Study to Evaluate the Efficacy, Safety and Tolerability of MAS825 in Patients With Monogenic IL-18 Driven Autoinflammatory Diseases, Including NLRC4-GOF, XIAP Deficiency, or CDC42 Mutations

1. History of hypersensitivity to any of the study drugs or to drugs of similar chemical classes or to any of the excipients.

2. Signs and symptoms, in the judgment of the investigator, of clinically significant active bacterial, fungal, parasitic or viral infections, excluding chronic Epstein-Barr Virus (EBV).

\- COVID-19 specific: If in line with health and governmental authority guidance, it is highly recommended that testing to exclude COVID-19 using PCR or comparable approved methodology be completed within 1 week prior to first dosing.

3. Any conditions or significant medical problems, which in the opinion of the investigator places the patient at unacceptable risk for MAS825 therapy

4. Previous treatment with anti-rejection and/or immunomodulatory drugs within the past 28 days or 5 half-lives (whichever is the longer) for immunomodulatory therapeutic antibodies (or as listed in the prohibited medications section) prior to MAS825 treatment with the exceptions of glucocorticoids, cyclosporin and targeted binding or blocking therapies.

5. A positive HIV test result at Screening. Evidence of prior testing within 3 months is sufficient.

6. A positive Hepatitis B surface antigen (HBsAg) or Hepatitis C test result at Screening. Evidence of prior testing within 3 months is sufficient.

7. Presence of tuberculosis infection as defined by a positive TB test at Screening. Evidence of prior testing within 3 months is sufficient.

8. Live vaccinations within 1 month prior to MAS825 treatment, during the trial, and up to 3 months following the last dose.

9. Pregnant or nursing (lactating) females.

10. Female patients of child-bearing potential (or Tanner stage 2 or above) who are or might become sexually active, agree to use highly effective contraceptive methods to prevent pregnancy while on MAS825 therapy

11. Patients weighing \>160 kg at Screening.

12. For CDC42 mutation patients: Takenouchi-Kosaki syndrome - CDC42 mutations associated with a diverse syndrome characterized by variable development delays, cardiac, brain and hematological abnormalities.

What this study is about