IgG4-related disease Market Summary

The US IgG4-Related Disease (IgG4-RD) market, valued at ~USD 90 million in 2024, is projected to grow significantly through 2034. IgG4-RD is a rare systemic fibroinflammatory condition that can affect multiple organs, including the pancreas, kidneys, lungs, and salivary glands. In 2024, there were nearly 148,970 diagnosed prevalent cases across the 7MM, with the U.S. recording the highest numbers and Japan reporting ~38,690 cases. The disease is often underdiagnosed due to its relatively recent discovery, male predominance, and variable presentation. Current treatment relies mainly on corticosteroids like prednisone, with immunosuppressants and Rituximab used in relapsing or resistant cases. However, no curative therapy exists. A major milestone occurred in April 2025, when the FDA approved Amgen’s UPLIZNA, the first-ever treatment for IgG4-RD, following its Breakthrough Therapy Designation. Other key pipeline therapies include obexelimab (Zenas BioPharma/Bristol Myers Squibb) and rilzabrutinib (Sanofi). UPLIZNA and obexelimab are expected to compete strongly, while rilzabrutinib, an oral candidate, could reshape the market with a convenient alternative to injectables. Leading players include Zenas BioPharma, Bristol Myers Squibb, Amgen, Sanofi, and others, with innovation set to transform this underserved market.

 

DelveInsight’s “IgG4-related disease Market Insights, Epidemiology, and Market Forecast-2034” report delivers an in-depth understanding of IgG4-related disease, historical and forecasted epidemiology as well as the IgG4-related disease market trends in the United States, EU5 (Germany, Spain, Italy, France, and United Kingdom), and Japan. The IgG4-related disease market report provides current treatment practices, emerging drugs, the market share of the individual therapies, and the current and forecasted IgG4-related disease market size from 2020 to 2034, segmented by seven major markets. The Report also covers current IgG4-related disease treatment practice/algorithm, market drivers, market barriers, and unmet medical needs to curate the best opportunities and assesses the underlying potential of the IgG4-related disease market.

 

The IgG4-Related Disease market is set for major growth with the approval of UPLIZNA and a robust pipeline including obexelimab and rilzabrutinib @ IgG4-related disease Market Forecast

 

Some facts of the IgG4-related disease Market Report are:

• The IgG4-Related Disease market size is anticipated to grow with a significant CAGR during the study period (2020-2034).
• DelveInsight estimates that the market size for IgG4-RD is expected to grow from USD 170 million in 2024, with a significant CAGR by 2034.
• IgG4 related disease is a systemic disease that causes fibrosis, tumor-like nodules, and lymphoid hyperplasia with infiltration of IgG4-positive plasma cells. It can manifest in many organ systems.
• There are no approved therapies for IgG4-related disease (IgG4-RD) specifically and hence, the current treatment landscape is driven by off-label therapies such as glucocorticoids, immunomodulators, and rituximab.
• Glucocorticoids (GCs) have been considered the first-line therapy in IgG4-related disease (IgG4-RD), whereas rituximab accounted for the majority of the market share as annual treatment cost is significantly higher for patients taking rituximab.
• The United States accounted for the largest market size (around USD 115 million) of IgG4-related disease treatment market, in comparison to EU4 (Germany, Spain, Italy, France), the United Kingdom, and Japan.
• Amgen recorded USD 379 million in UPLIZNA sales in 2024 from its original indication alone. However, the recent approval for IgG4-related disease presents a significant growth opportunity, as this new market includes a treatable patient population that is roughly twice as large as that for NMOSD.
• Limited number of therapies are being investigated for the treatment of IgG4 related disease. Some of the key players involved in the development are Zenas Biopharma (obexelimab), Amgen/Horizon Therapeutics (inebilizumab), and Sanofi (rilzabrutinib).
• Approval of ZB012 (obexelimab) and UPLIZNA (inebilizumab) will change the treatment pattern drastically over the forecast period as these will be the first few drugs to be launched for the treatment of IgG4-related disease.
• IgG4-related disease is a rare disease, with an estimated prevalence of 6 cases per 100,000 individuals. This condition primarily affects middle-aged to elderly men.
• The 7MM accounted for approximately 300,000 prevalent cases of IgG4-related disease in 2023. These cases are expected to increase due to increased awareness and improved diagnostic methods that contribute to the rise in identified cases of IgG4-related disease, especially among aging populations with higher incidences of autoimmune disorders.
• Key IgG4-Related Disease Companies: Zenas BioPharma, Horizon Therapeutics, Sanofi, Roche, AbbVie, Gilead Sciences, Takeda Pharmaceutical Company, and others
• Key IgG4-Related Disease Therapies: ZB012 (obexelimab), UPLIZNA (inebilizumab), Rilzabrutinib, and others
• The IgG4-Related Disease market is expected to surge due to the disease’s increasing prevalence and awareness during the forecast period. Furthermore, launching various multiple-stage IgG4-Related Disease pipeline products will significantly revolutionize the IgG4-Related Disease market dynamics.
• In April 2025, Amgen announced that the FDA had approved UPLIZNA as the first and only treatment for adults living with IgG4-RD.
• In March 2025, Zenas BioPharma announced that the company anticipates reporting topline results for the INDIGO trial by the end of 2025.
• In November 2024, Amgen presented new data at the annual American College of Rheumatology (ACR) Convergence 2024, demonstrating a significant reduction in disease activity in patients with IgG4-RD following treatment with UPLIZNA.
• In August 2024, Amgen announced that the US FDA had granted Breakthrough Therapy Designation (BTD) to UPLIZNA for the treatment of IgG4-RD based on data from the MITIGATE study.

