GPNMB augments Wnt-1 mediated breast tumor initiation and growth by enhancing PI3K/AKT/mTOR pathway signaling and ß-catenin activity.

Glycoprotein Nmb (GPNMB) is overexpressed in triple-negative and basal-like breast cancers and its expression is predictive of poor prognosis within this aggressive breast cancer subtype. GPNMB promotes breast cancer growth, invasion, and metastasis; however, its role in mammary tumor initiation remains unknown. To address this question, we overexpressed GPNMB in the mammary epithelium to generate MMTV/GPNMB transgenic mice and crossed these animals to the MMTV/Wnt-1 mouse model, which is known to recapitulate features of human basal breast cancers. We show that GPNMB alone does not display oncogenic properties; however, its expression dramatically accelerates tumor onset in MMTV/Wnt-1 mice. MMTV/Wnt-1 × MMTV/GPNMB bigenic mice also exhibit a significant increase in the growth rate of established primary tumors, which is attributable to increased proliferation and decreased apoptosis. To elucidate molecular mechanisms underpinning the tumor-promoting effects of GPNMB in this context, we interrogated activated pathways in tumors derived from the MMTV/Wnt-1 and MMTV/Wnt-1 × MMTV/GPNMB mice using RPPA analysis. These data revealed that MMTV/Wnt-1 × MMTV/GPNMB bigenic tumors exhibit a pro-growth signature characterized by elevated PI3K/AKT/mTOR signaling and increased ß-catenin activity. Furthermore, we extended these observations to an independent Wnt-1 expressing model of aggressive breast cancer, and confirmed that GPNMB enhances canonical Wnt pathway activation, as evidenced by increased ß-catenin transcriptional activity, in breast cancer cells and tumors co-expressing Wnt-1 and GPNMB. GPNMB-dependent engagement of ß-catenin occurred, in part, through AKT activation. Taken together, these data ascribe a novel, pro-growth role for GPNMB in Wnt-1 expressing basal breast cancers.

Effects of Febuxostat in Early Gout: A Randomized, Double-Blind, Placebo-Controlled Study.

OBJECTIVE: To assess the effect of treatment with febuxostat versus placebo on joint damage in hyperuricemic subjects with early gout (1 or 2 gout flares). METHODS: In this double-blind, placebo-controlled study, 314 subjects with hyperuricemia (serum uric acid [UA] level of ≥7.0 mg/dl) and early gout were randomized 1:1 to receive once-daily febuxostat 40 mg (increased to 80 mg if the serum UA level was ≥6.0 mg/dl on day 14) or placebo. The primary efficacy end point was the mean change from baseline to month 24 in the modified Sharp/van der Heijde erosion score for the single affected joint. Additional efficacy end points included change from baseline to month 24 in the Rheumatoid Arthritis Magnetic Resonance Imaging Scoring (RAMRIS) scores for synovitis, erosion, and edema in the single affected joint, the incidence of gout flares, and serum UA levels. Safety was assessed throughout the study. RESULTS: Treatment with febuxostat did not lead to any notable changes in joint erosion over 2 years. In both treatment groups, the mean change from baseline to month 24 in the modified Sharp/van der Heijde erosion score for the single affected joint was minimal, with no between-group differences. However, treatment with febuxostat significantly improved the RAMRIS synovitis score at month 24 compared with placebo treatment (change from baseline -0.43 versus -0.07; P <0.001), decreased the overall incidence of gout flares (29.3% versus 41.4%; P < 0.05), and improved serum UA control (62.8% versus 5.7%; P < 0.001). No major safety concerns were reported. CONCLUSION: Urate-lowering therapy with febuxostat improved magnetic resonance imaging-determined synovitis and reduced the incidence of gout flares in subjects with early gout.

Randomized controlled trial of febuxostat versus allopurinol or placebo in individuals with higher urinary uric acid excretion and calcium stones.

