E L Kneepkens1, Iam van den Oever1, C H Plasencia2, D Pascual-Salcedo3, A de Vries4, M Hart5, M T Nurmohamed1,6, A Balsa2, T Rispens5, G Wolbink1,5. 1. a Department of Rheumatology , Amsterdam Rheumatology and immunology Centre, location Reade , Amsterdam , The Netherlands. 2. b Department of Rheumatology , La Paz hospital Madrid , Spain. 3. c Immunology Unit , La Paz Hospital Madrid , Spain. 4. d Sanquin Diagnostic Services Amsterdam , The Netherlands. 5. e Department of Immunopathology , Sanquin Research and Landsteiner Laboratory, Academic Medical Centre Amsterdam , The Netherlands. 6. f Department of Rheumatology , Amsterdam Rheumatology and immunology Centre, VU Medical Centre , Amsterdam , The Netherlands.
Abstract
OBJECTIVES: To investigate the pharmacokinetics (PK) and dynamics of tocilizumab (TCZ) in daily practice. METHOD: An observational study of 66 consecutive RA patients treated with TCZ 8 mg/kg once every 4 weeks intravenously, monitored for 24 weeks. Spearman's rank test was used to investigate the correlation between TCZ concentration and C-reactive protein (CRP). Clinical improvement was assessed at week 24 using the Disease Activity Score in 28 joints (DAS28) compared to baseline, and its relationship with TCZ concentration was investigated using linear regression analyses. TCZ trough concentrations and anti-drug antibodies were measured using an enzyme-linked immunosorbent assay (ELISA) and antigen binding test, respectively. RESULTS: At baseline, 26 patients (39.4%) had a CRP level above 10 mg/L with a median (interquartile range, IQR) of 37.7 (21.9-49.7) mg/L. A TCZ concentration above 1 mg/L was sufficient to normalize CRP levels. Spearman's rank test showed a correlation coefficient of -0.460 (p < 0.0001). The TCZ concentration varied widely, with concentrations < 1 mg/L in 17-31% of patients, depending on the time point of measurement. Anti-TCZ antibodies were detected in one sample. Linear regression analyses showed a coefficient of 0.080 with a 95% confidence interval (CI) of 0.039-0.113 (p < 0.001) for the association between TCZ concentration and ΔDAS28. No confounders were identified. CONCLUSIONS: The TCZ standard regimen results in a wide variety of serum TCZ trough concentrations; this is mostly due to target binding and to a lesser extent to immunogenicity. The majority of patients obtained TCZ concentrations > 1 mg/L, which is sufficient for CRP normalization. Therefore, dose taper strategies might be possible in a substantial proportion of patients.
OBJECTIVES: To investigate the pharmacokinetics (PK) and dynamics of tocilizumab (TCZ) in daily practice. METHOD: An observational study of 66 consecutive RA patients treated with TCZ 8 mg/kg once every 4 weeks intravenously, monitored for 24 weeks. Spearman's rank test was used to investigate the correlation between TCZ concentration and C-reactive protein (CRP). Clinical improvement was assessed at week 24 using the Disease Activity Score in 28 joints (DAS28) compared to baseline, and its relationship with TCZ concentration was investigated using linear regression analyses. TCZ trough concentrations and anti-drug antibodies were measured using an enzyme-linked immunosorbent assay (ELISA) and antigen binding test, respectively. RESULTS: At baseline, 26 patients (39.4%) had a CRP level above 10 mg/L with a median (interquartile range, IQR) of 37.7 (21.9-49.7) mg/L. A TCZ concentration above 1 mg/L was sufficient to normalize CRP levels. Spearman's rank test showed a correlation coefficient of -0.460 (p < 0.0001). The TCZ concentration varied widely, with concentrations < 1 mg/L in 17-31% of patients, depending on the time point of measurement. Anti-TCZ antibodies were detected in one sample. Linear regression analyses showed a coefficient of 0.080 with a 95% confidence interval (CI) of 0.039-0.113 (p < 0.001) for the association between TCZ concentration and ΔDAS28. No confounders were identified. CONCLUSIONS: The TCZ standard regimen results in a wide variety of serum TCZ trough concentrations; this is mostly due to target binding and to a lesser extent to immunogenicity. The majority of patients obtained TCZ concentrations > 1 mg/L, which is sufficient for CRP normalization. Therefore, dose taper strategies might be possible in a substantial proportion of patients.
Authors: Anandani Nellan; Cynthia M Lester McCully; Rafael Cruz Garcia; Nalini Jayaprakash; Brigitte C Widemann; Daniel W Lee; Katherine E Warren Journal: Blood Date: 2018-06-28 Impact factor: 22.113
Authors: Charlotte Krieckaert; Borja Hernández-Breijo; Johanna Elin Gehin; Guillaume le Mélédo; Alejandro Balsa; Meghna Jani; Denis Mulleman; Victoria Navarro-Compan; Gertjan Wolbink; John Isaac; Astrid van Tubergen Journal: RMD Open Date: 2022-06
Authors: Carl K Orr; Aurelie Najm; Francis Young; Trudy McGarry; Monika Biniecka; Ursula Fearon; Douglas J Veale Journal: Front Med (Lausanne) Date: 2018-08-03