A non-inferiority study of the novel selective urate reabsorption inhibitor dotinurad versus febuxostat in hyperuricemic patients with or without gout

Changes in Urinary Uric Acid Concentration after Dotinurad Administration to Patients with Hyperuricemia: A Post Hoc Analysis of Two Clinical Trials in Japan

Dotinurad has been approved in Japan as a selective urate reabsorption inhibitor for the treatment of gout and hyperuricemia. The relationship between uric acid crystallization and the use of uricosuric drugs is widely acknowledged; however, the relationship between changes in urinary uric acid concentration and urine pH or volume has not been sufficiently analyzed. Therefore, we investigated the changes in urinary uric acid concentration following dotinurad administration as well as the relationship between urine pH or volume and urinary uric acid concentration. This post hoc analysis used data from 2 clinical trials that included 12 and 26 patients with hyperuricemia who received dotinurad treatment (for 7 days on an inpatient basis and 14 weeks on an outpatient basis, respectively). The urinary uric acid concentration transiently increased in the early stages of dotinurad use and when its dose was increased, but decreased over time. No uric acid concentrations exceeded the soluble limit at any urine pH. An inverse correlation was observed between urine volume and urinary uric acid concentration. This study highlights the significance of adequately managing urinary uric acid concentrations by increasing urine volume and alkalinizing urine to prevent uric acid crystallization during dotinurad administration.

Overview of the pharmacokinetics and pharmacodynamics of URAT1 inhibitors for the treatment of hyperuricemia and gout

INTRODUCTION

Hyperuricemia is a common metabolic disease, which is a risk factor for gouty arthritis and ureteral stones and may also lead to cardiovascular and chronic kidney disease (CDK). Therefore, hyperuricemia should be treated early. Xanthine oxidase inhibitors (XOIs) and uricosuric agents (UAs), which target uric acid, are two types of medications that are used to treat gout and hyperuricemia. XOIs stop the body from producing excessive uric acid, while UAs eliminate it rapidly via the kidneys. Urate transporter 1 (URAT1) belongs to the organic anion transporter family (OAT) and is specifically localized to the apical membrane of the epithelial cells of proximal tubules. Unlike other organic anion transporter family members, URAT1 identifies and transports organic anions that are primarily responsible for urate transport.

AREAS COVERED

This article reviews the pharmacokinetics and pharmacodynamics of the existing URAT1 inhibitors to serve as a reference for subsequent drug studies.

EXPERT OPINION

The URAT1 inhibitors that are currently used as clinical drugs mainly include dotinurad, benzbromarone, and probenecid. Results indicate that RDEA3170 may be the most promising inhibitor, in addition to SHR4640, URC-102, and MBX-102, which are in the early stages of development.

Systematic review and model-based analysis to identify whether renal safety risks of URAT1 inhibitors are fully determined by uric acid-lowering efficacies

OBJECTIVE

Renal safety risk is currently an important factor that hinders the development of uric acid transporter 1 (URAT1) inhibitors. This study aimed to compare the renal safety and uric acid-lowering efficacy of different URAT1 inhibitors and clarify the association between them.

METHODS

A systematic review of published randomized controlled trials on URAT1 inhibitors was conducted to investigate the incidence of renal safety events. A model-based analysis was performed to predict the uric acid-lowering efficacy of representative URAT1 inhibitors.

RESULTS

The overall renal safety event incidences of lesinurad, verinurad, dotinurad, SHR4640, and benzbromarone in patients with hyperuricemia were 11.2 % (142/1264), 12.0 % (34/284), 0.5 % (2/421), 2.3 % (5/213), and 1.3 % (5/393), respectively. A semi-mechanistic pharmacokinetic/pharmacodynamic model was used to establish the dose-exposure-effect relationship of lesinurad, verinurad, dotinurad, and SHR4640 with or without the combination of xanthine oxidase inhibitors (XOIs). The efficacy ranking of the intermediate dose of URAT1 inhibitors with once-daily dosing was 2 mg dotinurad > 10 mg verinurad > 5 mg SHR4640 > 400 mg lesinurad. The combination of 80 mg febuxostat and 600 mg allopurinol reduced the 24-h cumulative renal uric acid excretion by 48.4 % and 48.3 %, respectively.

