Oak Hill Bio, a clinical-stage rare disease therapeutics company, announced the closing of a $32.5 million Series A financing round to advance rugonersen, its investigational antisense oligonucleotide (ASO) therapy for Angelman syndrome, into a pivotal Phase 3 clinical study expected to begin in mid-2026.
The financing round was co-led by Balyasny Asset Management, venBio, and Janus Henderson Investors, with participation from KCap Biotechnology Fund. The funding will support the continued development of rugonersen, which was originally developed by Roche and is designed to restore UBE3A production in neurons. Several former members of the Roche rugonersen program have joined Oak Hill Bio to help lead the therapy’s development.
Angelman syndrome is a rare neurodevelopmental disorder affecting approximately 30,000 diagnosed patients across the United States and EU5 countries. There are currently no approved disease-modifying treatments for the condition.
In connection with the financing, Oak Hill Bio expanded its board of directors with the appointments of Doug Fambrough, founder and portfolio manager of the KCap Biotechnology Fund and former CEO of Dicerna Pharmaceuticals; Rich Gaster, managing partner at venBio; and Sandeep Kulkarni, co-founder and CEO of Zura Bio and former co-founder and CEO of Tourmaline Bio.
Oak Hill Bio said the financing and board additions position the company to advance rugonersen into late-stage clinical development as it seeks to address a significant unmet need in Angelman syndrome.
The company’s lead program, rugonersen (OHB-724), is an ASO designed to target the UBE3A-ATS transcript, enabling expression of the paternal copy of the UBE3A gene. By restoring UBE3A protein production in neurons, the therapy aims to address the underlying cause of Angelman syndrome and potentially improve neuronal development and function.
Oak Hill Bio operates as the trading name for OHB Pediatrics Ltd., a subsidiary of Oak Hill Bio Holdings. In addition to rugonersen, Oak Hill Bio Holdings is developing OHB-607, a replacement therapy intended to prevent complications of prematurity in extremely preterm infants, which is currently being evaluated in a Phase 2b study.
KEY QUOTES:
“We are thrilled to welcome these exceptional investors and company-builders to our team. We really appreciate that they’ve recognized the strong science and data behind rugonersen and the tremendous need for a disease-modifying therapy in the Angelman syndrome community. With the financing and additions to our board, we are well-positioned to advance rugonersen into a Phase 3 study in the middle of 2026.”
Josh Distler, Chief Executive Officer, Oak Hill Bio
“We are proud to support Oak Hill Bio in its mission to address a critical need in Angelman syndrome. We were particularly impressed by rugonersen’s promising preclinical and Phase 1 data, which underscore rugonersen’s differentiation and potency. We believe rugonersen possesses best-in-class, disease-modifying potential and clearly demonstrates Oak Hill Bio’s ability to identify and acquire assets with significant therapeutic and commercial prospects.”
Doug Fambrough, Member of the Board of Directors, Oak Hill Bio
