Optimal range of serum urate concentrations to minimize risk of gouty attacks during anti-hyperuricemic treatment

Management and Cure of Gouty Arthritis

Gout is the most common inflammatory arthritis in the United States. Gouty arthritis is associated with significant morbidity and mortality and is the result of chronic hyperuricemia. Gout is effectively managed and potentially cured by decreasing the overall urate burden with serum urate-lowering therapy. When serum urate is maintained at less than 6.0 mg/dL, urate deposition is resolved, and gout can be cured. Unfortunately, because of less than optimal physician monitoring and dose escalation, many patients do not achieve these urate levels.

Management and Cure of Gouty Arthritis

Gout is the most common inflammatory arthritis in the United States. Gouty arthritis is associated with significant morbidity and mortality and is caused by hyperuricemia. Gout is effectively managed and potentially cured by decreasing the overall urate burden with serum urate-lowering therapy. When serum urate is maintained at less than 6.0 mg/dL urate deposition is resolved and gout can be cured. Unfortunately, owing to a lack of physician monitoring and dose escalation the majority of patients do not achieve these urate levels.

Dotinurad versus benzbromarone in Japanese hyperuricemic patient with or without gout: a randomized, double-blind, parallel-group, phase 3 study

Background

Dotinurad is a novel selective urate reabsorption inhibitor that reduces serum urate levels in hyperuricemic patients with or without gout by selectively inhibiting urate transporter 1. This study was conducted to compare the efficacy and safety of dotinurad with those of benzbromarone.

Methods

In this 14-week, randomized, multicenter, double-blind, parallel-group, dose escalation, benzbromarone-controlled, phase 3 study, hyperuricemic patients with or without gout were randomized to two groups that received either dotinurad 2 mg or benzbromarone 50 mg. Dotinurad or benzbromarone was administered once a day for 14 weeks. The primary endpoint was the percent change in serum uric acid level from the baseline to the final visit.

Results

A total of 201 Japanese hyperuricemic patients with or without gout (dotinurad: 102, benzbromarone: 99) received at least one dose of the study drug. The mean percent change in serum uric acid level from the baseline to the final visit in the dotinurad and benzbromarone groups was 45.9% and 43.8%, respectively. Non-inferiority of dotinurad 2 mg to benzbromarone 50 mg in lowering serum uric acid was verified by the predefined non-inferiority margin (95% CI − 1.27 to 5.37%). The incidence of adverse events and adverse drug reactions was comparable between the two groups.

Conclusion

Dotinurad 2 mg was verified to have a non-inferior serum uric acid lowering effect compared with benzbromarone 50 mg, in Japanese hyperuricemic patients with or without gout.

ClinicalTrials.gov Identifier

NCT03100318.

Open-label study of long-term administration of dotinurad in Japanese hyperuricemic patients with or without gout

BACKGROUND

Dotinurad is a novel selective urate reabsorption inhibitor (SURI) which reduces serum uric acid levels by selectively inhibiting urate transporter 1 (URAT1). This study was intended to verify the efficacy and safety of dotinurad following treatment for 34 or 58 weeks in hyperuricemic patients with or without gout.

METHODS

This long-term study had an open-label design with dose escalation. The dose of dotinurad started at 0.5 mg/day and was increased progressively to 2 mg/day. If the serum uric acid level of patients did not reach ≤ 6 mg/dL at week 14, the dose was increased to 4 mg/day. The primary endpoint was the percent change in serum uric acid level from the baseline to each visit.

RESULTS

At a dose of 2 mg, serum uric acid levels at week 34 and 58 were reduced from the baseline by 46.73% and 47.17%, respectively; at 4 mg, the respective values were 54.92% and 57.35%. At week 34 and 58, the percentages of patients achieving a serum uric acid levels ≤ 6.0 mg/dL with 2-mg dose were 89.11% and 91.30%, respectively; with 4 mg, the respective rates were 97.50% and 100.00%. In addition, the incidences of adverse events and adverse drug reactions were 65.2% and 21.8%, respectively.

CONCLUSION

Dotinurad at doses of 2-4-mg sufficiently reduced serum uric acid levels in hyperuricemic patients with or without gout, and its efficacy and safety were verified for long-term administration. ClinicalTrials.gov Identifier: NCT03006445.

Clinical efficacy and safety of dotinurad, a novel selective urate reabsorption inhibitor, in Japanese hyperuricemic patients with or without gout: randomized, multicenter, double-blind, placebo-controlled, parallel-group, confirmatory phase 2 study

BACKGROUND

Dotinurad, a novel selective urate reabsorption inhibitor (SURI), reduces serum uric acid levels by selectively inhibiting urate transporter 1 (URAT1) for the treatment of hyperuricemia with or without gout. We confirmed the serum uric acid lowering effect and safety of dotinurad.

METHODS

This was a confirmatory, 12-week, randomized, multicenter, double-blind, placebo-controlled, parallel-group, dose escalation, late phase 2 study. The study arms were dotinurad 0.5, 1, 2, or 4 mg and placebo. The primary endpoint was the percent change in serum uric acid level from the baseline to the final visit. The secondary endpoint was the percentage of patients achieving a serum uric acid level ≤ 6.0 mg/dL at the final visit.

