Italfarmaco and JCR Pharmaceuticals Enter Exclusive Agreement to Advance JR-141 for Hunter Syndrome in Global Markets
Italfarmaco S.p.A. and JCR Pharmaceuticals Co., Ltd. (TSE: 4552) have entered into an exclusive license agreement to develop and commercialize JR-141, an investigational blood-brain barrier (BBB)-penetrating enzyme replacement therapy for Hunter syndrome, across the United States, Europe, and Latin America. The agreement expands the companies’ existing relationship and establishes a framework for potentially bringing JR-141 to patients outside Japan following regulatory approval.
JR-141, also known as pabinafusp alfa, is currently being evaluated in a Phase III clinical program for Hunter syndrome, also known as mucopolysaccharidosis type II (MPS II). The pivotal development program includes clinical trial NCT04573023. JCR previously developed the therapy using its proprietary J-Brain Cargo® technology, which is designed to enable therapeutic enzymes to cross the blood-brain barrier.
The therapy was approved and launched in Japan in 2021 under the brand name IZCARGO™. Through the newly announced agreement, JCR and Italfarmaco intend to pursue regulatory approvals for JR-141 in the United States, European Union, United Kingdom, and Brazil. The companies will seek approvals from the U.S. Food and Drug Administration (FDA), European Medicines Agency (EMA), U.K. Medicines and Healthcare products Regulatory Agency (MHRA), and Brazilian Health Regulatory Agency (ANVISA).
If regulatory approvals are obtained, Italfarmaco will be responsible for commercializing and distributing JR-141 throughout the licensed territories. JCR will retain responsibility for manufacturing the therapy following marketing authorization.
The agreement represents another step in the companies’ collaboration in rare and genetic diseases and builds on an earlier partnership established in December 2025 involving the commercialization of givinostat in Japan for Duchenne muscular dystrophy (DMD), along with a strategic partnership covering rare disease therapies.
JR-141 Targets Hunter Syndrome and the Central Nervous System
Hunter syndrome is a rare genetic disorder caused by deficiency or dysfunction of the enzyme iduronate-2-sulfatase (IDS). The condition is classified as a lysosomal storage disorder and can result in the accumulation of certain complex molecules called glycosaminoglycans within cells and tissues.
The disease can affect multiple organs and systems. Patients may develop a range of somatic manifestations, including skeletal abnormalities, joint problems, airway and respiratory complications, hearing impairment, cardiovascular involvement, and other systemic effects.
A subset of patients also experiences neurological involvement, sometimes described as neuronopathic disease. Progressive cognitive impairment can occur in these patients, creating a particularly difficult treatment challenge because many conventional enzyme replacement therapies administered intravenously have limited ability to cross the blood-brain barrier.
This biological barrier protects the brain by restricting the movement of many substances from the bloodstream into the central nervous system. While this protective function is essential for normal brain health, it can also make it difficult for certain therapeutic molecules to reach neurological tissues.
JR-141 was developed specifically to address this challenge.
J-Brain Cargo Technology Designed to Cross the Blood-Brain Barrier
JR-141 is a recombinant fusion protein that combines an antibody targeting the human transferrin receptor with iduronate-2-sulfatase, the enzyme that is missing or dysfunctional in people with Hunter syndrome.
The antibody component is designed to interact with the transferrin receptor, which is involved in the transport of substances across the blood-brain barrier. JCR’s J-Brain Cargo® platform uses this mechanism as a means of facilitating the transport of therapeutic enzymes into the brain.
By linking the enzyme to an antibody capable of engaging the transferrin receptor, JR-141 is designed to cross the blood-brain barrier and deliver iduronate-2-sulfatase to the central nervous system.
The development strategy is intended to address both the systemic and neurological aspects of Hunter syndrome. This is particularly relevant for patients with neuronopathic disease, where neurological involvement can include progressive cognitive decline.
