Gold therapy in rheumatoid arthritis. Interim report of the Canadian multicenter prospective trial comparing sodium aurothiomalate and auranofin.

One hundred and twelve patients with classical or definite rheumatoid arthritis (RA) were randomly assigned to receive either sodium aurothiomalate (GSTM) or auranofin (AF). Monthly clinical assessments (morning stiffness, grip strength, articular index, pain, quality of life) and concurrent hematological, biochemical, and urine studies were performed to monitor the efficacy/toxicity (E/T) ratio. Ninety-two patients have completed 3 months; 65, 6 months; 47, 9 months; and 30, 12 months. The groups were numerically balanced at each time period. Analysis of the 0-6 month period suggests that both drugs were equally and significantly beneficial after 3 months and that this was maintained at 6 months. Toxicity was as frequent in both groups but more serious in the GSTM group. The main side effects were gastrointestinal (diarrhea) in the AF group and mucocutaneous in the GSTM group. Half of the withdrawals (14 in each group) were because of side effects in the GSTM group and for inadequate therapeutic efficacy in the AF group. This study suggests that after 6 months of treatment the E/T ratio of AF is greater than or equal to that of GSTM. These conclusions will need to be confirmed during the ongoing longer observation period. A significant clinical difference between the 2 drugs is that in a given patient treated with GSTM, the onset of toxicity coincides with a good therapeutic effect. This relationship does not appear to exist during AF treatment.