CONCLUSION

Uric acid-lowering efficacy is not an independent factor for the renal safety risk of different URAT1 inhibitors, and structural differences could be responsible for the difference. The adverse renal effects of URAT1 inhibitors are dose-dependent, and the combination with high doses of XOIs can significantly reduce the renal safety risk by reducing uric acid excretion by the kidneys.

Emerging Urate-Lowering Drugs and Pharmacologic Treatment Strategies for Gout: A Narrative Review

Hyperuricemia with consequent monosodium urate crystal deposition leads to gout, characterized by painful, incapacitating inflammatory arthritis flares that are also associated with increased cardiovascular event and related mortality risk. This narrative review focuses on emerging pharmacologic urate-lowering treatment (ULT) and management strategies in gout. Undertreated, gout can progress to palpable tophi and joint damage. In oral ULT clinical trials, target serum urate of < 6.0 mg/dL can be achieved in ~ 80-90% of subjects, with flare burden reduction by 1-2 years. However, real-world ULT results are far less successful, due to both singular patient nonadherence and prescriber undertreatment, particularly in primary care, where most patients are managed. Multiple dose titrations commonly needed to optimize first-line allopurinol ULT monotherapy, and substantial potential toxicities and other limitations of approved, marketed oral monotherapy ULT drugs, promote hyperuricemia undertreatment. Common gout comorbidities with associated increased mortality (e.g., moderate-severe chronic kidney disease [CKD], type 2 diabetes, hypertension, atherosclerosis, heart failure) heighten ULT treatment complexity and emphasize unmet needs for better and more rapid clinically significant outcomes, including attenuated gout flare burden. The gout drug armamentarium will be expanded by integrating sodium-glucose cotransporter-2 (SGLT2) inhibitors with uricosuric and anti-inflammatory properties as well as clinically indicated antidiabetic, nephroprotective, and/or cardioprotective effects. The broad ULT developmental pipeline is loaded with multiple uricosurics that selectively target uric acid transporter 1 (URAT1). Evolving ULT approaches include administering selected gut anaerobic purine degrading bacteria (PDB), modulating intestinal urate transport, and employing liver-targeted xanthine oxidoreductase mRNA knockdown. Last, emerging measures to decrease the immunogenicity of systemically administered recombinant uricases should simplify treatment regimens and further improve outcomes in managing the most severe gout phenotypes.

Clinical effects of a selective urate reabsorption inhibitor dotinurad in patients with hyperuricemia and treated hypertension: a multicenter, prospective, exploratory study (DIANA)

INTRODUCTION

Dotinurad is a newer urate-lowering agent that selectively inhibits urate transporter 1 in the renal proximal tubule and increases urinary urate excretion. Currently, little is known about the clinical efficacies of dotinurad in patients with hyperuricemia and hypertension. The aim of this study was to assess the clinical effects of a selective urate reabsorption inhibitor dotinurad on serum uric acid (SUA) levels and relevant vascular markers in patients with hyperuricemia and treated hypertension.

METHODS

This investigator-initiated, multicenter, prospective, single-arm, open-label, exploratory clinical trial in Japan enrolled patients with hyperuricemia and treated hypertension who received a 24-week dotinurad therapy (a starting dose at 0.5 mg once daily and up-titrated to 2 mg once daily). The primary endpoint was a percentage change in the SUA level from baseline to week 24. The secondary endpoints were cardiovascular and metabolic measurements, including changes in the cardio-ankle vascular index (CAVI) and derivatives of reactive oxygen metabolites (d-ROMs) concentration at week 24.

RESULTS

Fifty patients (mean age 70.5 ± 11.0 years, with 76.0% being men, and mean SUA level 8.5 ± 1.2 mg/dL) were included in the analysis. The percentage change from baseline in the SUA level at week 24 was - 35.8% (95% confidence interval [CI] - 39.7% to - 32.0%, P < 0.001), with approximately three quarters of patients achieving an SUA level of ≤ 6.0 mg/dL at week 24. The proportional changes from baseline in the geometric mean of CAVI and d-ROMs at week 24 were 0.96 (95% CI 0.92 to 1.00, P = 0.044) and 0.96 (95% CI 0.92 to 1.00, P = 0.044), respectively.

