Hydroxychloroquine treatment does not prevent RA onset in at-risk individuals

In individuals at risk of rheumatoid arthritis (RA), 12 months of treatment with hydroxychloroquine falls short of preventing the development of the disease, according to the results of a phase II trial.

The trial included 144 participants (mean age 50.5 years, 79.9 percent female, 79.2 percent White) who had serum elevations of anticyclic citrullinated peptide (anti-CCP) antibodies (at least two times the upper limit of normal).

The participants were randomly assigned to receive treatment with either hydroxychloroquine (155 mg of active drug per 200 mg tablet) (n=71) or placebo (n=73). Treatment was administered once or twice daily, as dictated by ideal body weight, for 12 months, with post-treatment follow-up of up to 24 months.

The primary outcome was the development of clinical RA at 36 months. Other outcomes included safety, the incidence of inflammatory arthritis, and participant-reported joint symptoms.

In the modified intent-to-treat analysis, the incidence of clinical RA did not significantly differ between the two treatment groups, occurring in 30.4 of hydroxychloroquine-treated participants vs 32.9 percent of those who received placebo. The estimated risk of clinical RA at 36 months was 0.336 with hydroxychloroquine vs 0.394 with placebo (difference, −0.058, 95 percent confidence interval, −0.336 to 0.220; p=0.52).

Results for inflammatory arthritis were similar. Additionally, there was no significant between-group difference observed in the occurrence and severity of joint symptoms.

The incidence of adverse events was comparable between the two treatment groups.