Hunter Syndrome Treatment Market - Global Industry Size, Share, Trends, Opportunity, and Forecast, Segmented By Treatment (Enzyme Replacement Therapy, Hematopoietic Stem Cell Transplant), By End User (Hospitals & Clinics, Ambulatory Care Centers, Others), By Region and Competition, 2021-2031F

Forecast Period	2027-2031
Market Size (2025)	USD 1.41 Billion
CAGR (2026-2031)	5.46%
Fastest Growing Segment	Enzyme Replacement Therapy
Largest Market	North America
Market Size (2031)	USD 1.94 Billion

Market Overview

The Global Hunter Syndrome Treatment Market will grow from USD 1.41 Billion in 2025 to USD 1.94 Billion by 2031 at a 5.46% CAGR. The Global Hunter Syndrome Treatment Market encompasses the development and distribution of therapeutic interventions, primarily enzyme replacement therapies and emerging gene-based treatments, intended to manage Mucopolysaccharidosis II, a rare genetic disorder caused by iduronate-2-sulfatase deficiency. The market is fundamentally supported by robust drivers such as the increasing implementation of newborn screening programs which facilitate early intervention, and favorable regulatory frameworks like orphan drug designations that mitigate the financial risks of research and development. This momentum is evidenced by the accelerated activity in the broader rare disease sector; according to the Pharmaceutical Research and Manufacturers of America, in 2024, regulatory agencies approved seven novel cell and gene therapies for rare conditions, signaling a maturing clinical environment favorable for the advancement of next-generation Hunter Syndrome biologics.

However, a significant challenge impeding broader market expansion is the physiological difficulty of delivering therapeutics across the blood-brain barrier. Current standard-of-care enzyme replacement therapies often fail to adequately address the progressive cognitive decline associated with the severe, neuronopathic form of the disease, thereby limiting clinical efficacy and restricting the addressable patient population for existing products.

Key Market Drivers

Advancements in gene therapy and genome editing are fundamentally reshaping the clinical landscape by offering potential one-time curative treatments that address the underlying genetic root of Mucopolysaccharidosis II. Unlike chronic management, these modalities aim to restore the functional production of iduronate-2-sulfatase, significantly reducing the systemic burden of the disease and validating high-value valuation models for developers. This shift is heavily supported by a regulatory environment increasingly focused on orphan conditions; according to the U.S. Food and Drug Administration, in 2024, 28 of the 55 novel drugs approved in the previous year were for rare diseases, highlighting the agency's commitment to accelerating orphan drug development. Specific clinical progress in this domain is evident in late-stage trials. According to Regenxbio Inc., September 2024, in the 'Press Release', patients treated with the pivotal dose of RGX-121 demonstrated a median reduction of 85% in cerebrospinal fluid heparan sulfate D2S6, a key biomarker of brain disease activity, confirming the therapeutic viability of this approach.

Innovations in blood-brain barrier delivery mechanisms are simultaneously overcoming the historical limitations of intravenous enzyme replacement therapies, which traditionally fail to treat the severe neuronopathic manifestations of the disorder. Emerging technologies now utilize receptor-mediated transport to actively shuttle large therapeutic molecules across the blood-brain barrier, ensuring they reach affected central nervous system tissues. This breakthrough is critical for preventing progressive cognitive decline in severe phenotypes and expanding the addressable patient population. According to Denali Therapeutics Inc., September 2024, in the 'Press Release', the Phase 1/2 study of tividenofusp alfa showed a 90% mean reduction in cerebrospinal fluid heparan sulfate from baseline at Week 24, indicating robust central nervous system penetration. These engineering triumphs are expanding the market by validating that systemic treatments can effectively target neurological symptoms previously considered untreatable.

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Key Market Challenges

The physiological inability of therapeutic agents to cross the blood-brain barrier represents a formidable impediment to the expansion of the Global Hunter Syndrome Treatment Market. Current standard-of-care enzyme replacement therapies possess large molecular structures that prevent them from penetrating the central nervous system, rendering them ineffective against the progressive cognitive decline characteristic of the severe, neuronopathic form of Mucopolysaccharidosis II. This delivery constraint creates a bifurcated market where the somatic symptoms are managed, but the neurological pathology remains untreated. Consequently, the commercial potential of existing biologics is significantly capped because they fail to provide a comprehensive cure for the patient population most in need of intervention, thereby limiting the overall value proposition and market penetration of current products.

This scientific hurdle directly hampers market growth by sustaining a high level of unmet clinical need that existing portfolios cannot address. The complexity of engineering large-molecule drugs to bypass physiological barriers slows the development timeline and increases the risk profile for manufacturers. According to the Pharmaceutical Research and Manufacturers of America, in 2024, the industry had 148 medicines in development for genetic disorders, yet the successful formulation of therapies capable of overcoming central nervous system barriers remains a distinct operational bottleneck. This disparity between broad pipeline activity and the scarcity of brain-penetrant approvals underscores how the blood-brain barrier continues to restrict the advancement and commercial scalability of the Hunter Syndrome market.

Key Market Trends

Development of Ex Vivo Stem Cell Gene Therapy Approaches is establishing a distinct therapeutic class beyond the prevailing in vivo viral vector modalities. This approach involves modifying autologous hematopoietic stem cells to express iduronate-2-sulfatase, allowing them to differentiate into microglia and deliver enzymes directly to the brain. This mechanism mitigates the systemic immunogenicity risks associated with direct viral injection while ensuring durable central nervous system correction. According to University College London, November 2025, in the article 'Boy given world-first gene therapy made by UCL scientists thriving', a patient treated with this novel ex vivo therapy displayed dramatic improvements in speech, agility, and cognitive development nine months post-transplant, validating its potential to arrest neurodegenerative progression.