BACKGROUND AND OBJECTIVES: Higher urinary uric acid excretion is a suspected risk factor for calcium oxalate stone formation. Febuxostat, a xanthine oxidoreductase inhibitor, is effective in lowering serum urate concentration and urinary uric acid excretion in healthy volunteers and people with gout. This work studied whether febuxostat, compared with allopurinol and placebo, would reduce 24-hour urinary uric acid excretion and prevent stone growth or new stone formation. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS: In this 6-month, double-blind, multicenter, randomized controlled trial, hyperuricosuric participants with a recent history of calcium stones and one or more radio-opaque calcium stone ≥ 3 mm (as seen by multidetector computed tomography) received daily febuxostat at 80 mg, allopurinol at 300 mg, or placebo. The primary end point was percent change from baseline to month 6 in 24-hour urinary uric acid. Secondary end points included percent change from baseline to month 6 in size of index stone and change from baseline in the mean number of stones and 24-hour creatinine clearance. RESULTS: Of 99 enrolled participants, 86 participants completed the study. Febuxostat led to significantly greater reduction in 24-hour urinary uric acid (-58.6%) than either allopurinol (-36.4%; P=0.003) or placebo (-12.7%; P<0.001). Percent change from baseline in the size of the largest calcium stone was not different with febuxostat compared with allopurinol or placebo. There was no change in stone size, stone number, or renal function. No new safety concerns were noted for either drug. CONCLUSIONS: Febuxostat (80 mg) lowered 24-hour urinary uric acid significantly more than allopurinol (300 mg) in stone formers with higher urinary uric acid excretion after 6 months of treatment. There was no change in stone size or number over the 6-month period.

Preservation of renal function during gout treatment with febuxostat: a quantitative study.

BACKGROUND: Hyperuricemia can accelerate renal decline associated with aging. Chronic kidney disease is frequently seen in patients with hyperuricemia and gout. OBJECTIVES: Assess the impact of urate-lowering therapy on renal function in subjects with gout who were treated with febuxostat for ≤ 48 months. METHODS: Subjects from 2 phase 3 clinical studies were enrolled in the phase 3, long-term, open-label Febuxostat/Allopurinol Comparative Extension Long-Term (EXCEL) study. In the EXCEL study, 1086 subjects initially were treated with febuxostat 80 or 120 mg daily, or allopurinol 300 mg daily. The subjects were permitted to switch between doses of febuxostat and/or allopurinol during the first 6 months of treatment to achieve and maintain a serum uric acid (SUA) level ≥ 3 to < 6 mg/dL. For the analysis presented in this article, data from 551 subjects who received only febuxostat throughout the duration of both the phase 3 and EXCEL studies (≤ 48 months) were used to determine the impact of SUA reduction on estimated glomerular filtration rates (eGFRs). RESULTS: At baseline of the 2 original phase 3 studies, subjects' mean SUA level was 9.8 mg/dL. Greater sustained decreases in subjects' SUA levels were associated with less renal function decline (P < 0.001) by statistical modeling. The study data predicted that for every 1 mg/dL of chronic reduction of SUA level in subjects with gout, there would be a preservation of 1.15 mL/min of eGFR. CONCLUSION: Sustained urate-lowering therapy with febuxostat appears to impede renal decline in patients with gout. The results discussed in this article support similar observations previously reported in 116 hyperuricemic subjects with gout who received febuxostat for ≤ 5 years.

The efficacy and safety of febuxostat for urate lowering in gout patients ≥65 years of age.

