Intravenous versus subcutaneous tocilizumab in Takayasu arteritis: multicentre retrospective study

OBJECTIVES

In this large multicentre study, we compared the effectiveness and safety of tocilizumab intravenous versus subcutaneous (SC) in 109 Takayasu arteritis (TAK) patients.

METHODS

We conducted a retrospective multicentre study in referral centres from France, Italy, Spain, Armenia, Israel, Japan, Tunisia and Russia regarding biological-targeted therapies in TAK, since January 2017 to September 2019.

RESULTS

A total of 109 TAK patients received at least 3 months tocilizumab therapy and were included in this study. Among them, 91 and 18 patients received intravenous and SC tocilizumab, respectively. A complete response (NIH <2 with less than 7.5 mg/day of prednisone) at 6 months was evidenced in 69% of TAK patients, of whom 57 (70%) and 11 (69%) patients were on intravenous and SC tocilizumab, respectively (p=0.95). The factors associated with complete response to tocilizumab at 6 months in multivariate analysis, only age <30 years (OR 2.85, 95% CI 1.14 to 7.12; p=0.027) and time between TAK diagnosis and tocilizumab initiation (OR 1.18, 95% CI 1.02 to 1.36; p=0.034). During the median follow-up of 30.1 months (0.4; 105.8) and 10.8 (0.1; 46.4) (p<0.0001) in patients who received tocilizumab in intravenous and SC forms, respectively, the risk of relapse was significantly higher in TAK patients on SC tocilizumab (HR=2.55, 95% CI 1.08 to 6.02; p=0.033). The overall cumulative incidence of relapse at 12 months in TAK patients was at 13.7% (95% CI 7.6% to 21.5%), with 10.3% (95% CI 4.8% to 18.4%) for those on intravenous tocilizumab vs 30.9% (95% CI 10.5% to 54.2%) for patients receiving SC tocilizumab. Adverse events occurred in 14 (15%) patients on intravenous route and in 2 (11%) on SC tocilizumab.

CONCLUSION

In this study, we confirm that tocilizumab is effective in TAK, with complete remission being achieving by 70% of disease-modifying antirheumatic drugs-refractory TAK patients at 6 months.

Efficacy and safety of TNF-α antagonists and tocilizumab in Takayasu arteritis: Multicenter retrospective study of 209 patients

OBJECTIVE

To assess safety and efficacy of TNF-α antagonists and tocilizumab in patients with Takayasu arteritis (TAK).

METHODS AND RESULTS

Two-hundred nine patients with TAK [median age of 29 years [7-62], and 186 (89%) females] were included. They received either TNF-α antagonists [n = 132 (63%) with 172 lines; infliximab (n = 109), adalimumab (n = 45), golimumab (n = 8), certolizumab (n = 6) and etanercept (n = 5)], or tocilizumab [n = 77 (37%) with 121 lines; intravenous and subcutaneous in 95 and 26 cases, respectively]. A complete response at 6 months was evidenced in 101/152 (66%) on TNF-α antagonists and 75/107 (70%) on tocilizumab, respectively. Age ≥ 30 years [OR = 2.09 [1.09; 3.99]] was associated with complete response, whereas vascular signs [0.26 [0.1; 0.65]], baseline prednisone ≥ 20 mg/day [0.51 [0.28; 0.93]] were negatively associated with the complete response to TNF-α antagonists or tocilizumab. During a median follow-up of 36 months, 103 relapses were noted. Supra-aortic branches and thoracic aorta involvements [HR 2.44 (1.06; 5.65) and 3.66 (1.18; 11.4), respectively], and systemic signs at baseline [HR 2.01 (1.30; 3.11)] were significantly associated with relapse. The cumulative incidence of treatment discontinuation and relapse were similar in TNFα antagonists and tocilizumab. Fifty-eight (20%) adverse effects occurred on biological-targeted therapies of whom 37 (21%) and 21 (17%), (p= 0.4) on TNF-α antagonists and tocilizumab, respectively.

CONCLUSION

This large multicentre study shows high efficacy of biological-targeted treatments in refractory TAK. Efficacy, relapse and drug retention rate were equivalent with TNF-α antagonists and tocilizumab.

Practical issues encountered while determining Minimal Clinically Important Difference in Patient-Reported Outcomes

Background

Using a real dataset, we highlighted several major methodological issues raised by the estimation of the Minimal Clinically Important Difference (MCID) of a Patient-Reported Outcomes instrument. We especially considered the management of missing data and the use of more than two times of measurement. While inappropriate missing data management and inappropriate use of multiple time points can lead to loss of precision and/or bias in MCID estimation, these issues are almost never dealt with and require cautious considerations in the context of MCID estimation.

Methods

We used the LIGALONGO study (French Randomized Controlled Trial). We estimated MCID on the SF-36 General Health score by comparing many methods (distribution or anchor-based). Different techniques for imputation of missing data were performed (simple and multiple imputations). We also consider all measurement occasions by longitudinal modeling, and the dependence of the score difference on baseline.

Results

Three hundred ninety-three patients were studied. With distribution-based methods, a great variability in MCID was observed (from 3 to 26 points for improvement). Only 0.2 SD and 1/3 SD distribution methods gave MCID values consistent with anchor-based methods (from 4 to 7 points for improvement). The choice of missing data imputation technique clearly had an impact on MCID estimates. Simple imputation by mean score seemed to lead to out-of-range estimate, but as missing not at random mechanism can be hypothesized, even multiple imputations techniques can have led to an slight underestimation of MCID. Using 3 measurement occasions for improvement led to an increase in precision but lowered estimates.

Conclusion

This practical example illustrates the substantial impact of some methodological issues that are usually never dealt with for MCID estimation. Simulation studies are needed to investigate those issues.

Trial registration

NCT01240772 (ClinicalTrials.gov) registered on November 15, 2010.