 

IgG4-related disease Overview

IgG4-related disease (IgG4-RD) is a rare, chronic, and systemic fibroinflammatory condition characterized by the infiltration of IgG4-positive plasma cells and elevated serum IgG4 levels. It can affect nearly any organ, with common involvement of the pancreas, bile ducts, salivary glands, lacrimal glands, kidneys, lungs, and retroperitoneum. Clinical manifestations often mimic malignancies or other autoimmune diseases, making diagnosis challenging and frequently delayed. The disease shows a male predominance and typically presents between the fourth and sixth decades, though pediatric cases are also reported. Current management relies on corticosteroids such as prednisone, with immunosuppressants or biologics like rituximab used in relapsed or refractory cases. Novel targeted therapies, including UPLIZNA and obexelimab, are emerging to address unmet needs.

 

Do you know what will be the IgG4-related disease market share in 7MM by 2034 @ IgG4-related disease Treatment Market

 

IgG4-Related Disease (IgG4-RD) Treatment & Market Outlook

In 2024, the U.S. led the IgG4-RD market with nearly USD 90 million, followed by the EU4 and UK (~USD 80 million, with Germany as the largest European contributor). Japan’s market stood at ~USD 6 million but is projected to grow rapidly through 2034. IgG4-Related Disease companies are driving innovation include Zenas BioPharma, Amgen, and Sanofi, each advancing late-stage candidates to address unmet needs. If successful, these therapies could reshape the IgG4-RD landscape, improve patient outcomes, and expand market potential across the 7MM.

Glucocorticoids remain the first-line therapy for IgG4-RD, with prednisone (30–40 mg/day or 0.6 mg/kg/day) commonly used for remission induction. In some cases, DMARDs are prescribed, and plasmablast levels serve as biomarkers to guide B-cell–targeted therapy.

The treatment landscape is expected to undergo significant transformation with multiple pipeline therapies under development. However, challenges around pricing, reimbursement, regulatory precedent, and standardized trial endpoints may impact adoption and market growth. Rituximab, though effective and cost-friendly, faces restrictions in Japan due to insurance limitations.

 

IgG4-related disease Epidemiology

In 2024, the diagnosed prevalent population of IgG4-related disease (IgG4-RD) in the United States was estimated at ~56,800 cases, with males (~39,100 cases) outnumbering females (~17,700 cases). Across the EU4 and the UK, diagnosed prevalence was ~53,550 cases, comprising ~38,850 males and ~14,750 females. Age-stratified analysis categorized cases into six groups: 0–17 years, 18–29 years, 30–44 years, 45–64 years, 65–74 years, and ≥75 years. In Japan, the ≥75 years age group represented the highest disease burden, accounting for ~12,800 cases in 2024. Across all geographies, the diagnosed prevalence of IgG4-RD is projected to increase steadily from 2025 to 2034, driven by improved recognition, diagnostic awareness, and broader clinical reporting.