RESULTS

The study drugs were administered to 200 Japanese hyperuricemic patients with or without gout. The mean percent change in serum uric acid level from the baseline to the final visit in the dotinurad 0.5, 1, 2, and 4 mg groups and the placebo group was 21.81%, 33.77%, 42.66%, 61.09%, and - 2.83%, respectively. The percentage of patients achieving a serum uric acid level ≤ 6.0 mg/dL at the final visit in each group was 23.1%, 65.9%, 74.4%, 100%, and none, respectively. Regarding safety, the incidence of adverse events did not increase with dose escalation in the dotinurad groups. No significant differences were observed in the incidence of gouty arthritis in each group.

CONCLUSION

The serum uric acid lowering effect and safety of dotinurad were confirmed in hyperuricemic patients with or without gout. CLINICALTRIALS.

GOV IDENTIFIER

NCT02416167.

Clinical efficacy and safety of dotinurad, a novel selective urate reabsorption inhibitor, in Japanese hyperuricemic patients with or without gout: an exploratory, randomized, multicenter, double-blind, placebo-controlled, parallel-group early phase 2 study

Background

Dotinurad, a novel selective urate reabsorption inhibitor (SURI) that has a future potential for the treatment of hyperuricemia, reduces serum uric acid levels by selectively inhibiting urate transporter 1 (URAT1). We evaluated the efficacy and safety of dotinurad in hyperuricemic Japanese patients with or without gout.

Methods

The study design was an exploratory, early phase 2 study that ran for 8 weeks. It was a randomized, multicenter, double-blind, placebo-controlled, parallel-group study, and performed in a dose escalation manner. There were four study arms consisting of dotinurad 1, 2, or 4 mg, and placebo. The primary endpoint was the percent change in serum uric acid level from the baseline to the final visit. The secondary endpoint was the percentage of patients achieving a serum uric acid level ≤ 6.0 mg/dL at the final visit.

Results

A total of 80 hyperuricemic patients with or without gout were enrolled and randomly assigned to the dotinurad or placebo groups. The mean percent change in serum uric acid level from the baseline to the final visit in the dotinurad 1, 2, 4 mg, and placebo groups was 37.03%, 50.91%, 64.37%, and 0.85%, respectively. The percentages of patients achieving a serum uric acid level ≤ 6.0 mg/dL at the final visit in each group were 75.0%, 89.5%, 95.2%, and none, respectively. The incidence of adverse events was comparable among all groups.

Conclusion

Dotinurad has a substantial serum uric acid lowering effect in patients with hyperuricemia. No serious adverse event was found.

ClinicalTrials.gov Identifier

NCT02344862

Raman Spectroscopy as an Assay to Disentangle Zinc Oxide Carbon Nanotube Composites for Optimized Uric Acid Detection

Refluxed zinc oxide (ZnO) nanoparticles (NPs) were prepared and attached to carboxylic acid functionalized multi-walled carbon nanotubes (COOH-MWNTs) via sonication. Practical optimization of electrocatalysts using sonication to disentangle a carbon nanotube composite for monitoring uric acid (UA) is shown. Monitoring UA is important for the management of medical disorders. Selection of sonication time is a crucial step in producing the desired composite. We report, for the first time, the practical use of Raman spectroscopy to tune the sonication involved in tethering ZnO NPs to the multi-walled carbon nanotube (MWNT) surface. Maximum current for detecting UA, using chronoamperometry and cyclic voltammetry, correlated with the highest sp2-hybridized carbon signal, as seen in the integrated Raman G band peak areas denoting maximum COOH-MWNT disentanglement. An array of ZnO/COOH-MWNT composites were prepared ranging from 60 to 240 min sonication times. Optimum sonication (150 min) corresponded with both maximum measured current and MWNT disentanglement. The sensor was able to quantitatively and selectively measure UA at clinically relevant concentrations (100–900 μM) with rapid current response time (< 5 s).

Previous Dosage of Allopurinol Is a Strong Determinant of Febuxostat Efficacy

Febuxostat has currently played pivotal role in the treatment of hyperuricemia, but there is little comprehensive information for the determinants of individual difference in efficacy of febuxostat. Therefore, the present study, a retrospective investigation, was carried out to analyze the effects of patient characteristics on the efficacy of febuxostat. A total of 225 patients who were continuously prescribed the same dose of febuxostat for 8-12 weeks from the initial therapy were enrolled in the present study. The data, including patient information and laboratory data, were collected from electronic medical records. Serum urate lowering effects of febuxostat were evaluated by calculating the change in serum urate level at baseline and at 8-12 weeks after starting febuxostat. The multiple regression analysis showed the change in serum urate level was significantly lower in male patients and in those with a lower baseline serum urate level, higher previous dose of allopurinol, lower dose of febuxostat and lower body surface area-unadjusted estimated glomerular filtration rate. Concomitantly administered drugs did not show a significantly influence on the efficacy of febuxostat. In conclusion, it should be noted that the serum urate lowering efficacy of febuxostat may decrease in patients with a higher previous dose of allopurinol, renal impairment or male patients. The basic findings of the present study are believed to contribute to the proper use of febuxostat.

Effects of the Dietary Approaches to Stop Hypertension (DASH) Diet and Sodium Intake on Serum Uric Acid

OBJECTIVE

Randomized trial data guiding dietary recommendations to lower serum uric acid (UA), the etiologic precursor of gout, are scarce. We undertook this study to examine the effects of the Dietary Approaches to Stop Hypertension (DASH) diet (a well-established diet that lowers blood pressure) and levels of sodium intake on serum UA.

