Background/Purpose: Clinical remission is the aim of rheumatoid arthritis (RA) treatment  and baseline disease characteristics that predict an increased likelihood of reaching remission are of interest to clinicians. Patients with moderately active RA make up the majority of patients in the clinic  and achieve far better outcomes than patients with severe disease  but receive far less attention in clinical trials. The objective of this study was to analyze baseline characteristics that may predict remission in patients with moderately active RA (disease activity score in 28 joints [DAS28] >3.2 and ≤5.1) treated with combination etanercept (ETN) 50 mg once weekly (QW) + methotrexate (MTX) at Week 36 (Period 1) of the PRESERVE trial .
Methods: Patients with DAS28 >3.2 and ≤5.1, despite stable doses of oral MTX for ≥8 weeks, received open-label ETN 50 mg QW + MTX for 36 weeks. Remission was defined as DAS28 <2.6, simplified disease activity index (SDAI) ≤3.3, and clinical disease activity index (CDAI) ≤2.8. Predictors of remission were analyzed using logistic models and adjusted for geographic region and baseline DAS28, SDAI, or CDAI. Statistical tests were not adjusted for multiplicity.
Results: At Week 36, 67%, 25%, and 27% of patients achieved DAS28, SDAI, and CDAI remission, respectively. Younger age of patient (≤40 vs. >40) and lower health assessment questionnaire (HAQ) score (≤0.5 vs. >1.5) at baseline were significantly more predictive of SDAI, CDAI, and DAS28 remission (P<0.05 for all, Table). A lower HAQ score of ≤0.5 vs. 1.0-1.5 was predictive of CDAI and DAS28 remission (P<0.05 for both) and male gender was significantly predictive of SDAI and DAS28 remission (P<0.05 for both). Levels of rheumatoid factor (RF) and anticyclic citrullinated peptide (anti-CCP) levels at baseline were not predictive of remission response at Week 36 (P>0.10). Results for the continuous versions of these baseline predictors support the dichotomous results presented here. The only continuous baseline characteristic from DAS28, CDAI, and SDAI that was significantly predictive of all 3 remission measurement tools, after adjusting for baseline measurements, was DAS28 (P<0.05). However, baseline CDAI and SDAI were significantly predictive of CDAI and SDAI remission, respectively (P<0.05 for both).
Conclusions: Younger age, lower HAQ and lower DAS28 at baseline may be significantly predictive of SDAI, CDAI, and DAS28 remission in patients with moderately active RA on combined ETN-MTX therapy. Baseline RF and anti-CCP levels were not predictive of remission. These data may help clinicians manage patients according to the current treatment guidelines and more effectively treat patients to remission.
References: 1. Smolen JS, et al. Ann Rheum Dis 2010;69:631. 2. Pincus T, et al. Arthritis Rheum 2005;52:1009. 3. Mader R, et al. J Rheumatol Suppl 2007;80:16. 4. Smolen J, et al. Presented at Excellence in Rheumatology, 2011, Istanbul, Turkey.
Disclosure: J. Smolen, Pfizer Inc, 2, Pfizer Inc, 5 ; A. Szumski, None; L. Marshall, Pfizer Inc, 1, Pfizer Inc, 3 ; A. S. Koenig, Pfizer Inc, 1, Pfizer Inc, 3 .