IgG4-related disease Epidemiology Segmented by:

• Total diagnosed prevalent cases of IgG4-RD
• Gender-specific diagnosed prevalent cases of IgG4-RD
• Age-specific diagnosed prevalent cases of IgG4-RD

 

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IgG4-related disease Drugs Uptake

Obexelimab (XmAb5871) – Developed by Zenas BioPharma and Bristol Myers Squibb, this bifunctional monoclonal antibody targets CD19 and FcγRIIb to inhibit B-cell activity. It is administered subcutaneously (SC) and is currently in Phase III development.

Rilzabrutinib (PRN1008/SAR444671) – A small molecule oral Bruton’s Tyrosine Kinase (BTK) inhibitor from Sanofi, positioned in Phase II clinical development for IgG4-RD.

 

IgG4-related disease Market Drivers and Barriers

IgG4-related disease Market Drivers

• Rising Diagnosis and Awareness – Improved recognition of IgG4-RD by clinicians, supported by growing research and clinical guidelines.
• Unmet Medical Need – Lack of approved therapies until recently creates strong demand for effective, targeted treatments.
• Novel Therapeutics Pipeline – Approval of UPLIZNA (Amgen, 2025) and advancement of obexelimab (Zenas/BMS) and rilzabrutinib (Sanofi) drive innovation.
• Increasing Prevalence – Rising diagnosed patient pool in the US, EU, and Japan supports market expansion.
• Supportive Regulatory Designations – Breakthrough and orphan drug designations accelerate drug development.
• Shift Toward Targeted Therapies – Growing interest in B-cell modulation and BTK inhibitors to replace long-term steroid dependence.

 

IgG4-related disease Market Barriers

• Underdiagnosis & Misdiagnosis – Due to nonspecific symptoms and overlap with malignancies/autoimmune diseases.
• Limited Epidemiological Data – True prevalence remains unclear, impacting investment and healthcare planning.
• Pricing & Reimbursement Challenges – High-cost biologics face payer resistance, especially where off-label rituximab is used as a cheaper alternative.
• Clinical Development Risks – Lack of established regulatory precedent and standardized endpoints for IgG4-RD trials.
• Steroid Dependence – Corticosteroids remain the standard first-line therapy, delaying adoption of novel agents.
• Regional Variations – Limited drug access in markets like Japan, where rituximab use is restricted.

 

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IgG4-related disease Therapeutics Assessment

Major key companies are working proactively in the IgG4-related disease Therapeutics market to develop novel therapies which will drive the IgG4-related disease treatment markets in the upcoming years are Zenas BioPharma, Amgen Inc (NASDAQ: AMGN), Horizon Therapeutics (NASDAQ: HZNP), Sanofi (EPA: SAN), Roche (SWX: ROG), AbbVie (NYSE: ABBV), Gilead Sciences (NASDAQ: GILD), Takeda Pharmaceutical Company (TYO: 4502), and others.

 

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IgG4-related disease Report Key Insights

1. IgG4-related disease Patient Population

2. IgG4-related disease Market Size and Trends

3. Key Cross Competition in the IgG4-related disease Market

4. IgG4-related disease Market Dynamics (Key Drivers and Barriers)

5. IgG4-related disease Market Opportunities

6. IgG4-related disease Therapeutic Approaches

7. IgG4-related disease Pipeline Analysis

8. IgG4-related disease Current Treatment Practices/Algorithm

9. Impact of Emerging Therapies on the IgG4-related disease Market

 

Table of Contents

1. Key Insights

2. Executive Summary

3. IgG4-related disease Competitive Intelligence Analysis

4. IgG4-related disease Market Overview at a Glance

5. IgG4-related disease Disease Background and Overview

6. IgG4-related disease Patient Journey

7. IgG4-related disease Epidemiology and Patient Population

8. IgG4-related disease Treatment Algorithm, Current Treatment, and Medical Practices

9. IgG4-related disease Unmet Needs

10. Key Endpoints of IgG4-related disease Treatment

11. IgG4-related disease Marketed Products

12. IgG4-related disease Emerging Therapies

13. IgG4-related disease Seven Major Market Analysis

14. Attribute Analysis

15. IgG4-related disease Market Outlook (7 major markets)

16. IgG4-related disease Access and Reimbursement Overview

17. KOL Views on the IgG4-related disease Market

18. IgG4-related disease Market Drivers

19. IgG4-related disease Market Barriers

20. Appendix

21. DelveInsight Capabilities

22. Disclaimer

 

About DelveInsight

DelveInsight is a leading Life Science market research and business consulting company recognized for its off-the-shelf syndicated market research reports and customized solutions to firms in the healthcare sector.

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