A Phase II Trial to Evaluate the Clinical Efficacy, Safety and Tolerability of MAS825 in Pediatric and Adult Participants With Still's Disease

What this study involves

The registry says this study is recruiting. Individual locations may have different availability.

Study type

Interventional

Phase

Phase 2

Age range

1 years - Not specified

Sex eligible

All sexes

Healthy volunteers

Not accepted

Participants

30 Estimated

These are starting points, not an eligibility decision. The research team must review the full requirements.

About the research

The study is a phase II trial designed to evaluate the clinical efficacy, safety, and tolerability of MAS825 (arumakimig) in pediatric and adult participants with Still's disease

Who may be able to participate?

The list below is the sponsor’s full registry wording. It can include conditions, prior treatment, test results and other requirements. A match in search does not mean you qualify.

Inclusion Criteria:

• Age ≥ 1 with a diagnosis of Still's Disease
• Active diseases defined as:
• CRP or ferritin levels greater than ULN, and any of:

• Fever ≥ 38°C attributed to Still's Disease activity and documented for a number of days prior to Day 1 or
• Rash attributed to Still's Disease activity or
• Musculoskeletal involvement: arthritis in a number of joints per ACP criteria for active joint or
• Serositis or
• Macrophage activation syndrome activity as defined by ferritin levels and at least one of: platelet count, a biomarker or fibrinogen levels attributed to Still's Disease activity by the investigator
• Intolerance or inadequate response to available biologic therapy

Exclusion Criteria:

• Patients out of weight range
• Ongoing or previous treatment with immunomodulatory drugs

• A limited number of Still's Disease patients that have previously received MAS825 through a managed access program are permitted on the study
• Glucocorticoid dose exceeding a set limit
• Any conditions or significant medical problems which places the patient at unacceptable risk for MAS825 therapy

• Still's disease patients with evidence of macrophage activation syndrome are permitted in the study
• Still's Disease patients with evidence of interstitial lung disease including those requiring supplemental oxygen therapy are permitted in the study
• History of ongoing, chronic or possibly recurrent infection (e.g. HIV, TB, HCV, HBV) and/or symptoms and signs of clinically significant active bacterial, fungal or viral infections
• Live vaccinations within a set time prior to MAS825 treatment. Live vaccines are prohibited up to several months following the last dose
• History of malignancy of any organ system, including post-transplant lymphoproliferative disorder, treated or untreated, within a number of years, regardless of whether there is evidence of local recurrence and metastases
• History of hypersensitivity to any of the study drugs or to drugs of similar chemical classes or to any of the excipients
• Pregnant or breastfeeding women
• Women of child-bearing potential who do not agree to comply with required contraceptive use

Other protocol-defined inclusion/exclusion criteria may apply.

Treatment, groups and participation

The registry may describe treatments and study duration without a complete visit calendar. Ask the study team for the exact schedule, procedures, risks, costs and alternatives. Keep your usual care plan unless your treating clinician tells you otherwise.

Assignment

Not applicable

Masking

No masking

What researchers are measuring

Outcome measures describe what is being studied. They are not proof that a treatment works.

Primary measures

Secondary measures

Research locations (24)

The overall study status and a local site’s status can differ. Confirm that location’s availability before traveling.

24 locations

Study team and timeline

Lead sponsor

Novartis Pharmaceuticals

Study start

Nov 3, 2025 Actual

Primary completion

Apr 22, 2027 Estimated

Study completion

May 17, 2028 Estimated

First posted

Oct 2, 2025 Actual

Last updated

Nov 9, 2026 Actual

Official study contacts