JCR Pharmaceuticals

Hyogo, Japan – July 15, 2026 – JCR Pharmaceuticals Co., Ltd. (TSE 4552; “JCR”), a global specialty biopharmaceutical company dedicated to developing therapies for rare and genetic diseases, today announced its development plan in Japan for givinostat, a treatment for Duchenne muscular dystrophy (DMD), following consultation with the Pharmaceuticals and Medical Devices Agency (PMDA).

Based on the outcome of the consultation, JCR plans to:

• Submit a marketing authorization application in Japan in 2026, primarily using overseas clinical data
• Obtain approval and launch the treatment in Japan in 2027
• Conduct a separate clinical trial in Japanese patients with DMD to evaluate pharmacokinetics and safety

Givinostat is an oral histone deacetylase inhibitor licensed from Italfarmaco S.p.A. It has already been approved in multiple countries and regions, including the United States, the European Union, and the United Kingdom, for the treatment of DMD in patients aged 6 years and older, in accordance with local prescribing information. As announced in December 2025, JCR holds exclusive rights to develop and commercialize the treatment in Japan. Because its mechanism of action is not dependent on specific dystrophin gene mutations, givinostat has the potential to be used in patients with DMD regardless of underlying mutation type.

“Following our consultation with PMDA, we have established a specific development plan in Japan,” said Hiroyuki Sonoda, Ph.D., President and Chief Scientific Officer of JCR. “By using overseas clinical data, we believe this development strategy can help bring this treatment to patients with DMD in Japan more quickly. DMD remains an area of significant unmet medical need, and we will advance development with the goal of obtaining approval and launching it in Japan in 2027.”

JCR remains committed to advancing research and development to help meet the expectations of patients and families waiting for effective treatment options.

The impact of this announcement on JCR’s consolidated financial results for this fiscal year (ending March 31, 2027) is expected to be minor.

About Duchenne Muscular Dystrophy (DMD)
Duchenne muscular dystrophy (DMD) is a rare, progressive neuromuscular disorder caused by mutations in the dystrophin gene. These mutations prevent the production of functional dystrophin, causing the dystrophin-associated protein complex (DAPC) to break down. This makes muscle fibres more vulnerable to damage and increases histone deacetylase (HDAC) levels in the muscle cells, blocking the activation of important genes needed for muscle maintenance and repair. As a result, muscle fibres experience ongoing damage, leading to chronic inflammation and poor regeneration. Over time, muscle cells die and are replaced by scar tissue and fat1-4. DMD primarily affects males, with symptoms typically appearing between the ages of two and five years. As the condition progresses, muscle weakness worsens, leading to difficulty walking and eventually loss of ambulation. Over time, the heart and respiratory muscles are also affected, which are the leading causes of premature death5. DMD is one of the most severe and common forms of childhood muscular dystrophy, with a global birth incidence of approximately 1 in 5,050 boys6. DMD affects an estimated 3,500 patients in Japan7.

About Givinostat
Givinostat (Duvyzat®) was discovered through Italfarmaco’s research and development efforts in collaboration with Telethon and Duchenne Parent Project (Italy). Givinostat is an orally administered histone deacetylase (HDAC) inhibitor that regulates the excessive HDAC activity characteristic of DMD muscles. By doing so, it helps restore the expression of key genes and biological processes essential for muscle maintenance and repair. Its mechanism of action is independent of the specific dystrophin gene mutation causing the disease.

About Italfarmaco S.p.A.
Founded in 1938 in Milan, Italy, Italfarmaco is a private global pharmaceutical company that has led the successful development and approval of many pharmaceutical products around the world. The Italfarmaco group has operations in more than 90 countries through directly controlled or affiliated companies. The company is a leader in pharmaceutical research, product development, production and commercialisation with proven success in many therapeutic areas including immuno-oncology, gynaecology, neurology, cardiovascular disease and rare diseases. Italfarmaco’s rare disease unit includes programmes in Duchenne muscular dystrophy, Becker muscular dystrophy, amyotrophic lateral sclerosis and polycythaemia vera.

About JCR Pharmaceuticals Co., Ltd.
JCR Pharmaceuticals Co., Ltd. (TSE 4552) is a global specialty pharmaceutical company that develops treatments that go beyond rare diseases to solve the world’s most complex healthcare challenges. We continue to build upon our 50-year legacy in Japan while expanding our global footprint into the U.S., Europe, and Latin America. We improve patients’ lives by applying our scientific expertise and unique technologies to research, develop, and deliver next-generation therapies. Our approved products in Japan include therapies for the treatment of growth disorder, MPS II (Hunter syndrome), Fabry disease, acute graft-versus host disease, and renal anemia. Our investigational products in development worldwide are aimed at treating rare diseases including MPS I (Hurler, Hurler-Scheie and Scheie syndrome), MPS II, MPS IIIA and B (Sanfilippo syndrome type A and B), and more. Our core values – Putting people first, Forging our own path, Always advancing, and Committed to excellence – mean that the work we do benefits all our stakeholders, including partners, patients and employees. We strive to expand the possibilities for patients while accelerating medical advancement at a global level.

