This study will investigate the clinical efficacy, safety, pharmacokinetics (PK) and pharmacodynamics (PD) of ACZ885, administered intravenously and subcutaneously to patients with NALP3 mutations whose clinical symptoms are either untreated or insufficiently treated and require medical intervention.

Inclusion Criteria:

• Patients aged 4 to 75 years (inclusive)
• Body weight ≥ 12 kg and < 100 kg.
• Females of child-bearing potential must have a negative pregnancy test. Additional birth control details to be provided at screening.
• Documented molecular diagnosis of NALP3 mutations and clinical symptoms that are either untreated or insufficiently treated and require medical intervention.
• Patients under anakinra therapy or any other IL-1 blocking therapy, whose clinical symptoms improved under treatment and are willing to discontinue that therapy until a relapse becomes evident.
• Patients with a very severe characteristics requiring oral prednisone are eligible if the dose is stable (≤ 0.4 mg/kg/day or ≤ 20 mg/day, whichever is lower) for at least 1 week prior to the screening visit. Steroid therapy may be tapered during treatment with ACZ885 at the discretion of the investigator.
• Parents' or legal guardian's written informed consent (patient's informed consent for ≥ 18 years of age) and child's assent, if appropriate, are required prior to study participation.

Exclusion Criteria:

• Participation in any clinical trial investigation (except trials with anakinra) within 4 weeks prior to dosing or longer per local regulation

• Antiinflammatory therapy with colchicine, chlorambucil, dapsone, azathioprine, mycophenolate mofetil, within 3 weeks prior to dosing. Therapeutic antibodies (e.g. anti-TNF-alpha antibodies) must be discontinued at least 60 days before dosing.

• Donation or loss of 400 mL or more of blood within 8 weeks prior to dosing.

• A past personal or close family medical history of clinically significant ECG abnormalities or prolonged QT-interval syndrome.

• History of

  • Immunocompromise, including a positive HIV result.
  • Positive Hepatitis B surface antigen or Hepatitis C test result.
  • Drug or alcohol abuse within the 12 months prior to dosing.
  • Tuberculosis.
  • Renal transplant.
  • Evidence of lymphoma.

• Active medical condition preventing participation in the study such as infection, poorly controlled diabetes etc.

• No live vaccinations within 3 months prior to the start of the trial, during the trial, and up to 3 months following the last dose.