Long-term clinical outcomes in early rheumatoid arthritis that was treated-to-target in the BeSt and IMPROVED studies.

OBJECTIVES:To assess disease outcomes after 20 and 12 years of patients with rheumatoid (RA) or undifferentiated arthritis (UA), treated-to-target in the BeSt and IMPROVED trials. METHODS:In BeSt (inclusion 2000-2002, duration 10 years), 508 patients with early RA were randomized to: 1. sequential monotherapy, 2. step-up combination therapy, 3. initial csDMARD combination therapy, 4. initial bDMARD/csDMARD combination therapy. The treatment target was low disease activity (DAS ≤ 2.4).In IMPROVED (inclusion 2007-2010, duration 5 years), 610 patients with early RA/UA started MTX with prednisone bridging. The treatment target was remission (DAS < 1.6). Patients not in early remission were randomized to 1. csDMARD combination therapy or 2. bDMARD/csDMARD combination therapy.Between 2019-2022, these patients were invited for long-term follow-up. RESULTS:One-hundred-fifty-three ex-Best and 282 ex-IMPROVED patients participated in the follow-up study after median 12 and 20 years since study start.In ex-BeSt and ex-IMPROVED patients the rate of low disease activity was 91%, and 68% were in DAS remission. Median SHS was 14.0 in ex-BeSt (IQR 6.0-32.5; progression since end BeSt 6.0, IQR 2.0-12.5) and 8 in ex-IMPROVED participants (IQR 3-16; progression since end IMPROVED 4, IQR 2-9). Mean HAQ was 0.8 ± 0.6 in ex-BeSt (change since end BeSt: 0.3 ± 0.5) and 0.6 ± 0.6 in ex-IMPROVED participants (change since end IMPROVED: 0.06 ± 0.5). CONCLUSION:At 12/20 years after treatment start, the majority of RA and UA patients who had been treated to target low DAS or DAS remission were in DAS remission and had limited functional disability. Radiographic damage progression was mild although not completely suppressed.