Cautionary Statement Regarding Forward-Looking Statements
This document contains forward-looking statements that are subject to known and unknown risks and uncertainties, many of which are outside our control. Forward-looking statements often contain words such as “believe,” “estimate,” “anticipate,” “intend,” “plan,” “will,” “would,” “target” and similar references to future periods. All forward-looking statements regarding our plans, outlook, strategy and future business, financial performance and financial condition are based on judgments derived from the information available to us at this time. Factors or events that could cause our actual results to be materially different from those expressed in our forward-looking statements include, but are not limited to, a deterioration of economic conditions, a change in the legal or governmental system, a delay in launching a new product, impact on competitors’ pricing and product strategies, a decline in marketing capabilities relating to our products, manufacturing difficulties or delays, an infringement of our intellectual property rights, an adverse court decision in a significant lawsuit and regulatory actions.

This document involves information on pharmaceutical products (including those under development). However, it is not intended for advertising or providing medical advice. Furthermore, it is intended to provide information on our company and businesses and not to solicit investment in securities we issue.

Except as required by law, we assume no obligation to update these forward-looking statements publicly or to update the factors that could cause actual results to differ materially, even if new information becomes available in the future.

References:

1. Sandonà M, Cavioli G, Renzini A, et al. Histone Deacetylases: Molecular Mechanisms and Therapeutic Implications for Muscular Dystrophies. Int J Mol Sci. 2023;24(5):4306. https://doi.org/10.3390/ijms24054306.
2. Consalvi S, Saccone V, Giordani L, Minetti G, Mozzetta C, Puri PL. Histone Deacetylase Inhibitors in the Treatment of Muscular Dystrophies: Epigenetic Drugs for Genetic Diseases. Mol Med. 2011;17(5):457–465. https://doi.org/10.2119/molmed.2011.00049.
3. Bez Batti Angulski A, Hosny N, Cohen H, et al. Duchenne muscular dystrophy: disease mechanism and therapeutic strategies. Front Physiol. 2023;14:1183101. https://doi.org/10.3389/fphys.2023.1183101.
4. Giuliani G, Rosina M, Reggio A. Signaling pathways regulating the fate of fibro/adipogenic progenitors (FAPs) in skeletal muscle regeneration and disease. FEBS J. 2022;289(21):6484–6517. https://doi.org/10.1111/febs.16080.
5. Walter MC, Reilich P. Recent developments in Duchenne muscular dystrophy: facts and numbers. J Cachexia Sarcopenia Muscle. 2017;8(5):681–685. https://doi.org/10.1002/jcsm.12245.
6. Crisafulli S, Sultana J, Fontana A, Salvo F, Messina S, Trifirò G. Global epidemiology of Duchenne muscular dystrophy: an updated systematic review and meta-analysis. Orphanet J Rare Dis. 2020;15(1):141. https://doi.org/10.1186/s13023-020-01430-8.
7. Kawai M. The Number of Patients with Duchenne Muscular Dystrophy in Japan. No To Hattatsu. (Japanese) 2013;45(Supple.):S324.

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– Strategic partnership, announced in July 2025, utilizes JCR’s J-Brain Cargo® to develop a novel blood-brain barrier-penetrating therapy targeting a pathological driver of Alzheimer’s disease

– Option exercise puts Acumen’s Enhanced Brain Delivery (EBD™) program on track for IND filing in mid-2027

Hyogo, Japan – June 17, 2026 – JCR Pharmaceuticals Co., Ltd. (TSE 4552; JCR), a global specialty biopharmaceutical company dedicated to developing therapies for rare and genetic diseases, today announced that Acumen Pharmaceuticals, Inc. (NASDAQ: ABOS) exercised its exclusive option to develop, manufacture, and commercialize, on a global basis, up to two candidates for development in the treatment of Alzheimer’s disease (AD), enabled by JCR’s proprietary blood-brain barrier (BBB)-penetrating technology platform, J-Brain Cargo®.

The partnership, announced in July 2025, focuses on developing a BBB-penetrating treatment for AD that combines JCR’s J-Brain Cargo® with Acumen’s amyloid beta oligomer (AβO)-selective antibodies, which target toxic soluble AβOs, a key pathological driver in the onset and progression of AD. The collaborative program aims to demonstrate the feasibility of applying J-Brain Cargo® in delivering sabirnetug, Acumen’s targeted immunotherapy drug candidate, and other AβO-selective antibodies across the BBB to slow the progression of AD pathology. Earlier this year, Acumen presented non-clinical data from a mouse model of AD at the International Conference on Alzheimer’s and Parkinson’s Diseases and Related Neurological Disorders, which demonstrated that using AβO-selective antibodies with J-Brain Cargo® technology increased brain exposure while preserving target engagement as demonstrated by AβO selectivity. Acumen plans to file an investigational new drug application for this program in mid-2027.