BACKGROUND: The incidence of gout rises with increasing age. Management of elderly (≥65 years) gout patients can be challenging due to high rates of comorbidities, such as renal impairment and cardiovascular disease, and concomitant medication use. However, there is little data specifically addressing the efficacy and safety of available urate-lowering therapies (ULT) in the elderly. The objective of this post hoc analysis was to examine the efficacy and safety of ULT with febuxostat or allopurinol in a subset of elderly subjects enrolled in the CONFIRMS trial. METHODS: Hyperuricemic (serum urate [sUA] levels ≥ 8.0 mg/dL) gout subjects were enrolled in the 6-month, double-blind, randomized, comparative CONFIRMS trial and randomized, 1:1:1, to receive febuxostat, 40 mg or 80 mg, or allopurinol (200 mg or 300 mg based on renal function) once daily. Flare prophylaxis was provided throughout the study duration.Study endpoints were the percent of elderly subjects with sUA <6.0 mg/dL at the final visit, overall and by renal function status, percent change in sUA from baseline to final visit, flare rates, and rates of adverse events (AEs). RESULTS: Of 2,269 subjects enrolled, 374 were elderly. Febuxostat 80 mg was significantly more efficacious (82.0%) than febuxostat 40 mg (61.7%; p < 0.001) or allopurinol (47.3%; p < 0.001) for achieving the primary efficacy endpoint. Febuxostat 40 mg was also superior to allopurinol in this population (p = 0.029). In subjects with mild-to-moderate renal impairment, significantly greater ULT efficacy was observed with febuxostat 40 mg (61.6%; p = 0.028) and febuxostat 80 mg (82.5%; p < 0.001) compared to allopurinol 200/300 mg (46.9%). Compared to allopurinol 200/300 mg, the mean percent change in sUA from baseline was significantly greater for both febuxostat 80 mg (p < 0.001) and febuxostat 40 mg (p = 0.011) groups. Flare rates declined steadily in all treatment groups. Rates of AEs were low and comparable across treatments. CONCLUSIONS: These data suggest that either dose of febuxostat is superior to commonly prescribed fixed doses of allopurinol (200/300 mg) in subjects ≥65 years of age with high rates of renal dysfunction. In addition, in this high-risk population, ULT with either drug was well tolerated. TRIAL REGISTRATION: clinicaltrials.gov NCT#00430248.

African American patients with gout: efficacy and safety of febuxostat vs allopurinol.

BACKGROUND: African Americans are twice as likely as Caucasians to develop gout, but they are less likely to be treated with urate-lowering therapy (ULT). Furthermore, African Americans typically present with more comorbidities associated with gout, such as hypertension, obesity, and renal impairment. We determined the efficacy and safety of ULT with febuxostat or allopurinol in African American subjects with gout and associated comorbidities and in comparison to Caucasian gout subjects. METHODS: This is a secondary analysis of the 6-month Phase 3 CONFIRMS trial. Eligible gouty subjects with baseline serum urate (sUA) ≥ 8.0 mg/dL were randomized 1:1:1 to receive febuxostat 40 mg, febuxostat 80 mg, or allopurinol (300 mg or 200 mg depending on renal function) daily. All subjects received gout flare prophylaxis. Primary efficacy endpoint was the proportion of subjects in each treatment group with sUA < 6.0 mg/dL at the final visit. Additional endpoints included the proportion of subjects with mild or with moderate renal impairment who achieved a target sUA < 6.0 mg/dL at final visit. Adverse events (AEs) were recorded throughout the study. RESULTS: Of the 2,269 subjects enrolled, 10.0% were African American and 82.1% were Caucasian. African American subjects were mostly male (89.5%), obese (BMI ≥ 30 kg/m2; 67.1%), with mean baseline sUA of 9.8 mg/dL and mean duration of gout of 10.4 years. The proportions of African American subjects with a baseline history of diabetes, renal impairment, or cardiovascular disease were significantly higher compared to Caucasians (p < 0.001). ULT with febuxostat 80 mg was superior to both febuxostat 40 mg (p < 0.001) and allopurinol (p = 0.004). Febuxostat 40 mg was comparable in efficacy to allopurinol. Significantly more African American subjects with mild or moderate renal impairment achieved sUA < 6.0 mg/dL in the febuxostat 80 group than in either the febuxostat 40 mg or allopurinol group (p < 0.05). Efficacy rates in all treatment groups regardless of renal function were comparable between African American and Caucasian subjects, as were AE rates. CONCLUSIONS: In African American subjects with significant comorbidities, febuxostat 80 mg is significantly more efficacious than either febuxostat 40 mg or allopurinol 200/300 mg. Febuxostat was well tolerated in this African American population.Please see related article: http://www.biomedcentral.com/1741-7015/10/15.

