Impact of baseline B cells and IgG on efficacy and safety over the entire treatment period (mITT population)
| Biomarker | Number of SRI-4 responses* | Number of serious/severe infections* |
| B cells (CD19+) | 1.13 (1.03 to 1.23)† | 0.85 (0.63 to 1.15) |
| B cells (CD20+) | 1.13 (1.03 to 1.23)† | 0.71 (0.50 to 1.00) |
| Naïve B cells (CD19+/CD20+/CD27−) | 1.10 (1.01 to 1.21)† | 0.81 (0.61 to 1.07) |
| Memory B cells (CD19+/CD20+/CD27+) | 1.09 (1.00 to 1.18) | 1.00 (0.70 to 1.44) |
| Activated B cells (CD20+/CD69+) | 1.00 (0.92 to 1.09) | 1.06 (0.77 to 1.48) |
| Plasmacytoid B cells (CD19+/CD20+/CD138+) | 1.07 (0.98 to 1.17) | 1.21 (0.86 to 1.69) |
| SLE subset plasma cells (CD19+/CD27bright+/CD38bright+) | 0.86 (0.79 to 0.95)† | 0.97 (0.73 to 1.28) |
| Short-lived plasma B cells (CD19+/CD20−/CD27bright+) | 0.88 (0.80 to 0.96)† | 0.82 (0.57 to 1.17) |
| Plasma B cells (CD19+/CD20−/CD138+) | 0.93 (0.85 to 1.01) | 1.23 (0.81 to 1.87) |
| IgG | 1.01 (0.93 to 1.10) | 1.75 (1.24 to 2.46)† |
Rate ratios are calculated from a negative binomial regression model with offset log of follow-up time that includes terms for age, body mass index, baseline SLEDAI, baseline immunosuppressant use, treatment group and baseline biomarker tertile.
Tertile definitions are shown in online supplemental table S1.
*Rate ratio per tertile increase and 95% CIs based on baseline biomarker tertile.
†Statistical significance at 0.05 level.
CD, cluster of differentiation; mITT, modified intent-to-treat; SLEDAI, SLE Disease Activity Index; SRI, SLE Responder Index responses.