Chiesi Group and Arbor Biotechnologies Announce ABO-101 Granted Orphan Drug Designation by European Commission for Primary Hyperoxaluria

PARMA, Italy & CAMBRIDGE, MA, June 25, 2026 — Chiesi Group, an international research-oriented biopharmaceutical company, together with Arbor Biotechnologies, Inc., a biotechnology company discovering and developing the next generation of genetic medicines, today announced a milestone for ABO-101, an investigational gene editing therapy for primary hyperoxaluria type 1 (PH1). The European Commission (EC) has granted ODD to ABO-101 for the treatment of PH, a group of rare genetic disorders characterized by excessive oxalate production. ABO-101 is being developed for primary hyperoxaluria type 1 (PH1), the most common and severe form of PH, which can lead to recurrent kidney stones, kidney failure, and systemic complications. The designation marks an important inflection point in the companies’ global strategic collaboration, established in 2025, to develop and commercialize novel gene editing therapies for rare diseases, including ABO-101 for PH1.

ODD in the European Union (EU) is granted to medicines intended for the diagnosis, prevention, or treatment of rare conditions affecting fewer than five in 10,000 people.

“Receiving Orphan Drug Designation from the EC is an important recognition of the unmet need that exists for people living with PH1 and the promise of what gene editing approaches may offer,” said Mitch Goldman, MD, PhD, SVP Research & Development, Chiesi Global Rare Diseases. “Beyond that recognition, the designation provides meaningful support throughout the development lifecycle, which allows us to continue advancing this research with the resources and commitment the community deserves.”

“This designation underscores the growing potential of gene editing therapies to evolve the treatment landscape for rare genetic diseases,” said Devyn Smith, Ph.D., Chief Executive Officer of Arbor Biotechnologies. “As we continue advancing the ABO-101 clinical trial program alongside Chiesi, we remain focused on advancing innovative genetic medicines for people living with rare diseases and delivering on our commitment to address significant unmet medical needs.”

In addition to the EC’s designation, ABO-101 received ODD and Rare Pediatric Disease Designation (RPDD) from the U.S. Food and Drug Administration (FDA) in 2025. In the United States, the FDA grants ODD to drugs and biologics intended for the treatment, diagnosis, or prevention of rare diseases affecting fewer than 200,000 people, and RPDD to drugs and biologics intended to treat or prevent serious or life-threatening rare diseases that primarily affect children from birth to 18 years of age. These designations help advance the development of potential new treatment options for patients living with rare diseases, supporting continued innovation in areas where significant unmet medical needs remain.

ABO-101 is currently being evaluated in the global redePHine Phase 1/2 clinical study, with program updates to be presented at the upcoming 15th International Hyperoxaluria Workshop. John Lieske, M.D., Principal Investigator of the redePHine study, will deliver an overview of the ABO-101 clinical trial program titled, “redePHine: Advancing Gene Editing for Primary Hyperoxaluria Type 1,” on June 26, 2026, in Prague.

About Primary Hyperoxaluria Type I (PH1)

Primary hyperoxaluria type 1 is an ultra-rare lifelong genetic disease, where a mutation in the AGXT gene leads to an enzyme deficiency in the liver resulting in an overproduction of oxalate by the liver and eventual buildup of oxalate crystals in the kidney and other organ systems. As the disease progresses, it can cause recurring kidney stones, kidney damage and eventually lead to end-stage kidney disease (ESKD) and systemic oxalosis. Patients may eventually require intensive interventions such as dialysis and/or transplantation.1

About ABO-101

ABO-101 is an investigational gene editing therapy designed to be a one-time liver-directed gene editing technology that potentially results in a permanent loss of function of the HAO1 gene in the liver to reduce PH1-associated oxalate production. ABO-101 is currently being evaluated for PH1 in the redePHine Phase 1/2 clinical study (NCT06839235). ABO-101 consists of a lipid nanoparticle (LNP), licensed from Acuitas Therapeutics, encapsulating messenger RNA expressing a novel Type V CRISPR Cas12i2 nuclease and an optimized guide for RNA which specifically targets the human HAO1 gene. ABO-101 has not been approved for any use by the FDA or any other regulatory agency, including the EMA and MHRA.

About the redePHine Study 

The Phase 1/2 redePHine study is an open label global multi-center dose escalation study to evaluate safety, tolerability, pharmacokinetics, pharmacodynamics and preliminary efficacy of a single dose of ABO-101 in participants with primary hyperoxaluria type 1. The trial will consist of 2 Study Periods. During the first Study Period, there will be 2 parts. In Part A, adult participants will be treated with a single ascending dose to identify a recommended dose. In Part B, pediatric participants will be treated with the recommended dose. Following the first Study Period, participants will start Study Period 2, a long-term monitoring program to comply with local and national requirements. For more information on redePHine, visit clinicaltrials.gov (NCT06839235) and clinicaltrialsregister.eu.

About Chiesi Group

Chiesi is a research-oriented international biopharmaceutical group that develops and markets innovative therapeutic solutions in respiratory health, rare diseases, and specialty care. The company’s mission is to improve people’s quality of life and act responsibly towards both the community and the environment. By changing its legal status to a Benefit Corporation in Italy, the US, France and Colombia, Chiesi’s commitment to creating shared value for society as a whole is legally binding and central to company-wide decision-making. As a certified B Corp since 2019, Chiesi is part of a global community of businesses that meet high standards of social and environmental impact. The company aims to reach Net-Zero greenhouse gases (GHG) emissions by 2035.

With 90 years of experience, Chiesi is headquartered in Parma (Italy), with 31 affiliates worldwide, and counts more than 7,500 employees. The Group’s research and development centre in Parma works alongside 6 other important R&D hubs in France, the US, Canada, China, the UK, and Sweden.

For more information visit: www.chiesi.com

About Chiesi Global Rare Diseases 

Chiesi Global Rare Diseases is a business unit of the Chiesi Group established to deliver innovative therapies and solutions for people living with rare diseases. As a family business, Chiesi Group strives to create a world where it is common to have a therapy for all diseases and acts as a force for good, for society and the planet. The goal of the Global Rare Diseases unit is to ensure equal access so as many people as possible can experience their most fulfilling life. The unit collaborates with the rare disease community around the globe to bring voice to underserved people in the health care system.

For more information visit: www.chiesirarediseases.com.

About Arbor Biotechnologies, Inc.

Arbor Biotechnologies™, a clinical stage, next-generation gene editing company based in Cambridge, MA, is advancing a portfolio of first-in-class genomic medicines addressing serious diseases for which there are no existing functional cures, with a CNS pipeline initially prioritizing multiple ALS targets and a co-developed, clinical program, ABO-101, for the treatment of primary hyperoxaluria type 1. The company’s unique breadth of gene editing technologies goes beyond the limitations of early editing approaches to unlock access to new gene targets and expand the therapeutic reach of genomic medicines.

For more information, please visit: arbor.bio.

Chiesi Global Rare Diseases Media Contact:
Sky Striar
LifeSci Communications
sstriar@nulllifescicomms.com

Arbor Biotechnologies Media Contact:
Peg Rusconi
Deerfield Group
prusconi@nulldeerfieldgroup.com

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