Under the terms of the agreement, JCR will receive an option payment with Acumen’s decision to exercise its exclusive option to develop, manufacture, and commercialize, on a global basis, up to two candidates from the collaboration. JCR will also be eligible to receive future milestone payments of up to USD 40 million related to development, and up to USD 515 million related to sales, for a total of up to USD 555 million (approximately JPY83.2 billion converted at the exchange rate of JPY 150 to USD). In addition, JCR is entitled to receive tiered royalties based on net sales for any products that emerge from the collaboration.

“We’re pleased that our strategic partner, Acumen Pharmaceuticals, opted to exercise its exclusive option to develop, manufacture, and commercialize, on a global basis up to two candidates for the treatment of Alzheimer’s disease,” said Hiroyuki Sonoda, Ph.D., President and Chief Scientific Officer of JCR Pharmaceuticals. “Acumen continues to progress the collaborative development program in Alzheimer’s disease, and the non clinical data that Acumen reported earlier this year are truly encouraging. By combining our J-Brain Cargo® platform with Acumen’s novel, AβO-selective antibodies, we aim to overcome the challenge of delivering biologics to the brain to potentially improve the ability to treat AD safely and effectively.”

“As we build on the strength of our sabirnetug program, we’re pleased to exercise our exclusive option to develop, manufacture, and commercialize, on a global basis up to two candidates for the treatment of Alzheimer’s disease,” said Daniel O’Connell, Chief Executive Officer of Acumen Pharmaceuticals. “By pairing our AβO-selective antibody expertise with JCR’s blood-brain barrier-penetrating technology, J-Brain Cargo®, we have the potential to deliver a next-generation therapeutic which could further expand and enhance the treatment paradigm for people living with Alzheimer’s disease. We look forward to sharing updates when they are available.”

AD is a progressive neurodegenerative disorder affecting more than 50 million people globally and is a leading form of dementia. One of its defining pathological hallmarks is the accumulation of Aβ in the brain, which are believed to trigger a cascade of events leading to neuronal damage, cognitive decline, and memory loss.1 Delivering biologics across the BBB remains a fundamental obstacle to effectively treating the disease.

J-Brain Cargo® is JCR’s proprietary platform that enables the systemic delivery of biotherapeutics to the central nervous system (CNS) through a mechanism known as receptor-mediated transcytosis. The technology has been clinically validated with IZCARGO™, the first approved drug in Japan to use the platform, for the treatment of a lysosomal storage disorder with CNS involvement. With broad potential to deliver a wide range of biologic therapies across the BBB, J-Brain Cargo® is a versatile platform for advancing treatments for complex CNS conditions, including neurodegenerative diseases. The J-Brain Cargo® technology platform has a well-established safety profile through several non-clinical studies, clinical trials and marketing experience in Japan.

The impact of this announcement on JCR’s consolidated financial results for the fiscal year ending March 31, 2027, has already been factored into the current earnings forecast.

About Alzheimer’s Disease
Alzheimer’s disease is a progressive neurodegenerative disorder affecting more than 50 million people globally and is a leading cause of dementia. One of its defining pathological features is the accumulation of amyloid-beta (Aβ) in the brain, and increasing evidence highlights soluble Aβ oligomers as a particularly neurotoxic species that are thought to trigger a cascade of events leading to neuronal damage, cognitive decline, and memory loss.1

About the J-Brain Cargo® Platform Technology
JCR Pharmaceuticals has developed a proprietary blood-brain barrier-penetrating technology, J-Brain Cargo®, to bring biotherapeutics into the central nervous system. The first drug developed based on this technology is IZCARGO™ (INN: pabinafusp alfa), which was approved in Japan for the treatment of 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 JCR Pharmaceuticals Co., Ltd.
JCR Pharmaceuticals Co., Ltd. (TSE 4552) is a global specialty pharmaceutical company that develops treatments that go beyond rare diseases to solve the world’s most complex healthcare challenges. We continue to build upon our 50-year legacy in Japan while expanding our global footprint into the U.S., Europe, and Latin America. We improve patients’ lives by applying our scientific expertise and unique technologies to research, develop, and deliver next-generation therapies. Our approved products in Japan include therapies for the treatment of growth disorder, MPS II (Hunter syndrome), Fabry disease, acute graft-versus host disease, and renal anemia.