METHODS

We conducted an ancillary study of a randomized, crossover feeding trial in 103 adults with prehypertension or stage I hypertension. Participants were randomly assigned to receive either the DASH diet or a control diet (typical of the average American diet) and were further fed low, medium, and high levels of sodium for 30 days, each in random order. Body weight was kept constant. Serum UA levels were measured at baseline and following each feeding period.

RESULTS

Trial participants were 55% women and 75% black with a mean ± SD age of 51.5 ± 9.7 years and a mean ± SD serum UA level of 5.0 ± 1.3 mg/dl. The DASH diet reduced serum UA (-0.35 mg/dl [95% confidence interval (95% CI) -0.65, -0.05], P = 0.02), with a higher effect (-1.29 mg/dl [95% CI -2.50, -0.08]) among participants (n = 8) with a baseline serum UA level of ≥7 mg/dl. Increasing sodium intake from the low level decreased serum UA during the medium sodium intake period (-0.3 mg/dl [95% CI -0.5, -0.2], P < 0.001) and during the high sodium intake period (-0.4 mg/dl [95% CI -0.6, -0.3], P < 0.001).

CONCLUSION

The DASH diet lowered serum UA, and this effect was greater among participants with hyperuricemia. Moreover, we found that higher sodium intake decreased serum UA, which enhances our knowledge of urate pathophysiology and risk factors for hyperuricemia.

Clinical efficacy and safety of topiroxostat in Japanese hyperuricemic patients with or without gout: a randomized, double-blinded, controlled phase 2b study

Topiroxostat, a selective xanthine oxidoreductase inhibitor, is used in Japan for the treatment of hyperuricemic patients with or without gout. In terms of the effectiveness of topiroxostat in lowering serum urate levels, the dose-response relationship has been evaluated; however, it remains to be verified. A randomized, multi-center, double-blinded study of topiroxostat was performed for Japanese hyperuricemic patients with or without gout. During the 16-week study, 157 Japanese hyperuricemic patients with or without gout were randomly assigned to receive a placebo, topiroxostat at 120 or 160 mg/day, or allopurinol at 200 mg/day. The primary endpoint of this study was to determine the lowering rate of serum uric acid levels compared to those of baseline at the end of administration. A dose-response relationship (regarding decreases in the serum urate levels) was confirmed for the placebo and topiroxostat at 120 and at 160 mg/day. Moreover, at the end of administration, the lowering rate of serum urate levels was determined to be -44.8% in the topiroxostat 160-mg/day group. No significant difference in the incidence of adverse events was observed among all groups, including the allopurinol group. The serum urate-lowering effect of topiroxostat was found to have a dose-response relationship in Japanese hyperuricemic patients with or without gout.

Febuxostat: A Novel, Non-Purine Xanthine Oxidase Inhibitor

Objective:

To review the pharmacology and clinical data for febuxostat in the treatment of gout and hyperuricemia.

Data Sources:

Articles on febuxostat published in English between 1966 and November 2006 were identified through a MEDLINE search using the key words febuxostat, TEI-6720, TMX-67, gout, and hyperuricemia. Additional articles were identified through search of the publications' reference lists. Abstracts from the 2005 proceedings of the American College of Rheumatology, American College of Clinical Pharmacology, and American Society for Clinical Pharmacology and Therapeutics were also searched for febuxostat studies.

Study Selection and Data Extraction:

All published febuxostat trials in humans were selected for this review. Clinical, pharmacokinetic, and pharmacodynamic data were evaluated.

Data Synthesis:

Febuxostat is a non-purine, selective inhibitor of xanthine oxidase that has demonstrated efficacy in lowering serum uric acid levels in patients with hyperuricemia associated with gout. Compared with allopurinol 300 mg/day, febuxostat 80 or 120 mg/day was more effective in lowering serum uric acid levels to less than 6 mg/dL. Febuxostat appears to be safe, with the majority of treatment-related adverse events reported being transient and mild-to-moderate in severity. However, abnormal elevation of liver enzyme levels has been reported with its use. There have been no documented major drug interactions with febuxostat.

Conclusions:

Febuxostat is a novel, non-purine xanthine oxidase inhibitor undergoing review by the FDA. It represents a potential advancement in the treatment of hyperuricemia associated with gout.

Mobile applications to enhance self-management of gout

BACKGROUND

Gout is an arthritic condition that is characterised by extremely painful, debilitating acute attacks and eventual joint and organ damage if not controlled. Despite the availability of very effective therapies that, if adhered to, will prevent acute attacks and long-term damage, the disorder is increasingly prevalent. There is an urgent need to improve self-management of gout.

OBJECTIVES

Mobile health (mHealth) applications ('apps'), designed to facilitate management of chronic conditions, present novel opportunities for supporting patient self-management of gout. The aim of this review was to assess features of available gout management apps designed to assist consumers in managing their gout and their consistency with guidelines for gout management.

METHODS

English-language, smart-device apps designed to assist self-management of gout were identified using search term "gout" and downloaded from Apple and Google Play app stores. To be included in the review, apps had to allow users to monitor their gout disease (e.g. serum uric acid (sUA) tracking, record acute attacks) and/or educate patients about gout. Investigators derived patient-focused recommendations for gout management from contemporary guidelines. Features of reviewed apps were independently assessed by two reviewers for their facilitation of these recommendations.

RESULTS

The search identified 57 apps possibly relevant to gout management, of which six met the inclusion criteria. One app incorporated all recommendations for patient-focused gout management from guidelines including monitoring sUA, recording attacks and lifestyle advice. However, the majority of these elements were not functional within the app, and instead required users to manually complete printouts.

