Febuxostat for the treatment of gout

Introduction: Gout is a rheumatologic condition associated with elevated serum uric acid levels and deposition of monosodium urate crystals in joints and soft tissues. The xanthine oxidase inhibitor, allopurinol, has historically been the principle agent utilized for reducing elevated uric acid levels and treating underlying cause of gout symptoms; the availability of febuxostat, a newer non-purine selective xanthine oxidase inhibitor, represents an alternative therapy for those patients with contraindications or intolerance to allopurinol.

Areas covered: This article reviews the published literature on the pharmacologic characteristics and clinical safety and efficacy data on the use of febuxostat in the treatment of gout. A literature search of MEDLINE and MEDLINE In-Process & Other Non-Indexed Citations Databases (1996–November 2014) was conducted utilizing the key words ‘febuxostat’, ‘allopurinol’, and ‘gout’. All published articles regarding febuxostat were evaluated. References of selected articles, data from poster presentations, and abstract publications were additionally reviewed.

Expert opinion: Febuxostat has shown benefit with respect to symptomatic relief and uric acid level reduction. The safety profile of this agent makes it an ideal alternative in those patients with contraindications to or who are intolerant of allopurinol.     

治疗痛风和高尿酸血症药物的研究进展

随着痛风和高尿酸血症发病率的逐年攀升,临床常用治疗药物（别嘌醇、苯溴马隆、非布司他等）市场销售额也逐年递增,但这些药物均存在明显的副作用,国内外药企已将研发重点放在更安全、更高效的新型降尿酸药物尿酸盐重吸收转运子1（URAT1）抑制剂领域,已上市的雷西那德在近几年备受关注,而在研新药SHR4640、SIM1909-13已处于临床试验阶段,同时用中医药治疗高尿酸血症和痛风也是未来的研究方向。对治疗痛风及高尿酸血症的药物研究进展进行综述,以期为临床用药和新药研发提供参考。     

以黄嘌呤氧化酶为靶点的新型非嘌呤类抗痛风及高尿酸血症药物研究进展

黄嘌呤氧化酶（XO）催化黄嘌呤生成尿酸及次黄嘌呤生成黄嘌呤的过程,是抗高尿酸血症或痛风药物研究的关键靶点。黄嘌呤氧化酶抑制剂由于作用机制明确、疗效显著而倍受关注,研发新型XO抑制剂具有广阔的应用前景。XO的结构生物学及分子模拟技术为新一代非嘌呤类XO抑制剂的合理药物设计奠定了基础。本文综述了以黄嘌呤氧化酶为靶标的新型非嘌呤类小分子杂环化合物及天然产物来源的活性分子在抗高尿酸血症或痛风药物研究领域中的进展。     

Chronic gout: epidemiology,disease progression,treatment and disease burden

Abstract

Background:

Gout is a painful and disabling inflammatory arthritis of increasing prevalence associated with hyperuricemia and the deposition of monosodium urate crystals in soft tissues and joints. Diagnosed gout cases have been estimated at 2.13% of the 2009 US population. The highest incidence occurs in the 65+ year age group, with males more than twice as likely to be afflicted as females.     

An updated patent review: xanthine oxidase inhibitors for the treatment of hyperuricemia and gout (2011-2015)

Introduction: Xanthine oxidase (XO) is a versatile molybdoflavoprotein, widely distributed, occurring in milk, kidney, lung, heart, and vascular endothelium. Catalysis by XO to produce uric acid and reactive oxygen species leads to many diseases. Anti hyperuricemic therapy by xanthine oxidase inhibitors has been mainly employed for the treatment of gout.

Area covered: This review covers the patent literature (2011–2015) and also presents the interesting strategies/rational approaches employed for the design of xanthine oxidase inhibitors reported recently.

Expert opinion: Recent literature indicates that various non purine scaffolds have been extensively investigated for xanthine oxidase inhibition. The significant potential endowed by heteroaryl based compounds, in particularly fused heterocycles clearly highlights their clinical promise and the need for detailed investigation. Studies by various research groups have also revealed that the flavone framework is open for isosteric replacements and structural modifications for yielding potent non purine xanthine oxidase inhibitors. In addition, various plant extracts recently reported to possess significant xanthine oxidase inhibitory potential presents enough promise to initiate a screening program for the identification of other plant extracts and phytoconstituents possessing inhibitory potential towards the enzyme.     

