Low-dose Recombinant Human IL-2 for the Treatment of Relapsing Polychondritis

Ten patients with active RP at 18 to 70 years of age were enrolled. Without changing the original treatment plan, IL-2 1 million units was administered subcutaneously five days every week for 4 weeks and then once a week for 8 weeks. The clinical symptoms, disease score scale, laboratory parameters, immune cell subsets and cytokines should be monitored during the treatment.

Inclusion criteria

• Male or female ≥18 and ≤70 years
• Meet the revised Michet criteria
• Patients had an inadequate response to standard treatment for ≥ 4 weeks. The background treatment included corticosteroids (≤0.5 mg/ kg), immunosuppressants ( methotrexate, hydroxychloroquine, azathioprine, mycophenolate mofetil leflunomide, or cyclophosphamide)
• Negative urine pregnancy test
• Written informed consent form

Exclusion criteria

• Any subject who meets any of the following criteria shall be excluded:

• Use rituximab or other monoclonal antibodies within 1.6 months.
• 1 months after treatment with high dose glucocorticoid (> 1 mg/kg/d).
• Serious complications: heart failure (≥ New York Heart Association（NYHA） III grade), renal insufficiency (creatinine clearance rate ≤ 30 ml/min), liver function insufficiency (serum alanine transaminase or glutamic-pyruvic transaminaseT > 3 times normal upper limit, or total bilirubin > normal upper limit)
• Other serious, progressive or uncontrollable hematological, gastrointestinal, endocrine, lung, heart, nerve, or brain diseases (including demyelination diseases, such as multiple sclerosis).
• Known allergies, hyperresponsiveness or IL-2 or its excipients are intolerant.
• Severe infections (including, but not limited to, hepatitis, pneumonia, bacteremia, pyelonephritis, Epstein-Barr virus, tuberculosis infection), hospitalization for infection, or intravenous antibiotics 2 months before the first dose of treatment.
• Chest imaging showed abnormalities in malignant tumors or current active infections (including tuberculosis) within 3 months before the first use of the study.
• Infected with HIV (HIV antibody positive serology) or hepatitis C (Hep C antibody positive serology). If seropositive, consult a doctor with expertise in the treatment of HIV or hepatitis C virus infection.
• There has been any known malignant tumor or history of malignant tumor in the past 5 years (with the exception of non-melanoma skin cancer, non-melanoma skin cancer with no sign of recurrence or surgically cured cervical tumor within 3 months of use of the first study preparation).
• There are uncontrolled mental or emotional disorders, including a history of drug and alcohol abuse over the past three years, which may hinder the successful completion of the study.
• Within 3 months before the first injection of the research agent, during the study period or within 4 months after the last injection of the research agent, any live virus or bacterial vaccine is received or expected to be received. Bacillus Calmette-Guerin was vaccinated within 12 months after screening.
• Pregnant and lactating women (WCBP) are reluctant to use medically approved contraceptives during and 12 months after treatment.
• Men whose partners have fertility potential but do not want to use appropriate medically approved contraceptives during and within 12 months of treatment.