OP-0045 – Methotrexate (MTX) and Sulfasalazine (SSZ) Therapy in DMARD Naïve Patients with Early RA in a Real Life Setting: Comparison of Baseline Characteristics and Response Rates
Lie, Kaufmann, Mikkelsen, Rodevand, Koldingsnes, Kvien. Norway
Objective
The aim of this study was to characterize response and remission rates in early inflammatory arthritis patients who were treated with either MTX or SSZ monotherapy as initial first line therapy.
Methods
Data were provided by the NOR-DMARD register. Adult patients (>18 y.o.) with inflammatory arthropathies of less than 3 yrs duration, and who were DMARD naïve and treated with a DMARD or anti-TNF monotherapy, were consecutively included and followed longitudinally. Independent samples T test and Chi-squared test were used for comparison of baseline characteristics and response and remission rates.
Results
753 MTX, and 174 SSZ, treated patients were evaluated. Patients who were prescribed SSZ were younger, more often RF negative, and had milder disease than those started on MTX. Response and remission rates were as follows for the MTX and SSZ groups, respectively: EULAR good response 35/31% (p=0.39), SDAI major response 26/14% (p=0.004), CDAI major response 41/23% (p<0.001), DAS28 remission 27/31% (p=0.47), SDAI remission 10/9% (p=0.54), CDAI remission 12/13%. A survival analysis was performed (with adjustment for disease activity/severity via a propensity score). At 2000 days of followup, 59% of MTX treated patients remained on the drug, while only 27% of SSZ treated patients remained on the drug (hazard ratio for discontinuation of SSZ/MTX=2.56).
Conclusions
Response and remission rates were similar in the MTX and SSZ monotherapy groups. But patients were less likely to remain on SSZ than MTX in the long-term.
Editorial Comment
These data were derived from a registry, rather than a placebo controlled, randomized trial. Thus, the comparison of response and remission rates between the two treatment groups is hard to interpret because of the significant differences in baseline characteristics between the groups, for which the investigators apparently did not adjust. These differences (e.g., SSZ treated patients had milder and seronegative disease) may be important confounders of the results. In the survival analysis, the investigators did take into account these differences, and found a greater dropout of SSZ compared to MTX in the long-term, suggesting poorer efficacy and/or more adverse events in the SSZ treated group. It would have been instructive if the investigators had provided us with information as to the causes of dropout in each treatment group.
