Effects of mild and moderate renal dysfunction on pharmacokinetics, pharmacodynamics, and safety of dotinurad: a novel selective urate reabsorption inhibitor

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.

A brief review of urate transporter 1 (URAT1) inhibitors for the treatment of hyperuricemia and gout: Current therapeutic options and potential applications

Hyperuricemia is a common metabolic condition, cause by increased levels of serum urate (SUA). Reduced excretion of uric acid is reported as the key factor of primary hyperuricemia, accounting for approximately 90% of the cases. Urate transporter 1 (URAT1) is a major protein involved in uric acid reabsorption (about 90%). Therefore, URAT1 inhibitors are considered to be a highly effective and promising class of uricosuric agents for treating hyperuricemia. This review summarizes the development of URAT1 inhibitors for the treatment of hyperuricemia, including approved URAT1 inhibitors, URAT1 inhibitors under development in clinical trials, substances with URAT1 inhibitory effects from derivatives and natural products, and conventional drugs with new uses. This review provides new ideas regarding research on URAT1 inhibitors by introducing the structure, properties, and side effects of chemical drugs, as well as the sources and categories of natural drugs. We also discuss new mechanisms of classic drugs, which may provide guidance to many practicing clinicians. The research and discovery of new inhibitors remain in full swing, and tremendous developments are expected in the field.

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.

A drug-drug interaction study of a novel, selective urate reabsorption inhibitor dotinurad and the non-steroidal anti-inflammatory drug oxaprozin in healthy adult males

Background

Dotinurad is a novel, selective urate reabsorption inhibitor, which reduces serum uric acid levels by inhibiting the urate transporter 1. The results of nonclinical studies indicated the possibility that the concomitant use of the non-steroidal anti-inflammatory drug oxaprozin affects the pharmacokinetics of dotinurad. We evaluated drug–drug interactions with respect to the pharmacokinetics and safety of dotinurad when co-administered with oxaprozin.

Methods

This was an open-label, two-period, add-on study in healthy adult males. For a single dose of 4 mg of dotinurad with and without oxaprozin, we compared its pharmacokinetic parameters and evaluated safety.

Results

This study enrolled 12 subjects, 11 of whom completed the study. The geometric mean ratio (90% confidence interval [CI]) of the urinary excretion rate of glucuronate conjugates of dotinurad after co-administration with oxaprozin compared to administration of dotinurad alone was 0.657 (0.624–0.692), while the geometric mean ratios (90% CIs) of the maximum plasma concentration and area under the plasma concentration–time curve from time zero to infinity (AUC_0–inf) were 0.982 (0.945–1.021) and 1.165 (1.114–1.219), respectively. During the study, two adverse events occurred after administration of dotinurad alone and one occurred after administration of oxaprozin alone.

Conclusions

In comparison with administration of dotinurad alone, co-administration with oxaprozin was associated with a 34.3% decrease in the urinary excretion rate of the glucuronate conjugates of dotinurad, and a 16.5% increase in AUC_0–inf of dotinurad. However, no clinically meaningful drug–drug interactions were observed. Administration of dotinurad alone was similar safety to co-administration with oxaprozin.

Clinical trial registration

ClinicalTrials.gov Identifier: NCT03350386.

[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.