Table 2.
Comparisons of baseline characteristics and therapeutic response between TCZ monotherapy patients and combination therapy patients
| CDAI50 respondersa | |||
|---|---|---|---|
| TCZ monotherapy (n = 154) | TCZ + MTX (n = 174) | OR (95% CI)b | |
| Baseline characteristics | |||
| Age, years, mean (95% CI) | 66.6 (64.6, 68.6) | 58.9 (56.9, 60.9) | 1.05 (1.03, 1.07) |
| Male/female | 28/126 | 33/141 | 0.95 (0.54, 1.66) |
| RA duration, months, mean (95% CI) | 114.1 (95.0, 133.2) | 104.5 (89.8, 119.1) | 1.00 (0.99, 1.01) |
| Radiographic stages III/IV, number (%) | 90 (58.4) | 102 (58.0) | 1.02 (0.66, 1.58) |
| Anti-CCP (+), number (%) | 137 (89.0) | 151 (86.8) | 1.23 (0.63, 2.39) |
| CDAI at the start of TCZ treatment, mean (95% CI) | 27.5 (25.5, 29.4) | 24.6 (23.0, 26.3) | 1.02 (1.00, 1.04) |
| High CDAI (CDAI > 22), number (%) | 92 (59.7) | 88 (50.6) | 1.45 (0.94, 2.25) |
| Failure of previous RA treatmentc, number (%) | 104 (67.5) | 136 (78.2) | 0.58 (0.36, 0.95) |
| Previous use of biological DMARDs, number (%) | 63 (40.9) | 113 (64.9) | 0.37 (0.24, 0.59) |
| Concurrent use of other csDMARDsd, number (%) | 50 (32.5) | 43 (24.7) | 1.47 (0.90, 2.37) |
| Concurrent use of prednisolone, number (%) | 63 (40.9) | 72 (41.4) | 0.98 (0.63, 1.52) |
| Hypertension, number (%) | 61 (39.6) | 55 (31.6) | 1.42 (0.90, 2.24) |
| Type 2 diabetes, number (%) | 27 (17.5) | 22 (12.6) | 1.47 (0.80, 2.70) |
| CKD, number (%) | 42 (27.3) | 19 (10.9) | 3.06 (1.69, 5.54) |
| BMI, mean (95% CI) | 22.2 (21.6, 22.7) | 22.5 (21.8, 23.2) | 0.98 (0.93, 1.03) |
| Year of TCZ initiation (since 2012), number (%) | 109 (70.8) | 87 (50.0) | 2.42 (1.53, 3.83) |
| CDAI at 6 months, mean (95% CI) | 7.9 (6.9, 8.8) | 8.0 (6.9, 9.1) | 1.00 (0.97, 1.03) |
| High and moderate CDAI (CDAI > 10), number (%) | 42 (27.3) | 48 (27.6) | 0.95 (0.61, 1.60) |
| Remission (CDAI ≤ 2.8), number (%) | 34 (22.1) | 40 (23.0) | 0.95 (0.57, 1.60) |
| MCID-based CDAI improvement, number (%) | 139 (90.3) | 148 (85.1) | 1.63 (0.83, 3.20) |
| CDAI at 12 months of TCZ treatment, mean (95% CI) | 5.2 (4.5, 5.8) | 4.9 (4.4, 5.5) | 1.02 (0.96, 1.08) |
| High and moderate CDAI (CDAI > 10), number (%) | 14 (9.1) | 12 (6.9) | 1.35 (0.60, 3.02) |
| Remission (CDAI ≤ 2.8), number (%) | 49 (31.8) | 58 (33.3) | 0.93 (0.56, 1.48) |
| MCID-based CDAI improvement, number (%) | 154 (100) | 171 (98.3) | — |
aCDAI50 responders were defined as patients who had achieved and maintained a CDAI50 response during the first 12 months of TCZ treatment.
bORs (95% CI) are presented for monotherapy patients compared with combination therapy patients based on binominal logistic regression analysis. For continuous data, ORs are shown per 1 year more of age, 1 month more of RA duration, 1 mg more of MTX or prednisolone, 1 unit more for CDAI values and 1 unit more of BMI.
cPrevious RA treatment includes treatment with biologics and/or MTX.
dOther csDMARDs included tacrolimus, salazosulfapyridine, bucillamine and mizoribine. No patients used leflunomide or targeted synthetic DMARDs.
CDAI: clinical disease activity index; CKD: chronic kidney disease; MCID: minimum clinically important difference; TCZ: tocilizumab; DMARDs: disease-modifying antirheumatic drugs; OR: odds ratio.