Our investigational products in development worldwide are aimed at treating rare diseases including MPS I (Hurler, Hurler-Scheie and Scheie syndrome), MPS II, MPS IIIA and B (Sanfilippo syndrome type A and B), and more. Our core values – Putting people first, Forging our own path, Always advancing, and Committed to excellence – mean that the work we do benefits all our stakeholders, including partners, patients and employees. We strive to expand the possibilities for patients while accelerating medical advancement at a global level.

About Sabirnetug (ACU193)
Sabirnetug (ACU193) is a humanized monoclonal antibody (mAb) discovered and developed based on its selectivity for soluble amyloid beta oligomers (AβOs), which are a highly toxic and pathogenic form of Aβ, relative to Aβ monomers and amyloid plaques. Soluble AβOs have been observed to be potent neurotoxins that bind to neurons, inhibit synaptic function, and induce neurodegeneration. By selectively targeting toxic soluble AβOs, sabirnetug aims to address the hypothesis that soluble AβOs are an early and persistent underlying cause of the neurodegenerative process in Alzheimer’s disease (AD). Sabirnetug has been granted Fast Track designation for the treatment of early AD by the U.S. Food and Drug Administration and is currently being evaluated in a Phase 2 study in patients with early AD.

About Acumen Pharmaceuticals, Inc.
Acumen Pharmaceuticals is a clinical-stage biopharmaceutical company developing a novel therapeutic that targets toxic soluble amyloid beta oligomers (AβOs) for the treatment of Alzheimer’s disease (AD). Acumen’s scientific founders pioneered research on AβOs, which a growing body of evidence indicates are early and persistent triggers of Alzheimer’s disease pathology. Acumen is currently focused on advancing its investigational product candidate, sabirnetug (ACU193), a humanized monoclonal antibody that selectively targets toxic soluble AβOs, in its ongoing Phase 2 clinical trial ALTITUDE-AD (NCT06335173) in early symptomatic AD, following positive results in its Phase 1 trial INTERCEPT-AD. Acumen is investigating a subcutaneous formulation of sabirnetug using Halozyme’s proprietary ENHANZE® drug delivery technology. Acumen is also collaborating with JCR Pharmaceuticals to develop an Enhanced Brain Delivery™ (EBD™)-enabled therapy for Alzheimer’s disease utilizing a transferrin-receptor-targeting blood-brain barrier-penetrating technology. The company is headquartered in Newton, Mass. For more information, visit www.acumenpharm.com.

Cautionary Statement Regarding Forward-Looking Statements
This document contains forward-looking statements that are subject to known and unknown risks and uncertainties, many of which are outside our control. Forward-looking statements often contain words such as “believe,” “estimate,” “anticipate,” “intend,” “plan,” “will,” “would,” “target” and similar references to future periods. All forward-looking statements regarding our plans, outlook, strategy and future business, financial performance and financial condition are based on judgments derived from the information available to us at this time. Factors or events that could cause our actual results to be materially different from those expressed in our forward-looking statements include, but are not limited to, a deterioration of economic conditions, a change in the legal or governmental system, a delay in launching a new product, impact on competitors’ pricing and product strategies, a decline in marketing capabilities relating to our products, manufacturing difficulties or delays, an infringement of our intellectual property rights, an adverse court decision in a significant lawsuit and regulatory actions. This document involves information on pharmaceutical products (including those under development). However, it is not intended for advertising or providing medical advice. Furthermore, it is intended to provide information on our company and businesses and not to solicit investment in securities we issue. Except as required by law, we assume no obligation to update these forward-looking statements publicly or to update the factors that could cause actual results to differ materially, even if new information becomes available in the future.

Reference
1. Sadigh-Eteghad S, Sabermarouf B, Majdi A, Talebi M, Farhoudi M, Mahmoudi J. Amyloid-beta: a crucial factor in Alzheimer’s disease. Med Princ Pract. 2015;24(1):1-10. www.doi.org/10.1159/000369101.

Contact:
Investors & Media:
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Hyogo, Japan – June 8, 2026 – JCR Pharmaceuticals Co., Ltd. (TSE 4552; “JCR”), a global specialty biopharmaceutical company dedicated to developing therapies for rare and genetic diseases, announced today that it presented new clinical data in a poster session at the 18th International Symposium on MPS and Related Lysosomal Diseases, which was held June 4-7, 2026, in Florence, Italy.

“Due to the protective blood-brain barrier, lysosomal storage disorders historically have been challenging to treat due to the inability to deliver a therapy into the central nervous system. With our J-Brain Cargo® platform technology, we have the potential to address the progressive neurological symptoms associated with these rare and life-limiting diseases, many of which have inadequate treatment options or no approved therapies available,” said Hiroyuki Sonoda, Ph.D., President and Chief Scientific Officer of JCR Pharmaceuticals. “The data presented at this symposium demonstrate the safety and efficacy evidence of JR 171 (lepunafusp alfa) in people with mucopolysaccharidosis type I (MPS I) and highlight its potential. We look forward to sharing additional data from our J-Brain Cargo® platform technology as they are available. We wish to thank all of the patients who have participated in our clinical programs and their families, clinical investigators, and other partners who continue to support our work.”