CONCLUSION

In addition to meaningful SUA-lowering effects, 24 weeks of dotinurad therapy may favorably affect arterial stiffness and oxidative stress markers, suggesting off-target vascular protection of dotinurad. Further research is expected to verify our findings and elucidate the entire off-target effects of dotinurad. Trial registration jRCTs021210013, registration date June 24, 2021.

Science Popularization Interventions on Rational Medication in Patients with Hyperuricemia

Objective: This research aimed to explore the science of population intervention in the rational medication treatment of hyperuricemia patients in China. The research model was designed to determine interventions from three dimensions of science propylitization (empirical evidence, logical reasoning, and skeptical attitude). Methods: The data for this research was collected from hyperuricemia patients in China with a survey-based questionnaire. A partial least square-structural equation modeling statistical method was used for data evaluation. Results: The research investigated that science popularization can strongly influence hyperuricemia patients' rational medication with empirical evidence, logical reasoning, and a skeptical attitude. Furthermore, the research asserted that more focus on scientific knowledge of hyperuricemia patients can improve their health further. Conclusion: Theoretically, this research would have wider implications. First, the research model was based on science popularization interventions which is a novel contribution to the relationship with rational medication. Second, the practical implications of this study would lie in science population interventions improving the rational medications for hyperuricemia patients. Besides, this research asserted a few future directions for scholars to contribute and determine the impact of further variables to enhance the model of science popularization in relationship with rational medication.

Review of Urate-Lowering Therapeutics: From the Past to the Future

We reviewed all currently available ULT, as well as any medications in development using following databases: United States Food and Drug Administration (FDA), European Medicines Agency (EMA), Japanese Pharmaceutical and Medical Devices Agency (PMDA), and ClinicalTrials.gov. We identified a total of 36 drugs, including 10 approved drugs, 17 in clinical testing phases, and 9 in preclinical developmental phases. The 26 drugs currently undergoing testing and development include 5 xanthine oxidase inhibitors, 14 uricosurics, 6 recombinant uricases, and one with multiple urate-lowering mechanisms of action. Herein, we reviewed the benefit and risk of each drug summarizing currently available drugs. New trials of uricosuric agents are underway to develop the new indication. New drugs are going on to improve the potency of recombinant uricase and to develop the new route administration of such as oral formulation. This review will provide valuable information on the properties, indications, and limitations of ULTs.

A glance into the future of gout

Gout is characterized by monosodium urate (MSU) crystal deposits in and within joints. These deposits result from persistent hyperuricaemia and most typically lead to recurrent acute inflammatory episodes (gout flares). Even though some aspects of gout are well characterized, uncertainties remain; this upcoming decade should provide further insights into many of these uncertainties. Synovial fluid analysis allows for the identification of MSU crystals and unequivocal diagnosis. Non-invasive methods for diagnosis are being explored, such as Raman spectroscopy and imaging modalities. Both ultrasound and dual-energy computed tomography (DECT) allow the detection of MSU crystals; this not only provides a mean of diagnosis, but also has furthered gout knowledge defining the presence of a preclinical deposition in asymptomatic hyperuricaemia. Scientific consensus establishes the beginning of gout as the beginning of symptoms (usually the first flare), but the concept is currently under review. For effective long-term gout management, the main goal is to promote crystal dissolution treatment by reducing serum urate below 6 mg/dL (or 5 mg/dL if faster crystal dissolution is required). Current urate-lowering therapies' (ULTs) options are limited, with allopurinol and febuxostat being widely available, and probenecid, benzbromarone, and pegloticase available in some regions. New xanthine oxidase inhibitors and, especially, uricosurics inhibiting urate transporter URAT1 are under development; it is probable that the new decade will see a welcomed increase in the gout therapeutic armamentarium. Cardiovascular and renal comorbidities are common in gout patients. Studies determining whether optimal treatment of gout will positively impact these comorbidities are currently lacking, but will hopefully be forthcoming. Overall, the single change that will most impact gout management is greater uptake of international rheumatology society recommendations. Innovative strategies, such as nurse-led interventions based on these recommendations have recently demonstrated treatment success for people with gout.

What's new on the front-line of gout pharmacotherapy?

