Interventions for tophi in gout.

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.

Interventions for tophi in gout.

BACKGROUND: Tophi develop in untreated or uncontrolled gout. Their presence can lead to severe and potentially fatal complications. To date there have been no systematic reviews focused on the management of tophi in gout. OBJECTIVES: To assess the benefits and harms of non-surgical and surgical treatments for the management of tophi in gout. SEARCH METHODS: We searched three databases: the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, EMBASE. We handsearched American College of Rheumatology (ACR) and European League against Rheumatism (EULAR) abstracts from 2010 to 2011, references from included studies and trial registries. We completed the most recent search on 20 May 2013. SELECTION CRITERIA: All published randomised controlled trials (RCTs) or controlled clinical trials with quasi-randomised methods of allocating participants to treatment examining interventions for tophi in gout in adults. Possible interventions included urate-lowering pharmacological treatment (e.g. benzbromarone, probenecid, allopurinol, febuxostat, pegloticase), surgical removal or other interventions such as haemodialysis. DATA COLLECTION AND ANALYSIS: Two review authors extracted data from titles, abstracts and selected studies for detailed review, and extracted data and risk of bias independently. Major outcomes were number of participants with complete resolution of tophi, number of study participant withdrawals due to adverse events, joint pain reduction, function, quality of life, serum urate normalisation and total adverse events. MAIN RESULTS: Only one study, at low risk of all biases, met the inclusion criteria. This was the pooled results from two RCTs (225 participants, 145 with tophi at baseline) randomised to one of three arms; pegloticase infusion every two weeks (biweekly), monthly pegloticase infusion (pegloticase infusion alternating with placebo infusion every two weeks) and placebo. Moderate-quality evidence from one study indicated that biweekly pegloticase 8 mg infusion reduced tophi in the subset of participants with tophi, but increased withdrawals due to adverse events in all participants, and monthly infusion appeared to result in less benefit.Biweekly pegloticase treatment resulted in resolution of tophi in 21/52 participants compared with 2/27 who received placebo (risk ratio (RR) 5.45, 95% confidence intervals (CI) 1.38 to 21.54; number needed to treat for an additional beneficial outcome (NNTB) 3 (95% CI 2 to 6).Eleven of 52 participants with monthly pegloticase treatment had complete resolution of one or more tophi compared with 2/27 who received placebo (RR 2.86, 95% CI 0.68 to 11.97).Participant-reported pain relief of 30% or greater, function, quality of life, serum urate normalisation, were reported for all participants but not separately for those with tophi; therefore, we did not include the results.Pegloticase administered biweekly resulted in more withdrawals due to adverse events compared with placebo (15/85 participants with pegloticase versus 1/43 participants with placebo; RR 7.59, 95% CI 1.04 to 55.55; number needed to treat for an additional harmful outcome (NNTH) 7, 95% CI 4 to 17). Pegloticase administered monthly also resulted in more withdrawals due to adverse events than placebo (16/84 participants with pegloticase versus 1/43 participants with placebo; RR 8.19, 95% CI 1.12 to 59.71; NNTH 6, 95% CI 4 to 14). Most withdrawals were due to infusion reactions.Total adverse events were high in all treatment groups: 80/85 participants administered pegloticase biweekly reported an adverse event compared with 41/43 from the placebo group (RR 0.99, 95% CI 0.91 to 1.07); 84/84 participants administered pegloticase monthly reported an adverse event versus 41/43 in the placebo group (RR 1.05, 95% CI 0.98 to 1.14). As 80% of adverse events were due to flares of gout, probably unrelated to the drug treatment per se, this may explain the high rate of adverse events in the placebo group - who were essentially untreated. AUTHORS' CONCLUSIONS: This study showed pegloticase is probably beneficial in the management of tophi in gout, in terms of resolution of tophi, but with a high risk of adverse infusion reactions. However, there is a need for more RCT data considering other interventions, including surgical removal of tophi.