Sarilumab 150 mg subcutaneous (SC) injection every week (or every other week in case of safety issue) for 260 weeks, or until commercially available, or until discontinuation of the project, whichever came first.

Pharmaceutical form: solution for injection

Route of administration: subcutaneous

An adverse event (AE) was any untoward medical occurrence in a participant or clinical investigation participant administered a pharmaceutical product, regardless of the relationship to the investigational medicinal product (IMP). SAE was any untoward medical occurrence that at any dose resulted in death or was life-threatening or required inpatient hospitalization or prolongation of existing hospitalization or resulted in persistent or significant disability/incapacity or was a congenital anomaly/birth defect or was a medically important event. TEAEs were AEs that developed or worsened or became serious during the TEAE period (time from first dose of IMP up to the end of follow-up period).

Treatment response for ASAS20 was defined as: Improvement of ≥ 20% and ≥ 1 unit on a 0 (least) to 10 (worst) numerical rating score (NRS) in at least 3 of the 4 ASAS improvement criteria (ASASIC) domains, and no worsening of ≥ 20% and ≥ 1 unit on 0-10 NRS in the remaining domain. The 4 domains included were participant's global disease activity assessment, total back pain, physical function (Bath Ankylosing Spondylitis Functional Index), and Inflammation (mean of last 2 Bath Ankylosing Spondylitis Disease Activity Index questions on morning stiffness).

Sarilumab 150 mg SC injection every week (or every other week in case of safety issue) for 260 weeks, or until commercially available, or until discontinuation of the project, whichever came first.

An adverse event (AE) was any untoward medical occurrence in a participant or clinical investigation participant administered a pharmaceutical product, regardless of the relationship to the investigational medicinal product (IMP). SAE was any untoward medical occurrence that at any dose resulted in death or was life-threatening or required inpatient hospitalization or prolongation of existing hospitalization or resulted in persistent or significant disability/incapacity or was a congenital anomaly/birth defect or was a medically important event. TEAEs were AEs that developed or worsened or became serious during the TEAE period (time from first dose of IMP up to the end of follow-up period).

Analysis was performed on safety population defined as all participants who received at least one dose of the study treatment after signature of the informed consent.

Sarilumab 150 mg SC injection every week (or every other week in case of safety issue) for 260 weeks, or until commercially available, or until discontinuation of the project, whichever came first.