New Clinical Data Presentation

Three-Year safety and pharmacodynamics of lepunafusp alfa (JR-171) in patients with mucopolysaccharidosis type I (MPS-I): Results from a phase I/II trial and extension study (Presentation Number: 63)
Lead Author: Paul Harmatz, M.D. (UCSF Benioff Children’s Hospital, Oakland, CA)

Researchers reported on three years of data describing safety and pharmacodynamics of lepunafusp alfa (JR-171) in patients with mucopolysaccharidosis type I (MPS I) who were treated in a Phase I/II trial plus a three-year extension study (NCT04227600 and NCT04453085). Patients with MPS I were randomized to weekly intravenous lepunafusp alfa at a “Low” (2.0 mg/kg; n=6) or a “High” (4.0 mg/kg; n=8) dose and followed for three years. Enrollment was open to all MPS I phenotypes (Hurler [n=7], Hurler-Scheie [n=5], Scheie [n=2]); one Low-dose Hurler patient did not continue in the extension study.

Both the High‑ and Low‑dose cohorts demonstrated a favorable safety and tolerability profile, with compliance exceeding 90% in both groups. Overall, six patients experienced serious adverse events (SAEs) [5/8 in the High dose group, 1/5 in the Low dose group]. Of the 8 serious treatment-emergent adverse events (TEAEs), none were attributed to lepunafusp alfa. Adverse events of special interest — specifically anaphylaxis or infusion associated reactions — were uncommon, occurring in fewer than 5% of participants across both dose groups.

By Week 12, cerebrospinal fluid-heparan sulfate (CSF-HS) decreased in all patients. In the High dose group, CSF-HS decreases remained stable during the three-year study period in most patients; partial rebound was observed in one patient. In the Low dose group, two patients, both with Hurler syndrome, had a subsequent rebound in HS levels. Rebound did not correlate with presence/absence of antibodies.

The somatic symptoms (including serum HS levels, and liver and spleen volume) remained stable, or improved, in patients in both doses who received previous laronidase and decreased in the treatment-naïve patient.

With three years of follow-up, researchers concluded that weekly lepunafusp alfa is safe and well tolerated in a broad spectrum of patients with MPS I, with no serious TEAEs attributable to the study drug. Pharmacodynamic response of CSF-HS demonstrates that lepunafusp alfa crosses the blood-brain barrier (BBB), with a trend toward greater reduction in CSF-HS in the High dose cohort (4mg/kg). The long-term safety and clinical efficacy warrants evaluation in a larger clinical trial.

Encore Clinical Data Presentations

The following encore presentations provide additional evidence and context for the use of JR-141 (pabinafusp alfa) in the treatment of MPS II and were shared at the 22nd Annual WORLDSymposium™ 2026 (February 2-6, 2026).

Sustained cognitive and adaptive behavior outcomes of long-term treatment with pabinafusp alfa in patients with severe or attenuated mucopolysaccharidosis type II (Presentation Number: 61)
Lead Author: Roberto Giugliani, M.D., Ph.D. (Federal University of Rio Grande do Sul, Brazil)

In a longitudinal, pooled, post hoc analysis of patients with MPS II receiving pabinafusp alfa across five open-label trials with up to five years of follow-up, researchers reported on sustained cognitive and adaptive behavior outcomes of long-term treatment with pabinafusp alfa in patients with severe or attenuated MPS II. Researchers concluded that long-term treatment with pabinafusp alfa was well tolerated and associated with stabilization or continued skill acquisition in many patients with severe or attenuated MPS II, suggesting that, with timely initiation prior to the onset of irreversible neurodegeneration, treatment with pabinafusp alfa may provide a benefit to patients with MPS II.

Long-term somatic efficacy of pabinafusp alfa across a broad spectrum of age groups and phenotypes in patients with mucopolysaccharidosis type II (Presentation Number: 62)
Lead Author: Ana Maria Martins, M.D., Ph.D. (Federal University of São Paulo)

In a longitudinal, pooled, post hoc analysis of patients with MPS II receiving pabinafusp alfa in open-label trials with up to five years of follow-up, researchers reported on the somatic effects of pabinafusp alfa in a heterogenous population of patients with MPS II who initiated treatment at different ages. Researchers concluded that long-term treatment with pabinafusp alfa was well tolerated and provided positive somatic effects to a broad spectrum of severe and attenuated patients with MPS II.

