Oak Hill Bio to Go Public via SPAC Merger, Secures $175 Million to Advance Rugonersen for Angelman Syndrome Through Phase 3
核心洞察
Oak Hill Bio (搜索) and Research Alliance Corporation III (搜索) announced a business combination agreement expected to close by year-end 2026, providing approximately $175 million in gross proceeds.
The combined company will trade on Nasdaq under "OAKH" and advance rugonersen, an antisense oligonucleotide targeting UBE3A-ATS (搜索), through Phase 3 readout and potential NDA submission in 2H2029.
Rugonersen, licensed from Roche in February 2025, recently dosed its first patient in the pivotal Phase 3 BEACON trial (NCT07605429) in July 2026.
Oak Hill Bio (搜索), a clinical-stage rare disease therapeutics company, and Research Alliance Corporation III (搜索) (Nasdaq: RACC), a special purpose acquisition company sponsored by RA Capital Management (搜索), have entered into a definitive business combination agreement that will take Oak Hill Bio public. The transaction is expected to provide approximately $175 million in gross proceeds, including $75 million of cash in RACC's trust account fully backstopped by RA Capital Management and a $100 million committed private financing. Together with Oak Hill Bio's recent $32.5 million Series A financing, the combined funding is expected to provide cash runway for development of rugonersen through Phase 3 readout and potential new drug application submission in the second half of 2029.
The combined company will be renamed Oak Hill Bio (搜索), Inc. and is expected to trade on the Nasdaq Capital Market under the ticker symbol "OAKH" following the close of the transaction, anticipated by year-end 2026.
Rugonersen and the BEACON Trial
Rugonersen is an investigational antisense oligonucleotide designed to address the underlying disease biology of Angelman syndrome (搜索) by specifically and potently binding the UBE3A-ATS (搜索) transcript. This binding is intended to trigger degradation of the UBE3A-ATS transcript in the central nervous system, thereby unsilencing the paternal UBE3A (搜索) allele and allowing neuronal expression of the paternal wild-type copy of the UBE3A gene.
The therapy was originally developed by Roche as a highly potent and specific therapy to restore neuronal UBE3A (搜索) expression and was licensed by Oak Hill Bio (搜索) from Roche in February 2025. Several former members of the rugonersen program have joined Oak Hill Bio to lead further development.
In July 2026, Oak Hill Bio (搜索) dosed the first patient in the pivotal Phase 3 BEACON clinical trial (NCT07605429). Rugonersen's clinical and preclinical data have been published in Nature Medicine (Hipp, J.F., Bacino, C.A., Bird, L.M. et al., 2025) and Nucleic Acids Research (Jagasia et al., 2025).
"We are excited to announce a business combination with Research Alliance Capital III and partnering with RA Capital," said Josh Distler, Chief Executive Officer of Oak Hill Bio (搜索). "The resources provided by this amazing group of investors will enable us to continue to aggressively develop rugonersen. We have dosed the first patient in the Phase 3 BEACON trial and look forward to evaluating the potential of rugonersen to meaningfully impact the lives of patients living with Angelman syndrome (搜索) and their families."
Transaction Details
Of the $100 million private financing, $45 million was funded by RA Capital at signing pursuant to a SAFE investment in Oak Hill Bio (搜索), with the remaining amount expected to be funded at closing through an oversubscribed PIPE in RACC at $10.00 per share. Participants in the PIPE include Oak Hill Bio's Series A investors—Balyasny Asset Management, Janus Henderson Investors, KCap Biotechnology Fund, and venBio—as well as new investors including ADAR1 Capital Management, Affinity Asset Advisors, Ally Bridge Group, BVF Partners, Great Point Partners, Logos Capital, SilverArc Capital, and Trails Edge Capital Partners.
Oak Hill Bio (搜索)'s management team will lead the combined company post-combination, with CEO Josh Distler continuing in that role. Current RACC Director and former Avidity Biosciences CFO Mike MacLean will remain on the Board of the combined company.
Matthew Hammond, Partner at RA Capital and CEO and Director of RACC, stated: "Oak Hill Bio (搜索) combines compelling science, a management team with a broad range of experience, and an extremely promising rare disease asset, making for a solid foundation for continued success. We are excited to lead this transaction and support Oak Hill Bio as the team brings rugonersen into pivotal development and towards a potential registration for a best-in-class treatment for Angelman syndrome (搜索)."
Angelman Syndrome (搜索): Unmet Medical Need
Angelman syndrome (搜索) is a serious rare genetic neurodevelopmental disorder affecting approximately 15,000 patients in each of the U.S. and the EU5, with an estimated incidence of 1 in 12,000 to 20,000 live births. The condition is characterized by global developmental delay, intellectual disability, epilepsy (occurring in 90% of cases before age 3 years) with an atypical underlying electroencephalogram, ataxia, tremor, hyperactivity, limited speech, and sleep dysregulation. Symptoms often emerge during infancy and persist throughout life.
Deletions and mutations in the maternal ubiquitin protein ligase E3A (UBE3A (搜索)) allele cause Angelman syndrome (搜索), due to epigenetic silencing of the paternal UBE3A allele by a long non-coding antisense RNA (UBE3A-ATS (搜索)) in neurons. Currently, there are no approved disease-modifying therapies for the condition.
Series A Financing and Board Appointments
The SPAC transaction follows Oak Hill Bio (搜索)'s $32.5 million Series A financing, which closed in June 2026 and was co-led by Balyasny Asset Management, venBio, and Janus Henderson Investors, with participation from KCap Biotechnology Fund. In connection with that financing, Doug Fambrough (founder and portfolio manager of 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) joined the Board of Directors.
"We were particularly impressed by rugonersen's promising preclinical and Phase 1 data, which underscore rugonersen's differentiation and potency," said Doug Fambrough. "We believe rugonersen possesses best-in-class, disease-modifying potential and clearly demonstrates Oak Hill Bio (搜索)'s ability to identify and acquire assets with significant therapeutic and commercial prospects."
The business combination is expected to close by year-end 2026, subject to customary closing conditions including approval by shareholders and regulatory bodies. Leerink Partners, UBS Investment Bank, Wells Fargo Securities, and LifeSci Capital are serving as joint placement agents in connection with the PIPE financing.