Women with gout: efficacy and safety of urate-lowering with febuxostat and allopurinol.

OBJECTIVE: To compare the characteristics of female versus male gout patients and assess urate-lowering efficacy and safety of febuxostat or allopurinol treatment in women with gout. METHODS: This was a retrospective analysis of 4,101 hyperuricemic (serum urate [sUA] level ≥8.0 mg/dl) gout subjects enrolled in 3 phase III comparative trials and randomized to receive placebo, febuxostat (40 mg, 80 mg, 120 mg, or 240 mg daily), or allopurinol (100 mg, 200 mg, or 300 mg daily, based on renal function). Baseline demographics and characteristics were summarized and compared between female and male subjects. Urate-lowering efficacy, which was defined as the proportion of subjects with sUA levels <6.0 mg/dl at final visit, was assessed for all subjects and, among women, according to baseline renal function. RESULTS: Female gout subjects (n = 226) were older with significantly higher rates of obesity and metabolic and cardiovascular comorbidities than their male counterparts. The percentage of female subjects with sUA levels <6.0 mg/dl at final visit was 0% in the placebo group, 54.3%, 85.1%, 81.0%, and 100.0% in the febuxostat 40 mg, 80 mg, 120 mg, and 240 mg groups, respectively, and 45.9% in the allopurinol group. Similar patterns of urate-lowering efficacy rates were observed when stratified by renal function. Among all the female subjects, febuxostat 80 mg was significantly more efficacious than allopurinol (P < 0.001). Rates of adverse events (AEs) were low. The most frequently reported AEs were upper respiratory tract infections, musculoskeletal/connective tissue disorders, and diarrhea. CONCLUSION: These data suggest that febuxostat 80 mg may be more efficacious than commonly prescribed doses of allopurinol in female gout subjects with high rates of comorbidities.

Treating hyperuricemia of gout: safety and efficacy of febuxostat and allopurinol in older versus younger subjects.

Despite an increasing incidence of gout in older age patients with multiple metabolic and cardiovascular comorbidities, there are limited data addressing whether currently available urate-lowering therapy is comparably effective and safe in older (≥65 years of age) versus younger (<65 years of age) patients. In this secondary analysis of data from the CONFIRMS trial, we found that among 374 older subjects, urate-lowering therapy with approved doses of febuxostat or commonly prescribed doses of allopurinol was at least comparable to that in 1894 younger subjects and was well tolerated despite high rates of renal impairment and cardiovascular comorbidities in the older subjects.

Patient-reported outcomes in chronic gout: a report from OMERACT 10.

OBJECTIVE: To summarize the endorsement of measures of patient-reported outcome (PRO) domains in chronic gout at the 2010 Outcome Measures in Rheumatology Meeting (OMERACT 10). METHODS: During the OMERACT 10 gout workshop, validation data were presented for key PRO domains including pain [pain by visual analog scale (VAS)], patient global (patient global VAS), activity limitation [Health Assessment Questionnaire-Disability Index (HAQ-DI)], and a disease-specific measure, the Gout Assessment Questionnaire version 2.0 (GAQ v2.0). Data were presented on all 3 aspects of the OMERACT filters of truth, discrimination, and feasibility. One PRO, health-related quality of life measurement with the Medical Outcomes Study Short-form 36 (SF-36), was previously endorsed at OMERACT 9. RESULTS: One measure for each of the 3 PRO of pain, patient global, and activity limitation was endorsed by > 70% of the OMERACT delegates to have appropriate validation data. Specifically, pain measurement by VAS was endorsed by 85%, patient global assessment by VAS by 73%, and activity limitation by HAQ-DI by 71%. GAQ v2.0 received 30% vote and was not endorsed due to several concerns including low internal consistency and lack of familiarity with the measure. More validation studies are needed for this measure. CONCLUSION: With the endorsement of one measure each for pain, patient global, SF-36, and activity limitation, all 4 PRO for chronic gout have been endorsed. Future validation studies are needed for the disease-specific measure, GAQ v2.0. Validation for PRO for acute gout will be the focus of the next validation exercise for the OMERACT gout group.

