Dose-Response, Safety and Efficacy of Febuxostat in Subjects With Gout

Phase II, Dose-Response, Safety and Efficacy Study of Oral TMX-67 in Subjects With Gout.

The purpose of this study is to determine the efficacy of febuxostat, once daily (QD), in reducing serum urate levels in subjects with gout.

Gout is a chronic urate crystal deposition disorder, which if left untreated may result in progressive disease characterized by joint and bone destruction from tophaceous deposits and renal impairment due to gouty nephropathy. Hyperuricemia, defined as a serum urate concentration of >7.0 milligrams per deciliter (mg/dL), is the underlying metabolic aberration leading to urate crystal deposition in gout. Gout has several clinical presentations, including: recurrent acute attacks of inflammatory arthritis; deposition of monosodium urate monohydrate crystals in joints, bones and even parenchymal organs (tophaceous gout); renal impairment; and uric acid nephrolithiasis. As serum urate levels increase beyond >7.0 mg/dL, the risks for gouty arthritis or for renal calculi increase.

Currently allopurinol is the only xanthine oxidase inhibitor available. Allopurinol is the agent of choice for reduction of serum urate levels in patients with: uric acid overproduction; unresponsive or intolerant to uricosuric agents; impaired renal function; uric acid urolithiasis; or tophi.

Febuxostat (TMX-67) is a non-purine selective xanthine oxidase inhibitor being developed as an orally administered agent for management of hyperuricemia in patients with gout.

Inclusion Criteria:

• Hyperuricemia (serum uric acid ≥8.0 mg/dL).
• Must meet American College of Rheumatology criteria for gout.
• Must have adequate renal function (serum creatinine <1.5 mg/dL).
• Females of childbearing potential who are sexually active must agree to use adequate contraception, and can neither be pregnant nor lactating from Screening throughout the duration of the study.

Exclusion Criteria:

• History of xanthinuria
• Alcohol consumption >14/week
• Has a history of significant concomitant illness.
• Has active liver disease.
• Has a body mass index greater than 50 kilogram per meter² (kg/m²)
• Any other significant medical condition that would interfere with the treatment, safety or compliance with the protocol, as defined by the investigator.