New biologic shows promise for rare inflammatory disease in japan

Copied word for word from the study's registry entry, so the wording is the study team's rather than ours.

Inclusion Criteria: * Signed informed consent had to be obtained prior to participation in the study. Parent's or legal guardian's written informed consent and child's assent, if appropriate, were required before any assessment was performed for participants \< 20 years of age. * Japanese male and female participants aged ≥ 16 years were eligible. * Diagnosis of AOSD had to be confirmed as per Yamaguchi criteria, with disease onset at ≥ 16 years of age. The Yamaguchi criteria required at least five criteria, including two major criteria and no exclusion criteria. * Participants had to have active disease at baseline, defined as follows: * Fever (body temperature \> 38°C) due to AOSD for at least 1 day within 1 week before baseline * At least 2 active joints (tender or swollen) * CRP ≥ 10 mg/L Exclusion Criteria: * Pregnant or nursing (lactating) female participants were excluded. Pregnancy was defined as the state of a female after conception and until the termination of gestation, confirmed by a positive hCG laboratory test (\> 5 mIU/mL) at the screening visit. * Participants with a history of significant hypersensitivity to the study drug or to biologics were excluded. * Participants with a history or evidence of active macrophage activation syndrome or disseminated intravascular coagulation within 6 months prior to enrollment were excluded. * Participants with underlying metabolic, renal, hepatic, infectious, or gastrointestinal conditions that, in the opinion of the investigator, compromised the participant and/or placed the participant at unacceptable risk for participation in immunomodulatory therapy were excluded. * Participants with active or recurrent bacterial, fungal, or viral infections at the time of enrollment, including evidence of HIV infection, Hepatitis B, or Hepatitis C, were excluded. * Participants with an absolute neutrophil count \< 1500/mm³ at screening were excluded.