Tophus measurement as an outcome measure for clinical trials of chronic gout: progress and research priorities.

Despite the recognition that tophus regression is an important outcome measure in clinical trials of chronic gout, there is no agreed upon method of tophus measurement. A number of methods have been used in clinical trials of chronic gout, from simple physical measurement techniques to more complex advanced imaging methods. This article summarizes methods of tophus measurement and discusses their properties. Physical measurement using Vernier calipers meets most aspects of the Outcome Measures in Rheumatology (OMERACT) filter. Rigorous testing of the complex methods, particularly with respect to reliability and sensitivity to change, is needed to determine the appropriate use of these methods. Further information is also required regarding which method of physical measurement is best for use in future clinical trials. The need to develop and test a patient-reported outcome measure of tophus burden is also highlighted.

Serum urate in chronic gout--will it be the first validated soluble biomarker in rheumatology?

OBJECTIVE: To summarize evidence for and endorsement of serum urate (SU) as having fulfilled the OMERACT filter as a soluble biomarker in chronic gout at the 2010 Outcome Measures in Rheumatology Meeting (OMERACT 10). METHODS: Data were presented to support the use of SU as a soluble biomarker in chronic gout and specifically the ability to utilize it to predict future patient-reported outcomes. RESULTS: SU was accepted as having fulfilled the OMERACT filter by 78% of voters. However, consensus was not obtained regarding its use as a soluble biomarker in chronic gout. Although the majority of the criteria for a soluble biomarker were fulfilled, the key criterion of association of the biomarker with outcomes was not agreed upon. It was agreed that the appropriate choice of endpoint must be linked to its clinical importance to the individual with the disorder and its temporal relationship to the intervention. Appropriate outcomes in chronic gout may therefore include gout flares, reduction in tophi, and patient-reported outcomes. CONCLUSION: SU is a critical outcome measure. It has the potential to fulfil criteria for a soluble biomarker. Further analyses of existing data from randomized controlled trials will be required to determine whether SU can predict future important outcomes, in particular disability.

Bringing it all together: a novel approach to the development of response criteria for chronic gout clinical trials.

OBJECTIVE: To review a novel approach for constructing composite response criteria for use in chronic gout clinical trials that implements a method of multicriteria decision-making. METHODS: Preliminary work with paper patient profiles led to a restricted set of core-set domains that were examined using 1000Minds™ by rheumatologists with an interest in gout, and (separately) by OMERACT registrants prior to OMERACT 10. These results and the 1000Minds approach were discussed during OMERACT 10 to help guide next steps in developing composite response criteria. RESULTS: There were differences in how individual indicators of response were weighted between gout experts and OMERACT registrants. Gout experts placed more weight upon changes in uric acid levels, whereas OMERACT registrants placed more weight upon reducing flares. Discussion highlighted the need for a "pain" domain to be included, for "worsening" to be an additional level within each indicator, for a group process to determine the decision-making within a 1000Minds exercise, and for the value of patient involvement. CONCLUSION: Although there was not unanimous support for the 1000Minds approach to inform the construction of composite response criteria, there is sufficient interest to justify ongoing development of this methodology and its application to real clinical trial data.

Febuxostat in gout: serum urate response in uric acid overproducers and underexcretors.