Febuxostat: a non-purine,selective inhibitor of xanthine oxidase for the management of hyperuricaemia in patients with gout

Febuxostat is a non-purine, selective inhibitor of xanthine oxidase being developed for the management of hyperuricaemia in patients with gout. With febuxostat 10 – 120 mg, the pharmacokinetics are linear. No dose adjustment appears to be necessary in those with renal insufficiency or mild-to-moderate hepatic impairment. Febuxostat 10 – 120 mg/day rapidly and sustainably reduces serum uric acid by 25 – 70% in uric acid underexcretors and overproducers. Prophylaxis with colchicine or a non-steroidal anti-inflammatory drug can mitigate the gout-flare risk from the rapid urate lowering after febuxostat initiation. Febuxostat is well tolerated, the majority of treatment-related adverse events are transient and mild-to-moderate in severity. Febuxostat can broaden the therapeutic options for urate-lowering therapy in those with gout.     

3,4-Dihydroxy-5-nitrobenzaldehyde (DHNB) is a potent inhibitor of xanthine oxidase: A potential therapeutic agent for treatment of hyperuricemia and gout

Hyperuricemia, excess of uric acid in the blood, is a clinical problem that causes gout and is also considered a risk factor for cardiovascular disease. The enzyme xanthine oxidase (XO) produces uric acid during the purine metabolism; therefore, discovering novel XO inhibitors is an important strategy to develop an effective therapy for hyperuricemia and gout. We found that 3,4-dihydroxy-5-nitrobenzaldehyde (DHNB), a derivative of the natural substance protocatechuic aldehyde, potently inhibited XO activity with an IC₅₀ value of 3 μM. DHNB inhibited XO activity in a time-dependent manner, which was similar to that of allopurinol, a clinical XO inhibitory drug. DHNB displayed potent mixed-type inhibition of the activity of XO, and showed an additive effect with allopurinol at the low concentration. Structure–activity relationship studies of DHNB indicated that the aldehyde moiety, the catechol moiety, and nitration at C-5 were required for XO inhibition. DHNB interacted with the molybdenum center of XO and was slowly converted to its carboxylic acid at a rate of 10⁻¹⁰ mol/L/s. In addition, DHNB directly scavenged free radical DPPH and ROS, including ONOO⁻ and HOCl. DHNB effectively reduced serum uric acid levels in allantoxanamide-induced hyperuricemic mice. Furthermore, mice orally given a large dose (500 mg/kg) of DHNB did not show any side effects, while 42% of allopurinol (500 mg/kg)-treated mice died and their offspring lost their fur. Thus, DHNB could be an outstanding candidate for a novel XO inhibitory drug that has potent activity and low toxicity, as well as antioxidant activity and a distinct chemical structure from allopurinol.     

Recent patents in the discovery of small molecule inhibitors of JAK3

Importance of the field: Protein kinase enzymes have become increasingly important as the target of many disease modification drug discovery programs. Disruption of JAK3 function results in quantitative and qualitative deficiencies in both B- and T-cell compartments of the immune system of JAK3 deficient mice and development of severe combined immunodeficiency in humans with the JAK3 genetic aberration. JAK3 plays a specific role in immune function and lymphoid development and it only resides in the hematopoietic system, thus the rationale for selective targeting. Inhibitors of JAK3 have shown utility in many different autoimmune disorders, including allograft rejection during transplantation, acute lymphoblastic leukemia, Type 1 diabetes, rheumatoid arthritis and allergic and asthmatic diseases. These inhibitors are making their way into clinical trials with profound effects, thus, validating the target and strategy.

