Systemic Juvenile Idiopathic Arthritis (SJIA) - Market Insight, Epidemiology, and Market Forecast - 2034

Key Highlights:

• Juvenile idiopathic arthritis (JIA) is the most common chronic rheumatic disease in children, marked by persistent joint pain, swelling, and stiffness that begins before the age of 16. It is a group of diseases with various subtypes, each characterized by unique clinical features and potential complication.
• Systemic Juvenile Idiopathic Arthritis (sJIA) is a severe form of JIA characterized by arthritis, daily spiking fevers, and a distinctive rash. It is unique among JIA subtypes, as it is the only one considered an autoinflammatory disease rather than an autoimmune disorder.
• Approximately 10% to 20% of children diagnosed with JIA have a rare and severe subtype known as systemic juvenile idiopathic arthritis (sJIA), with incidence estimated at 1/166,000 and prevalence at 1/32,000 in the pediatric population.
• Systemic juvenile idiopathic arthritis is more common in children between 1 to 5 years, accounting for approximately 55% of all the cases.
• Approximately 10-40% of sJIA patients present a monocyclic disease course, recovering completely within 12-24 months.
• The cornerstone of the treatment strategy includes nonsteroidal anti-inflammatory drugs (NSAIDs), conventional synthetic disease-modifying anti-rheumatic drugs (csDMARDs) like methotrexate, corticosteroids, and biologics with physical therapy.
• The current FDA-approved drugs for systemic juvenile idiopathic arthritis, includes ILARIS (canakinumab), GAMIFANT (emapalumab-lzsg), and ACTEMRA (tocilizumab).
• The emerging pipeline for systemic juvenile idiopathic arthritis is very scarce with some therapies in pipeline including LY3009104 (Eli Lilly), KEVZARA (sarilumab) (Sanofi), and 101-PCG-005 (PIF Partners).
• In June 2025, Sobi announced that the US Food and Drug Administration (FDA) has granted the approval to GAMIFANT for treatment of adult and pediatric patients with hemophagocytic lymphohistiocytosis (HLH)/macrophage activation syndrome (MAS) in known or suspected Still's disease, including systemic Juvenile Idiopathic Arthritis (sJIA).

DelveInsight's "Systemic Juvenile Idiopathic Arthritis (sJIA) - Market Insight, Epidemiology, and Market Forecast - 2034" report delivers an in-depth understanding of systemic JIA, historical and forecasted epidemiology as well as the Systemic JIA market trends in the United States, EU4 (Germany, France, Italy, and Spain) and the United Kingdom, and Japan.

The systemic JIA market report provides current treatment practices, emerging drugs, systemic JIA share of individual therapies, and current and forecasted systemic JIA market size from 2020 to 2034, segmented by seven major markets. The report also covers current systemic JIA treatment practices/algorithms and unmet medical needs to curate the best of the opportunities and assess the underlying potential of the market.

Geography Covered:

• The United States
• EU4 (Germany, France, Italy, and Spain) and the United Kingdom
• Japan

Study Period: 2020-2034

Systemic Juvenile Idiopathic Arthritis (sJIA) Disease Understanding and Treatment Algorithm

Systemic Juvenile Idiopathic Arthritis (sJIA) Overview

Systemic Juvenile Idiopathic Arthritis (sJIA), also called Still's disease, is a rare and serious type of juvenile idiopathic arthritis (JIA) that can occurs any time during childhood, but it most commonly starts at around 2 years of age children. It is autoinflammatory disorder that causes arthritis (stiff, swollen, painful joints) and affects other parts of the body, including the liver, lungs and heart. Further, it is a lifelong disease for many patients and can continue into adulthood. The exact cause of sJIA is not clear, however it is likely due to combination of genetic predisposition, infection, and dysregulation of the innate immune system.

Symptoms of sJIA may include arthritis in one or more joints for more than 6 weeks, high fever, rashes, anemia, enlarged liver, spleen and lymph nodes, joint damage, and inflammation in lining of heart and lungs.