OBJECTIVE: Hyperuricemia of gout can arise due to either overproduction or underexcretion of uric acid. Not all available urate-lowering therapies are equally effective and safe for use in patients with renal disease. The objective of this post-hoc analysis was to determine the effectiveness of the xanthine oxidase inhibitor febuxostat in reducing serum urate (sUA) levels in gouty patients who were either overproducers or underexcretors. METHODS: Gouty subjects 18 to 85 years of age with sUA ≥ 8.0 mg/dl at baseline were enrolled in a Phase 2, 28-day, multicenter, randomized, double-blind, placebo-controlled trial and randomized to receive febuxostat 40 mg, 80 mg, or 120 mg daily, or placebo. The primary efficacy endpoint was the proportion of subjects with sUA < 6.0 mg/dl at Day 28. Secondary efficacy endpoints included percentage reductions in sUA and urinary uric acid (uUA) from baseline to Day 28. RESULTS: Of the 153 subjects, 118 (77%) were underexcretors (uUA ≤ 800 mg/24 h) and 32 (21%) were overproducers (uUA > 800 mg/24 h); baseline uUA data were missing for 3 subjects. Treatment with febuxostat led to the majority of subjects achieving sUA < 6.0 mg/dl at Day 28. Treatment with any dose of febuxostat led to significantly greater percentage reductions in uUA than that observed in the placebo group, for both underexcretors and overproducers. CONCLUSION: Febuxostat is a highly efficacious urate-lowering therapy in patients with gout regardless of overproduction or underexcretion status.

Renal function in gout: long-term treatment effects of febuxostat.

BACKGROUND: The association between hyperuricemia, gout, and impaired renal function has long been recognized. Recent data provide evidence for the causal relationship between elevated serum urate (sUA) and renal changes, leading to declines in glomerular filtration rates. In healthy adults, glomerular filtration rate wanes with age. Urate-lowering therapy (ULT) with allopurinol has been shown to stabilize or reverse this. OBJECTIVE: Here we examine the long-term effects of ULT with febuxostat on estimated glomerular filtration rate (eGFR). METHODS: This is a post hoc analysis of the Febuxostat Open-label Clinical trial of Urate-lowering efficacy and Safety study, during which 116 hyperuricemic gout subjects received daily doses of febuxostat (40, 80, or 120 mg) for up to 5 years. sUA concentrations and eGFR were assessed regularly. Results were stratified by mean change in sUA from baseline. Mathematical modeling was used to predict the effect of sUA reduction on eGFR. RESULTS: Maintenance or improvement in eGFR was inversely correlated with the quantitative reduction in sUA from baseline. For every 1 mg/dL decrease in sUA, the model projected an expected improvement in eGFR of 1 mL/min from the untreated value. CONCLUSION: Individuals with the greatest reductions in sUA may experience reduced rates of renal deterioration or even stabilization of renal function. Further studies examining the impact of long-term ULT on renal function in hyperuricemic gout patients are needed to both confirm our results and verify if improvements in renal function are feasible in such patients.

Glycoprotein nonmetastatic B is an independent prognostic indicator of recurrence and a novel therapeutic target in breast cancer.

PURPOSE: Although the murine orthologue of glycoprotein nonmetastatic B (GPNMB), Osteoactivin, promotes breast cancer metastasis in an in vivo mouse model, its importance in human breast cancer is unknown. We have examined the significance of GPNMB expression as a prognostic indicator of recurrence and assessed its potential as a novel therapeutic target in breast cancer. EXPERIMENTAL DESIGN: The clinical significance of GPNMB expression in breast cancer was addressed by analyzing GPNMB levels in several published gene expression data sets and two independent tissue microarrays derived from human breast tumors. GPNMB-expressing human breast cancer cell lines were further used to validate a toxin-conjugated anti-GPNMB antibody as a novel therapeutic agent. RESULTS: GPNMB expression correlates with shorter recurrence times and reduced overall survival of breast cancer patients. Epithelial-specific GPNMB staining is an independent prognostic indicator for breast cancer recurrence. GPNMB is highly expressed in basal and triple-negative breast cancers and is associated with increased risk of recurrence within this subtype. GPNMB expression confers a more migratory and invasive phenotype on breast cancer cells and sensitizes them to killing by CDX-011 (glembatumumab vedotin), a GPNMB-targeted antibody-drug conjugate. CONCLUSIONS: GPNMB expression is associated with the basal/triple-negative subtype and is a prognostic marker of poor outcome in patients with breast cancer. CDX-011 (glembatumumab vedotin) is a promising new targeted therapy for patients with metastatic triple-negative breast cancers, a patient population that currently lacks targeted-therapy options.

Effect of prophylaxis on gout flares after the initiation of urate-lowering therapy: analysis of data from three phase III trials.