INTRODUCTION

Gout is the most common form of inflammatory arthritis affecting millions of people around the world. Painful flares and tophaceous deposits can be debilitating, reducing quality of life among those affected and putting strain on health care systems.

AREAS COVERED

This review provides an overview of the treatment of gout for flare pain management and lowering serum urate. Firstline agents are discussed with emphasis on emerging evidence. Novel therapies are also covered.

EXPERT OPINION

Lifestyle modifications form a part of gout prevention. Regarding gout flare pharmacotherapy NSAIDs, colchicine and glucocorticoids are first line agents. The IL-1β antagonists also are highly effective for arresting flares but their cost-effectiveness render them as salvage therapies. Allopurinol is an agent of first choice for urate lowering therapy (ULT). In South East Asian and Black populations screening for HLA*B58:01 mutation is a cost-effective approach to decrease the occurrence of the rare but potentially very serious allopurinol hypersensitivity syndrome (AHS.). Febuxostat is another efficacious urate lowering therapy but it has received U.S. FDA black box warning for cardiovascular safety and careful consideration is warranted before its initiation in patients with high cardiovascular risk. Novel uricosurics are a class for continued drug development; verinurad and arhalofenate are agents with future promise. For patients with recalcitrant gout, pegloticase is another effective option in the rheumatologist's armamentarium. Its immunogenicity significantly threatens the achievement of sustained urate lowering responses. Abrogating pegloticase's immunogenicity with immunomodulatory co-therapy may lend to sustained efficacy.

Uric acid-lowering effect of dotinurad, a novel selective urate reabsorption inhibitor, in hypertensive patients with gout or asymptomatic hyperuricemia: a pooled analysis of individual participant data in phase II and III trials

Background: Hyperuricemia is a risk factor for the development of hypertension and is comorbid in many hypertensive patients. According to Japanese hypertension management guidelines published in 2019, a target serum uric acid level of ≤6.0 mg/dL is recommended in hypertensive patients with gout or asymptomatic hyperuricemia. Dotinurad is a novel uric acid-lowering drug classified as a selective urate reabsorption inhibitor. A pooled analysis was performed on the uric acid-lowering effect of dotinurad in 222 hypertensive patients with gout or asymptomatic hyperuricemia in four clinical trials (NCT02344862, NCT02416167, NCT03100318, NCT03372200). Moreover, we analyzed the long-term uric acid-lowering effect of dotinurad in 154 hypertensive patients with gout or asymptomatic hyperuricemia (NCT03006445).Results: In the pooled analysis, the percent change in the decrease of serum uric acid with the use of dotinurad was 42.17 ± 12.42% at a dose of 2 mg and 60.42 ± 8.03% at a dose of 4 mg; the percentage of patients who achieved a serum uric acid level of ≤6.0 mg/dL was 82.8% and 100.0%. The long-term uric acid-lowering effect of dotinurad showed almost the same results. In this study, the concomitant use of diuretics or angiotensin II receptor blockers affected the uric acid-lowering effect of dotinurad at only a dose of 2 mg in the pooled analysis.Conclusions: In the pooled analysis, dotinurad lowered serum uric acid levels. Dotinurad has an achievement rate of over 80% for serum uric acid level of ≤6.0 mg/dL in both analyses, and will be clinically useful for the management of hyperuricemic states in hypertensive patients.

Molecular Biological and Clinical Understanding of the Pathophysiology and Treatments of Hyperuricemia and Its Association with Metabolic Syndrome, Cardiovascular Diseases and Chronic Kidney Disease

