Oak Hill Bio Enters into Exclusive License Agreement with Roche to Obtain Global Rights for a Phase 3-Ready, Potential Best-in-Class Treatment for Individuals with Angelman Syndrome

April 15, 2025

Rugonersen, a novel RNA antisense oligonucleotide (ASO), has potential to be the first approved disease-modifying treatment for a disease affecting 500K individuals globally

Encouraging clinical efficacy results on exploratory endpoints related to brain function and measures of cognition and communication support further investigation

Pivotal Phase 3 study anticipated to be initiated in early 2026

Cambridge, Mass., USA, April 15, 2025 – Oak Hill Bio, a biotechnology company focused on acquiring and developing life-changing rare disease therapeutics, has entered into an exclusive license agreement with Roche (SIX: RO, ROG; OTCQX: RHHBY) to obtain global rights for rugonersen (RO7248824). Rugonersen is an ASO designed as a potential best-in- class treatment for individuals with Angelman syndrome, a rare, genetic neurodevelopmental condition for which there is no approved disease-modifying treatment. Oak Hill plans to initiate a Phase 3 study in early 2026.

“We are excited to take on this program. We are incredibly impressed by the rigorous research Roche has conducted, and the promising clinical data generated to date,” said Josh Distler, Chief Executive Officer of Oak Hill. “We have also been moved by the dedication of the patients, families, and investigators in the Angelman community and look forward to working closely with them to fully evaluate rugonersen’s potential to improve the lives of individuals with Angelman syndrome and their families.”

“I am very glad that the development of rugonersen will continue,” said Elizabeth Berry- Kravis, M.D., Ph.D., Pediatric Neurologist and Principal Investigator of the TANGELO trial at Rush University Medical Center. “Many of our trial participants have had meaningful improvements while in the rugonersen trial, and the TANGELO results suggest developmental and functional gains in multiple domains relative to natural history. We are very excited that the potential benefits of rugonersen will continue to be evaluated for these and other patients with Angelman syndrome.”

Angelman syndrome affects an estimated 500,000 individuals worldwide. It typically presents during early childhood and is characterized by cognitive and developmental issues, including speech and communication difficulties, motor impairment, balance issues, and debilitating seizures. The condition is caused by a loss of function of the maternally inherited UBE3A gene.

"We are incredibly excited and deeply grateful to see Oak Hill stepping in to continue the rugonersen program for Angelman syndrome. We, along with caregivers and providers, have seen the promise of rugonersen to help those with Angelman syndrome. This is a powerful signal to our community who have fought tirelessly for progress. Knowing that this work will continue means everything. We’re thankful for Oak Hill’s commitment to the community and for recognizing the urgent, unmet needs of individuals living with Angelman syndrome. The community stands ready to support this important effort in every way we can," said Amanda Moore (CEO, Angelman Syndrome Foundation, ASF) and Ryan Fischer (COO, Foundation for Angelman Syndrome Therapeutics, FAST).

About rugonersen

Rugonersen is a novel RNA antisense oligonucleotide (ASO) developed as a potential treatment option for individuals with Angelman syndrome, a rare genetic neurodevelopmental condition that affects the central nervous system and causes severe physical and learning disabilities.

Rugonersen has been designed to modify disease progression by boosting expression of the paternal version of the UBE3A gene. In the TANGELO study, an open-label, non- randomized, adaptive study led by Roche, rugonersen demonstrated encouraging exploratory effects compared to natural history on multiple clinical measures and on a pharmacodynamic biomarker of brain function, EEG delta power. These data were presented at FAST’s Annual Global Science Summit in November 2024. Oak Hill believes these results support rugonersen’s potential to address multiple disease domains.

Pending review of the final Phase 3 protocol by regulatory authorities, Oak Hill anticipates initiating a pivotal Phase 3 trial in early 2026 for rugonersen as a potential treatment for individuals with Angelman syndrome.

About Oak Hill Bio

Oak Hill Bio Ltd is a clinical-stage biotechnology company focused on acquiring and developing life-changing rare disease therapeutics. The company’s pipeline includes three programs in late-stage clinical development – potential treatments for Angelman syndrome and complications of extremely premature birth – as well as a preclinical program for diabetic macular edema. Oak Hill has operations in the United States and the United Kingdom. For more information, visit the company’s website at www.oakhillbio.com.

Contacts:

Oak Hill Bio

Josh Distler, Chief Executive Officer josh.distler@oakhillbio.com

Media

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