Association Between Baseline Anti-cyclic Citrullinated Peptide Antibodies and 6-Month Clinical Response Following Abatacept or TNF Inhibitor Treatment: A Real-World Analysis of Biologic-Experienced Patients with RA

Abstract

Introduction: Anti-cyclic citrullinated peptide (anti-CCP) antibodies are associated with poor prognosis in patients with rheumatoid arthritis (RA). Previous data from randomized controlled trials and clinical practice have shown anti-CCP-positive (+) patients had a better response to treatment with abatacept or tumor necrosis factor inhibitor (TNFi) treatment than those who were anti-CCP negative. This study assessed the association between baseline anti-CCP2 [a surrogate for anti-citrullinated protein antibody (ACPA)] concentration and 6-month treatment responses to abatacept or TNFi in patients with RA.

Methods: This real-world analysis included biologic-experienced patients from CERTAIN (Comparative Effectiveness Registry to study Therapies for Arthritis and Inflammatory CoNditions) who initiated abatacept or TNFi, had prior biologic disease-modifying drug exposure and baseline anti-CCP2 concentration/serostatus and serum samples (baseline and 6 months). Baseline demographics and disease characteristics were compared. Change from baseline at 6 months in Clinical Disease Activity Index (CDAI) score and patient-reported outcomes [PROs: pain, fatigue, patient global assessment (PtGA), modified Health Assessment Questionnaire (mHAQ) score], by baseline anti-CCP2 quartile and binary cut-off (> 10-250 and > 250 U/ml), were evaluated separately in the abatacept and TNFi groups using a linear regression model adjusted for age, sex, CDAI/PROs, comorbidity index, and methotrexate use.

Results: Included were 138 abatacept and 137 TNFi initiators who were anti-CCP2+. At baseline, there were significant differences between anti-CCP2 quartiles and mean CDAI, swollen joint count 28, C-reactive protein (CRP), Disease Activity Score 28 (CRP), rheumatoid factor (RF), mHAQ and physician global assessment among abatacept initiators, and in mean RF, mHAQ, and PtGA among TNFi initiators. Among abatacept (but not TNFi) initiators, CDAI numerically improved (p = 0.208) and PROs significantly improved (p < 0.05) with increasing baseline anti-CCP2.

Conclusions: In patients treated with abatacept, not TNFi, higher anti-CCP2 concentrations at baseline were associated with numerically greater improvements in CDAI and significant improvements in PROs after 6 months.

Clinical trial number: NCT01625650.

Keywords: Abatacept; Patient-reported outcome measures; Rheumatoid arthritis; Tumor necrosis factor inhibitors.

Figures

Fig. 1

Patient disposition. *Serum available at baseline and 6-month visit, has 6-month follow-up visit in CERTAIN, moderate or severe CDAI score at baseline visit, CCP3+ at baseline visit. CCP3 cyclic citrullinated peptide 3, CERTAIN Comparative Effectiveness Registry to study Therapies for Arthritis and Inflammatory CoNditions, TNFi tumor necrosis factor inhibitor/s

Fig. 2

Adjusted mean improvement from baseline* in CDAI score and PROs for abatacept-treated patients, by anti-CCP2 quartile. Data are mean (95% CI); quartile 1 (n = 30) was used as the reference. *Adjusted for age, sex, baseline CDAI score or PROs, Charlson Comorbidity Index and current methotrexate use. Anti-CCP2 anti-cyclic citrullinated peptide 2, CDAI Clinical Disease Activity Index, CI confidence interval, mHAQ modified Health Assessment Questionnaire, PRO patient-reported outcome, PtGA patient global assessment, Q quartile

Fig. 3

Adjusted mean improvement from baseline* in CDAI score and PROs for TNFi-treated patients, by anti-CCP2 quartile. Data are mean (95% CI); quartile 1 (n = 36) was used as the reference. *Adjusted for age, sex, baseline CDAI score or PROs, Charlson Comorbidity Index and current methotrexate use. Anti-CCP2 anti-cyclic citrullinated peptide 2, CDAI Clinical Disease Activity Index, CI confidence interval, mHAQ modified Health Assessment Questionnaire, PRO patient-reported outcome, PtGA patient global assessment, Q quartile, TNFi tumor necrosis factor inhibitor/s