Background The majority of patients with rheumatoid arthritis (RA) initiating biologics have moderate disease activity (MDA)1 and achieve better outcomes than those with severe disease activity (SDA).2 The PRESERVE trial reported similar rates of low disease activity/remission (LDA/REM) at 88 weeks in MDA patients reaching LDA/REM after 36 weeks of etanercept(ETN)+methotrexate(MTX), whether they had continued full or half dose of ETN+MTX.3 PRESERVE did not address if patients would have done equally well on ETN vs. ETN+MTX.
Objectives The open-label CAMEO trial sought to determine if withdrawing MTX is as effective as continuing ETN+MTX in MDA and SDA after 6 months of ETN+MTX.4 This pre-specified post-hoc analysis assessed month 12 response in MDA (3.25.1) patients.
Methods TNF inhibitor naive, RA patients with active disease [≥3 swollen joints, DAS28≥3.2] despite MTX (≥15mg/wk, or 10mg/wk if intolerant) for >12 weeks were enrolled. Patients received ETN(50mg/wk sc)+MTX for 6 months. At month 6, patients were randomized to continue ETN+MTX or switch to ETN alone for 18 more months. Here we present DAS28 from month 6 to 12 by MDA or SDA at baseline (BL).
Results 258 patients were enrolled (female: 76%; mean disease duration: 8.9±8.4 yrs; mean # prior DMARDS: 2.7±1.0; prior oral prednisone: 52%). 205 were randomized at month 6, 121(59.0%) with BL SDA vs 84(41.0%) with BL MDA. Nearly twice as many with MDA vs. SDA patients reached LDA/REM(DAS28<3.2) at month 6 (61.3%(49/80) vs. 35.8%(43/120); OR[95%CI]=2.5[1.38-4.41]). MDA patients maintained stable DAS28 to month 12 whether continuing ETN+MTX (mean DAS28 [95% CI]=3.10[2.66-3.53]) or on ETN alone (mean DAS28[95% CI]=3.06[2.59-3.52]). In contrast, patients with SDA continued to improve to month 12 when maintaining ETN+MTX (mean DAS28[95% CI]=3.39[3.02-3.76]) but not on ETN alone (mean DAS28[95% CI]=4.31[3.85-4.76])[Fig1].
Conclusions It may be possible to withdraw MTX in a relatively high proportion of patients initiating treatment with MDA after 6 months of combination ETN+MTX, as more of these patients maintain LDA/REM. Patients with initial SDA, however, may need to continue combination therapy. This analysis provides important information on the disease state required to make a therapeutic adjustment in order to achieve and maintain LDA/REM.
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Acknowledgements Amgen Canada Inc. oversaw the design, conduct, & collection of data in the study & assisted in the analysis/interpretation of data.
Disclosure of Interest E. Keystone Grant/research support from: Abbott Laboratories, Amgen Inc., AstraZeneca Pharmaceuticals LP, Bristol-Myers Squibb, Centocor Inc, F. Hoffmann-LaRoche Inc, Genzyme, Merck, Novartis Pharmaceuticals, Pfizer Pharmaceuticals, UCB, Genentech Inc, Nycomed, Speakers bureau: Abbott Laboratories, Bristol-Myers Squibb, F. Hoffmann-LarRaoche Inc, Merck, Pfizer Pharmaceuticals, UCB, B. Haraoui Grant/research support from: Abbott, Amgen, Bristol-Meyers Squibb, Merck, Pfizer, Roche, UCB, Consultant for: Abbott, Amgen, Bristol-Meyers Squibb, Merck, Pfizer, Roche, UCB, Speakers bureau: Abbott, Amgen, Bristol-Meyers Squibb, Merck, Pfizer, Roche, UCB, C. Thorne Grant/research support from: Amgen, Pfizer, Abbott, Bristol-Myers Squibb, Roche, UCB, Merck, Centocor, Consultant for: Amgen, Pfizer, Abbott, Bristol-Myers Squibb, Roche, UCB, Merck, Centocor, M. Poulin-Costello Employee of: Amgen Canada, E. Trottier Employee of: Amgen Canada, A. Vieira Employee of: Amgen Canada, J. E. Pope Grant/research support from: Abbott, Amgen, Actelion, AstraZeneca, Bristol-Meyers Squibb, Glaxo-Smith Kline, Hoffmann-LaRoche, Janssen, Novartis, Pfizer, UCB, Consultant for: Abbott, Amgen, Actelion, AstraZeneca, Bristol-Meyers Squibb, Glaxo-Smith Kline, Hoffmann-LaRoche, Janssen, Novartis, Pfizer, UCB