Background Certolizumab pegol (CZP) is a PEGylated Fab' fragment of a humanized anti-TNF antibody and it brings rapid improvement of the signs and symptoms of RA. Musculoskeletal ultrasound (US) has been proved to be useful at assessing synovitis precisely in patients with RA. There are few reports, however, that verify the early response to CZP in RA patients by US. Moreover, it remains to be ascertained whether early US assessment of synovitis can predict future clinical response in treatment with CZP.
Objectives In the present study we investigate whether US is useful for predicting future clinical response to CZP in RA patients.
Methods Twenty patients with RA were treated with subcutaneous CZP 400 mg at weeks 0, 2, 4 followed by 400 mg every 4 weeks or 200 mg every 2 weeks. The mean age of patients was 55.2 years old and the mean disease duration was 5.9 years. The mean disease activity at baseline (week 0) was 4.91 for 28-joint disease activity score (DAS28). Fifteen (75%) patients were naïve to biologic agents. Seventeen (85%) and 9 (36%) patients were treated with methotrexate and glucocorticoids concurrently. At baseline and weeks 2, 4 and 12, US examination was performed at bilateral MCP, PIP, IP, and wrist joints. Gray-scale (GS) and pulse Doppler (PD) signal was recorded in each joint using semi-quantitative score (0 to 3). The sum of these scores obtained from each joint was used as GSUS and PDUS score.
Results At weeks 0, 2, 4, and 12, mean GSUS score was 24.1, 20.4, 17.5, and 16.7, respectively. Mean PDUS score at weeks 0, 2, 4, and 12, was 14.6, 10.8, 10.8, and 9.9, respectively. Both GSUS and PDUS score were improved significantly as early as 2 weeks after treatment (p=0.031 and 0.011) and reduced by degrees during study period. At weeks 0, 4, 8, 12, and 24, mean DAS28 was 4.91, 3.61, 3.55, 3.50, and 3.05, respectively. DAS28 was significantly improved as early as 4 weeks after treatment (p<0.001). Clinical response was evaluated as achievement of DAS remission (DAS <2.6), and we classified 10 patients (50%) who achieved DAS remission at week 24 as “responders”. The improvement in US assessment at week 2 was compared between responders and non-responders. Four patients showed a >50% reduction in PDUS score from baseline (PDUS 50 response) at week 2. At week2, none achieved a >50% reduction of GSUS score from baseline, whereas 8 patients indicated a >20% reduction in GSUS score from baseline (GSUS 20 response) at week 2. There was a marked high responder rate (80%: 4 out of 5) in the patients showing PDUS 50 response at week 2. Similarly, the responder rate (88%: 7 out of 8) of the patients showing GSUS 20 response at week 2 was remarkably high and significantly higher than that (25%: 3 out of 12, p=0.020) of the patients without GSUS 20 response.
Conclusions Early response to CZP was confirmed by US examination and the early assessment of synovitis by US is useful to predict future clinical response to CZP in patients with RA.
Disclosure of Interest None declared