BACKGROUND: Use of urate-lowering therapy (ULT), such as febuxostat or allopurinol, is recommended for the long-term management of hyperuricemia in patients with gout to reduce the incidence of acute flares. Because of the paradoxical relationship between early use of ULT and the increased incidence of gout flares, prophylaxis with either low-dose colchicine or NSAIDs has been recommended, although there have been concerns about the long-term prophylactic use of these agents. OBJECTIVES: The present analysis examined flare rates during the 3 Phase III trials of febuxostat based on mean postbaseline serum urate (sUA) concentrations and duration of prophylaxis. Adverse events (AEs) were assessed by prophylaxis with colchicine or naproxen. METHODS: This investigator-initiated, post hoc reanalysis of data on gout flares from the 3 randomized, placebo-controlled, Phase III trials evaluated the proportion of patients requiring treatment for gout flares at 4-week intervals based on mean postbaseline sUA concentrations <6.0 and ≥ 6.0 mg/dL. The 3 trials enrolled males or females aged 18-85 years who had a diagnosis of gout and a baseline sUA concentration ≥ 8.0 mg/dL. Patients received ULT (febuxostat or allopurinol) or placebo for 6 months or 1 year and flare prophylaxis with colchicine 0.6 mg/d or naproxen 250 mg BID for 8 weeks or 6 months. The prophylactic regimen was chosen at the discretion of the investigator, based on renal function and known intolerance to either drug. Patients with an estimated creatinine clearance <50 mL/min were not to receive naproxen. AEs were summarized based on prophylaxis with colchicine or naproxen. RESULTS: The 3 trials enrolled a total of 4101 patients with gout. The majority were white (80.1%), male (94.5%), and obese (body mass index ≥ 30 kg/m(2)) (62.8%). The mean duration of gout ranged from 10.9-11.9 years, and the mean baseline sUA concentration ranged from 9.6-9.9 mg/dL. Flare rates increased sharply (up to 40%) at the end of 8 weeks of prophylaxis and then declined gradually, whereas flare rates were consistently low (range, 3%-5%) at the end of 6 months of prophylaxis. Mean postbaseline sUA concentrations were correlated with flare rates; by the end of each study, patients with a mean postbaseline sUA concentration <6.0 mg/dL had fewer flares than did those with a mean postbaseline sUA concentration ≥ 6.0 mg/dL. There were differences in rates of AEs between prophylaxis groups, but the rates did not increase with increased duration of prophylaxis. CONCLUSION: This analysis of gout flare data from the 3 Phase III trials of febuxostat found that flare prophylaxis for up to 6 months during the initiation of ULT appeared to provide greater benefit than flare prophylaxis for 8 weeks, with no increase in AEs.

Progress in measurement instruments for acute and chronic gout studies.

Consensus exercises have identified and prioritized domains of measurement for studies in acute and chronic gout. In parallel, the technical properties of instruments for measurement in many of these domains have been assessed, with the main objective to consider the instruments in the context of the OMERACT filter of truth, discrimination, and feasibility. These data were presented and discussed at OMERACT 9 in the gout workshop, in breakout groups, and at informal meetings of the gout group. In acute gout, instruments for domains of pain, joint swelling, joint tenderness, and patient and physician global assessment have been assessed. In chronic gout, some validation exercises have been performed in instruments for domains serum urate, tophus measurement, health-related quality of life (HRQOL). In voting at OMERACT 9, the Medical Outcomes Study Short-Form 36 was endorsed as a valid instrument for measurement of HRQOL. Methods of tophus measurement were considered to have met some criteria of the OMERACT filter, but these require further work, particularly regarding sensitivity to change over shorter time periods. Priorities for future research include measurement of joint inflammation in acute gout and disability in acute and chronic gout.

Clinical efficacy and safety of successful longterm urate lowering with febuxostat or allopurinol in subjects with gout.