Areas covered in this review: A review that covers around 90 patents and patent applications made in the last 10 years in the area involving JAK3 inhibitors is provided. Specifically, what this content will provide is the genus, highlighted compounds of particular interest, filing organization and some biological measure of these compounds as inhibitors of this protein kinase or none if it is not provided. Some information from original research articles appearing in peer reviewed literature is provided, but this article is not a review of the literature. Furthermore, an overview of the current clinical status and future outcomes of this field is provided as summary.

What the reader will gain: A strong understanding for the current state of the art in patents dealing with inhibitors of JAK3 including genus and species designations, potential commercial interest of this target in the pharmaceutical community, depth of coverage by numbers of examples and selected proof of action against the target. Also, a brief understanding of the biology and pharmacology involved in the processes involving the research, discovery, characterization and clinical status of JAK3 inhibitors.

Take home message: This review is intended for medicinal chemists and patent agents who want to get a quick understanding of the state of the art in the field of JAK3 inhibitors. It further serves as a reference point to go into more depth on any series reported and to be able to evaluate any original research ideas in this area in the future.     

染料木素、芹菜素、槲皮素、芦丁和落新妇苷对高尿酸血症小鼠黄嘌呤氧化酶活性及血清尿酸水平的影响

目的探讨黄酮类化合物染料木素、芹菜素、槲皮素、芦丁和落新妇苷体外对黄嘌呤氧化酶活性的影响,对高尿酸血症小鼠血清和肝脏黄嘌呤氧化酶活性的影响,同时评价对小鼠血清尿酸水平的作用。方法采用改良的紫外分光光度法测定染料木素、芹菜素、槲皮素、芦丁和落新妇苷体外对黄嘌呤氧化酶的抑制作用;采用尿酸酶抑制剂氧嗪酸钾诱导小鼠高尿酸血症模型,以分光光度法研究对小鼠血清和肝脏黄嘌呤氧化酶活性的影响,以磷钨酸法测定对小鼠血清尿酸水平的作用。结果体外实验表明这些黄酮类化合物对黄嘌呤氧化酶活性无明显影响。然而,体内实验观察到能够明显升高或降低黄嘌呤氧化酶的活性,而且,血清尿酸水平与血清黄嘌呤氧化酶活性密切相关,与肝脏黄嘌呤氧化酶活性无明显关联。该研究表明用这些黄酮类化合物给药的小鼠血清尿酸水平都高于正常对照组。结论这5种黄酮类化合物不能够作为替代别嘌醇的药物用来降低血清尿酸水平。     

Current therapies for the treatment of systemic sclerosis-related pulmonary arterial hypertension: efficacy and safety

Introduction: Systemic sclerosis (SSc) is a rare connective tissue disease characterized by chronic inflammation and fibrosis of the skin, vascular abnormalities and variable involvement of organs. Patients with limited SSc typically develop pulmonary arterial hypertension (PAH). TNF-α, VEGF, platelet-derived growth factor and endothelin-1 play a key role in the development of PAH.

Areas covered: This paper addresses the efficacy and safety of current drugs used for the treatment of PAH.

Expert opinion: Bosentan, ambrisentan, sildenafil, tadalafil, iloprost, epoprostenol and treprostinil were associated with hemodynamic improvements in PAH patients. Ambrisentan has a better safety profile compared with bosentan, regarding the risk of increase in hepatic transaminases. Flushing, dyspepsia and diarrhea were the most frequent adverse events in patients treated with sildenafil, while headache, myalgia and flushing were the adverse events in those receiving tadalafil. Inhaled iloprost is also effective, but it requires multiple daily nebulizations up to 15 min each and may induce cough, flushing, jaw pain and headache. Epoprostenol is considered the most effective approved therapy for severe PAH in WHO functional class III and class IV. TNF-α inhibitors reduce the systemic inflammation in patients with chronic immune-mediated diseases and improve the endothelial function, decreasing the risk of PAH progression.     