About the International Symposium on MPS and Related Lysosomal Diseases
The International Symposium on MPS and Related Lysosomal Diseases brings together healthcare professionals, researchers, and industry leaders to accelerate progress in mucopolysaccharidoses (MPS) and related lysosomal storage disorders through collaborative innovation. We unite diverse perspectives to advance early diagnosis through cutting-edge technologies, develop revolutionary therapies, and ensure equitable global access to care. Our mission is to foster the next generation of rare disease advocates and professionals while creating sustainable partnerships that transform scientific breakthroughs into real-world improvements in patient outcomes worldwide. For more information, please visit https://mps2026.com/.

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 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 Mucopolysaccharidosis Type I (Hurler, Hurler-Scheie, Scheie Syndrome)
Mucopolysaccharidosis type I (MPS I) is an autosomal recessive lysosomal storage disorder (LSD) caused by a deficiency of α-L-iduronidase, an enzyme that breaks down glycosaminoglycans (mucopolysaccharides) in the body. The current worldwide prevalence of MPS I is estimated to be approximately 3,000-4,000 (according to JCR internal research). MPS I gives rise to a wide range of somatic and neurological symptoms. A major limitation of current enzyme replacement therapy (ERT) is that it does not address central nervous system (CNS) symptoms because of the enzyme’s inability cross the blood brain barrier (BBB). MPS I is the only LSD in which hematopoietic stem cell transplantation (HSCT) is part of the standard of case for the severe form of the disease. Significant unmet medical need persists in all forms of MPS I.

About JR-171
JR-171 (lepunafusp alfa) is a recombinant fusion protein of an antibody against the human transferrin receptor and α-L-iduronidase, the enzyme that is missing or malfunctioning in patients with mucopolysaccharidosis type I (MPS I).^1,2 By crossing the blood brain-barrier (BBB) through transferrin receptor mediated transcytosis, it is expected to be effective against central nervous system (CNS) signs and symptoms of the disease thereby addressing a significant unmet need for the treatment of MPS I. JR-171 previously was granted Fast Track designation by the US Food and Drug Administration (FDA).

About Mucopolysaccharidosis Type II (Hunter Syndrome)
Mucopolysaccharidosis type II (MPS II, or Hunter syndrome) 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. Central nervous system symptoms related to MPS II have been unmet medical needs so far.

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.^3,4

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.⁵ Clinical studies have also demonstrated the positive effects of pabinafusp alfa on CNS symptoms.^6,7,8

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.”

About JCR Pharmaceuticals Co., Ltd.
JCR Pharmaceuticals Co., Ltd. (TSE 4552) is a global specialty pharmaceutical company that develops treatments that go beyond rare diseases to solve the world’s most complex healthcare challenges. We continue to build upon our 50-year legacy in Japan while expanding our global footprint into the U.S., Europe, and Latin America. We improve patients’ lives by applying our scientific expertise and unique technologies to research, develop, and deliver next-generation therapies. Our approved products in Japan include therapies for the treatment of growth disorder, MPS II (Hunter syndrome), Fabry disease, acute graft-versus host disease, and renal anemia. Our investigational products in development worldwide are aimed at treating rare diseases including MPS I (Hurler, Hurler Scheie and Scheie syndrome), MPS II, MPS IIIA and B (Sanfilippo syndrome type A and B), and more. Our core values – Putting people first, Forging our own path, Always advancing, and Committed to excellence – mean that the work we do benefits all our stakeholders, including partners, patients and employees. We strive to expand the possibilities for patients while accelerating medical advancement at a global level.

Cautionary Statement Regarding Forward-Looking Statements
This document contains forward-looking statements that are subject to known and unknown risks and uncertainties, many of which are outside our control. Forward-looking statements often contain words such as “believe,” “estimate,” “anticipate,” “intend,” “plan,” “will,” “would,” “target” and similar references to future periods. All forward-looking statements regarding our plans, outlook, strategy and future business, financial performance and financial condition are based on judgments derived from the information available to us at this time. Factors or events that could cause our actual results to be materially different from those expressed in our forward-looking statements include, but are not limited to, a deterioration of economic conditions, a change in the legal or governmental system, a delay in launching a new product, impact on competitors’ pricing and product strategies, a decline in marketing capabilities relating to our products, manufacturing difficulties or delays, an infringement of our intellectual property rights, an adverse court decision in a significant lawsuit and regulatory actions. This document involves information on pharmaceutical products (including those under development). However, it is not intended for advertising or providing medical advice. Furthermore, it is intended to provide information on our company and businesses and not to solicit investment in securities we issue. Except as required by law, we assume no obligation to update these forward-looking statements publicly or to update the factors that could cause actual results to differ materially, even if new information becomes available in the future.

