SAT0207 Comparison of Efficacies of Abatacept and Tocilizumab in Patients with Rheumatoid Arthritis by a Propensity-Score Matching

Genetic and clinical biomarkers of tocilizumab response in patients with rheumatoid arthritis

The aim of this study was to investigate the influence of clinical and genetic factors on response to tocilizumab (TCZ) response, remission, low disease activity (LDA) and DAS28 improvement. A retrospective cohort study in 79 RA patients treated with TCZ during 6/18 months of therapy was conducted. CD69(rs11052877), GALNT18(rs4910008), CLEC2D(rs1560011), KCNMB1(rs703505), ENOX1(rs9594987), rs10108210, and rs703297 gene polymorphisms, identified in a recent GWAS as putative predictors of TCZ response, were analysed. Variables independently associated to satisfactory EULAR response at 6 months were GALNT18-CC genotype (ORCC/T-:12.8; CI95%:1.5,108.7; p=0.02), CD69 gene polymorphism (ORAA/GG:17.2; CI95%:2.5,119.6; p=0.004) and lower number of previous biological therapy, BT (OR: 0.45; CI95%:0.3, 0.7; p=0.001). The factors independently associated to higher remission were lower number of previous BT (OR:0.56; CI95%:0.38, 0.82; p=0.003), and GALNT18 CC genotype (ORCT/CC:0.09; CI95%:0.02,0.45;p=0.004; ORTT/CC:0.14; CI95%:0.02,0.79; p=0.026). The A-allele of CD69 (ORA_/GG:6.68;CI95%:1.68,26.51;p=0.007) and lower number of previous BT (OR:0.50; CI95%:0.32,0.77; p=0.002) were independent factors capable to predict higher LDA rates at 6 months. Independent factors associated to higher improvement in DAS28 at 6 months were CD69-AA genotype (B=-0.56; CI95%:-1.09, -0.03; p=0.039), GALNT18-CC genotype (B=-0.88;CI95%:-1.49, -0.27; p=0.005), subcutaneous administration (B=1.03; CI95%:0.44,1.62; p=0.001) and higher baseline DAS28 (B=0.82; CI95%:0.59, 1.05; p=4.9×10(-10)). Lower number of previous BT was the only independent predictor of satisfactory EULAR response (OR:0.60; CI95%:0.34,0.88; p=0.010) and higher remission (OR:0.65; CI95%:0.46,0.93; p=0.018) at 18 months. The C-allele of GALNT18 (ORC-/TT:4.60; CI95%:1.16, 18.27; p=0.03) and lower number of previous BT (OR:0.47; CI95%:0.29,0.74; p=0.001) were independent factors capable to predict higher LDA rates at 18 months. In conclusion, RA patients treated with TCZ showed better EULAR response, remission, LDA and DAS28 improvement rates in patients carrying the GALNT18 C-allele or the CD69 A-allele, particularly when lower number of BT were previously administered.

Anti-citrullinated peptide antibodies and their value for predicting responses to biologic agents: a review

Anti-citrullinated peptide antibodies (ACPAs) play an important pathogenic role both at the onset and during the disease course. These antibodies precede the clinical appearance of rheumatoid arthritis (RA) and are associated with a less favorable prognosis, both clinically and radiologically. The objective of this work was to conduct a comprehensive review of studies published through September 2015 of ACPAs' role as a predictor of the therapeutic response to the biological agents in RA patients. The review also includes summary of the biology and detection of ACPAs as well as ACPAs in relation to joint disease and CV disease and the possible role of seroconversion. The reviews of studies examining TNF inhibitors and tocilizumab yielded negative results. In the case of rituximab, the data indicated a greater probability of clinical benefit in ACPA(+) patients versus ACPA(-) patients, as has been previously described for rheumatoid factor. Nonetheless, the effect is discreet and heterogeneous. Another drug that may have greater effectiveness in ACPA(+) patients is abatacept. Some studies have suggested that the drug is more efficient in ACPA(+) patients and that those patients show greater drug retention. In a subanalysis of the AMPLE trial, patients with very high ACPA titers who were treated with abatacept had a statistically significant response compared to patients with lower titers. In summary, the available studies suggest that the presence of or high titers of ACPA may predict a better response to rituximab and/or abatacept. Evidence regarding TNFi and tocilizumab is lacking. However, there is a lack of studies with appropriate designs to demonstrate that some drugs are superior to others for ACPA(+) patients.