The ability to deliver an enzyme replacement therapy to the brain represents an important area of research in lysosomal storage disorders. Conventional enzyme replacement therapies can address systemic disease by supplying the deficient enzyme through intravenous administration, but the blood-brain barrier can limit enzyme exposure in the central nervous system.
JCR’s approach is therefore focused on creating an enzyme replacement therapy capable of reaching both peripheral tissues and the brain.
Phase III Development Program Underway
JR-141 is currently in Phase III development for Hunter syndrome. The companies are seeking to build on clinical development and regulatory experience accumulated through the therapy’s development and use in Japan.
The Phase III program is expected to provide additional evidence to support regulatory submissions in the licensed territories. However, the announcement does not disclose the companies’ anticipated regulatory filing dates or potential approval timelines for the United States, European Union, United Kingdom, or Brazil.
Regulatory review will ultimately determine whether JR-141 meets the applicable standards for approval in each jurisdiction. Requirements can differ among regulatory authorities, and the companies will need to provide the clinical, manufacturing, quality, and other information required by each agency.
JCR and Italfarmaco have identified four regulatory agencies that they intend to approach: the FDA, EMA, MHRA, and ANVISA. Approval by these agencies would be required before commercial launch in the corresponding markets.
The regulatory strategy reflects the companies’ objective of expanding access to JR-141 beyond Japan and establishing the therapy as a potential treatment option for patients with Hunter syndrome in additional regions.
Italfarmaco to Lead Commercialization Outside Japan
Under the agreement, Italfarmaco will assume responsibility for commercialization and distribution of JR-141 in the United States, Europe, and Latin America following regulatory approvals.
The company will therefore be responsible for preparing the therapy for potential market entry and establishing the commercial infrastructure necessary to distribute the product across the licensed territories.
Italfarmaco has experience in rare disease development and commercialization and operates internationally. The company will work with JCR to pursue regulatory approval and, if successful, bring JR-141 to healthcare systems and patients in the covered markets.
The agreement also gives Italfarmaco an opportunity to expand its rare disease portfolio into a therapy that uses a specialized technology designed to address central nervous system delivery.
JCR, meanwhile, will remain responsible for manufacturing JR-141 following marketing authorization. Maintaining manufacturing responsibility allows JCR to continue leveraging its experience with the product and its underlying technology while Italfarmaco focuses on international commercialization.
This division of responsibilities reflects the complementary capabilities of the two companies and provides a structure for advancing JR-141 through regulatory and commercial stages.
Financial Terms Include Upfront, Milestone and Royalty Payments
As part of the agreement, JCR will receive an upfront payment as well as milestone payments and royalties. The company will also receive revenue associated with supplying the product to Italfarmaco.
The announcement does not disclose the value of the upfront payment, potential milestone payments, or royalty rates.
JCR confirmed that the upfront payment has been incorporated into its consolidated earnings forecast for the fiscal year ending March 31, 2027.
The financial structure gives JCR several potential revenue streams associated with the partnership, including the initial upfront payment, development and regulatory milestones, royalties on commercial sales, and product supply revenues.
For Italfarmaco, the agreement provides rights to commercialize JR-141 in major international markets while allowing JCR to retain manufacturing responsibilities and continue supporting the product’s technical development.
Expanding an Existing Rare Disease Partnership
The new JR-141 agreement builds on the relationship between Italfarmaco and JCR that was established through an agreement announced in December 2025.
Under that earlier collaboration, the companies entered into an exclusive license agreement for the commercialization of givinostat in Japan. Givinostat is a treatment for Duchenne muscular dystrophy, a rare genetic disorder characterized by progressive muscle weakness and degeneration.
The companies also established a strategic partnership focused on rare disease therapies.
The new agreement expands the relationship into Hunter syndrome and introduces a second area of rare disease collaboration. Together, the partnerships provide a broader platform for cooperation between JCR’s drug development and technology capabilities and Italfarmaco’s international commercialization infrastructure.
The companies’ focus on rare and genetic diseases reflects the challenges associated with developing treatments for patient populations that can be relatively small but may have significant unmet medical needs.