Uric acid (UA) is synthesized mainly in the liver, intestines, and vascular endothelium as the end product of an exogenous purine from food and endogenously from damaged, dying, and dead cells. The kidney plays a dominant role in UA excretion, and the kidney excretes approximately 70% of daily produced UA; the remaining 30% of UA is excreted from the intestine. When UA production exceeds UA excretion, hyperuricemia occurs. Hyperuricemia is significantly associated with the development and severity of the metabolic syndrome. The increased urate transporter 1 (URAT1) and glucose transporter 9 (GLUT9) expression, and glycolytic disturbances due to insulin resistance may be associated with the development of hyperuricemia in metabolic syndrome. Hyperuricemia was previously thought to be simply the cause of gout and gouty arthritis. Further, the hyperuricemia observed in patients with renal diseases was considered to be caused by UA underexcretion due to renal failure, and was not considered as an aggressive treatment target. The evidences obtained by basic science suggests a pathogenic role of hyperuricemia in the development of chronic kidney disease (CKD) and cardiovascular diseases (CVD), by inducing inflammation, endothelial dysfunction, proliferation of vascular smooth muscle cells, and activation of the renin-angiotensin system. Further, clinical evidences suggest that hyperuricemia is associated with the development of CVD and CKD. Further, accumulated data suggested that the UA-lowering treatments slower the progression of such diseases.

Comparative study of a novel selective urate reabsorption inhibitor "dotinurad" among patient groups with different stages of renal dysfunction

BACKGROUND

Dotinurad is a selective urate reabsorption inhibitor (SURI), which selectively inhibits URAT1 to lower serum uric acid levels in patients with hyperuricemia. Herein, the effects of dotinurad were compared among patient groups with different stages of renal dysfunction.

METHODS

Patient data from four clinical trials were pooled and divided into four groups according to the stage of renal dysfunction to compare the effects of dotinurad at different stages. The grouping (stages G1-G3b) was based on the estimated glomerular filtration rate (eGFR) of the patients. In addition, patient data from a long-term study (34 or 58 weeks) were evaluated in the same manner.

RESULTS

In the pooled analysis, the percentage of patients achieving a serum uric acid level of ≤ 6.0 mg/dL was 64.7-100.0% at a dose of 2 or 4 mg. In the long-term analysis, the percentage of patients achieving a serum uric acid level of ≤ 6.0 mg/dL was 60.0-100.0% at a dose of 2 or 4 mg. Although the outcomes in stage G3b were worse due to higher baseline serum uric acid levels, satisfactory outcomes were observed in all stages. Even in stages G3a and G3b, when renal function declined, the eGFR remained constant throughout the dose period.

CONCLUSION

The efficacy of dotinurad was confirmed in hyperuricemic patients with normal renal function (stage G1) and mild to moderate renal dysfunction (stage G2-G3b). Dotinurad was found to be effective in the treatment of hyperuricemia in patients with mild to moderate renal dysfunction.

Dotinurad: a novel selective urate reabsorption inhibitor for the treatment of hyperuricemia and gout

INTRODUCTION

Gout is an inflammatory disease triggered by deposition of urate crystals secondary to longstanding hyperuricemia, and its management implies both the treatment of flares and management of hyperuricemia. Dotinurad is a selective urate reabsorption inhibitor (SURI), potently inhibits urate transporter 1 in the apical surface of renal proximal tubular cells, and has been approved for the treatment of gout and hyperuricemia in Japan.

AREAS COVERED

This overview of dotinurad covers nonclinical and clinical pharmacology studies in special populations and its efficacy and safety in Japanese hyperuricemic patients with and without gout.

EXPERT OPINION

Dotinurad, as an SURI, is expected to inhibit urate reabsorption more effectively than conventional urate-lowering agents. It is noninferior to benzbromarone or febuxostat in reducing serum urate levels in hyperuricemic patients with or without gout. Its efficacy is not attenuated in patients with mild to moderate renal impairment or with hepatic impairment. At a maintenance dose of 2 or 4 mg once daily, most patients achieved the target serum urate level of ≤6 mg/dL in a long-term study. No findings that raised safety concerns, including liver injury, were identified. Dotinurad is expected to be a new therapeutic option in hyperuricemic patients with and without gout.

Efficacy and Safety of Dotinurad in Hyperuricemic Patients With or Without Gout: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

