of Rapafusyn, commented. “We are pleased to have BioTrack Capital and Yonjin Capital join this financing round.”

“Rapafusyn and the RapaGlue™ platform are rewriting what's possible in drug discovery with a new class of macrocyclic molecules,” said Dr. Karen Liu, a Founding Partner at 3E Bioventures. “I am excited about the platform's ability to expand beyond traditional small molecules and recent degrader molecules to approach previously undruggable targets.”

Existing investors Haolin Sung, Partner of Proxima Ventures and Jian Li, Partner of Lapam Capital, each expressed enthusiasm for the new financing and looked forward to joining forces with the new investors as Rapafusyn accelerates its platform and pipeline development.

Kai Chen, Vice President of BioTrack Capital commented, “We are thrilled to invest in Rapafusyn for the potential of their innovative non-degrading molecular glue platform. It stands out as a highly differentiated drug modality for previously undruggable disease targets which hold substantial promise for diseases with unmet need.”

Wen Chen, Partner at Yonjin Capital added, “The Rapafusyn team has made remarkable progress in discovering high potential drug candidates using their RapaGlue™ platform. We are also very impressed by Rapafusyn's operating and advisory teams and are delighted to join the Series A round.”

About BioTrack Capital

Established in 2017, BioTrack is a venture capital firm that focuses on investing in and incubating outstanding early-stage biotech, medtech as well as healthcare cross disciplinary sectors (AI and digital healthcare, consumer healthcare, etc). The BioTrack professional investment team possess strong and complementary skills in research and development, clinical operations, consulting, and investment.

About Yonjin Capital

Yonjin Capital is a leading international investment firm that specializes in early- and mid-stage life science companies in therapeutics, diagnostics and medical devices. The Yonjin Capital team has broad global knowledge, in-depth experience, and extensive networks which enable their portfolio companies to achieve remarkable results. Yonjin Capital is the North America and Europe investment arm of Yonjin Group and the sister firm of Yonghua Capital, both based in China with headquarters in Shanghai.

About Rapafusyn Pharmaceuticals

Rapafusyn emerged from the laboratory of Dr. Jun O. Liu's, Professor of Pharmacology and Molecular Sciences at Johns Hopkins University, with a mission to develop transformational medicines to address high unmet medical needs and enhance patient care.  The platform leverages non-degrading macrocyclic molecular glues (RapaGlues™) to address challenging therapeutic targets.  Rapafusyn has constructed both DNA-encoded libraries (DELs) and arrayed libraries of RapaGlues™ that form neo-PPIs to inhibit a protein from its native activity. These compounds are rationally designed and engineered to bind FKBP and form a ternary complex with the disease target protein, offering a promising avenue for modulating intricate protein-protein interactions.  RapaGlues™ have proven effective in producing innovative chemical starting points for challenging drug targets.  The modular architecture enables SAR and subsequent optimization for potency, selectivity, and physicochemical properties to accelerate drug discovery and development. RapaGlues™ frequently exhibit cell permeability directly from the starting point, enhancing their potential for therapeutic development.

For more information, please visit rapafusyn.com or contact Heather Lavin: hlavin@rapafusyn.com