OBJECTIVE: To determine longterm urate-lowering efficacy and clinical benefits and safety of therapy with febuxostat or allopurinol in subjects with gout. METHODS: Subjects (n=1086) in this open-label extension study were assigned to fixed-dose daily urate-lowering treatment (ULT) with febuxostat (80 mg or 120 mg) or allopurinol (300 mg). ULT reassignment was permitted during months 1 to 6 to achieve serum urate (SUA) concentrations between 3.0 and <6.0 mg/dl. Flares requiring treatment, tophus size, safety, and SUA levels were monitored during up to 40 months of ULT maintenance. RESULTS: After 1 month initial treatment, >80% of subjects receiving either febuxostat dose, but only 46% of subjects receiving allopurinol, achieved SUA<6.0 mg/dl. After ULT reassignment, >80% of all remaining subjects maintained the primary efficacy endpoint of SUA<6.0 mg/dl at each visit. More subjects initially randomized to allopurinol required ULT reassignment to achieve SUA<6.0 mg/dl compared with subjects receiving febuxostat. Maintenance of SUA<6.0 mg/dl resulted in progressive reduction to nearly 0 in proportion of subjects requiring gout flare treatment. Baseline tophus resolution was achieved by 46%, 36%, and 29% of subjects maintained on febuxostat 80 mg, febuxostat 120 mg, and allopurinol, respectively. Overall adverse event rates (including cardiovascular adverse event rates), adjusted for 10-fold greater febuxostat than allopurinol exposure, did not differ significantly among treatment groups. CONCLUSION: Durable maintenance of goal range SUA level with either dose of febuxostat or in smaller numbers of subjects with allopurinol resulted in near elimination of gout flares and improved tophus status over time. Registered as NCT00175019.

Effects of febuxostat versus allopurinol and placebo in reducing serum urate in subjects with hyperuricemia and gout: a 28-week, phase III, randomized, double-blind, parallel-group trial.

OBJECTIVE: To compare the urate-lowering efficacy and safety of febuxostat, allopurinol, and placebo in a large group of subjects with hyperuricemia and gout, including persons with impaired renal function. METHODS: Subjects (n = 1,072) with hyperuricemia (serum urate level > or = 8.0 mg/dl) and gout with normal or impaired (serum creatinine level >1.5 to < or = 2.0 mg/dl) renal function were randomized to receive once-daily febuxostat (80 mg, 120 mg, or 240 mg), allopurinol (300 or 100 mg, based on renal function), or placebo for 28 weeks. RESULTS: Significantly (P < or = 0.05) higher percentages of subjects treated with febuxostat 80 mg (48%), 120 mg (65%), and 240 mg (69%) attained the primary end point of last 3 monthly serum urate levels <6.0 mg/dl compared with allopurinol (22%) and placebo (0%). A significantly (P < 0.05) higher percentage of subjects with impaired renal function treated with febuxostat 80 mg (4 [44%] of 9), 120 mg (5 [45%] of 11), and 240 mg (3 [60%] of 5) achieved the primary end point compared with those treated with 100 mg of allopurinol (0 [0%] of 10). Proportions of subjects experiencing any adverse event or serious adverse event were similar across groups, although diarrhea and dizziness were more frequent in the febuxostat 240 mg group. The primary reasons for withdrawal were similar across groups except for gout flares, which were more frequent with febuxostat than with allopurinol. CONCLUSION: At all doses studied, febuxostat more effectively lowered and maintained serum urate levels <6.0 mg/dl than did allopurinol (300 or 100 mg) or placebo in subjects with hyperuricemia and gout, including those with mild to moderately impaired renal function.

Determinants of the clinical outcomes of gout during the first year of urate-lowering therapy.

Clinical benefit early in urate-lowering treatment of gout is difficult to document. We examined data from 1,832 gouty subjects treated with either urate-lowering agents or placebo to identify determinants of gout flare incidence and tophus size during year 1 of treatment. Reductions from pretreatment serum urate levels influenced flare frequency and tophus size, but the effect of urate level on flare incidence was biphasic. Lower urate levels were associated with higher flare incidence early in treatment but lower incidence by one year. The complex relationship between urate-lowering and clinical outcome early in treatment has implications for both clinical and investigative approaches to urate-lowering management.