Generalized estimating equation model to compare drug effects on synovitis of the dominant wrist in severe rheumatoid arthritis between tocilizumab versus adalimumab versus abatacept using high‐resolution ultrasound

Purpose The use of biological agents has revolutionized the treatment of rheumatoid arthritis (RA). However, details of serial synovial changes in imaging evaluation are unclear. Using power Doppler (PD) ultrasound, this study aimed to evaluate the comparative efficacy of biologicals for patients with refractory RA, with the hope that these findings could aid in clinical decision making. Methods Patients with RA who received abatacept, adalimumab or tocilizumab therapy were enrolled. All underwent gray scale synovial hypertrophy and PD assessments of the dominant wrist (dorsal aspect) at baseline and at 1, 3 and 6 months after therapy. A generalized estimating equation model was used to compare efficacy among the three drugs. Results Of the 103 patients enrolled, 32 received adalimumab, 38 abatacept and 33 tocilizumab. There were no significant differences in age or sex among the three groups. All had a treatment response according to gray scale (P = 0.000) and PD (P = 0.001) synovitis scores. The tocilizumab group had a significantly lower synovial hypertrophy score at 6 months (P = 0.006), and the adalimumab group also had a lower score although without statistical significance (P = 0.043). The adalimumab group had a lower PD score than the other two groups (P < 0.05). Conclusion In a 6-month head-to-head comparison of patients with RA, tocilizumab and adalimumab had a greater effect on reducing synovial hypertrophy, while adalimumab had a greater effect in controlling inflammation in PD.