Interventions for tophi in gout.

ABSTRACT

BACKGROUND: Tophi develop in untreated or uncontrolled gout. This is an update of a Cochrane Review first published in 2014.  OBJECTIVES: To assess the benefits and harms of non-surgical and surgical treatments for the management of tophi in gout. SEARCH METHODS: We updated the search of Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE and Embase databases to 28 August 2020. SELECTION CRITERIA We included all published randomised controlled trials (RCTs) or controlled clinical trials examining interventions for tophi in gout in adults. DATA COLLECTION AND ANALYSIS: We used standard methodological procedures expected by Cochrane. MAIN RESULTS: We included one trial in our original review. We added four more trials (1796 participants) in this update. One had three arms; pegloticase infusion every two weeks (biweekly), monthly pegloticase infusion (pegloticase infusion alternating with placebo infusion every two weeks) and placebo. Two studies looked at lesinurad 200 mg or 400 mg in combination with allopurinol. One trial studied lesinurad 200 mg or 400 mg in combination with febuxostat. One trial compared febuxostat 80 mg and 120 mg to allopurinol. Two trials were at unclear risk of performance and detection bias due to lack of information on blinding of participants and personnel. All other trials were at low risk of bias. Moderate-certainty evidence (downgraded for imprecision; one study; 79 participants) showed that biweekly pegloticase resolved tophi in 21/52 participants compared with 2/27 on placebo (risk ratio (RR) 5.45, 95% confidence interval (CI) 1.38 to 21.54; number needed to treat for a benefit (NNTB) 3, 95% CI 2 to 6). Similar proportions of participants receiving biweekly pegloticase (80/85) had an adverse event compared to placebo (41/43) (RR 0.99, 95% CI 0.91 to 1.07). However, more participants on biweekly pegloticase (15/85) withdrew due to an adverse event compared to placebo (1/43) (RR 7.59, 95% CI 1.04 to 55.55; number needed to treat for a harm (NNTH) 7, 95% CI 4 to 16). More participants on monthly pegloticase (11/52) showed complete resolution of tophi compared with placebo (2/27) (RR 2.86, 95% CI 0.68 to 11.97; NNTB 8, 95% CI 4 to 91). Similar numbers of participants on monthly pegloticase (84/84) had an adverse event compared to placebo (41/43) (RR 1.05, 95% CI 0.98 to 1.14). More participants on monthly pegloticase (16/84) withdrew due to adverse events compared to placebo (1/43) (RR 8.19, 95% CI 1.12 to 59.71; NNTH 6, 95% CI 4 to 14). Infusion reaction was the most common reason for withdrawal. Moderate-certainty evidence (2 studies; 103 participants; downgraded for imprecision) showed no clinically significant difference for complete resolution of target tophus in the lesinurad 200 mg plus allopurinol arm (11/53) compared to the placebo plus allopurinol arm (16/50) (RR 0.40, 95% CI 0.04 to 4.57), or in the lesinurad 400 mg plus allopurinol arm (12/48) compared to the placebo plus allopurinol arm (16/50) (RR 0.79, 95% CI 0.42 to 1.49). An extension study examined lesinurad 200 mg or 400 mg in combination with febuxostat, or placebo (low-certainty evidence, downgraded for indirectness and imprecision). Participants on lesinurad in the original study continued (CONT) on the same dose. Lesinurad 400 mg plus febuxostat may be beneficial for tophi resolution; 43/65 in the lesinurad 400 mg CONT arm compared to 38/64 in the lesinurad 200 mg CONT arm had tophi resolution (RR 1.11, 95% CI 0.85 to 1.46). Lesinurad 400 mg plus febuxostat may result in no difference in adverse events; 57/65 in the lesinurad 400 mg CONT arm had an adverse event compared to 50/64 in lesinurad 200 mg CONT arm (RR 1.12, 95% CI 0.96 to 1.32). Lesinurad 400 mg plus febuxostat may result in no difference in withdrawals due to adverse events; 10/65 participants in the lesinurad 400 mg CONT arm withdrew due to an adverse event compared to 10/64 participants in the lesinurad 200 mg CONT arm (RR 0.98, 95% CI 0.44 to 2.20). Lesinurad 400 mg plus febuxostat may result in no difference in mean serum uric acid (sUA), which was 3 mg/dl in the lesinurad 400 mg CONT group compared to 3.9 mg/dl in the lesinurad 200 mg CONT group (mean difference -0.90, 95% CI -1.51 to -0.29). Participants who were not on lesinurad in the original study were randomised (CROSS) to lesinurad 200 mg or 400 mg, both in combination with febuxostat. Low-certainty evidence downgraded for indirectness and imprecision showed that lesinurad 400 mg (CROSS) may result in tophi resolution (17/34) compared to lesinurad 200 mg (CROSS) (14/33) (RR 1.18, 95% CI 0.70 to 1.98). Lesinurad 400 mg in combination with febuxostat may result in no difference in adverse events (33/34 in the lesinurad 400 mg CROSS arm compared to 27/33 in the lesinurad 200 mg (CROSS); RR 1.19, 95% CI 1.00 to 1.41). Lesinurad 400 mg plus febuxostat may result in no difference in withdrawals due to adverse events, 5/34 in the lesinurad 400 mg CROSS arm withdrew compared to 2/33 in the lesinurad 200 mg CROSS arm (RR 2.43, 95% CI 0.51 to 11.64). Lesinurad 400 mg plus febuxostat results in no difference in sUA (4.2 mg/dl in lesinurad 400 mg CROSS) compared to lesinurad 200 mg (3.8 mg/dl in lesinurad 200 mg CROSS), mean difference 0.40 mg/dl, 95% CI -0.75 to 1.55. AUTHORS' CONCLUSIONS: Moderate-certainty evidence showed that pegloticase is probably beneficial for resolution of tophi in gout. Although there was little difference in adverse events when compared to placebo, participants on pegloticase had more withdrawals due to adverse events. Lesinurad 400 mg plus febuxostat may be beneficial for tophi resolution compared with lesinurad 200 mg plus febuxostat; there was no difference in adverse events between these groups. We were unable to determine whether lesinurad plus febuxostat is more effective than placebo. Lesinurad (400 mg or 200 mg) plus allopurinol is probably not beneficial for tophi resolution, and there was no difference in adverse events between these groups. RCTs on interventions for managing tophi in gout are needed, and the lack of trial data is surprising given that allopurinol is a well-established treatment for gout.