Examining Gout and Emerging Treatments
Gout is a form of inflammatory arthritis caused by deposition of monosodium uric acid crystals in the joints and surrounding tissues as a result of uric acid burden.1 It is more common in men 45 years of age and older, but can occur in anyone, at any age. Factors ranging from a family history of gout to having other health issues, such as high blood pressure, diabetes, obesity, or kidney disease, can increase disease risk. Gout has 4 clinical stages: (1) asymptomatic hyperuricemia, (2) acute gouty arthritis, (3) intercritical gout, and (4) chronic tophaceous. Gout may occur after years of sustained hyperuricemia, which can be defined as a serum urate (sUA) level >6.8 mg/dL.2
The prevalence of gout in the US population is estimated to be 8.3 million (3.9%). For the majority of individuals, excruciatingly painful gout attacks are the major clinical burden of the disease. Approximately 60% of patients experience a recurrent gout flare within 1 year after an initial event, 78% experience a recurrent flare within 2 years.3
The goal of an sUA-lowering treatment is to reduce sUA levels to the target level of <6.0 mg/dL as recommended by both the American College of Rheumatology and the European League Against Rheumatism. In individuals with greater disease severity and urate burden, guidelines recommend lowering sUA to <5.0 mg/dL to achieve better disease control.4,5 Nonsteroidal anti-inflammatory drugs, colchicine, and steroids are commonly used in the acute treatment of gout. Medications to lower uric acid levels and prevent future attacks may include urate-lowering agents. Maintaining a healthy lifestyle and diet are also an important part of the treatment plan.2
Gout and gout flares represent a significant burden in terms of both direct health care cost and reduced health-related quality of life.1,6 A 2013 literature review estimated the cost of gout at more than $6 billion annually in direct and indirect costs for prevalent cases.7 In a separate retrospective cohort study in a managed care setting, researchers looked at administrative claims data from a large US health plan to assess the association of frequent flares with health care burden. They found that follow-up gout-related health care costs and gout-related inpatient stays, emergency room visits, and ambulatory visits were higher among patients with ≥2 flares versus those with <2 flares. Adjusted annual gout-related costs were $1804, $3014, and $4363 in those with 0 to 1, 2, and 3+ gout flares, respectively.3
The pipeline of drugs for gout management is growing, with many investigational agents in phase II and phase III clinical trials. Over the past decade, researchers have learned more about the mechanism of crystal-induced inflammation and renal excretion of uric acid, which has led to more specific targeting of gout therapies. These novel-gout specific anti-inflammatories include the interleukin-1ß inhibitors, the melanocortins, and caspase inhibitors.8 The armamentarium of uric acid-lowering therapies is poised for growth with the development of new treatments, including the December 22, 2015 US Food and Drug Administration approval of lesinurad for the treatment of high levels of uric acid in the blood associated with gout, when used in combination with a xanthine oxidase inhibitor.8,9
Data confirms the growing prevalence of gout and its significant burden on health care and patients. As a result, one study concluded that “effective urate-lowering treatments are likely to be valued if they can be clearly demonstrated to be clinically effective and cost-effective.”6—Eileen Koutnik-Fotopoulos