JCR Highlights Global Patient Access
Hiroyuki Sonoda, Ph.D., President and Chief Scientific Officer of JCR Pharmaceuticals, said the company is pleased to establish the strategic agreement with Italfarmaco and identified the company as a global commercialization partner for JR-141.
“We are pleased to enter into this strategic agreement with Italfarmaco and collaborate with an ideal global commercialization partner as we work toward our goal of delivering JR-141 to people living with Hunter syndrome around the world,” Sonoda said.
He highlighted Italfarmaco’s experience in developing and commercializing therapies internationally and said JCR looks forward to working with the company to make JR-141 available to patients outside Japan.
Sonoda also described the agreement as an extension of JCR’s commitment to its partnership with Italfarmaco in developing therapies for rare and genetic diseases.
The comments underscore JCR’s intention to use international partnerships to expand the reach of its proprietary technologies and products beyond its domestic market.
The agreement could provide JCR with an established commercial pathway in regions where it does not independently manage commercialization of JR-141.
Italfarmaco Brings Rare Disease Development Expertise
Francesco Di Marco, Chief Executive Officer of Italfarmaco Group, described the agreement as an important milestone in the relationship between the companies.
“This agreement marks an important milestone in the relationship between Italfarmaco and JCR Pharmaceuticals and reflects a shared commitment to advancing innovative therapies for people living with rare and genetic diseases,” Di Marco said.
He highlighted the combination of JCR’s expertise in blood-brain barrier technologies with Italfarmaco’s capabilities in rare disease development and commercialization.
The partnership could allow the companies to combine specialized scientific technology with an international development and commercial infrastructure. For patients with rare diseases, the ability to move therapies from clinical development to regulatory review and ultimately commercial availability can be particularly important because treatment options may be limited.
Di Marco said the collaboration creates a foundation for accelerating innovation for underserved patient communities.
Partnership Reinforces Focus on Rare and Genetic Diseases
Antonio Nardi, Vice President and Head of Business & Portfolio Development at Italfarmaco, also highlighted the connection between the JR-141 agreement and the companies’ existing work in Duchenne muscular dystrophy.
“Building on the success of our existing collaboration in Duchenne muscular dystrophy, this agreement further strengthens our partnership and reinforces our shared ambition to be a leading force in the rare and genetic disease field,” Nardi said.
He added that the companies intend to continue working together to advance treatments for patients and families affected by rare diseases.
The comments reflect the companies’ broader strategic focus on developing and commercializing therapies in areas where specialized treatment approaches may be needed.
The collaboration around JR-141 adds a different therapeutic technology to the partnership. While the earlier collaboration centered on givinostat for DMD, the new agreement focuses on an enzyme replacement therapy specifically engineered to address the blood-brain barrier.
Potential Significance for Patients With Neuronopathic Hunter Syndrome
One of the key features of JR-141’s development is its focus on neurological manifestations of Hunter syndrome.
The central nervous system represents a significant challenge in many lysosomal storage disorders because the blood-brain barrier can restrict the delivery of large therapeutic proteins. As a result, therapies that can cross the barrier may have the potential to address aspects of disease that conventional systemic treatments cannot adequately reach.
JR-141’s J-Brain Cargo technology is designed around this challenge. By using the transferrin receptor pathway to facilitate transport across the blood-brain barrier, the therapy is intended to deliver iduronate-2-sulfatase directly to the brain.
The approach does not yet establish a regulatory outcome for JR-141 in the licensed territories. The ongoing Phase III development program and subsequent regulatory reviews will be important in determining the therapy’s safety, efficacy, and potential role in clinical practice outside Japan.
Next Steps for JR-141
The immediate focus of the partnership will be continued development of JR-141 and preparation for potential regulatory submissions in the United States, Europe, United Kingdom, and Brazil.
If the necessary approvals are obtained, Italfarmaco will commercialize and distribute the therapy across the licensed territories, while JCR will manufacture the product.