Systemic Juvenile Idiopathic Arthritis (sJIA) Diagnosis

The diagnosis of systemic juvenile idiopathic arthritis involves a detailed medical history, thorough physical examination, and laboratory tests showing signs of systemic inflammation (elevated ESR, CRP, ferritin, leukocytosis) while excluding infections, malignancy (e.g., leukemia or lymphoma), other autoimmune/autoinflammatory diseases, and other forms of juvenile idiopathic arthritis. Imaging studies like echocardiograms, chest X-rays, or CT scans may be used to assess for inflammation of the heart or lungs.

Further, screening for complications like macrophage activation syndrome (MAS), a severe and potentially life-threatening complication marked by persistent fever, rash, cytopenias, and abnormal blood markers, is essential. Early diagnosis by pediatric rheumatologists allows prompt treatment to prevent joint and organ damage and improve long-term outcomes

Systemic Juvenile Idiopathic Arthritis (sJIA) Treatment

The systemic juvenile idiopathic arthritis is a chronic condition that cannot be cured, but remission is possible with effective treatment. The treatment of sJIA aims to reduce inflammation, relieve symptoms, and prevent long-term joint damage or other complications. It typically includes a combination of medications, such as nonsteroidal anti-inflammatory drugs (NSAIDs) to relieve pain and fever, conventional synthetic disease-modifying anti-rheumatic drugs (csDMARDs) like methotrexate to slow disease progression, corticosteroids for more severe inflammation, and biologics that specifically target immune system components involved in the disease. Further, physical therapy plays a key role in preserving joint movement and function, and in cases of advanced joint damage, surgery may be considered.

Systemic Juvenile Idiopathic Arthritis (sJIA) Epidemiology

The sJIA epidemiology chapter in the report provides historical as well as forecasted epidemiology segmented by the total diagnosed prevalent cases of JIA, diagnosed prevalent cases of systemic JIA, and Total Treated Cases of sJIA in the 7MM market covering the United States, EU4 (Germany, France, Italy, and Spain) and the United Kingdom, and Japan from 2020 to 2034.

• JIA is the most common rheumatic disease in children, with an estimated global incidence ranging from 1.6 to 23 cases per 100, 000 population and a prevalence of 3.8 to 400 cases per 100,000 population.
• In Europe, sJIA accounts for 5-15% of all children with chronic arthritis with an annual incidence of. 0.3-0.8 cases per 100,000 children under 16 years.
• As per National Rheumatoid Arthritis Society, approximately 12,000 children and young people in the UK have JIA which represents 1 child in every 1000 under the age of 16.

Systemic Juvenile Idiopathic Arthritis (sJIA) Drug Chapters

The drug chapter segment of the sJIA report encloses a detailed analysis sJIA marketed and emerging pipeline products. It also deep dives into sJIA's pivotal clinical trial details, recent and expected market approvals, patent details, the latest news, and recent deals and collaborations.

Currently, ILARIS (canakinumab) (Novartis), GAMIFANT (emapalumab-lzsg) (Sobi), and ACTEMRA (tocilizumab) (Chugai Pharmaceutical and Genentech) are some FDA-approved products for treating sJIA. The drug chapter also helps understand the sJIA clinical trial details, expressive pharmacological action, agreements and collaborations, approval, and patent details, and the latest news and press releases.

Marketed Drugs

ILARIS (canakinumab): Novartis

ILARIS (canakinumab) is a human monoclonal antibody that selectively targets interleukin-1B (IL-1B), a key cytokine involved in the inflammatory cascade. It is approved by the US FDA in May 2013 for the treatment of systemic juvenile idiopathic arthritis (sJIA) in patients aged 2 years and older.

ILARIS works by neutralizing IL-1B activity, thereby reducing systemic and joint inflammation. Administered subcutaneously once every four weeks, ILARIS offers a convenient dosing regimen and is particularly beneficial for patients who are refractory or intolerant to conventional therapies.