CONCLUSIONS

Currently, only one app exists that includes all recommendations to facilitate patient self-management of gout, however some features can only be actioned manually. Given the lack of progress in achieving better patient outcomes and the promise of mHealth interventions to deliver significant gains, new or updated gout management apps are required to promote successful self-management of this chronic disease.

Comparison of topiroxostat and allopurinol in Japanese hyperuricemic patients with or without gout: a phase 3, multicentre, randomized, double-blind, double-dummy, active-controlled, parallel-group study

WHAT IS KNOWN AND OBJECTIVE

There are no clinical reports that have compared topiroxostat, a selective xanthine oxidase inhibitor, with allopurinol in serum urate-lowering efficacy. The aim of this study was to compare the efficacy and safety of topiroxostat and allopurinol in Japanese hyperuricemic patients with or without gout.

METHODS

A phase 3, multicentre, randomized, double-blind, double-dummy, active-controlled, parallel-group study conducted in Japan. Patients who had inadequate serum urate levels (a gout patient: serum urate level ≥416·4 μmol/L; an asymptomatic hyperuricemic patient with specific complications (urinary lithiasis, hypertension, hyperlipidemia and/or diabetes): serum urate level ≥475·8 μmol/L; and an asymptomatic hyperuricemic patient with no specific complications: serum urate level ≥535·3 μmol/L) were randomized to topiroxostat 120 mg/day or allopurinol 200 mg/day, with an equal allocation ratio, for 16 weeks. To prevent the onset of gouty arthritis by rapid serum urate reduction, these doses were increased in a stepwise manner. The primary efficacy endpoint was the per cent change in serum urate level from baseline to the final visit.

RESULTS AND DISCUSSION

Overall, 206 patients were randomly assigned to topiroxostat and allopurinol. Two hundred and three patients (allopurinol: n = 105, topiroxostat: n = 98) received at least one dose of the study drug and had their serum urate level assessed at least once. The baseline characteristics were comparable between groups. The mean age of patients was 53·0 ± 11·4 years and 99% of patients were male. The primary efficacy endpoint was -34·3 ± 11·1% in the allopurinol group (n = 105) and -36·3 ± 12·7% in the topiroxostat group (n = 98). Non-inferiority of the serum urate-lowering efficacy of topiroxostat to allopurinol was proved by the predefined non-inferiority margin (95% confidence interval, -5·3 to 1·3%). The overall incidences of adverse events and adverse drug reactions were similar between both groups.

WHAT IS NEW AND CONCLUSION

Topiroxostat 120 mg/day provides non-inferior serum urate reduction compared with allopurinol 200 mg/day and is well tolerated in Japanese hyperuricemic patients with or without gout.

Clinical efficacy and safety of topiroxostat in Japanese male hyperuricemic patients with or without gout: an exploratory, phase 2a, multicentre, randomized, double-blind, placebo-controlled study

WHAT IS KNOWN AND OBJECTIVE

In Japan, although topiroxostat, a selective xanthine oxidoreductase inhibitor, has been used for the treatment of patients with hyperuricemia including gout, no published randomized controlled studies evaluating the dose-dependent relationship with respect to the serum urate-lowering efficacy have been reported. The aim of this study was to evaluate the dose-dependent relationship with serum urate-lowering efficacy and safety of topiroxostat in Japanese hyperuricemic patients including gout.

METHODS

We conducted an exploratory, phase 2a, multicentre, randomized, double-blind, 8-week, placebo-controlled study in Japanese hyperuricemic patients with or without gout. The study arms were placebo and topiroxostat 40, 60, 80 or 120 mg/day. The primary efficacy endpoint was the per cent change in serum urate level from baseline to the final visit.

RESULTS AND DISCUSSION

One hundred and eighty-seven eligible patients were randomized and 186 received at least one dose of the study drug. The study results demonstrated a dose-dependent serum urate reduction effect ranging from 40 to 120 mg/day (P < 0·001, Jonckheere-Terpstra test). The mean per cent change in serum urate level from baseline at the final visit was -30·8% in the 120-mg group and 1·6% with placebo, with a between-group difference of -32·4% ([95% confidence interval, -38·9% to -25·9%]; P < 0·001). Incidences of overall adverse events (AEs) in the topiroxostat groups were comparable to those in the placebo group; however, the incidence of AEs in the 120-mg group was statistically lower than that in the placebo group. The incidences of gouty arthritis were not statistically but numerically higher in the topiroxostat 80- and 120-mg groups.

WHAT IS NEW AND CONCLUSIONS

A dose-dependent serum urate-lowering efficacy of topiroxostat was observed in Japanese hyperuricemic male patients with or without gout. Further clinical studies aimed at evaluating the long-term safety and clinical efficacy are warranted.

How neutrophil extracellular traps orchestrate the local immune response in gout

Neutrophil granulocytes possess a large arsenal of pro-inflammatory substances and mechanisms that empower them to drive local acute immune reactions to invading microorganisms or endogenous inflammatory triggers. The use of this armory needs to be tightly controlled to avoid chronic inflammation and collateral tissue damage. In gout, inflammation arises from precipitation of uric acid in the form of needle-shaped monosodium urate crystals. Inflammasome activation by these crystals in local immune cells results in a rapid and dramatic recruitment of neutrophils. This neutrophil influx is accompanied by the infamously intense clinical symptoms of inflammation during an acute gout attack. Neutrophilic inflammation however is equipped with a built-in safeguard; activated neutrophils form neutrophil extracellular traps (NETs). At the very high neutrophil densities that occur at the site of inflammation, NETs build aggregates that densely pack the monosodium urate (MSU) crystals and trap and degrade pro-inflammatory mediators by inherent proteases. Local removal of cytokines and chemokines by aggregated NETs explains how acute inflammation can stop in the consistent presence of the inflammatory trigger. Aggregated NETs resemble early stages of the typical large MSU deposits that constitute the pathognomonic structures of gout, tophi. Although tophi contribute to muscosceletal damage and mortality in patients with chronic gout, they can therefore be considered as a payoff that is necessary to silence the intense inflammatory response during acute gout.

