Hunter syndrome is a rare lysosomal disorder that mainly impacts young boys and causes severe complications, including cardiac and respiratory dysfunction, skeletal malformations, and cognitive impairment.

As part of their exclusive worldwide license agreement and collaborative research funding agreement, Avrobio and the University of Manchester will launch a clinical trial to study whether AVR-RD-05 gene therapy can prevent some of the lifelong complications of Hunter syndrome.

The therapy involves collecting patients' own hematopoietic stem cells and transducing them with therapeutic transgenes that supply a protein they lack. The cells are then grafted to the patient's bone marrow in hopes of producing generations of daughter cells that can produce and distribute the needed enzyme.

The company will also use a proprietary protein tag designed to improve enzyme stability and facilitate uptake by tissues.

As part of the agreement, Avrobio paid the University of Manchester an upfront, undisclosed cash payment. The company will make additional payments based on development and regulatory milestones and pay the university a royalty on annual net sales of any licensed products.

Abrobio is also funding a phase I/II clinical trial, which is expected to enter the clinic in late 2021. The company is conducting similar trials for Fabry disease, cystinosis, and Gaucher disease, as well as a preclinical program for Pompe disease.