Ilaris® Effects in Schnitzler Syndrome (ILESCH)

Inclusion Criteria: * Adults (18 years or older) * Informed consent signed and dated * Able to read, understand and willing to sign the informed consent form and abide with study procedures * SchS diagnosis based on diagnostic criteria defined in Appendix * Patients with symptomatic Schnitzler syndrome \[SchS\] (as defined by the physician's global assessment with a minimum score of 8 and C-reactive protein \[CRP\] \> upper limit of normal \[ULN\]) * Willing, committed and able to return for all clinic visits and complete all study-related procedures, including willingness to have subcutaneous injections administered by a qualified person * In females of childbearing potential: Negative pregnancy test; females willing to use highly effective contraception (Pearl-Index \< 1). A woman will be considered not of childbearing potential if she is post-menopausal for greater than two years or surgically sterile (bilateral tubal ligation, bilateral oophorectomy or hysterectomy) * Subjects are considered eligible, if they meet the following tuberculosis \[TB\] screening criteria: no history of latent or active TB prior to screening, no signs or symptoms suggestive of active TB, no recent close contacts with a person with active TB, and negative QuantiFERON-TB test at screening (if QuantiFERON-TB test is positive, the patient can only be included if active TB is ruled out with appropriate measurements according to standard of care) * No participation in other clinical trials 4 weeks before and after participation in this study Exclusion Criteria: * Concurrent/ongoing treatment with anakinra (Kineret®) or recent treatment within 48 hours prior to day 0 * Concurrent/ongoing treatment with other biologics or recent treatment (less than 5 half lives) * Concurrent/ongoing treatment with immunosuppressives (e.g. cyclosporine, methotrexate, dapsone or others) within 4 weeks or 5 half lives prior to day 0, whichever is longer * Concurrent/ongoing treatment with high doses of systemic steroids (\>20mg prednisolone equivalent) * Evidence of recurrent or latent systemic infection such as TB * Significant medical condition rendering the patient immunocompromised or not suitable for a clinical trial * Treatment with a live (attenuated) virus vaccine during three months prior to day 0 and for 3 months after end of study * Evidence of tuberculosis as defined by local guidelines/ local medical practice (at screening) * An abnormal chest radiograph consistent with clinical signs of prior or present tuberculosis infection whether or not previously treated with anti-tuberculosis agents * A history of listeriosis, active persistent chronic or active infection(s) requiring treatment with parenteral antibiotics, parenteral antivirals, or parenteral antifungals within four weeks prior to day 0 * Significant concomitant illness that would adversely affect the subject's participation or evaluation in this study * Evidence of current HIV, active hepatitis B, or hepatitis C infection by serological screening * History of malignancies within five years prior to screening other than a successfully treated non-metastatic cutaneous, basal, or squamous cell carcinoma and/or in situ cancer * Presence of any of the following laboratory abnormalities at enrollment visit: creatinine \>2.0 x ULN, WBC \<3000/µl; platelet count \<100000/µl ; alanine aminotransferase \[ALT\] or aspartate aminotransferase \[AST\] \>3.0 x ULN * Lactating females or pregnant females * Subjects for whom there is concern about compliance with the protocol procedures * Any medical condition which, in the opinion of the Investigator, would interfere with participation in the study or place the subject at risk * History of substance abuse (drug or alcohol) or any other factor (e.g., serious psychiatric condition) within the last 5 years that could limit the subject's ability to comply with study procedures * Subjects who are detained officially or legally to an official institute