Xanthine oxidase inhibition by allopurinol affects the reliability of urinary caffeine metabolic ratios as markers for N-acetyltransferase 2 and CYP1A2 activities

Objectives: To evaluate the in vivo effect of xanthine oxidase (XO) inhibition by allopurinol on the determination of polymorphic N-acetyltransferase 2 (NAT2) and cytochrome P450 1A2 (CYP1A2) with urinary caffeine metabolic ratios. Methods: In an open, prospective study involving 21 healthy subjects (eight fast, 13 slow NAT2 acetylators) allopurinol (300 mg perday) was administered orally on trial days 1–8, followed by a wash-out period of 8 days. Urinary caffeine tests (200 mg caffeine p.o.) were performed repetitively. Urine was collected for 8 h and venous blood samples for the determination of allopurinol, oxypurinol and uric acid were drawn. The urinary caffeine metabolites 1-methyluric acid (1MU), 1-methylxanthine (1MX), 1,7-dimethyluric acid (17MU), 1,7-dimethylxanthine (17MX), 5-acetylamino-6-formylamino-3-methyluracil (AFMU), plasma allopurinol and oxypurinol were analysed using high-performance liquid chromatography (HPLC). Results: During XO inhibition by allopurinol, the formation of 1MU from 1MX and therefore the XO ratio 1MU/1MX decreased to 15.9 (1.2)% [mean with (SEM)] of baseline values (P < 0.005). The NAT2 ratio AFMU/1MX decreased likewise to 56.7 (6.3)% (P < 0.005). AFMU/(AFMU + 1MX + 1MU), an alternative NAT2 ratio, remained constant, but the CYP1A2 ratio (AFMU + 1MX + 1MU)/17MU, used to express CYP1A2 activity, transiently increased to 167 (13)% (P < 0.005). The NAT2 phenotype did not influence CYP1A2 and XO ratios or plasma oxypurinol pharmacokinetics. Conclusions: Several caffeine metabolic ratios are commonly used to express the activities of NAT2, CYP1A2 and XO both in healthy volunteers and in polymedicated patients, although their reliability has not been evaluated thoroughly during concurrent drug administration. The findings of this study suggest that NAT2 phenotyping should be performed using the ratio AFMU/(AFMU + 1MX + 1MU) if an XO inhibitor may be present. It also shows that the determination of CYP1A2 activity with caffeine as a metabolic probe is considerably altered under these conditions. Thus, concomitant drug administration may impair the robustness of multiple pathways of the complex caffeine test. This points to the need for alternative probes, designed to assess only the activity of a single enzyme because, in contrast to healthy volunteers, in patients known or unknown drug interactions may often be present. Received: 10 August 1998 / Accepted in revised form: 5 October 1998     

Seletracetam, a small molecule SV2A modulator for the treatment of epilepsy

UCB SA was developing the high-affinity synaptic vesicle glycoprotein 2A ligand, seletracetam, an analog of levetiracetam, for the potential oral treatment of epilepsy. Phase II epilepsy trials were underway, but in July 2007, the company stated that development of seletracetam had been put on hold and it is unknown whether planned phase IIb/III trials will begin.     

BAP updated guidelines: evidence-based guidelines for the pharmacological management of substance abuse, harmful use, addiction and comorbidity: recommendations from BAP

The British Association for Psychopharmacology guidelines for the treatment of substance abuse, harmful use, addiction and comorbidity with psychiatric disorders primarily focus on their pharmacological management. They are based explicitly on the available evidence and presented as recommendations to aid clinical decision making for practitioners alongside a detailed review of the evidence. A consensus meeting, involving experts in the treatment of these disorders, reviewed key areas and considered the strength of the evidence and clinical implications. The guidelines were drawn up after feedback from participants. The guidelines primarily cover the pharmacological management of withdrawal, short- and long-term substitution, maintenance of abstinence and prevention of complications, where appropriate, for substance abuse or harmful use or addiction as well management in pregnancy, comorbidity with psychiatric disorders and in younger and older people.     

Risk of acute pancreatitis with incretin-based therapy: a systematic review and updated meta-analysis of cardiovascular outcomes trials

ABSTRACT

Background

The link of acute pancreatitis (AP) with Incretin based therapies (IBTs) in type 2 diabetes has existed since United States Food and Drug Administration alert in 2010. This issue still remains unresolved due to conflicting results among studies.     

