[{"id":"mobility-acr20","name":"ACR20 at Week 24","type":"CO_PRIMARY","unit":"%","results":[{"value":66,"arm_id":"sarilumab-200-mobility","p_value":"<0.0001","arm_name":"Sarilumab 200mg"},{"value":33,"arm_id":"placebo-mobility","arm_name":"Placebo + MTX"}],"timepoint":"Week 24","description":"≥20% improvement in ACR criteria (tender/swollen joints + 3 of 5 measures). Standard RA efficacy measure."},{"id":"mobility-haq","name":"Change in HAQ-DI at Week 16","type":"CO_PRIMARY","unit":"points","results":[{"notes":"Difference vs placebo: -0.25","value":-0.53,"arm_id":"sarilumab-200-mobility","p_value":"<0.0001","arm_name":"Sarilumab 200mg"},{"value":-0.29,"arm_id":"placebo-mobility","arm_name":"Placebo"}],"timepoint":"Week 16","description":"Physical function improvement. MCID = 0.22."},{"id":"mobility-structural","name":"Change in mTSS at Week 52","type":"CO_PRIMARY","unit":"points","results":[{"notes":"91% less joint destruction vs placebo (0.25 vs 2.78)","value":0.25,"arm_id":"sarilumab-200-mobility","p_value":"<0.0001","arm_name":"Sarilumab 200mg"},{"value":2.78,"arm_id":"placebo-mobility","arm_name":"Placebo"}],"timepoint":"Week 52","description":"Radiographic joint damage. Lower = less destruction. Shows whether drug prevents permanent joint damage."}]

Met all 3 co-primary endpoints: ACR20 66% vs 33% (p<0.0001), HAQ-DI improvement (p<0.0001), 91% less radiographic progression (mTSS 0.25 vs 2.78, p<0.0001).

MOBILITY (n=1197, 52 weeks): Infections 40% vs 32%, neutropenia 6.4% vs 0.8%, ALT>3xULN 4.3% vs 1.5%. IL-6R class effects.

MOBILITY: 66% ACR20 and 91% less joint damage. Works well but entered a crowded RA market. Structural protection data is the standout.

IL-6 drives RA joint inflammation and destruction. Sarilumab is fully human anti-IL-6Rα.