Reducing Immunogenicity of Pegloticase With Concomitant Use of Mycophenolate Mofetil in Patients With Refractory Gout: A Phase II, Randomized, Double-Blind, Placebo-Controlled Trial.

OBJECTIVE: Pegloticase is used for the treatment of severe gout, but its use is limited by immunogenicity. This study was undertaken to evaluate whether mycophenolate mofetil (MMF) prolongs the efficacy of pegloticase. METHODS: Participants were randomized 3:1 to receive 1,000 mg MMF twice daily or placebo for 14 weeks, starting 2 weeks before receiving pegloticase and continuing while receiving intravenous pegloticase 8 mg biweekly for 12 weeks. Participants then received pegloticase alone from week 12 to week 24. The primary end points were the proportion of patients who sustained a serum urate level of ≤6 mg/dl at 12 weeks and the rate of adverse events (AEs). Secondary end points included 24-week durability of serum urate level ≤6 mg/dl. Fisher's exact test and Wilcoxon's 2-sample test were used for analyses, along with Kaplan-Meier estimates and log rank tests. RESULTS: A total of 32 participants received ≥1 dose of pegloticase. Participants were predominantly men (88%), with a mean age of 55.2 years, mean gout duration of 13.4 years, and mean baseline serum urate level of 9.2 mg/dl. At 12 weeks, a serum urate level of ≤6 mg/dl was achieved in 19 (86%) of 22 participants in the MMF arm compared to 4 (40%) of 10 in the placebo arm (P = 0.01). At week 24, the serum urate level was ≤6 mg/dl in 68% of MMF-treated patients versus 30% of placebo-treated patients (P = 0.06), and rates of AEs were similar between groups, with more infusion reactions occurring in the placebo arm (30% versus 0%). CONCLUSION: Our findings indicate that MMF therapy with pegloticase is well tolerated and shows a clinically meaningful improvement in targeted serum urate level of ≤6 mg/dl at 12 and 24 weeks. This study suggests an innovative approach to pegloticase therapy in gout.

The effects of urate lowering therapy on inflammation, endothelial function, and blood pressure (SURPHER) study design and rationale.

BACKGROUND: The association between hyperuricemia and hypertension is controversial. Animal models, epidemiological data, and small clinical trials have favored a causative role for hyperuricemia in hypertension but more studies are necessary to elucidate putative mechanisms, population susceptibility, and potential for urate-lowering therapies (ULT) to decrease blood pressure (BP). PURPOSE: To describe the background and design of the Serum Urate Reduction to Prevent Hypertension (SURPHER) study. METHODS: SURPHER is a single center, double-blinded, crossover trial in which participants are randomly assigned to allopurinol (300mg) or placebo. Enrollment focused on adults 18-40years old with baseline systolic blood pressure≥120 and <160mmHg or diastolic blood pressure≥80 and <100mmHg, and serum urate ≥5.0mg/dL or ≥4.0mg/dL for men or women, respectively. SURPHER recruitment targets participants without chronic kidney disease (estimated glomerular filtration rate>60mL/min/1.73m2), and without prior diagnosis of gout or use of ULT to treat gout. The primary outcome is change from baseline in blood pressure assessed by 24hour ambulatory blood pressure monitoring and mechanistic outcomes include changes in endothelial function as measured by flow-mediated dilation, as well as C-reactive protein levels. RESULTS: Since June 16, 2014 until present, SURPHER is recruiting participants in the city of Birmingham, Alabama. LIMITATIONS: The study aims to enroll otherwise healthy young adults for a pharmacological intervention study with multiple study-related procedures. Challenges related to recruitment are anticipated and multiple strategies for increasing recruitment and retention are planned if necessary.