Australian and New Zealand recommendations for the diagnosis and management of gout: integrating systematic literature review and expert opinion in the 3e Initiative

AIM

To develop evidence-based recommendations for the diagnosis and management of gout in Australia and New Zealand as part of the multi-national 3e Initiative.

METHOD

Using a formal voting process, a panel of 78 international rheumatologists selected 10 key clinical questions pertinent to the diagnosis and management of gout. An additional question was also developed by participating Australian and New Zealand rheumatologists. Each question was investigated with a systematic literature review. MEDLINE, EMBASE, Cochrane CENTRAL and abstracts from 2010 to 2011 European League Against Rheumatism and American College of Rheumatology meetings were searched in each review. Relevant studies were independently reviewed by two individuals for data extraction and synthesis and risk of bias assessment. Using this evidence, 47 Australian and New Zealand rheumatologists developed national recommendations. For each recommendation the level of agreement was assessed and the level of evidence graded.

RESULT

Eleven recommendations were produced relating to the diagnosis of gout, different aspects of the management of gout, cardiovascular and renal comorbidities and the management of asymptomatic hyperuricemia. The mean level of agreement with the recommendations was 9.1 on a 1-10 scale, with 10 representing full agreement.

CONCLUSION

Eleven Australian and New Zealand recommendations on the diagnosis and management of gout were developed combining systematically reviewed evidence with local expertise, enhancing their utility in clinical practice.

[Diagnosis and management of gout in Austria. Survey of current practice considering the EULAR recommendations]

BACKGROUND AND OBJECTIVES

Gout shows an increasing incidence and has become a major health problem in the Western world. Despite effective treatment options, neither diagnosis nor therapeutic efforts can be regarded sufficient to date. It was of interest to investigate current handling of gout among Austrian rheumatologists.

MATERIAL AND METHODS

In 2012, a survey of Austrian rheumatologists concerning diagnosis and management of hyperuricemia and gout was performed. With the consent of the Austrian Society of Rheumatology, 574 society members (343 via electronic mail, 23 via mail) were sent a questionnaire consisting of 17 questions. This is the first survey assessing the management of gout among Austrian rheumatologists.

RESULTS

The overall response rate was 22.1 %. Of all the contacted members (email and mail), 19.9 % answered the questionnaire electronically and only 5.6 % by mail. The adherence to the EULAR recommendations for gout ranged between 69 and 95 % (median 84 %).

CONCLUSION

Among Austrian rheumatologists, the knowledge about gout, its diagnostic and imaging procedures, management and therapeutic goals is good and mainly in line with current international recommendations. To improve the management of patients with gout and hyperuricemia, a more frequent referral to rheumatologists could be beneficial.

Current concepts in the treatment of gouty arthritis

Gouty arthritis is an extremely painful condition that causes functional impairment. Gouty arthritis has become increasingly complex because of multiple comorbidities, iatrogenic factors and hyperuricemia that is refractory to treatment. In this review, we present a general overview of gouty arthritis including its pathophysiology, clinical presentations, diagnosis, predisposing factors and prophylactic therapy for preventing gouty arthritis flares.

Multinational evidence-based recommendations for the diagnosis and management of gout: integrating systematic literature review and expert opinion of a broad panel of rheumatologists in the 3e initiative

We aimed to develop evidence-based multinational recommendations for the diagnosis and management of gout. Using a formal voting process, a panel of 78 international rheumatologists developed 10 key clinical questions pertinent to the diagnosis and management of gout. Each question was investigated with a systematic literature review. Medline, Embase, Cochrane CENTRAL and abstracts from 2010-2011 European League Against Rheumatism and American College of Rheumatology meetings were searched in each review. Relevant studies were independently reviewed by two individuals for data extraction and synthesis and risk of bias assessment. Using this evidence, rheumatologists from 14 countries (Europe, South America and Australasia) developed national recommendations. After rounds of discussion and voting, multinational recommendations were formulated. Each recommendation was graded according to the level of evidence. Agreement and potential impact on clinical practice were assessed. Combining evidence and clinical expertise, 10 recommendations were produced. One recommendation referred to the diagnosis of gout, two referred to cardiovascular and renal comorbidities, six focused on different aspects of the management of gout (including drug treatment and monitoring), and the last recommendation referred to the management of asymptomatic hyperuricaemia. The level of agreement with the recommendations ranged from 8.1 to 9.2 (mean 8.7) on a 1-10 scale, with 10 representing full agreement. Ten recommendations on the diagnosis and management of gout were established. They are evidence-based and supported by a large panel of rheumatologists from 14 countries, enhancing their utility in clinical practice.

