To determine the efficacy and the safety of IX 207-887 treatment in rheumatoid arthritis. The IX compound [10-methoxy-4H-benzo(4,5)cyclohepta-(1,2-b)thiophene-4-yliden acetic acid] is effective in several animal models of rheumatoid arthritis and has a mechanism of action involving the inhibition of interleukin-1 release.
A double-blind, controlled trial of 16 weeks' duration comparing placebo with IX at a daily dosage of 800 mg or 1,200 mg (20 patients/group) was conducted.
Thirteen patients withdrew from the study, 3 because of lack of efficacy (all in the placebo group) and 10 because of side effects (1 in the placebo group [skin rash] and 9 in the IX groups [skin rash in 5, intestinal disturbances in 2, hepatitis in 1, meningitis in 1]). Intent-to-treat analysis showed a statistically significant difference in the variations of clinical and laboratory parameters between the 3 groups. Between-group comparisons showed an improvement in all these variables in the IX groups versus the placebo group. According to Paulus' criteria, 2 of the 20 placebo-treated patients (10%), 9 of the 20 IX 800 mg-treated patients (45%), and 11 of the 20 IX 1,200 mg-treated patients (55%) were considered responders (P = 0.008).
The findings of this study suggest that the tolerability of IX is acceptable in rheumatoid arthritis patients, and that IX is an effective slow-acting drug for use in rheumatoid arthritis.