Abstract
Objectives
Interventions aimed at increasing tumour-necrosis factor-alpha inhibitor serum drug levels (SDLs) may improve treatment response; however, previous studies suggesting SDL cut-offs have not accounted for treatment adherence. The aim of this study was to establish the relationship between Adalimumab/Certolizumab SDLs and EULAR good vs non/moderate response, and to define SDL cut-offs associated with good response in fully adherent patients.
Methods
In a prospective observational study, 475 patients with RA were treated with Certolizumab (n=192) or Adalimumab (n=283). At baseline, 3/6/12-months patients had DAS28, self-reported treatment adherence, and SDLs measured. Fully adherent patients were analysed as a subgroup. Follow-up data at 3/6/12-months was analysed separately. Median SDLs were compared in good vs non/moderate response, and receiver-operator characteristics curves (ROC) were used to establish cut-off SDLs.
Results
Fully adherent good responders had significantly higher median Adalimumab/Certolizumab SDLs compared to non/moderate responders (p=0·04 and p=0·0005, respectively). ROC analysis reported 3-month non-trough Adalimumab SDLs discriminated good vs non/moderate response with an AUC of 0·63 (95% CI 0·52 – 0·75), with a cut-off of 7·5mg/L being 39·1% specific, and 80·9% sensitive. Similarly, 3-month non-trough Certolizumab SDLs discriminated good vs non/moderate response with an AUC of 0·65 (95% CI 0·51 – 0·78), with a cut-off of 26·0mg/L being 43·9% specific, and 77·8% sensitive.
Conclusion
In fully adherent patients, higher SDLs are detected in good responders suggesting that interventions to improve SDLs such as encouraging adherence could improve treatment response. 3-month non-trough SDL cut-offs of 7·5mg/L for Adalimumab and 26·0mg/L for Certolizumab may be useful in clinical practice.
Interventions aimed at increasing tumour-necrosis factor-alpha inhibitor serum drug levels (SDLs) may improve treatment response; however, previous studies suggesting SDL cut-offs have not accounted for treatment adherence. The aim of this study was to establish the relationship between Adalimumab/Certolizumab SDLs and EULAR good vs non/moderate response, and to define SDL cut-offs associated with good response in fully adherent patients.
Methods
In a prospective observational study, 475 patients with RA were treated with Certolizumab (n=192) or Adalimumab (n=283). At baseline, 3/6/12-months patients had DAS28, self-reported treatment adherence, and SDLs measured. Fully adherent patients were analysed as a subgroup. Follow-up data at 3/6/12-months was analysed separately. Median SDLs were compared in good vs non/moderate response, and receiver-operator characteristics curves (ROC) were used to establish cut-off SDLs.
Results
Fully adherent good responders had significantly higher median Adalimumab/Certolizumab SDLs compared to non/moderate responders (p=0·04 and p=0·0005, respectively). ROC analysis reported 3-month non-trough Adalimumab SDLs discriminated good vs non/moderate response with an AUC of 0·63 (95% CI 0·52 – 0·75), with a cut-off of 7·5mg/L being 39·1% specific, and 80·9% sensitive. Similarly, 3-month non-trough Certolizumab SDLs discriminated good vs non/moderate response with an AUC of 0·65 (95% CI 0·51 – 0·78), with a cut-off of 26·0mg/L being 43·9% specific, and 77·8% sensitive.
Conclusion
In fully adherent patients, higher SDLs are detected in good responders suggesting that interventions to improve SDLs such as encouraging adherence could improve treatment response. 3-month non-trough SDL cut-offs of 7·5mg/L for Adalimumab and 26·0mg/L for Certolizumab may be useful in clinical practice.
| Original language | English |
|---|---|
| Journal | Rheumatology (Print) |
| Publication status | Accepted/In press - 17 Sep 2022 |