Introduction A systematic review and meta-analysis of the available randomized controlled trials (RCTs) were conducted to investigate the efficacy and safety of dotinurad in hyperuricemic patients with or without gout. Dotinurad is a novel selective urate reabsorption inhibitor (SURI) that increases uric acid excretion by selectively inhibiting urate transporter 1 (URAT1). To the best of our knowledge, this is the first meta-analysis conducted to gauge the efficacy and safety of dotinurad.  Methods Electronic databases (PubMed, the Cochrane Library, and ClinicalTrials.gov) were searched from inception till March 2, 2021, according to the Preferred Reporting Items for Systematic Review and Meta-Analysis statement. Randomized controlled trials comparing the efficacy and safety of dotinurad with placebo- or active (febuxostat or benzbromarone) control were included. The eligible studies were analyzed with RevMan 5.3 Software (The Nordic Cochrane Centre, Cochrane Collaboration, Copenhagen). Results Four eligible studies, consisting of 684 hyperuricemic patients were included. The number of patients who achieved serum uric acid (sUA) levels ≤ 6.0 mg/dl favoured dotinurad 1 mg group as compared to placebo group (risk ratio {RR} = 39.27, 95% onfidence interval {CI}, 5.59 to 275.65; p = 0.0002), dotinurad 2 mg group compared with placebo group (RR = 45.36, 95% CI, 6.48 to 317.38; p= 0.0001), and dotinurad 4 mg group compared with placebo group (RR = 54.16, 95% CI, 7.76 to 377.77; p < 0.0001). Conversely, there was no significant difference in the number of patients who achieved the target sUA levels between dotinurad 2 mg and active control (RR = 1.00, 95% CI, 0.92 to 1.08; p = 0.91). Moreover, the percentage change in sUA levels from baseline to final visit favoured dotinurad 1 mg vs. placebo ((RR = 36.51, 95% CI, 33.00 to 40.02; p < 0.00001), dotinurad 2 mg vs. placebo (RR = 46.70, 95% CI, 42.53 to 50.87; p < 0.00001), and dotinurad 4 mg vs. placebo (RR = 63.84, 95% CI, 60.51 to 67.16; p < 0.00001), while no significant difference was seen in dotinurad 2 mg vs. active control (RR = -0.08, 95% CI, -4.27 to 4.11; p= 0.97). Compared with active or placebo control, dotinurad 2 mg showed no significant difference in the number of events of gouty arthritis (RR= 1.31, 95% CI, 0.47 to 3.71; p = 0.60), the number patients with adverse events (RR = 1.09, 95% CI, 0.91 to 1.30; p = 0.36), and the number of patients who experienced adverse drug reactions (RR = 1.00, 95% CI, 0.68 to 1.47; p = 0.99). Conclusion Dotinurad shows significant improvement in serum uric acid levels in hyperuricemic individuals with or without gout. Its urate-lowering effect is comparable to the commonly available anti-hyperuricemic agents. Moreover, it is effective at doses 1 mg, 2 mg, and 4 mg and well-tolerated at a dose of 2 mg.

[Pharmacological properties and clinical efficacy of dotinurad (URECE® tablets), a novel hypouricemic agent]

In Jan 2020, dotinurad (URECE^® tablets) was approved for gout and hyperuricemia therapy in Japan. We developed a novel hypouricemic agent because benzbromarone, a commercially available uricosuric agent, has several problems, such as drug-induced liver injury or drug-drug interaction caused by CYP2C9 inhibition. In transporter-overexpressing cells, dotinurad potently inhibited URAT1 which is localized in the renal proximal tubules and functions as a urate reabsorption. On the contrary, dotinurad hardly inhibited urate secretion transporters, ABCG2 or OAT1/3. In Cebus monkeys, dotinurad dose-dependently decreased plasma urate levels at low doses compared with benzbromarone. Inhibitory effect of dotinurad on mitochondria was weaker than that of benzbromarone and there was no observation suggesting a risk of drug-induced liver injury taking into consideration the clinical dose or exposure. Dotinurad weakly inhibited CYPs and further analysis indicated there was no drug-drug interaction risk in the clinical dose. In clinical pharmacology studies, there was no difference among sex and age. Furthermore, dosage and administration are equal even in hepatic impairment patients (mild to severe) and renal impairment patients (mild to moderate). In confirmatory phase II and long-term studies, dotinurad decreased serum urate levels at low doses and almost patients using maintenance dose (2 or 4 mg) achieved a serum urate level ≤ 6.0 mg/dL. Moreover, there was no finding to raise safety concern including liver injury. In conclusion, dotinurad, a selective urate reabsorption inhibitor (SURI) could be a therapeutic option because of its more effective hypouricemic action at low doses than those of commercially available uricosuric agents.