References
1: Kida S, et al. Enzyme replacement with transferrin receptor-targeted α-L-iduronidase rescues brain pathology in mucopolysaccharidosis I mice. Mol Ther Methods Clin Dev. 2023; 29: 439-449.
2: Harmatz P, et al. α-L-iduronidase fused with humanized anti-human transferrin receptor antibody (lepunafusp alfa) for mucopolysaccharidosis type I: A phase 1/2 trial. Mol Ther. 2024;32(3): 609-618.
3: Sonoda, et al. A blood-brain-barrier-penetrating anti-human transferrin receptor antibody fusion protein for neuronopathic mucopolysaccharidosis II. Mol. Ther. 2018; 26(5): 1366-1374.
4: Morimoto, et al. Clearance of heparin sulfate in the brain prevents neurodegeneration and neurocognitive impairment in MPS II mice. Mol. Ther. 2021; 29(5): 1853-1861.
5: Okuyama, et al. Iduronate-2-sulfatase with Anti-human Transferrin Receptor Antibody for Neuropathic Mucopolysaccharidosis II: A Phase 1/2 Trial. Mol Ther. 2020; 27(2): 456-464.
6: Okuyama, et al. A Phase 2/3 Trial of Pabinafusp Alfa, IDS Fused with Anti-Human Transferrin Receptor Antibody, Targeting Neurodegeneration in MPS-II. Mol Ther. 2021; 29(2): 671-679.
7: Giugliani, et al. Iduronate-2-sulfatase fused with anti-human transferrin receptor antibody, pabinafusp alfa, for treatment of neuronopathic and non-neuronopathic mucopolysaccharidosis II: Report of a phase 2 trial in Brazil. Mol Ther. 2021; 29(7): 2378-2386.
8: Giugliani, et al. Enzyme Replacement Therapy with Pabinafusp Alfa for Neuronopathic Mucopolysaccharidosis II; an Integrated Analysis of Preclinical and Clinical Data. Int. J. Mol. Sci. 2021, Volume 22, Issue 20, 10938.

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Hyogo, Japan – May 28, 2026 – JCR Pharmaceuticals Co., Ltd. (TSE 4552; “JCR”), a global specialty biopharmaceutical company dedicated to developing therapies for rare and genetic diseases, announced today that it will present new clinical data in a poster session at the 18th International Symposium on MPS and Related Lysosomal Diseases, being held June 4-7 in Florence, Italy. The poster presentation will demonstrate the potential benefits of the investigational therapy, JR-171 (lepunafusp alfa), and of J-Brain Cargo®, JCR’s proprietary technology that delivers medicine across the blood-brain barrier (BBB) for the treatment of lysosomal storage disorders and other neurodegenerative diseases.

The details of the new clinical data presentation are listed below:

Title: Three-Year safety and pharmacodynamics of lepunafusp alfa (JR-171) in patients with mucopolysaccharidosis type I (MPS-I): Results from a phase I/II trial and extension study
Lead Author: Paul Harmatz, M.D. (UCSF Benioff Children’s Hospital, Oakland, CA)
Presentation Number: 63

In addition, researchers will also share the following encore presentations on JR-141 (pabinafusp alfa) in the treatment of MPS II that were disclosed at the 22nd Annual WORLDSymposium™ 2026 (February 2-6, 2026).

Title: Sustained cognitive and adaptive behavior outcomes of long-term treatment with pabinafusp alfa in patients with severe or attenuated mucopolysaccharidosis type II
Lead Author: Roberto Giugliani, M.D., Ph.D. (Federal University of Rio Grande do Sul, Brazil)
Presentation Number: 61

Title: Long-term somatic efficacy of pabinafusp alfa across a broad spectrum of age groups and phenotypes in patients with mucopolysaccharidosis type II
Lead Author: Ana Maria Martins, M.D., Ph.D. (Federal University of São Paulo)
Presentation Number: 62

Attendees who would like to receive more information about JCR Pharmaceuticals can visit JCR’s on-site conference booth (#5).

The full program can be found on the International Symposium on MPS and Related Lysosomal Diseases website at https://mps2026.com/program. All posters will be available during the Networking Break and Poster Viewing sessions throughout the entire symposium.

About the International Symposium on MPS and Related Lysosomal Diseases
The International Symposium on MPS and Related Lysosomal Diseases brings together healthcare professionals, researchers, and industry leaders to accelerate progress in mucopolysaccharidoses (MPS) and related lysosomal storage disorders through collaborative innovation. We unite diverse perspectives to advance early diagnosis through cutting-edge technologies, develop revolutionary therapies, and ensure equitable global access to care. Our mission is to foster the next generation of rare disease advocates and professionals while creating sustainable partnerships that transform scientific breakthroughs into real-world improvements in patient outcomes worldwide. For more information, please visit https://mps2026.com/.

