Objectives To compare rates of sustained low and minimal disease activity and ACR/EULAR remission during 3-year follow-up in rheumatoid arthritis (RA) patients treated with etanercept and adalimumab in routine care.
Methods 407 RA patients previously unexposed to tumor necrosis factor antagonists were treated with etanercept (n=203) or adalimumab (n=204) and assessed at 3- and later 6 month intervals. Clinical parameters and anti-adalimumab antibodies (AAA) were measured at each time point. Clinical response was defined as sustained (at least 12 consecutive months) low disease activity (sLDA; DAS28 <3.2), minimal disease activity (sMDA; DAS28 <2.6) or ACR/EULAR remission (sSDAI). Non-overlapping response rates were calculated.
Results In the adalimumab group, 13% reached sLDA but not sMDA, 15% reached sMDA but not sSDAI and 16% reached sSDAI remission. In the etanercept group corresponding rates were 16%, 11% and 12%, respectively (overall test for linear trend: p=0.42). Adalimumab-treated patients without antibodies (AAA–; n=150, 74%) had best outcomes and AAA+ patients the worst, with etanercept-treated patients in between (p<0.0001). Differences were most apparent in the sSDAI and sMDA categories. For example, 40% of AAA–, 23% of etanercept and 4% of AAA+ patients achieved at least sMDA (Fig. 1).
Conclusions Overall, etanercept and adalimumab treatment appeared similar in inducing a good long-term clinical outcome. The occurrence of AAA hampered the long-term clinical efficacy of adalimumab. Treatment response rates to adalimumab might be increased by strategies that counteract the development of AAA.
Disclosure of Interest C. Krieckaert: None Declared, A. Jamnitski: None Declared, M. Nurmohamed Grant/Research support from: Abbott, Roche, Pfizer, Consultant for: Abbott, Roche, Phizer, MSD, UCB, SOBI and BMS, Speakers Bureau: Abbott, Roche, Pfizer, P. Kostense: None Declared, M. Boers Consultant for: Roche, GSK, Novartis, Speakers Bureau: UCB, Abbott, G. Wolbink Grant/Research support from: Pfizer, Speakers Bureau: Pfizer, Amgen