PARMA, Italy & CAMBRIDGE, Mass., June 25, 2026
Chiesi Group and Arbor Biotechnologies have achieved a significant regulatory milestone after the European Commission (EC) granted Orphan Drug Designation (ODD) to ABO-101, an investigational gene editing therapy being developed for Primary Hyperoxaluria Type 1 (PH1), an ultra-rare inherited metabolic disorder with no curative treatment. The designation strengthens the companies’ global collaboration established in 2025 and reinforces the growing momentum behind CRISPR-based gene editing technologies designed to address severe rare diseases at their genetic source. ABO-101 is engineered as a one-time liver-directed gene editing therapy that permanently reduces hepatic oxalate production by targeting the HAO1 gene, potentially preventing the progressive kidney damage associated with PH1. The European regulatory recognition provides important incentives that support clinical development while highlighting the urgent unmet medical need faced by patients living with this life-threatening genetic disease.
European Orphan Drug Designation Strengthens Gene Editing Development
The European Commission’s Orphan Drug Designation recognizes medicines intended for rare diseases affecting fewer than five in 10,000 people across the European Union and offers valuable regulatory incentives that encourage innovation for underserved patient populations. For Chiesi Group and Arbor Biotechnologies, the designation represents another important validation of ABO-101’s therapeutic potential while accelerating its clinical development pathway.
The investigational therapy previously received both Orphan Drug Designation and Rare Pediatric Disease Designation from the U.S. Food and Drug Administration (FDA) in 2025, demonstrating growing regulatory confidence across major global markets. These designations are expected to facilitate continued investment in the program while supporting future regulatory interactions aimed at bringing innovative gene editing therapies to patients suffering from rare inherited disorders.
ABO-101 Targets the Root Cause of Primary Hyperoxaluria Type 1
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Unlike conventional therapies that primarily manage symptoms, ABO-101 has been designed to address the underlying genetic cause of Primary Hyperoxaluria Type 1 through CRISPR Cas12i2 gene editing technology delivered using a lipid nanoparticle (LNP) platform. The therapy aims to permanently disable the HAO1 gene in liver cells, significantly reducing excessive oxalate production responsible for kidney stones, progressive kidney failure, systemic oxalosis, and other life-threatening complications.
Primary Hyperoxaluria Type 1 results from mutations in the AGXT gene, leading to chronic overproduction of oxalate and progressive organ damage throughout a patient’s lifetime. Because current treatment options remain limited and many patients eventually require dialysis or kidney transplantation, the development of a single-dose gene editing therapy represents a potentially transformative advancement for rare disease medicine and precision genetic therapies.
Global Phase 1/2 Study Advances Toward Clinical Validation
ABO-101 is currently being evaluated in the ongoing global Phase 1/2 redePHine clinical study, which is assessing its safety, tolerability, pharmacokinetics, pharmacodynamics, and preliminary efficacy in both adult and pediatric patients with Primary Hyperoxaluria Type 1. The multicenter trial follows a dose-escalation design intended to identify the optimal therapeutic dose before expanding into pediatric enrollment and long-term follow-up. Clinical updates from the program are being presented during the 15th International Hyperoxaluria Workshop, reflecting increasing scientific interest in next-generation gene editing medicines for rare genetic diseases.
The collaboration between Chiesi Group and Arbor Biotechnologies combines Chiesi’s extensive expertise in rare disease commercialization with Arbor’s advanced genomic medicine platform, positioning ABO-101 as a promising candidate capable of redefining future treatment standards for Primary Hyperoxaluria Type 1. If successful, the therapy could become one of the first one-time gene editing treatments capable of delivering durable clinical benefits for patients living with this devastating inherited disorder while further demonstrating the expanding role of precision genomic medicine in transforming rare disease care.
Source: Chiesi Group, Arbor Biotechnologies press release
