ASSOCIATION BETWEEN BASELINE ACPA STATUS AND RESPONSE TO ABA OR NON-TNFI THERAPY
Objectives:
– Assess whether baseline anti-CCP antibody status was associated with response to treatment with abatacept vs non-TNFi b/tsDMARDs in patients with RA.
– Assess whether baseline anti-CCP antibody status was associated with difference in clinical response to treatment for patients receiving tsDMARDs.
Introduction:
RA is characterized by the production of autoantibodies, including anti-citrullinated protein antibodies (ACPA). Patients with RA who are ACPA positive are more likely to develop severe, erosive disease than those who are ACPA negative.
Response to RA therapy may vary based on ACPA status.
Data from a US national observational study conducted in a clinical practice setting have shown that patients who were anti-cyclic citrullinated peptide (a surrogate for ACPA; anti-CCP) positive had a greater clinical response to treatment with abatacept, but not to a TNF inhibitor (TNFi), than those who were anti-CCP negative.
Real-world data comparing treatment responses to abatacept and other non-TNFi biologic or targeted synthetic (b/ts) DMARDs by ACPA status are lacking.
Discussion:
After 6 months of therapy, the improvement in outcomes among anti-CCP+ patients treated with abatacept or rituximab was significantly better than outcomes among the respective anti-CCP– patients.
No significant difference in clinical response was observed between anti-CCP+ and anti-CCP– patients treated with tocilizumab or tofacitinib.
An analysis comparing the effectiveness of abatacept versus other non-TNFi b/tsDMARDs by ACPA status is planned.
Summary:
Overall, 982 patients initiating abatacept, 399 initiating tocilizumab, 244 initiating rituximab and 420 initiating tofacitinib were identified.
Across treatments, those who were anti-CCP+ had a longer duration of RA and were more likely to have erosive changes on X-ray, compared with patients who were anti-CCP–.
Additionally, a higher percentage of anti-CCP+ patients were RF+ and more were in ACR functional class III–IV at index.
For patients initiating abatacept, during most time periods of treatment initiation, the adjusted mean changes in CDAI, PGA and mHAQ at 6 months following the index date were significantly higher for anti-CCP+ versus anti-CCP– patients.
In addition, for abatacept-treated patients, for the majority of secondary outcomes, the odds of achieving any one outcome were significantly higher for anti-CCP+ versus anti-CCP– patients.
For patients initiating rituximab, the adjusted mean change in CDAI and PGA and the odds of achieving CDAI LDA were significantly higher among anti-CCP+ versus anti-CCP– patients; differences in other secondary outcomes were observed but were not statistically significant.
No significant differences in outcomes by anti-CCP status were observed in tocilizumab- or tofacitinib-treated patients.
Leslie Harrold, MD, MPH is a board certified rheumatologist and epidemiologist whose work has focused on rheumatoid arthritis, gout, osteoarthritis, and vasculitis. She is a population-based researcher with expertise in using large datasets to examine medication use and safety issues. More recently her work as focused on quality of care and patient self-management.