GAMIFANT (emapalumab-lzsg): Sobi

GAMIFANT (emapalumab-lzsg), is the only approved anti-interferon gamma (IFNY) monoclonal antibody. GAMIFANT works by binding to and neutralizing IFNY. When IFNY is secreted in an uncontrolled manner, hyperinflammation occurs within the body. GAMIFANT is indicated for administration through intravenous infusion over one hour.

In June 2025, Sobi announced that FDA has granted the approval to GAMIFANT for treatment of adult and pediatric patients with hemophagocytic lymphohistiocytosis (HLH)/macrophage activation syndrome (MAS) in known or suspected Still's disease, including systemic Juvenile Idiopathic Arthritis (sJIA).

Emerging Therapies

LY3009104 (baricitinib): Eli Lilly

LY3009104 is an investigational drug for the treatment of children and adolescents with systemic juvenile idiopathic arthritis (sJIA). It works by selectively inhibiting the enzymes JAK1 and JAK2, which are involved in transmitting inflammatory signals from cytokines like interleukin-6 (IL-6). By blocking these enzymes, baricitinib reduces activation of the JAK-STAT pathway, helping to control inflammation and modulate an overactive immune response. This mechanism helps to control immune-mediated sJIA by attenuating excessive inflammatory responses and modulating immune system activity. Currently, the drug is being evaluated in Phase III clinical trial (NCT04088396). While there is not much update on Eli Lilly's clinical developmental pipeline.

101-PCG-005: PIF Partners

101-PCG-005 is a novel Type IA prodrug of dexamethasone that targets CD206+ macrophage, which are implicated in the inflammatory cascade in sJIA.

In December 2024, the US FDA granted Rare Pediatric Disease Designation (RPDD) to 101-PGC-005 for the treatment of systemic juvenile idiopathic arthritis (sJIA) flares. While there is no further updates on the therapy post December 2024.

Drug Class Insight

Interleukin-1 beta (IL-1B) inhibitor

Interleukin-1 beta (IL-1B) inhibitors are therapies that block the activity of IL-1B, a pro-inflammatory cytokine central to many diseases. These inhibitors reduce inflammation by targeting conditions where IL-1B plays a significant role, such as autoimmune and autoinflammatory disorders. In systemic juvenile idiopathic arthritis (sJIA), IL-1B drives systemic inflammation and joint involvement. Blocking IL-1B rapidly decreases fever, rash, and inflammation, promoting remission and reducing reliance on steroids. Early treatment can modify disease progression and improve long-term outcomes. However, the effectiveness varies based on factors like disease duration, age at onset, number of affected joints, and inflammatory markers. IL-1B inhibitors are also important in managing macrophage activation syndrome, a serious sJIA complication. Overall, IL-1B inhibition is a cornerstone of sJIA therapy due to its key role in disease pathogenesis.

Systemic Juvenile Idiopathic Arthritis (sJIA) Market Outlook

The treatment of systemic juvenile idiopathic arthritis is personalized based on disease severity, joint involvement, and additional conditions, as well as patient and family preferences. Management of sJIA primarily focuses at reducing inflammation, relieving symptoms, and preventing complications. SJIA treatment may include NSAIDs such as ibuprofen, csDMARDs (methotrexate), and in some cases, biologic drugs. In the past, high-dose glucocorticoids were the first choice for the treatment of sJIA to suppress the cytokine storm. Recently, treatment strategies such as targeted therapy and early aggressive use of biologics have been available for these patients and have improved outcomes for patients with sJIA.

Several FDA-approved medications are available for treating systemic juvenile idiopathic arthritis (sJIA), including ILRIS (canakinumab), GAMIFANT (emapalumab-lzsg), and ACTEMRA (tocilizumab).

