Population-based blood concentration ranges that are associated with clinical response, per biopharmaceutical and disease
| Drug | Rheumatoid arthritis | Axial spondyloarthritis | Psoriatic arthritis |
| ADA | ~>8 µg/mL: remission (DAS-28 <2.6) ~>2 µg/mL: LDA (DAS-28 <3.2) <1 µg/mL: no response Range: 2–8 µg/mL11 52–56 66 77 87 88 93 | ~8 µg/mL: major improvement (ΔASDAS ≥2.0) ~5 µg/mL: low disease activity ~2.5 µg/mL: clinical improvement (ΔASDAS ≥1.1) Range: 2.5–8.0 µg/mL9 63–65 95 | >1 µg/mL: clinical efficacy* >4 µg/mL: optimal efficacy* Range: 1–8 µg/mL75 96 |
| ETN | Range: inconclusive53 54 56 82 89 93 | Range: inconclusive67 | Range: inconclusive75 |
| IFX | Induction phase (week 6): ≥2.5 µg/mL: response Maintenance phase: >1 µg/mL: LDA (DAS-28 <3.2) Range: inconclusive 47 56 68 75 84 90 93 | No data | No data |
| GLM | Range: >1 µg/mL80 | 0.7–1.4 µg/mL: clinical improvement (ΔASDAS ≥1.1) Range: >1 µg/mL12 80 | Range: >1 µg/mL80 |
| CZP | 23–28 µg/mL: remission (DAS-28 <2.3) Range: 20–39.9 µg/mL (largest improvement in DAS-28)76 91 92 | Range: 20–39.9 µg/mL (largest improvement in ASDAS)76 | Range: 20–39.9 µg/mL (largest improvement in DAS-28)76 |
| TCZ | Intravenous: >1 µg/mL: DAS-28 ≥1.2 improvement Range: >1 µg/mL6 Subcutaneous: range: inconclusive94 | NA | NA |
DAS-28: either erythrocyte sedimentation rate or C reactive protein.
*No clear definition of clinical or optimal efficacy with regard to disease activity measurement outcome.
.ADA, adalimumab; ASDAS, Ankylosing Spondylitis Disease Activity Score; CZP, certolizumab pegol; DAS-28, Disease Activity Score in 28 Joints; ETN, etanercept; GLM, golimumab; IFX, infliximab; LDA, low disease activity; NA, not applicable; TCZ, tocilizumab.