Sustained discontinuation of infliximab with a raising-dose strategy after obtaining remission in patients with rheumatoid arthritis: the RRRR study, a randomised controlled trial

Abstract

Objectives: The aim of this study is to determine whether the 'programmed' infliximab (IFX) treatment strategy (for which the dose of IFX was adjusted based on the baseline serum tumour necrosis factor α (TNF-α)) is beneficial to induction of clinical remission after 54 weeks and sustained discontinuation of IFX for 1 year.

Methods: In this multicentre randomised trial, patients with IFX-naïve rheumatoid arthritis with inadequate response to methotrexate were randomised to two groups; patients in programmed treatment group received 3 mg/kg IFX until week 6 and after 14 weeks the dose of IFX was adjusted based on the baseline levels of serum TNF-α until week 54; patients in the standard treatment group received 3 mg/kg of IFX. Patients who achieved a simplified disease activity index (SDAI) ≤3.3 at week 54 discontinued IFX. The primary endpoint was the proportion of patients who sustained discontinuation of IFX at week 106.

Results: A total of 337 patients were randomised. At week 54, 39.4% (67/170) in the programmed group and 32.3% (54/167) in the standard group attained remission (SDAI ≤3.3). At week 106, the 1-year sustained discontinuation rate was not significantly different between two groups; the programmed group 23.5% (40/170) and the standard group 21.6% (36/167), respectively (2.2% difference, 95% CI -6.6% to 11.0%; p=0.631). Baseline SDAI <26.0 was a statistically significant predictor of the successfully sustained discontinuation of IFX at week 106.

Conclusion: Programmed treatment strategy did not statistically increase the sustained remission rate after 1 year discontinuation of IFX treatment.

Keywords: TNF-α; infliximab; randomized controlled trials; remission; rheumatoid arthritis.

Figure 1

Consort flow diagram.

Figure 2

Change from baseline in SDAI (A) and DAS28-ESR, and proportion of remission based on SDAI (C) and DAS28-ESR (D). Least square means and 95% CIs were estimated plotted for the standard treatment group and programmed treatment group. $ shows p<0.05. DAS28-ESR, disease activity score in 28 joints using erythrocyte sedimentation rate; SDAI, simplified disease activity index.

Figure 3

Proportions of sustained discontinuation by the standard and programmed treatment group (A) and by the dose of infliximab (B) in patients randomised in RRRR study. The standard treatment group and TNF-low group received 3 mg/kg of infliximab, TNF-int group received 6 mg/kg after 22 weeks and TNF-high group received 10 mg/kg after 22 weeks. RRRR, Remission induction by Raising the dose of Remicade in Rheumatoid arthritis; TNF, tumour necrosis factor.

Figure 4

Association between clinical background factors and the sustained discontinuation at 1 year in the multiple logistic regression analysis. MTX, methotrexate; RF, rheumatoid factor; SDAI, simplified disease activity index; TNF-α, tumour necrosis factor α.