Background Remission (REM) or low disease activity (LDA) are key clinical targets in patients with rheumatoid arthritis (RA).¹ The CAMEO study, an open-label trial in RA patients, demonstrated that those with LDA after 6 months of etanercept (ETN) and methotrexate (MTX) therapy had similar clinical outcomes at 12 months whether they continued ETN+MTX or switched to ETN monotherapy at month 6 (M6).² Conversely, patients who had not achieved LDA at M6 showed reduced response when treated with ETN alone after withdrawing MTX.²

Objectives This post-hoc analysis of the CAMEO study examined the achievement and sustainability of REM or LDA for up to 24 months in patients who continued ETN+MTX or switched to ETN monotherapy following 6 months of combination therapy.

Methods TNF inhibitor naïve patients with active RA (≥3 swollen joints, Disease Activity Score [DAS28] ≥3.2), despite MTX therapy (≥15 mg/week or 10 mg/week if intolerant) for >12 weeks, were enrolled. Following 6 months of ETN (50 mg/week SC) + MTX treatment, patients were randomized (1:1) to continue ETN+MTX or to switch to ETN monotherapy for an additional 18 months. DAS28 was assessed at baseline through month 24 (M24).

Results A total of 258 patients enrolled (76% female, mean age 54.7±12.5 yrs, disease duration 8.9±8.4 yrs, baseline DAS28 5.4±1.1) and 205 (79%) were randomized at M6 to maintain ETN+MTX (n=107) or to begin ETN alone (n=98). Among patients who achieved REM (DAS28 <2.6) at M6, REM rates were similar at M24 whether on combination or monotherapy (Table 1). Similarly, in patients who achieved M6 LDA (DAS28 <3.2), the proportion of individuals maintaining LDA at M24 was comparable between treatment arms (ETN: 36% vs. ETN+MTX: 40%). In contrast, in subgroups without M6 REM or LDA but who achieved M12 REM or LDA, fewer patients in the ETN arm maintained REM (ETN: 2% vs. ETN+MTX: 6%; Table 1) or LDA (ETN: 0% vs. ETN+MTX: 10%) to M24. For patients without M6 REM, completion rates at M24 were 45% and 70% in the ETN and ETN+MTX arms, respectively; in patients achieving M6 REM, completion rates were 65% in the ETN arm and 70% in the ETN+MTX arm.

Conclusions This analysis demonstrates that a substantial proportion of patients who achieve LDA/REM at M6 sustain LDA/REM through M24 whether on combination or monotherapy. These results suggest that ETN monotherapy may be considered in those patients who achieve LDA/REM after 6 months of combination therapy.

References

1. Smolen JS, et al. Ann Rheum Dis. 2010;69:631-637.

2. Pope JE, et al. Ann Rheum Dis. 2013 August [Epub ahead of print].

Acknowledgements Amgen Canada Inc. oversaw the design, conduct, and data collection and assisted in the analysis and interpretation of data.

Disclosure of Interest : J. Pope Grant/research support: Abbott/AbbVie, Amgen, Actelion, AstraZeneca Pharmaceuticals, Bristol-Meyers Squibb, Glaxo-Smith Kline, Hoffmann-LaRoche, Janssen, Novartis Pharmaceuticals, Pfizer Pharmaceuticals, UCB, Consultant for: Abbott/AbbVie, Amgen, Actelion, AstraZeneca Pharmaceuticals, Bristol-Meyers Squibb, Glaxo-Smith Kline, Hoffmann-LaRoche, Janssen, Novartis Pharmaceuticals, Pfizer Pharmaceuticals, UCB, B. Haraoui Grant/research support: Abbott/AbbVie, Amgen, Bristol-Myers Squibb, Janssen, Pfizer, Roche, UCB, Consultant for: Abbott/AbbVie, Amgen, Bristol-Meyers Squibb, Merck, Pfizer, Roche, UCB, J. C. Thorne Grant/research support: Amgen, Pfizer, Abbott/AbbVie, Bristol-Myers Squibb, Centocor, Merck, Roche, UCB, Consultant for: Amgen, Pfizer, Abbott/AbbVie, Bristol-Myers Squibb, Centocor, Merck, Roche, UCB, K. Phan-Chronis Employee of: Amgen Canada, M. Poulin-Costello Employee of: Amgen Canada, A. Vieira Employee of: Amgen Canada (Former employee), E. Keystone Grant/research support: Abbott/AbbVie, Amgen, AstraZeneca Pharmaceuticals, Bristol-Meyers Squibb, Centocor, F. Hoffmann-LaRoche, Genzyme, Merck, Novartis Pharmaceuticals, Pfizer Pharmaceuticals, UCB, Genentech, Janssen, Consultant for: Abbott/AbbVie, Bristol-Meyers Squibb, F. Hoffmann-LaRoche, Merck, Pfizer Pharmaceuticals, UCB, Janssen

DOI 10.1136/annrheumdis-2014-eular.1054