Background There are several definitions of remission (REM), which are composite measures, including physician, laboratory, and patient (pt) assessments. The Boolean definition of REM is the most stringent.
Objectives To determine which components limit pts from achieving REM based on the Boolean definition.
Methods Pt data originated from 3 trials: PREMIER [treatment-naive pts with early RA treated with methotrexate (MTX) alone or MTX + adalimumab (ADA)]; OPTIMA-arm 5 (pts with early RA, who failed MTX treatment, treated with open-label ADA + MTX); DE019 (pts with established RA treated with MTX alone, or MTX+ ADA, 20/40 mg every other wk). The Simplified Disease Activity Index (SDAI) is comprised of swollen and tender joint count (SJC/TJC, 0-28 joints), pt and physician global disease activity (PGA/PhGA, 0-10 cm VAS), and C-reactive protein, (CRP mg/dL); SDAI REM is defined as a score of ≤3.3. The 28-joint Disease Activity Score based on C-reactive protein [DAS28(CRP)] is comprised of SJC28, TJC28, CRP (mg/L) and PGA (0-10 cm VAS); DAS28 REM is defined as a score of <2.6. Boolean REM is defined as: TJC28 ≤1, SJC28 ≤1, CRP ≤1 mg/dl, PGA ≤1. For pts who achieved Boolean REM, SDAI REM but not Boolean REM, or DAS28 REM but not Boolean REM in the first 52 weeks (wks) of the trial, the following were assessed at the first visit at which REM was recorded: SJC28, TJC28, CRP, PGA, PhGA, SDAI, DAS28, Health assessment questionnaire (HAQ) score, and mean change from baseline for all of the above. The endpoints were compared for pts who achieved SDAI REM or DAS28 REM but not Boolean REM vs pts who achieved Boolean REM.
Results In PREMIER, compared with pts in DAS28 REM but not Boolean REM, pts in Boolean REM had significantly lower values for most variables (table), while they had only slightly lower TJC and PGA compared to pts in SDAI REM but not Boolean REM. Notably, pts in DAS28 REM but not Boolean REM had significantly higher residual joint counts on the 66/68 joint assessment compared with Boolean REM. Similar results for DAS28 REM but not Boolean REM were seen for DE019 and OPTIMA-arm 5. Pts in SDAI REM but not Boolean REM had similar SJC and TJC and similar changes in SJC/TJC as pts in Boolean REM. However, pts in Boolean REM had numerically slightly lower PGA than pts who reached SDAI REM but not Boolean REM.
Conclusions Pts with DAS28 REM but not Boolean REM had significantly higher joint counts, PGA and PhGA. In contrast, except for lower PGA, pts who reached Boolean REM had comparable scores to pts who reached SDAI REM but not Boolean REM, suggesting that, similar to previous reports1, differences in PGA are the limiting factor for pts in SDAI REM not meeting the Boolean REM criteria.
Studenic et al, ARD 2012:71
Acknowledgements AbbVie sponsored the studies, contributed to their design, and participated in the collection, analysis, and interpretation of the data, and in the writing, reviewing, and approval of the final version. Statistical support was provided by Yinglin Xia PhD, and Peigang Li PhD; medical writing support was provided by Naina Barretto PhD, all of AbbVie.
Disclosure of Interest J. Smolen Grant/research support from: AbbVie, Consultant for: AbbVie, D. Aletaha Grant/research support from: AbbVie, Pfizer, Grünenthal, Merck, Medac, UCB, Mitsubishi/Tanabe, Janssen, and Roche, Consultant for: AbbVie, Pfizer, Grünenthal, Merck, Medac, UCB, Mitsubishi/Tanabe, Janssen, and Roche, X. Wang Employee of: AbbVie, S. Florentinus Employee of: AbbVie