TOKYO, Japan — October 5, 2026
JCR Pharmaceuticals Co., Ltd. announced a strategic agreement with Italfarmaco S.p.A. to advance the global development and commercialization of JR-141 (pabinafusp alfa), a blood-brain barrier (BBB)-penetrating enzyme replacement therapy for Hunter syndrome (mucopolysaccharidosis type II or MPS II). JR-141 is currently being evaluated in a Phase 3 clinical trial (NCT04573023) and is already approved and marketed in Japan under the brand name IZCARGO™. Under the agreement, JCR and Italfarmaco intend to pursue regulatory approvals for JR-141 with the U.S. FDA, European Medicines Agency, U.K. MHRA and Brazil’s ANVISA. Following regulatory approvals, Italfarmaco will commercialize and distribute the therapy in licensed territories, while JCR will retain responsibility for manufacturing. JCR will receive upfront, milestone and royalty payments, as well as revenue associated with product supply. The agreement expands the companies’ existing relationship in rare and genetic diseases and creates a potential pathway to make JR-141 available to patients with Hunter syndrome outside Japan.
JR-141 Targets Hunter Syndrome Beyond the Body
JR-141 is a next-generation recombinant fusion protein combining an antibody against the human transferrin receptor with iduronate-2-sulfatase, the enzyme that is deficient or malfunctioning in people with Hunter syndrome. The therapy incorporates JCR’s proprietary J-Brain Cargo® technology, which is designed to transport therapeutic enzymes across the BBB through transferrin receptor-mediated transcytosis. This approach is intended to enable enzyme delivery to the central nervous system while also addressing somatic manifestations of MPS II. Hunter syndrome is an X-linked recessive lysosomal storage disorder caused by deficiency of iduronate-2-sulfatase, resulting in accumulation of glycosaminoglycans in the body and a range of somatic and neurological symptoms. According to JCR, current enzyme replacement therapy can address systemic disease but does not adequately address CNS-related manifestations. Preclinical studies of pabinafusp alfa demonstrated BBB passage, enzyme uptake in brain tissues and reductions in substrate accumulation, while clinical studies generated evidence of reduced heparan sulfate concentrations in cerebrospinal fluid, a biomarker associated with CNS disease.
J-Brain Cargo Technology Enables CNS Delivery
J-Brain Cargo® is the central technology behind JCR’s strategy to overcome the BBB challenge in lysosomal storage diseases. The platform is designed to enable biotherapeutics to enter the central nervous system, potentially allowing enzyme replacement therapies to address neurological disease components that conventional approaches cannot readily reach. JR-141 uses transferrin receptor-mediated transport to cross the BBB, after which cellular uptake is mediated through the mannose-6-phosphate receptor. JCR has reported evidence from clinical studies supporting reductions in cerebrospinal fluid heparan sulfate and positive effects on CNS symptoms. Pabinafusp alfa was approved in Japan in 2021 and in the United Arab Emirates in 2026, providing an existing regulatory and commercial foundation as the companies pursue additional markets. The global regulatory strategy now extends toward the United States, Europe, the United Kingdom and Brazil, where approvals would allow Italfarmaco to commercialize and distribute JR-141 under the terms of the partnership.
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Phase 3 Program Supports Global Expansion
The agreement comes as JR-141 advances through Phase 3 development, positioning the program for potential regulatory submissions in major international markets. Italfarmaco will contribute its global rare-disease development and commercialization capabilities, while JCR will maintain manufacturing responsibility following potential marketing authorizations. The companies previously expanded their relationship through a December 2025 agreement covering commercialization of givinostat in Japan for Duchenne muscular dystrophy, together with a strategic partnership focused on rare disease therapies. The latest agreement broadens that relationship into Hunter syndrome and strengthens the companies’ focus on underserved patients with rare genetic diseases. With JR-141 already approved in Japan and the UAE, Phase 3 development underway, and regulatory pathways being pursued in additional territories, JCR and Italfarmaco are seeking to extend access to a BBB-penetrating enzyme replacement approach designed to address both systemic and neurological manifestations of Hunter syndrome.
Source: JCR Pharmaceuticals, press release
