MEDIPAL HOLDINGS Corporation

MEDIPAL HOLDINGS CORPORATION and JCR Pharmaceuticals Co., Ltd. announced that the first participant has been dosed in the global Phase I/II trial of JR-446 for mucopolysaccharidosis type IIIB, also known as Sanfilippo syndrome type B. JR-446 is a blood-brain barrier-penetrating alpha-N-acetylglucosaminidase developed by JCR using its proprietary J-Brain Cargo technology, and MEDIPAL holds commercialization rights for JR-446 outside Japan. The global, multicenter, open-label trial is enrolling patients with MPS IIIB under six years of age and is registered on ClinicalTrials.gov under identifier NCT07640984. MPS IIIB is an ultra-rare lysosomal storage disorder estimated to affect approximately 500 to 1,000 people worldwide, and there is currently no approved treatment. Under a September 2023 licensing agreement, MEDIPAL holds exclusive worldwide commercialization rights excluding Japan with the right to sublicense, while JCR leads the global Phase I/II trial and development activities as sponsor; a separate Phase I/II trial, JR-446-101, is ongoing in Japan under the companies' co-development agreement, and JR-446 received orphan drug designation in the United States, the European Union, and Japan in 2025.