Background Although it is advised to treat Rheumatoid Arthritis (RA) patients with Methotrexate (MTX) as co-medication in the treatment with Tumor Necrosis Factor inhibitors (TNFi), there is a body of patients that is treated with TNFi mono-therapy or combination therapy without MTX in daily clinical practice. We hypothesize a difference in effectiveness and drug survival between TNFi mono-therapy, combination therapy (TNFi + MTX) and non MTX-DMARD combination therapy.
Objectives To compare TNFi mono-therapy with TNFi combination therapy with and without MTX on drug survival and DAS28 over time in patients with RA.
Methods Data from the DREAM registry was used. Patients starting with their first TNFi treatment were analyzed, comparing mono-therapy and combination therapy with and without MTX. Drug survival was analyzed with Kaplan-Meijer and Cox regression. Effectiveness on DAS28 was analyzed by repeated measure analyses. Both analyses were corrected for confounders (age, gender, disease duration, weight, erosive disease, rheumatoid factor, DAS28 + HAQ-DI at baseline).
Results 261 patients started mono-therapy, 335 combination therapy without MTX, and 1337 with MTX. The 3 groups differed at some baseline characteristics: % female (74.3, 71.9, 66.9), disease duration (10.3, 10.3, 9.2), and DAS28 (5.15, 4.98, 4.87) and HAQ-DI at baseline (1.44, 1.45, 1.30) (p-value < 0.1). Combination therapy with MTX had a significantly longer drug survival (Figure1), median time of use 6.0, 1.3 and 2.6 years respectively, (p-value=0.000), and significantly better DAS28 (Figure2) over time (p-value=0.000), both after correction for confounders, than the mono- and the combination without MTX therapy group. Combination therapy without MTX had a significantly longer drug survival than mono-therapy (p-value=0.000) but no better DAS28 over time (p-value=0.245).
Conclusions All 3 therapy strategies provide positive outcomes but combination therapy with MTX is significantly better than TNFi mono-therapy and combination therapy without MTX in daily practice. Therefore it is important that rheumatologists follow the recommendations of the clinical guidelines and prescribe TNFi with MTX as co-medication. If this is not possible, combination therapy without MTX is the next best alternative for better drug survival.
Disclosure of Interest None Declared