OP0235 ACHIEVING A LOW DAS IN THE FIRST 4-MONTHS AFTER DIAGNOSIS IS IMPORTANT FOR THE LONG-TERM CHANCE OF ACHIEVING DMARD-FREE REMISSION

M. Verstappen; E. Niemantsverdriet; A. Van der Helm - van Mil

doi:10.1136/annrheumdis-2020-eular.1837

Abstract

Background: Sustained DMARD-free remission (SDFR) is increasingly achievable in RA. The pathogenesis underlying SDFR-development is unknown and patient-characteristics at diagnosis poorly explain whether SDFR will be achieved. This limits substantiated decisions to discontinue DMARD-treatment in clinical practice.

Objectives: To increase the understanding of SDFR, we studied the course of disease activity scores (DAS) over time in relation to SDFR-development. Subsequently, we explored whether DAS-time course could be helpful to identify patients likely to achieve SDFR.

Methods: 761 RA-patients consecutively included in the Leiden Early Arthritis Clinic, treated with initial methotrexate and treat-to-target treatment, were studied (median follow-up 7 years). The course of DAS was compared between patients achieving SDFR within 7 years and those who did not, using linear mixed models, stratified for ACPA. Subsequently, the relation between DAS at 4 months and the probability of achieving SDFR within 7 years was studied with logistic regression. Kaplan-Meier curves were constructed to illustrate cumulative incidence of SDFR for different DAS categories at 4 months, respectively <1.6, 1.6-2.4, 2.4-3.6, >3.6.

Results: Patients achieving SDFR were characterized by a remarkedly different DAS response within 4 months after diagnosis. Compared to patients who did not achieve SDFR, the SDFR-group showed a prominently stronger decline in DAS between baseline and 4 months; 1.59 units decline (95%CI,1.24-1.95) versus 0.96 units (95%CI, 0.85-1.07) decline (p<0.001) (figure 1). Stratification for ACPA yielded a similar and statistically significant effect in ACPA-negative RA. In ACPA-positive RA this effect was absent. Subsequently, the probability of achieving SDFR during 7 years was studied in ACPA-negative RA and it was observed to be lower for patients with higher DAS at 4 months. After 7 years of disease, the cumulative incidence for SDFR in ACPA-negative patients with DAS<1.6 at 4 months was high (71.0%), whilst SDFR was rare among those with DAS>3.6 at 4 months (7.1%) (figure 2).

Conclusion: In RA-patients treated according to current guidelines, SDFR is predominantly achieved in patients with a strong decline in DAS during the first four months after diagnosis. Especially in ACPA-negative RA, the DAS at 4-months can be useful for later decisions to stop DMARDs.