Integration of Neurofilament Light Chain Biomarkers in Clinical Trials shifts the analytical focus from metabolic substrates to direct neuronal health measures. Validating neuroprotection is now essential for therapies targeting the neuronopathic phenotype, with neurofilament light chain providing a quantifiable metric of axonal damage. This offers a more immediate readout of neurological efficacy compared to longitudinal cognitive assessments. According to Nasdaq, February 2025, in the article 'Denali Therapeutics Reports Promising Long-Term Data for Tividenofusp Alfa in Hunter Syndrome', the Phase 1/2 study of tividenofusp alfa demonstrated robust, sustained reduction in neurofilament light chain levels after a median follow-up of two years, confirming the biomarker's utility in substantiating clinical value.

Segmental Insights

Enzyme Replacement Therapy represents the fastest-growing segment in the global Hunter Syndrome treatment market because it directly addresses the essential enzyme deficiency causing the disorder. This approach is increasingly adopted by medical professionals as it provides superior clinical outcomes compared to palliative care options. Continued support from regulatory entities such as the U.S. Food and Drug Administration has streamlined market access, ensuring these essential treatments reach patients effectively. The consistent demand for lifelong disease management ensures this therapeutic category maintains its leading position in market development.

Regional Insights

North America holds a dominant position in the Global Hunter Syndrome Treatment Market primarily due to established healthcare infrastructure that supports early diagnosis and screening. The region benefits from favorable reimbursement policies and extensive research activities focused on rare diseases. A key factor driving this leadership is the supportive regulatory framework maintained by the U.S. Food and Drug Administration, which encourages the development and approval of orphan drugs. Additionally, the presence of major pharmaceutical companies ensures consistent availability of therapeutics, securing the region's status as the primary market revenue generator.

Recent Developments

• In January 2025, Denali Therapeutics announced that the US Food and Drug Administration had granted Breakthrough Therapy Designation to tividenofusp alfa (DNL310), its investigational enzyme replacement therapy for Hunter Syndrome. This regulatory status serves to expedite the development and review of drugs intended to treat serious conditions, acknowledging the potential of the candidate to provide substantial improvement over existing therapies. The designation was supported by clinical data showing that the treatment significantly reduced cerebrospinal fluid heparan sulfate and neurofilament light chain levels. The company stated that it planned to submit a biologics license application to make the therapy available to patients sooner.
• In November 2024, GC Biopharma achieved a major regulatory milestone with the approval of Hunterase ICV (idursulfase beta) in Russia for the treatment of patients with Hunter Syndrome. This decision represented the second global marketing authorization for the device-aided therapy, which had previously been approved in Japan. The treatment is uniquely designed to be administered directly into the cerebral ventricles, allowing the enzyme to bypass the blood-brain barrier and effectively reach brain cells. The company emphasized that this approval validated its innovative approach to addressing the significant unmet medical need for therapies that can treat the neurocognitive decline associated with the severe form of the disease.
• In September 2024, REGENXBIO reported positive new results from the pivotal phase of the CAMPSIITE clinical trial evaluating RGX-121, an investigational one-time gene therapy for Mucopolysaccharidosis Type II. The data demonstrated that patients treated with the therapy achieved a robust median reduction of 85% in heparan sulfate levels in the cerebrospinal fluid, a key biomarker of brain disease activity. Furthermore, a significant majority of patients were able to discontinue standard enzyme replacement therapy. Following these promising outcomes, the company announced it was proceeding with a rolling submission of a Biologics License Application to the US regulatory authorities under the accelerated approval pathway.
• In June 2024, JCR Pharmaceuticals announced the termination of its collaboration with a major pharmaceutical partner, thereby regaining full global development and commercialization rights for JR-141 (pabinafusp alfa). This investigational therapy, approved in Japan as IZCARGO, utilizes proprietary technology to cross the blood-brain barrier and treat both somatic and central nervous system symptoms of Hunter Syndrome. The company confirmed that it would continue to lead the ongoing global Phase 3 clinical trials in the United States, Europe, and Brazil without interruption. Management expressed a strong commitment to bringing this potential new treatment option to patients worldwide as an independent entity.

Key Market Players

• Takeda Pharmaceutical Co Ltd
• F Hoffmann-La Roche AG
• Abbott Laboratories Inc
• Johnson & Johnson
• GSK PLC
• Bayer AG
• Novartis AG
• Pfizer Inc
• Zimmer Biomet Holdings Inc
• Sangamo Therapeutics, Inc

By Treatment	By End User	By Region
Enzyme Replacement Therapy Hematopoietic Stem Cell Transplant	Hospitals & Clinics Ambulatory Care Centers Others	North America Europe Asia Pacific South America Middle East & Africa

Report Scope:

In this report, the Global Hunter Syndrome Treatment Market has been segmented into the following categories, in addition to the industry trends which have also been detailed below:

• Hunter Syndrome Treatment Market , By Treatment:

• Enzyme Replacement Therapy
• Hematopoietic Stem Cell Transplant

• Hunter Syndrome Treatment Market , By End User:

• Hospitals & Clinics
• Ambulatory Care Centers
• Others

• Hunter Syndrome Treatment Market , By Region:

• North America
• United States
• Canada
• Mexico
• Europe
• France
• United Kingdom
• Italy
• Germany
• Spain
• Asia Pacific
• China
• India
• Japan
• Australia
• South Korea
• South America
• Brazil
• Argentina
• Colombia
• Middle East & Africa
• South Africa
• Saudi Arabia
• UAE