Inclusion Criteria:

1. Established diagnosis of Systemic SOJIA according to ILAR criteria for at least six months before the study entry, with inadequate response or intolerance to standard therapy with oral steroids and/or methotrexate, with or without previously used biologic agents.

2. Active disease for at least one month prior to enrolment as defined by the following criteria:

   • Presence of arthritis plus at least one of the following:

     • Fever, defined as a body temperature >= 37,5 C degree at least once a day during at least five consecutive days or presence of typical SOJIA intermittent temperature chart
     • Rash, defined by presence of typical SOJIA salmon pink rash on the trunk and elsewhere during the febrile episodes
     • Serositis (pericarditis, pleuritis, peritonitis) confirmed by ultrasound and/or X-ray exploration or by presence of typical ECG findings in the case of pericarditis
     • Lymphadenopathy, defined by lymph nodes enlargement to 1,5 cm or more localized anywhere within the body, and/or hepatomegaly and/or splenomegaly, confirmed by ultrasound evaluation and established after comparison to age standards for organ size
     • ESR >= 20 mm/h (first hour) and/or CRP >= 10 mg/L. in the absence of arthritis, two definite or one definite and one probable diagnostic criteria plus ESR >=20 mm/h (first hour) and/or CRP >=10 mg/L
3. Age at enrolment between 2 and 25 years
4. Age at first SOJIA diagnosis < 16 years
5. Previously introduced standard treatment of disease with steroids without satisfactory effect and concomitant treatment with oral steroids at a dose equivalent to >= 0,2 mg/kg/day of prednisolone, unmodified for at least four weeks before patient's enrolment
6. In case of concomitant methotrexate treatment, it has to be on stable dose >= 10mg/m2 weekly for al least 4 weeks before pt enrollment

7. Previous treatment with biologics, if any, during at least three months without satisfactory effect or with drug intolerability, discontinued for at least the period specified below before patient's enrolment:

   • Two months for etanercept
   • Six months for infliximab
8. Other disease-modifying anti-rheumatic drugs possibly previously introduced have to be discontinued for a period of at least five half lives
9. Concomitant nonsteroidal anti-inflammatory drugs, if any, on a stable dose for at least four weeks before patient's enrolment
10. Female of childbearing potential, using safe contraceptive measures
11. Signed written informed consent before starting any study procedure

Exclusion Criteria:

1. Ongoing clinical relevant viral infection (eg.: Herpes Zoster, Ebstein barr, CMV, Systemic fungal infections or history of recurrent serious bacterial infection)
2. History of macrophage activation syndrome
3. Clinically significant illness i.e. any condition (including laboratory abnormalities) that in the opinion of the Investigator places the patient to unacceptable risk for adverse outcome if he/she were to participate in the study
4. Psychiatric illness/social situations that would limit compliance with study medication and protocol requirements
5. Congenital heart and/or central nervous system disorders
6. Inherited metabolic diseases
7. Positive serological testing for anti HCV, anti HIV and HBsAg (to be performed at screening)
8. Pregnant or lactating women
9. Presence of malignancy
10. Any previous evidence, irrespective of its severity, of coronary disease, cardiac rhythm abnormalities or congestive heart failure
11. QTc interval > 450 msec at screening evaluation
12. Serum magnesium and potassium below the LLN at screening
13. Unavoidable concomitant treatment with any drug known for potential risk of causing Torsades de Pointes