US-based Selecta Biosciences, and Japanese firm Astellas Pharma have 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 (AAV)-based treatment for Late-Onset Pompe disease (LOPD) 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 commercialise Xork for use in Pompe disease with an Astellas gene therapy investigational or authorized product, with a current focus on AT845.

Pompe disease is a rare (estimated at 1 in every 40,000 births), inherited and often fatal disorder that disables the heart and skeletal muscles. It is caused by mutations in a gene that makes an enzyme called acid alpha-glucosidase (GAA).

Naoki Okamura, Chief Strategy Officer of Astellas added, “This agreement provides an opportunity to deliver potentially transformative gene therapy treatments to a specific population of LOPD adult patients who might otherwise be ineligible for clinical trials or treatment with Astellas’ investigational product.”