A steroid-sparing strategy for IgG4-related disease: lenalidomide put to the test

Copied word for word from the study's registry entry, so the wording is the study team's rather than ours.

Inclusion Criteria: 1. Adults aged 18 to 75 years at the time of screening. 2. Diagnosis of IgG4-related disease according to the 2019 American College of Rheumatology/European Alliance of Associations for Rheumatology (ACR/EULAR) classification criteria. 3. Patients with IgG4-related disease who have achieved sustained clinical remission following glucocorticoid therapy. 4. No documented IgG4-related disease relapse within the previous 12 months before screening. 5. IgG4-related disease Responder Index (IgG4-RD RI) score of 0 at screening. 6. Receiving stable low-dose glucocorticoid therapy with prednisone-equivalent dose ≤7.5 mg/day for at least 6 months before randomization. 7. Ability to provide written informed consent and comply with study procedures. Exclusion Criteria: 1. Active IgG4-related disease requiring induction therapy or escalation of immunosuppressive treatment at screening. 2. Previous treatment with lenalidomide or known hypersensitivity to lenalidomide or related compounds. 3. Requirement for prohibited concomitant medications during the study period. 4. Significant uncontrolled infection or active severe infection. 5. Clinically significant hematologic abnormalities, including severe neutropenia or thrombocytopenia. 6. Significant hepatic or renal dysfunction that may affect study participation or drug safety evaluation. 7. History of thromboembolic events or conditions associated with unacceptable thrombotic risk according to investigator assessment. 8. Pregnancy, breastfeeding, or unwillingness to use effective contraception when applicable. 9. Malignancy or other severe medical conditions that may interfere with study participation or outcome assessment. 10. Any condition that, in the investigator's opinion, may compromise participant safety or affect the reliability of study results.