The companies have not announced specific dates for regulatory submissions or potential commercial launches. Future milestones are expected to depend on the progress of the Phase III program, regulatory interactions, and the decisions of the relevant health authorities.
The agreement nevertheless establishes a global commercialization framework for JR-141 and expands JCR’s collaboration with Italfarmaco into another rare genetic disease.
With JR-141 already approved and launched in Japan as IZCARGO™, the partnership gives the companies a pathway to pursue regulatory approval in additional major markets. Its blood-brain barrier-penetrating design distinguishes the therapy from conventional enzyme replacement approaches and reflects JCR’s focus on developing technologies capable of delivering biologic medicines to the central nervous system.
For Italfarmaco, the agreement adds a late-stage rare disease program to its international portfolio and builds on its existing relationship with JCR. For JCR, the partnership provides access to Italfarmaco’s global commercialization capabilities while allowing the Japanese company to retain manufacturing responsibility.
The collaboration ultimately represents an effort to extend the availability of a specialized enzyme replacement therapy to patients with Hunter syndrome beyond Japan. The success of that effort will depend on clinical and regulatory outcomes in the United States, Europe, the United Kingdom, and Latin America, but the agreement establishes the commercial and development structure through which the companies intend to pursue that goal.
About the J-Brain Cargo® Platform Technology
JCR Pharmaceuticals has developed a proprietary blood-brain barrier (BBB)-penetrating technology, J-Brain Cargo®, to bring biotherapeutics into the central nervous system (CNS). The first drug developed based on this technology is IZCARGO™ (INN: pabinafusp alfa), which is approved in Japan for the treatment of Hunter syndrome, a lysosomal storage disorder (LSD). With J-Brain Cargo®, JCR seeks to address the unresolved clinical challenges of LSDs by delivering the enzyme to both the body and the brain.
About Hunter Syndrome (Mucopolysaccharidosis Type II, or MPS II)
Hunter syndrome (mucopolysaccharidosis type II, or MPS II) is an X-linked recessive lysosomal storage disorder caused by a deficiency of iduronate-2-sulfatase, an enzyme that breaks down complex carbohydrates called glycosaminoglycans (GAGs, also known as mucopolysaccharides) in the body. Hunter syndrome, which affects an estimated 2,000-3,000 individuals worldwide (according to JCR research), gives rise to a wide range of somatic and neurological symptoms. The current standard of care for Hunter syndrome is enzyme replacement therapy, which does not address the central nervous system-related symptoms of this lysosomal disease.
About JR-141
JR-141 (pabinafusp alfa) is a recombinant fusion protein of an antibody against the human transferrin receptor and iduronate-2-sulfatase, the enzyme that is missing or malfunctioning in subjects with Hunter syndrome. It incorporates J-Brain Cargo®, JCR’s proprietary blood-brain barrier (BBB)-penetrating technology, to cross the BBB through transferrin receptor-mediated transcytosis, and its uptake into cells is mediated through the mannose-6-phosphate receptor. This novel mechanism of action is expected to make pabinafusp alfa effective against the central nervous system (CNS) symptoms of Hunter syndrome.
In pre-clinical trials, JCR has confirmed both high-affinity binding of pabinafusp alfa to transferrin receptors and passage across the BBB into neuronal cells. In addition, JCR has confirmed enzyme uptake in various brain tissues. The company has also confirmed a reduction of substrate accumulation in the CNS and peripheral organs in an animal model of Hunter syndrome.1,2
In several clinical trials of pabinafusp alfa, JCR obtained evidence of reducing heparan sulfate (HS) concentrations in the cerebrospinal fluid (CSF), a biomarker for assessing effectiveness against CNS symptoms; these results were consistent with those obtained in pre-clinical studies.3 Clinical studies have also demonstrated the positive effects of pabinafusp alfa on CNS symptoms.4,5,6
Pabinafusp alfa was approved in Japan by the Ministry of Health, Labour and Welfare and marketed since May 2021 under the brand name “IZCARGO™ I.V. Infusion 10mg.” It was also approved in the United Arab Emirates (UAE) in 2026.