Selecta Biosciences, Inc. and Astellas Pharma Inc. announced an exclusive licensing and development agreement for IdeXork (Xork). Xork is being studied as a potential next generation immunoglobulin G (IgG) protease that will be developed by Astellas for use with AT845, an investigational, adeno-associated virus-based treatment for Late-Onset Pompe disease in adults. Under the terms of the agreement, Selecta will receive a $10 million upfront payment and is eligible to receive up to $340 million for certain additional development and commercial milestones plus royalties on any potential commercial sales where Xork is used as a pre-treatment for AT845.

Selecta is responsible for the development and manufacturing of Xork and will maintain the rights for the development of additional indications beyond Pompe disease. Astellas would have the sole and exclusive right to commercialize Xork for use in Pompe disease with an Astellas gene therapy investigational or authorized product, with a current focus on AT845. About AT845 for the treatment of Late-Onset Pompe Disease (LOPD); Astellas is developing AT845, a novel gene replacement therapy using an AAV8 vector under a muscle-specific promotor to deliver a functional copy of the GAA gene, for the treatment of adult LOPD.

AT845 is being investigated to determine whether it can deliver a functional GAA gene that is efficiently transduced to express GAA directly in tissues affected by the disease, including skeletal and cardiac muscle.