Background/Purpose: Anti-cyclic citrullinated peptide positivity (CCP+) is associated with a better response to abatacept than anti-CCP negativity in patients with RA^1,2; however, there are no head-to-head or comparative effectiveness research studies available evaluating responses to biologics in CCP+ patients in a real-world setting. The aim of this study was to compare the effectiveness of abatacept vs a TNF inhibitor (TNFi) in patients with RA who are CCP+. Methods: We identified adult patients with RA from a large observational US cohort (Dec 1, 2005–Aug 31, 2016) who initiated abatacept or a TNFi and who were CCP+ (≥20 U/mL) at or prior to initiation. Both groups had to have no prior exposure to other non-TNFi biologics or targeted synthetic DMARDs. TNFi initiators were excluded if they had prior use of abatacept. Using propensity score matching (1:1) stratified by prior TNFi use (0, 1 and 2+), effectiveness at 6 months after initiation was evaluated. Mean change in CDAI over 6 months following initiation was the primary outcome and secondary outcomes were: achievement of remission (CDAI ≤2.8), modified (m)ACR20, 50 and 70 responses and achievement of LDA/remission (CDAI ≤10) in those with moderate/high disease activity at initiation. A subset analysis was performed to consider separately patients who were biologic naïve and those who were biologic experienced at initiation.

Results: The 330 pairs of propensity score-matched abatacept and TNFi initiators had no substantial differences in baseline characteristics. Both treatment groups had similar mean change in CDAI at 6 months as well as achievement of LDA, remission and mACR20/50/70 responses (Table). Among the 97 matched biologic-naïve pairs, there was no significant difference in change in CDAI for abatacept initiators vs TNFi initiators (p=0.19). However, in the 233 matched biologic-experienced pairs, those initiating abatacept had a greater improvement in mean change in CDAI (p=0.033) and were more likely to achieve an mACR50 response (p=0.014).

Conclusion: Patients with RA who were CCP+ and received either abatacept or TNFi had a substantial improvement in clinical disease activity. In the overall propensity score-matched sample, similar outcomes were observed for both treatment groups. However, analysis of the biologic-experienced cohort found that abatacept initiators had a greater improvement in disease activity than TNFi initiators.

1. Sokolove J, et al. Ann Rheum Dis 2016;75:709–14.

2. Harrold LR, et al. Ann Rheum Dis 2016;75(Suppl 2):505–6.

Original abstract © EULAR/BMJ. First presented at EULAR 2017 and published in Ann Rheum Dis 2017;76 (Suppl 2):AB0408. Any reprints, promotional options, education material etc have to be done through the original source (ARD/BMJ).