Emerging first line treatment options for bladder cancer: a review of phase II and III therapies in the pipeline

Introduction: The treatment of urothelial carcinoma (UC) had remained unchanged for several years until the recent FDA approval of immune checkpoint inhibitors (CPIs) in the salvage setting. Novel dual CPI-CPI and CPI-chemotherapy combinations are now being investigated aggressively as first line therapy for metastatic disease.

Areas covered: We discuss the recent insights into the tumor biology of UC, which may impact the prognosis as well as assist in developing precision medicine. This is followed by an overview of existing treatment including conventional chemotherapy as well as the trials that led to the recent approval of PD-1 and PD-L1 inhibitors. Ongoing phase II and phase III trials developing PD-1/PD-L1 inhibitors, CTLA-4 inhibitors and VEGF inhibitors as first-line therapy are discussed.

Expert opinion: The treatment paradigm for the first-line therapy of UC is expected to shift from conventional platinum-based combination chemotherapy towards novel therapy incorporating CPI immunotherapy. Finding the right combination of drugs in the appropriate disease setting and identifying the right patient population based on biomarkers are important questions to be answered. Another major challenge will be the financial burden associated with these new drugs.     

Emerging and future therapies for the treatment of bone loss associated with chronic inflammation

Currently there are many emerging therapies for the treatment of chronic osteoporosis. This is a major problem world wide and particularly of concern in post-menopausal women. This has offered a large expanding market for the pharmaceutical industry and consequently large amounts of money and resources have been used to develop new treatments. These new and emerging treatments have largely targeted the mechanisms of bone loss associated with post-menopausal osteoporosis. However, there are many other important bone loss disorders and it is possible that some of these new therapies may be useful in treating bone loss associated with other diseases. This review identifies several of these pharmacologic treatments of osteoporosis and discusses the possibility of using these drugs for the treatment of bone loss associated with inflammatory diseases. In addition, other approaches, such as regulating apoptosis and intracellular signalling, may be developed in the future and may better target bone loss associated with chronic inflammation are identified. Received and accepted 30 August 2006     

New and developing non-adrenoreceptor small molecule drugs for the treatment of asthma

Introduction: Inhaled corticosteroids (ICS) alone or in combination with an inhaled long-acting beta₂-agonist (LABA) are the preferred long-term treatment for adults and adolescents with symptomatic asthma. Additional drugs include leukotriene-receptor antagonists, slow-release theophylline and the long-acting muscarinic antagonist (LAMA) tiotropium (approved in 2015). There is a need for more effective therapies, as many patients continue to have poorly controlled asthma.

Areas covered: New and developing long-acting non-adrenoreceptor synthetic drugs for the treatment of symptomatic chronic asthma despite treatment with an ICS alone or combined with a LABA. Data was reviewed from studies published up until November 2016.

Expert opinion: Tiotropium improves lung function and has a modest effect in reducing exacerbations when added to ICS alone or ICS and LABA. The LAMAs umeclidinium and glycopyrronium are under development in fixed dose combination with ICS and LABA. Novel small molecule drugs, such as CRTH2 receptor antagonists, PDE₄ inhibitors, protein kinase inhibitors and nonsteroidal glucocorticoid receptor agonists and ‘off-label’ use of licensed drugs, such as macrolides and statins are under investigation for asthma, although their effectiveness in clinical practice is not established. To better achieve the goal of developing effective novel small molecule drugs for asthma will require greater understanding of mechanisms of disease and the different phenotypes and endotypes of asthma.     

针药结合治疗对慢性肾小球肾炎大鼠IL-1、IL-2的影响

目的探讨针药结合治疗对实验性肾炎大鼠免疫因子IL-1、IL-2的影响。方法通过小鼠胸腺细胞增值法观察针药结合治疗对尾静脉注射小牛血清白蛋白所诱发慢性肾小球肾炎大鼠免疫因子IL-1、IL-2影响。结果针药结合治疗后,各组大鼠血清IL-1、IL-2水平明显降低,其中针药结合组,中药组与模型组比较有显著性差异（P〈0.05）。结论针药结合治疗可以抑制细胞IL-1、IL-2的释放,调节免疫,提示其作用机制可能与免疫因子调节有关。