The developmental pipeline of sJIA remains notably limited, comprising only a few therapeutic candidates currently under investigation, including LY3009104 (Eli Lilly), KEVZARA (sarilumab) (Sanofi), and 101-PCG-005 (PIF Partner). Among these, LY3009104 is the first investigational oral therapy in this area, which is expected to represent a potential paradigm shift from currently approved treatments, which are mostly injectable biologic therapies. However, there are limited updates about LY3009104 on Eli Lilly's clinical development pipeline.

KEVZARA is currently an effective treatment option for several diseases. If it continues to demonstrate similar results in patients with systemic juvenile idiopathic arthritis, it may capture significant market share in near future.

Furthermore, 101-PCG-005 has received Rare Pediatric Disease Designation (RPDD) from FDA for treatment of sJIA. However, since December 2024, there have been no further updates on the clinical progress or regulatory milestones of the therapy, which creates uncertainty about its future availability for sJIA patients.

Systemic Juvenile Idiopathic Arthritis (sJIA) Drugs Uptake

This section focuses on the uptake rate of potential drugs expected to be launched in the market during 2025-2034. The landscape of sJIA treatment has experienced a profound transformation with the uptake of novel medicines. These innovative therapies are redefining standards of care.

Systemic Juvenile Idiopathic Arthritis (sJIA) Pipeline Development Activities

The report provides insights into different therapeutic candidates in Phase III, Phase II, and Phase I/II stage. It also analyzes key players involved in developing targeted therapeutics.

Pipeline Development Activities

The report covers detailed information on collaborations, acquisitions and mergers, licensing, and patent details for sJIA emerging therapies.

KOL- Views

To keep up with current market trends, we take KOLs and SMEs' opinions working in the domain through primary research to fill the data gaps and validate our secondary research. Some of the leaders like MD, Professors, Directors, PhD, and others. Their opinion helps to understand and validate current and emerging therapies and treatment patterns or sJIA market trends. This will support the clients in potential upcoming novel treatments by identifying the overall scenario of the market and the unmet needs.

DelveInsight's analysts connected with 15+ KOLs to gather insights; however, interviews were conducted with 5+ KOLs in the 7MM. Centers such as the University of Florida, Great Ormond Street Hospital for Children NHS Foundation Trust etc. were contacted. Their opinion helps understand and validate sJIA epidemiology and market trends.

Qualitative Analysis

We perform qualitative and market intelligence analysis using various approaches, such as SWOT and conjoint analysis. In the SWOT analysis, strengths, weaknesses, opportunities, and threats in terms of disease diagnosis, patient awareness, patient burden, competitive landscape, cost-effectiveness, and geographical accessibility of therapies are provided. These pointers are based on the Analyst's discretion and assessment of the patient burden, cost analysis, and existing and evolving treatment landscape.

Conjoint Analysis analyzes multiple approved and emerging therapies based on relevant attributes such as safety, efficacy, frequency of administration, designation, route of administration, and order of entry. Scoring is given based on these parameters to analyze the effectiveness of therapy.

The analyst analyzes multiple emerging therapies based on relevant attributes such as safety, efficacy, frequency of administration, route of administration, and order of entry.

In efficacy, the trial's primary and secondary outcome measures are evaluated.

Further, the therapies' safety is evaluated wherein the acceptability, tolerability, and adverse events are majorly observed, and it sets a clear understanding of the side effects posed by the drug in the trials.

Market Access and Reimbursement

Reimbursement may be referred to as the negotiation of a price between a manufacturer and a payer that allows the manufacturer access to the market. It is provided to reduce the high costs and make the essential drugs affordable. Health technology assessment (HTA) plays an important role in reimbursement decision-making and recommending the use of a drug. These recommendations vary widely throughout the seven major markets, even for the same drug. In the US healthcare system, both Public and Private health insurance coverage are included. Also, Medicare and Medicaid are the largest government-funded programs in the US. The major healthcare programs, including Medicare, Medicaid, Health Insurance Program (CHIP), and the state and federal health insurance marketplaces, are overseen by the Centers for Medicare & Medicaid Services (CMS). Other than these, Pharmacy Benefit Managers (PBMs) and third-party organizations that provide services and educational programs to aid patients are also present.