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 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 Mucopolysaccharidosis Type I (Hurler, Hurler-Scheie, Scheie Syndrome)
Mucopolysaccharidosis I (MPS I) is an autosomal recessive lysosomal storage disorder (LSD) caused by a deficiency of α-L-iduronidase, an enzyme that breaks down glycosaminoglycans (mucopolysaccharides) in the body. The current worldwide prevalence of MPS I is estimated to be approximately 3,000-4,000 (according to JCR internal research). MPS I gives rise to a wide range of somatic and neurological symptoms. A major limitation of current enzyme replacement therapy (ERT) is that it does not address central nervous system (CNS) symptoms because of the enzyme’s inability cross the blood-brain barrier (BBB). MPS I is the only LSD in which hematopoietic stem cell transplantation (HSCT) is part of the standard of case for the severe form of the disease. Significant unmet medical need persists in all forms of MPS I.

About JR-171
JR-171 (lepunafusp alfa) is a recombinant fusion protein of an antibody against the human transferrin receptor and α-L-iduronidase, the enzyme that is missing or malfunctioning in patients with mucopolysaccharidosis type I (MPS I).1,2 By crossing the blood brain-barrier (BBB) through transferrin receptor mediated transcytosis, it is expected to be effective against central nervous system (CNS) signs and symptoms of the disease thereby addressing a significant unmet need for the treatment of MPS I. JR-171 previously was granted Fast Track designation by the US Food and Drug Administration (FDA).

About Mucopolysaccharidosis Type II (Hunter Syndrome)
Mucopolysaccharidosis type II (MPS II, or Hunter syndrome) 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. Central nervous system symptoms related to MPS II have been unmet medical needs so far.

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 IZCARGOTM 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.3,4

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.5 Clinical studies have also demonstrated the positive effects of pabinafusp alfa on CNS symptoms.6,7,8

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.”

About JCR Pharmaceuticals Co., Ltd.
JCR Pharmaceuticals Co., Ltd. (TSE 4552) is a global specialty pharmaceutical company that develops treatments that go beyond rare diseases to solve the world’s most complex healthcare challenges. We continue to build upon our 50-year legacy in Japan while expanding our global footprint into the U.S., Europe, and Latin America. We improve patients’ lives by applying our scientific expertise and unique technologies to research, develop, and deliver next-generation therapies. Our approved products in Japan include therapies for the treatment of growth disorder, MPS II (Hunter syndrome), Fabry disease, acute graft-versus host disease, and renal anemia. Our investigational products in development worldwide are aimed at treating rare diseases including MPS I (Hurler, Hurler-Scheie and Scheie syndrome), MPS II, MPS IIIA and B (Sanfilippo syndrome type A and B), and more. Our core values – Putting people first, Forging our own path, Always advancing, and Committed to excellence – mean that the work we do benefits all our stakeholders, including partners, patients and employees. We strive to expand the possibilities for patients while accelerating medical advancement at a global level.

References
1: Kida S, et al. Enzyme replacement with transferrin receptor-targeted α-L-iduronidase rescues brain pathology in mucopolysaccharidosis I mice. Mol Ther Methods Clin Dev. 2023; 29: 439-449.
2: Harmatz P, et al. α-L-iduronidase fused with humanized anti-human transferrin receptor antibody (lepunafusp alfa) for mucopolysaccharidosis type I: A phase 1/2 trial. Mol Ther. 2024; 32(3): 609-618.
3: Sonoda, et al. A blood-brain-barrier-penetrating anti-human transferrin receptor antibody fusion protein for neuronopathic mucopolysaccharidosis II. Mol. Ther. 2018; 26(5): 1366-1374.
4: Morimoto, et al. Clearance of heparin sulfate in the brain prevents neurodegeneration and neurocognitive impairment in MPS II mice. Mol. Ther. 2021; 29(5): 1853-1861.
5: Okuyama, et al. Iduronate-2-sulfatase with Anti-human Transferrin Receptor Antibody for Neuropathic Mucopolysaccharidosis II: A Phase 1/2 Trial. Mol Ther. 2020; 27(2): 456-464.
6: Okuyama, et al. A Phase 2/3 Trial of Pabinafusp Alfa, IDS Fused with Anti-Human Transferrin Receptor Antibody, Targeting Neurodegeneration in MPS-II. Mol Ther. 2021; 29(2): 671-679.
7: Giugliani, et al. Iduronate-2-sulfatase fused with anti-human transferrin receptor antibody, pabinafusp alfa, for treatment of neuronopathic and non-neuronopathic mucopolysaccharidosis II: Report of a phase 2 trial in Brazil. Mol Ther. 2021; 29(7): 2378-2386.
8: Giugliani, et al. Enzyme Replacement Therapy with Pabinafusp Alfa for Neuronopathic Mucopolysaccharidosis II; an Integrated Analysis of Preclinical and Clinical Data. Int. J. Mol. Sci. 2021, Volume 22, Issue 20, 10938.

Contact:
Investors & Media:
JCR Pharmaceuticals Co., Ltd.
Corporate Communications
ir-info@jp.jcrpharm.com