Oak Hill Bio is developing the antisense therapy rugonersen, which it licensed from Roche in 2025, for Angelman syndrome.
Oak Hill Bio is joining the throng of biotechs going public this year—but the Massachusetts-based company is taking a slightly different path. Instead of holding a traditional initial public offering, Oak Hill on Monday announced a merger with the shell entity Research Alliance Corporation III.
The arrangement is more commonly known as a SPAC, for special purpose acquisition company, referring to blank-check companies that hold their own IPOs to raise money, which then sits in a trust account. Eventually, these SPACs merge with a target, taking that company to the public markets and giving them a hefty sum of capital.
In Oak Hill’s case, the SPAC deal will provide $75 million, plus $100 million more in committed private financing. The shell company is sponsored by RA Capital Management, the investor firm behind several promising biopharma players, including Aktis Oncology, Metsera (acquired by Pfizer for $9.8 billion) and Moderna.
The SPAC merger is expected to close by the end of the year, after which Oak Hill will trade on the Nasdaq under the symbol OAKH.
The SPAC raise adds to Oak Hill’s $32.5 million series A raise from last month, which the biotech has earmarked for lead asset rugonersen, an investigational antisense therapy.
Rugonersen is being developed for the rare neurodevelopmental disorder Angelman syndrome. Around 500,000 patients worldwide have the condition, which is caused by mutations to the UBE3A gene that render the resulting protein defunct. Common symptoms include seizures, developmental delays and sleep problems.
Rugonersen addresses Angelman by restoring the expression of the UBE3A protein in neurons. The asset was originally developed by Roche but was licensed by Oak Hill in April 2025, though financial details of the arrangement weren’t revealed.
Phase 1 data published in Nature Medicine a few months later showed that rugonersen partially normalized pathological brain activity in patients, while delivering a safety profile consistent with other antisense oligonucleotides. The asset is currently in the Phase 3 BEACON trial, which dosed its first patient earlier this month, Oak Hill said on Monday. The study has a primary completion date in 2029.
With a lower upfront cost, SPACs present a relatively easier and quicker way to the public markets than IPOs. This was especially the case during the pandemic-driven heyday of 2021. Some examples of companies that have entered the public markets through a SPAC include Cerevel, which was acquired by AbbVie in 2024 for $8.7 billion, and Roivant, which has since spawned several subsidiaries—which it calls “vants”—each dedicated to advancing a novel therapy.