Questionnaire survey evaluating disease-related knowledge for 149 primary gout patients and 184 doctors in South China

This study aims to investigate the disease-related knowledge of gout patients and doctors in south China and to identify the important targets of education for patients and doctors. A cross-section survey of 154 primary gout patients and 185 doctors who may see gout patients was conducted with a modified questionnaire with ten items of gout-related knowledge. The participants were considered to have gout-related knowledge if he or she correctly answered seven or more items. One hundred and forty-nine valid questionnaires from patients, 33 from rheumatology physicians, and 151 from non-rheumatology doctors were collected for statistical analysis. The mean correctly answered items of three groups were 6.6 ± 2.2, 9.6 ± 0.53, and 8.0 ± 1.4, with rate of being considered to have knowledge about gout 51.7, 100, and 90.1 %, respectively (P < 0.05). The correct answer rate for each particular item was over 80 % in the rheumatology physician group. Patients or non-rheumatology doctors knew the optimal serum uric acid (sUA) level (48.3 vs 55.6 %), the need to take lifelong urate-lowering drugs (29.5 vs 43.6 %), that allopurinol is a urate-lowering drug (55.7 vs 76.0 %), and how to prevent attacks induced by urate-lowering therapy (ULT) (60.4 vs 74.0 %). Logistic regression showed that higher education predicted which patients had gout-related knowledge. Both the gout patients and non-rheumatology doctors in south China had poor knowledge on ULT. Since many gout patients do not see rheumatologists, our data suggest that further education should focus on patients and non-rheumatologists and emphasize the use of urate-lowering drugs, treatment duration, the target sUA level, and prophylaxis against acute attacks.

Treatment of chronic gouty arthritis: it is not just about urate-lowering therapy

OBJECTIVES

The management of gouty arthritis is focused on treating pain and inflammation associated with acute flares and preventing further acute flares and urate crystal deposition. A challenge associated with the successful management of gouty arthritis is an increased risk of acute flares during the first months after initiation of urate-lowering therapy (ULT). This increase in flare frequency can occur regardless of the choice of ULT and is linked to suboptimal patient adherence to ULT. Current treatment recommendations for the use of prophylaxis are limited. There are no definitive recommendations as to which agents should be used or for how long therapy is beneficial after starting ULT. This article aims to improve awareness of the importance of gouty arthritis flare prophylaxis when initiating ULT and to summarize current recommendations and clinical findings related to the efficacy and safety of currently available and investigational new therapies.

METHODS

This review discusses the pathophysiology of acute gouty arthritis flares during initiation of ULT and examines the literature on the use of anti-inflammatory prophylaxis for reduction of these flares.

RESULTS

It has recently become clear that, even when the patient is asymptomatic, chronic inflammation is often present in patients with chronic gouty arthritis. Chronic anti-inflammatory therapy should therefore be added to chronic ULT. Prophylaxis with colchicine as well as with nonsteroidal anti-inflammatory drugs (NSAIDs) during ULT initiation can reduce the incidence and severity of gouty arthritis flares substantially; however, safety concerns associated with colchicine and NSAIDs may limit their use.

CONCLUSION

When colchicine and NSAIDs are contraindicated or poorly tolerated, rilonacept and canakinumab, interleukin-1 inhibitors in trials, may prove to be useful alternatives for flare prevention. (Of note, although both inhibit the IL-1β pathway, rilonacept also binds to IL-1α and IL-1RA, in contrast to canakinumab, which binds selectively to IL-1β.).

Japanese guideline for the management of hyperuricemia and gout: second edition

Gout is a urate deposition disease caused by persistent hyperuricemia. Because gout patients present with a variety of clinical symptoms, it is necessary to have a guideline for the standard management and care of gout and hyperuricemia. The Japanese Society of Gout and Nucleic Acid Metabolism, a scientific society committed to study nucleic acid metabolism and related diseases, established the first edition of the "Guideline for the Management of Hyperuricemia and Gout" in 2002, and published the revised version in January 2010. This second edition is not only evidence based on a search of systemic literature, but also includes consensus levels by a Delphi exercise to determine the strength of the recommendations. A draft version of this guideline was reviewed by internal and external reviewers as well as a patient. In this guideline, key messages from each chapter are listed as statements together with the evidence level, consensus level, and strength of the recommendation. In this proceeding, several selected chapters on the clinical management of gout and hyperuricemia are described. We hope this guideline is appropriately used for the standard management and care of patients with hyperuricemia and gout in daily practice.

The epidemiology and treatment of gout

The development and expression of gout depends on three key steps: (1) chronic hyperuricemia, (2) the growth of monosodium urate (MSU) crystals, and (3) interaction between MSU crystals and the inflammatory system. Epidemiological studies have continued to improve our understanding of the environmental and genetic factors which influence chronic hyperuricemia and gout. The influence of obesity, alcohol, race, sex, age, and specific dietary components will be discussed below. The primary mechanism of hyperuricemia is insufficient renal clearance of uric acid which in turn is dependent on transport of uric acid in the proximal renal tubule. Knowledge of the transport mechanisms has improved understanding of the genetic influences on gout and is relevant to understanding of the effects of drugs which can increase or decrease renal uric acid clearance. The application of established principles of management including diagnosis through crystal identification, the gradual introduction of hypouricemic therapy with the use of prophylaxis to reduce the risk of flares, identification of a suitably low target of plasma urate, a progressive increase in therapy to achieve the target and taking steps to encourage good compliance, has the potential to improve outcomes for patients with this very common affliction. The potential role for new therapies will also be discussed.

Canakinumab reduces the risk of acute gouty arthritis flares during initiation of allopurinol treatment: results of a double-blind, randomised study

Objective

This study assessed the efficacy and safety of canakinumab, a fully human anti-interleukin 1β monoclonal antibody, for prophylaxis against acute gouty arthritis flares in patients initiating urate-lowering treatment.

