Selecta Biosciences, Inc. and Astellas Pharma Inc. have announced an exclusive licensing and development agreement for IdeXork (Xork). \n\n\n\nXork 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.\n\n\n\nPompe disease is a rare (one 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). Normally, the body uses GAA to break down glycogen, a stored form of sugar used for energy. \n\n\n\nThe enzyme works in intracellular compartments called lysosomes. Lysosomes ingest multiple substances including glycogen, which is converted by the GAA into glucose, a sugar that fuels muscles. In Pompe disease, mutations in the GAA gene reduce or completely eliminate this essential enzyme. \n\n\n\nExpanding access\n\n\n\n"Currently many patients are ineligible for clinical trials with investigational AAV gene therapy products due to the presence of naturally occurring antibodies against AAV gene therapy capsids," said Carsten Brunn, president and CEO of Selecta Biosciences. \n\n\n\n"Xork has the potential to expand access to life-changing gene therapies by addressing pre-existing immunity to AAV. Most other IgG proteases in development are derived from common human pathogens, and as a result there is a high prevalence of pre-existing antibodies against these proteases that can restrict their use. Xork is differentiated by its low cross-reactivity to pre-existing antibodies in human serum. We are thrilled to partner with Astellas as they advance their robust gene therapy portfolio through the clinic."\n\n\n\nTransformative gene therapy\n\n\n\nNaoki Okamura, chief strategy officer of Astellas said: "We are looking forward to partnering with Selecta as we strive to expand our therapies to a broader range of patients living with debilitating diseases, who have limited treatment options. 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."\n\n\n\nUnder the terms of the agreement, Selecta Biosciences 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. \n\n\n\nSelecta Biosciences 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.