Multicenter, open-label study of long-term administration of febuxostat (TMX-67) in Japanese patients with hyperuricemia including gout.

BACKGROUND: In previous clinical studies of hyperuricemia including gout, although serum uric acid (sUA) levels reduced to 6.0 mg/dL or less in about 80% of patients treated with 40 mg/d febuxostat, a nonpurine selective xanthine oxidase inhibitor, a few patients did not show this result.

OBJECTIVE: The objective of the study was to evaluate the efficacy and safety of long-term febuxostat administration at up to 60 mg/d in patients with hyperuricemia and gout.

METHODS: In a 52-week, multicenter, open-label trial, febuxostat was initially administered at 10 mg/d; then, the dosage was increased in a stepwise fashion to 40 mg/d. For sUA levels greater than 6.0 mg/dL at week 10, the dosage was increased to 60 mg/d from week 14 onward (60-mg group), but it was maintained at 40 mg/d until the end of the study for patients with sUA levels 6.0 mg/dL or less at week 10 (40-mg group).

RESULTS: The sUA levels in both groups decreased dose dependently. At 52 weeks, 84.5% and 85.0% of the 40- and 60-mg groups, respectively, achieved mean sUA levels 6.0 mg/dL or less. There was no marked difference between the 2 dosage groups in terms of the incidence of adverse events. Furthermore, there were no noteworthy adverse events or adverse drug reactions in the patients with renal dysfunction, and no differences in drug efficacy up to 60 mg/d were noted between the patients with moderate or mild renal dysfunction and those with normal renal function.

CONCLUSIONS: Febuxostat seems to be a promising therapeutic drug for gout or hyperuricemia, even in patients with renal dysfunction.