Effect of Febuxostat on Renal Function in Patients With Gout and Moderate to Severe Renal Impairment

Change From Baseline to Month 12 in Estimated Glomerular Filtration Rate (eGFR)

Change from baseline to Month 12 in estimated Glomerular Filtration Rate (eGFR) using the Modification of Diet in Renal Disease (MDRD) formula (as calculated by the central laboratory).

Time frame: Baseline and Month 12

Percentage of Participants With Serum Urate (sUA) Less Than 6 mg/dL at Month 12

Serum urate concentrations were determined using the enzymatic method as performed by the Central Laboratory.

Time frame: Month 12

Mean Clearance (CL/F) of Febuxostat at Steady State

Mean CL/F at steady state were estimated using a population pharmacokinetic (PK) approach, based on 2 PK samples collected prior to dosing, and 4 PK samples collected postdose.

Time frame: The 2 pre-dose PK samples collected were collected at any 2 of the following visits: Months 3, 6, 9, and/or 12, at -0.25 to 0 hours. The 4 postdose PK samples were collected at Months 3, 6, and/or 9, at 0.25; 0.75 to 2.0; 2.5 to 4.0; and 5 to 12 hours.

Mean Area Under the Concentration-Time Curve During the Dosing Interval (AUC[0-τ]) of Febuxostat at Steady State

Mean AUC during the dosing interval at steady state was estimated using a population pharmacokinetic (PK) approach, based on 2 PK samples collected prior to dosing, and 4 PK samples collected postdose.

Time frame: The 2 pre-dose PK samples collected were collected at any 2 of the following visits: Months 3, 6, 9, and/or 12, at -0.25 to 0 hours. The 4 postdose PK samples were collected at Months 3, 6, and/or 9, at 0.25; 0.75 to 2.0; 2.5 to 4.0; and 5 to 12 hours.