IntroductionAnti-citrullinated protein antibodies (ACPAs) are highly specific serological biomarkers that are indicative of a poor prognosis in patients with rheumatoid arthritis (RA). The effectiveness of biologic disease-modifying antirheumatic drugs (bDMARDs) with different mechanisms of action may vary, based on patients' serostatus. The aim of this study is to compare the effectiveness of abatacept versus tumor necrosis factor inhibitors (TNFis) in patients with RA who were anti-cyclic citrullinated peptide antibody positive (anti-CCP+).
MethodsAbatacept or TNFi initiators with anti-CCP+ status (≥ 20 U/ml) at or prior to treatment initiation were identified from a large observational US cohort (1 December 2005-31 August 2016). Using propensity score matching (1:1), stratified by prior TNFi use (0, 1 and ≥ 2), effectiveness at 6 months after initiation was evaluated. Primary outcome was mean change in Clinical Disease Activity Index (CDAI) score. Secondary outcomes included achievement of remission (CDAI ≤ 2.8), low disease activity/remission (CDAI ≤ 10), modified American College of Rheumatology 20/50/70 responses and mean change in modified Health Assessment Questionnaire score.
ResultsAfter propensity score matching, the baseline characteristics between 330 pairs of abatacept and TNFi initiators (biologic naïve, n = 97; TNFi experienced, n = 233) were well balanced with absolute value standardized differences of ≤ 0.1. Both overall, and in the biologic-naïve cohort, there were no significant differences in mean change in CDAI score at 6 months. However, in the TNFi-experienced cohort, there was a significantly greater improvement in CDAI score at 6 months with abatacept versus TNFi initiators (p = 0.033). Secondary outcomes showed similar trends.
ConclusionsImprovements in clinical disease activity were seen in anti-CCP+ abatacept and TNFi initiators. TNFi-experienced anti-CCP+ patients with RA had more improvement in disease activity with abatacept versus TNFis, whereas outcomes were similar between treatments in the overall population and in biologic-naïve patients.
Trial registrationClinicalTrials.gov identifier: NCT01625650.
FundingThis study is sponsored by Corrona, LLC and funded by Bristol-Myers Squibb. Bristol-Myers Squibb funded the publication of this manuscript.