The report further provides detailed insights on the country-wise accessibility and reimbursement scenarios, cost-effectiveness scenario of currently used therapies, programs making accessibility easier and out-of-pocket costs more affordable, insights on patients insured under federal or state government prescription drug programs, etc.

Scope of the Report:

• The report covers a descriptive overview of sJIA, explaining its causes, signs and symptoms, pathogenesis, and currently available therapies.
• Comprehensive insight has been provided into sJIA epidemiology and treatment.
• Additionally, an all-inclusive account of both the current and emerging therapies for sJIA is provided, along with the assessment of new therapies, which will have an impact on the current treatment landscape.
• A detailed review of the sJIA market; historical and forecasted is included in the report, covering the 7MM drug outreach.
• The report provides an edge while developing business strategies, by understanding trends shaping and driving the 7MM sJIA market.

Systemic Juvenile Idiopathic Arthritis (sJIA) Report Insights

Systemic Juvenile Idiopathic Arthritis (sJIA) Report Insights

• Patient Population
• Therapeutic Approaches
• sJIA Pipeline Analysis
• sJIA Market Size and Trends
• Market Opportunities
• Impact of Upcoming Therapies

Systemic Juvenile Idiopathic Arthritis (sJIA) Report Key Strengths

• Ten Years Forecast
• 7MM Coverage
• sJIA Epidemiology Segmentation
• Key Cross Competition
• Highly Analyzed Market
• Drugs Uptake

Systemic Juvenile Idiopathic Arthritis (sJIA) Report Assessment

• Current Treatment Practices
• Unmet Needs
• Pipeline Product Profiles
• Market Attractiveness
• Qualitative Analysis (SWOT and Conjoint Analysis)

FAQs:

• What was the sJIA market share (%) distribution in 2020 and what it would look like in 2034?
• What would be the sJIA total market size as well as market size by therapies across the 7MM during the study period (2020-2034)?
• What are the key findings about the market across the 7MM and which country will have the largest sJIA market size during the study period (2020-2034)?
• At what CAGR, the sJIA market is expected to grow at the 7MM level during the study period (2020-2034)?
• What would be the sJIA market growth till 2034?
• What are the disease risks, burdens, and unmet needs of sJIA?
• What is the historical sJIA patient pool in the United States, EU4 (Germany, France, Italy, and Spain), and the UK, and Japan?
• What will be the growth opportunities across the 7MM concerning the patient population of sJIA?
• Amon the 7MM which country would have the most prevalent cases of sJIA?
• At what CAGR the population is expected to grow across the 7MM during the study period (2020-2034)?
• How many companies are developing therapies for the treatment of sJIA?
• How many emerging therapies are in the mid-stage and late stage of development for the treatment of sJIA?
• What are the key collaborations (industry-industry, industry-academia), Mergers and acquisitions, and licensing activities related to sJIA therapies?
• What are the recent novel therapies, targets, mechanisms of action, and technologies developed to overcome the limitations of existing therapies?
• What are the key designations that have been granted for the emerging therapies for sJIA?
• What are the 7MM historical and forecasted market of sJIA?

Reasons to buy:

• The report will help in developing business strategies by understanding trends shaping and driving the sJIA market.
• To understand the future market competition in the sJIA market and insightful review of the SWOT analysis of sJIA.
• Organize sales and marketing efforts by identifying the best opportunities for sJIA in the US, EU4 (Germany, France, Italy, and Spain), the United Kingdom, and Japan.
• Identification of strong upcoming players in the market will help in devising strategies that will help in getting ahead of competitors.
• Organize sales and marketing efforts by identifying the best opportunities for the sJIA market.
• To understand the future market competition in the sJIA.