Methods

In this double-blind, double-dummy, dose-ranging study, 432 patients with gouty arthritis initiating allopurinol treatment were randomised 1:1:1:1:1:1:2 to receive: a single dose of canakinumab, 25, 50, 100, 200, or 300 mg subcutaneously; 4×4-weekly doses of canakinumab (50+50+25+25 mg subcutaneously); or daily colchicine 0.5 mg orally for 16 weeks. Patients recorded details of flares in diaries. The study aimed to determine the canakinumab dose having equivalent efficacy to colchicine 0.5 mg at 16 weeks.

Results

A dose-response for canakinumab was not apparent with any of the four predefined dose-response models. The estimated canakinumab dose with equivalent efficacy to colchicine was below the range of doses tested. At 16 weeks, there was a 62% to 72% reduction in the mean number of flares per patient for canakinumab doses ≥50 mg versus colchicine based on a negative binomial model (rate ratio: 0.28–0.38, p≤0.0083), and the percentage of patients experiencing ≥1 flare was significantly lower for all canakinumab doses (15% to 27%) versus colchicine (44%, p<0.05). There was a 64% to 72% reduction in the risk of experiencing ≥1 flare for canakinumab doses ≥50 mg versus colchicine at 16 weeks (hazard ratio (HR): 0.28–0.36, p≤0.05). The incidence of adverse events was similar across treatment groups.

Conclusions

Single canakinumab doses ≥50 mg or four 4-weekly doses provided superior prophylaxis against flares compared with daily colchicine 0.5 mg.

Febuxostat for the management of hyperuricaemia in patients with gout: a NICE single technology appraisal

As part of the National Institute for Health and Clinical Excellence (NICE) single technology appraisal (STA) process, the manufacturer of febuxostat (Adenuric®; Ipsen, UK) was invited to submit evidence for the clinical and cost effectiveness of febuxostat for the management of hyperuricaemia in patients with gout. The School of Health and Related Research Technology Appraisal Group (ScHARR-TAG) at the University of Sheffield were commissioned to act as the independent Evidence Review Group (ERG). This article provides details of the company's initial submission, the ERG's clarification questions and the ERG report submitted to NICE. The decision made by NICE is provided alongside a brief comment on additional results produced by a substantially different model, which were presented by the manufacturer after the production of the appraisal consultation document. The ERG produced a critical review of the evidence for the clinical evidence and cost effectiveness of the technology based upon the manufacturer's submission to NICE. The clinical evidence was derived from two head-to-head, phase III, multi-arm, randomized, double blind, controlled trials comparing the efficacy and safety of febuxostat with fixed-dose allopurinol (300/100 mg/day) in patients with hyperuricaemia and gout. The ERG considered that the trials were of reasonable methodological quality and measured a clinically relevant range of outcomes. Although a simple pooled analysis of the individual patient-level data from the two trials was undertaken, the statistical approach for combining the data was considered inappropriate by the ERG as it failed to preserve randomization and introduced bias and confounding. There was substantial uncertainty in the relationships reported by the manufacturer regarding serum uric acid levels and the incidence of gout flares and underlying patient utility. The mathematical model developed was flawed and was not corrected despite ERG comments. It focused only on patients receiving febuxostat (80 mg/day titrated to 120 mg/day if necessary) with fixed-dose allopurinol (300/100 mg/day). Sequential treatment was not modeled, nor was titrating allopurinol to 900 mg/day, which is regarded as best practice. Numerous other errors were identified, which included the uncertain price of febuxostat being sampled within the probabilistic sensitivity analyses. Supplementary exploratory modelling addressing the position of febuxostat where patients were intolerant or contraindicated to allopurinol was provided to the NICE Appraisal Committee following the release of the appraisal consultation document. The NICE Appraisal Committee concluded that febuxostat be recommended as an option for the management of chronic hyperuricaemia in gout only for people who are intolerant to allopurinol or for whom allopurinol is contraindicated.

Pharmacokinetic and Pharmacodynamic Interaction Between Allopurinol and Probenecid in Patients with Gout

Objective.

To investigate the pharmacokinetic and pharmacodynamic interaction between probenecid and oxypurinol (the active metabolite of allopurinol) in patients with gout.

Methods.

This was an open-label observational clinical study. Blood and urine samples were collected to measure oxypurinol and urate concentrations. We examined the effects of adding probenecid to allopurinol therapy upon plasma concentrations and renal clearances of urate and oxypurinol.

Results.

Twenty patients taking allopurinol 100–400 mg daily completed the study. Maximum coadministered doses of probenecid were 250 mg/day (n = 1), 500 mg/day (n = 19), 1000 mg/day (n = 7), 1500 mg/day (n = 3), and 2000 mg/day (n = 1). All doses except the 250 mg daily dose were divided and dosing was twice daily. Estimated creatinine clearances ranged from 28 to 113 ml/min. Addition of probenecid 500 mg/day to allopurinol therapy decreased plasma urate concentrations by 25%, from mean 0.37 mmol/l (95% CI 0.33–0.41) to mean 0.28 mmol/l (95% CI 0.24–0.32) (p < 0.001); and increased renal urate clearance by 62%, from mean 6.0 ml/min (95% CI 4.5–7.5) to mean 9.6 ml/min (95% CI 6.9–12.3) (p < 0.001). Average steady-state plasma oxypurinol concentrations decreased by 26%, from mean 11.1 mg/l (95% CI 5.0–17.3) to mean 8.2 mg/l (95% CI 4.0–12.4) (p < 0.001); and renal oxypurinol clearance increased by 24%, from mean 12.7 ml/min (95% CI 9.6–15.8) to mean 16.1 ml/min (95% CI 12.0–20.2) (p < 0.05). The additional hypouricemic effect of probenecid 500 mg/day appeared to be lower in patients with renal impairment.

