Chiesi Group Licenses Arbor Biotechnologies’ CRISPR Therapy for Rare Liver Disease

MILAN, ITALY / CAMBRIDGE, MA –Oct 6, 2025- Italian pharmaceutical company Chiesi Group announced a major foray into the gene editing space on Monday, striking a deal with Arbor Biotechnologies to license and develop Arbor’s CRISPR-based therapy for Primary Hyperoxaluria Type 1 (PH1), a rare and deadly kidney disorder.

The agreement could see Cambridge, MA-based Arbor receive up to $115 million in upfront and near-term payments for the PH1 program, including use of its gene editing platform for other rare liver diseases. Arbor is also eligible for up to $2 billion in development, regulatory, and commercial milestone payments.

Advancing Gene Editing Beyond Cas9

Arbor’s investigational therapy is designed to permanently block the gene that produces the enzyme responsible for the buildup of toxic oxalate, which causes kidney stones in PH1 patients. This mechanism is similar to Alnylam Pharmaceuticals’ approved siRNA drug, Oxlumo, but Arbor’s treatment is designed as a one-time CRISPR infusion rather than a recurrent injection.

The Arbor platform is rooted in the work of founder and CRISPR pioneer Feng Zhang. The company utilizes next-generation CRISPR enzymes beyond the widely known Cas9, specifically its Cas12i2 enzyme, which cleaves a larger section of the gene. Arbor believes this approach offers a more effective and potentially safer gene disruption mechanism.

The deal comes less than ten weeks after Arbor dosed the first PH1 patient in its clinical trial. Giacomo Chiesi, Executive Vice President of Chiesi Global Rare Diseases, confirmed the company reviewed preclinical non-human primate data, which provides a “strong precedent for predicting human efficacy.”

Arbor CEO Devyn Smith stated that the disease has a clear approvable biomarker, and the gene edit is expected to produce clinical data efficiently in the coming months, helping to determine the final dose.

Strategic Shift and Industry Momentum

Chiesi’s rare disease business accounted for €763 million in revenue last year, making it a strategic partner for the highly specialized PH1 program. Arbor, which was not initially planning to partner the therapy, will use the financial boost to significantly extend its funding runway into 2027 and pivot its focus toward more complex programs.

“There’s a newcomer that’s very focused on rare diseases and is kind of all in on editing. So it’s fantastic,” said CEO Devyn Smith, commenting on the collaboration’s significance to the gene editing field, which has faced recent pipeline cuts and layoffs.

The company’s next strategic programs will involve developing CRISPR therapies for Central Nervous System (CNS) diseases, including three distinct strategies to treat the neurological disorder ALS. Smith indicated that human testing for the ALS programs would commence in the “realm of months, not years.”

The agreement follows a similar high-value deal this summer—Eli Lilly’s acquisition of Verve Therapeutics—signaling that gene editing is becoming a “more mature modality” where specific drug programs are attracting significant investment from major pharmaceutical companies.