Abatacept has better clinical response than TNFi in ACPA-positive RA patients: study

Patients with rheumatoid arthritis (RA) who are anti-citrullinated protein antibody (ACPA)-positive have been shown to respond better to abatacept and rituximab than patients who are ACPA negative. Yet, the evidence regarding comparative efficacy of biologic agents stratified by patient's ACPA serostatus is very limited in Asian patients with RA. Hence, Min Jung Kim et al conducted a study to compare the efficacy of abatacept and tumor necrosis factor inhibitor (TNFi) in patients with ACPA- positive rheumatoid arthritis (RA) and identify those who benefit most from abatacept over TNFi.

This observational study identified RA patients who were ACPA-positive and initiated abatacept or TNFi from the Korean College of Rheumatology Biologics and Targeted therapy registry. Propensity score (PS) matching was performed to balance baseline confounding in abatacept- or TNFi-treated patients. The major endpoints were changes in Clinical Disease Activity Index (CDAI) and achievement of CDAI remission/low disease activity after 1 year of treatment. Subgroup analysis was mainly performed stratified by prior biologics use.

Key findings of the study were:

• A total of 291 PS-matched, ACPA-positive RA patients who initiated abatacept (n = 97) and TNFi (n = 194) were included.

• From baseline CDAI scores of 26.52 in the abatacept group and 26.38 in the TNFi group, the mean changes after 1 year were - 16.78 and - 13.61, respectively (difference - 3.17, p = 0.020).

• The proportion of patients achieving CDAI remission/low disease activity was 68.0% with abatacept and 52.6% with TNFi (p = 0.013).

• In the subgroup analysis, patients that were biologics-naive had better improvement in CDAI after treatment with abatacept than TNFi (difference - 3.35, p = 0.021).

The authors concluded that - This study, based on data from this nationwide biologic registry, suggests that abatacept may show a significant improvement in clinical outcomes compared to TNFi in patients with established ACPA-positive RA. Abatacept may be particularly beneficial over TNFi in patients with ACPA-positive RA who are bDMARD-naive or have an ACPA titer of 100 U/ml or less. These findings suggest that stratification of patients by ACPA serostatus, along with disease duration and previous biologic treatment, is important in predicting treatment response of abatacept, thereby improving the clinical response by selecting a suitable biological treatment option for the right patient.

Further reading:

Efficacy of Abatacept Versus Tumor Necrosis Factor Inhibitors in Anti-citrullinated Protein Antibody Positive Patients with Rheumatoid Arthritis: Results from a Korean Nationwide Biologics Registry

Min Jung Kim, Sun-Kyung Lee et al

Rheumatol Ther (2022) 9:1143–1155

https://doi.org/10.1007/s40744-022-00467-4