Conclusion.

Coadministration of allopurinol with probenecid had a significantly greater hypouricemic effect than allopurinol alone despite an associated reduction of plasma oxypurinol concentrations. Australian Clinical Trials Registry ACTRN012606000276550.

New advances in the treatment of gout: review of pegloticase

Treatment-failure gout (TFG) affects approximately 50,000 patients or about 1% of the overall population of patients with gout in the United States of America. The severity of TFG is manifested by frequent acute attacks of disabling arthritis, chronic deforming joint disease, destructive masses of urate crystals (tophi), progressive physical disability, and poor health-related quality of life. Pegloticase (Krystexxa^®; Savient Pharmaceuticals, Inc), a novel PEGylated urate oxidase (uricase) enzyme, has been resubmitted for US Food and Drug Administration approval. In a 6-month, placebo-controlled clinical trial, 8 mg of pegloticase for every 2 weeks induced a lytic decrease of serum urate (sUr) concentrations, leading to dissolution of tophi in 40% of patients at final visit. However, 58% were nonresponders to the defined target sUr of 0.36 mmol/L (80% were nonresponders during months 3 and 6), possibly due to anti-body formation. Also, 26%–31% experienced infusion reactions (IRs) and 77% suffered from gout flares. Although long-term data are awaited, an anti-inflammatory strategy, eg, based on glucocorticosteroids, is needed to prevent pegloticase antibody formation leading to IRs and diminished or shortened efficacy, and might also prevent gout flares. According to the current clinical data, pegloticase might have an important role as a (bridging) treatment in sUr-responsive patients for tophi clearance in severe chronic refractory gout.

Current and future therapeutic options for the management of gout

The incidence of gout and the clinical manifestation of hyperuricemia continue to rise. In addition to painful acute attacks, chronic gout can lead to the development of crystal arthropathy, tophi, and renal lithiasis, coincidental with declines in quality of life. As a greater appreciation for the associations between hyperuricemia, gout, and certain comorbidities, such as renal impairment and cardiovascular diseases, grows, so does the search for new therapeutic options to both alleviate the painful symptoms of acute gout attacks and reduce the underlying hyperuricemia. This manuscript reviews the pathophysiology of hyperuricemia and gout, and associated comorbidities, and then discusses traditional therapeutic options, newly available agents, and future targets for pharmacologic management.

Management of gout: beyond allopurinol

The basic concepts of the pathogenesis and management of gout have not altered for many years. Monosodium urate monohydrate crystals drive the disease and identification of these crystals is required for certain diagnosis. In contrast, our understanding of the mediators of gouty inflammation, the appropriate target serum urate concentration during treatment, the drugs available and the best ways to use those drugs have all advanced in recent years and will be the focus of this review.

Treating to target: a strategy to cure gout

Acute gout attacks and the long-term complications of gout are associated with the deposition of monosodium urate (MSU) monohydrate crystals in the joints and soft tissues, causing acute and chronic inflammation. The aim of long-term treatment is to reduce the serum urate (sUA) level to 6 mg/dl (< or =360 micromol/l), below the saturation point of MSU, so that new crystals cannot form and existing crystals are dissolved. Serial joint aspiration studies confirmed the disappearance of crystals with effective urate-lowering therapy. There is good evidence that achieving sUA <6 mg/dl (360 micromol/l) results in freedom from acute gout attacks, and shrinkage and eventual disappearance of tophi. Gout patients must be informed about their diagnosis and educated about gout management including the importance of compliance with long-term treatment. Patients starting urate-lowering therapy need to understand the importance of prophylactic therapy with colchicine or NSAIDs to reduce the risk of 'mobilization flares' in the first few months. In the long term, reduction in the sUA below the target level will result in gout being effectively cured.

Management of hyperuricemia in gout: focus on febuxostat

Gout is the most common inflammatory arthritis in an elderly population, and can be diagnosed with absolute certainty by polarization microscopy. However, diagnosis may be challenging because atypical presentations are more common in the elderly. Management of hyperuricemia in the elderly with gout requires special consideration because of co-medication, contra-indications, and risk of adverse reactions. Urate-lowering agents include allopurinol and uricosuric agents. These also must be used sensibly in the elderly, especially when renal function impairment is present. However, if used at the lowest dose that maintains the serum urate level below 5.0 to 6.0 mg/dL (0.30 to 0.36 mmol/L), the excess urate in the body will eventually be eliminated, acute flares will no longer occur, and tophi will resolve. Febuxostat, a new xanthine oxidase inhibitor, is welcomed, as few alternatives for allopurinol are available. Its pharmacokinetics and pharmacodynamics are not significantly altered in patients with moderate renal function or hepatic impairment. Its antihyperuricemic efficacy at 80 to 120 mg/day is better than “standard dosage” allopurinol (300 mg/day). Long-term safety data and efficacy data on tophus diminishment and reduction of gout flares have recently become available. Febuxostat may provide an important option in patients unable to use allopurinol, or refractory to allopurinol.