Recruitment Details

Key information relevant to the recruitment process for the overall study, such as dates of the recruitment period and locations
Subjects were enrolled at 112 investigative sites, 106 in the United States and 6 in Canada, from 11 July 2002 to 20 February 2004.

Pre-Assignment Details

Significant events and approaches for the overall study following participant enrollment, but prior to group assignment
Subjects currently receiving urate-lowering therapy discontinued those urate-lowering therapies and initiated prophylactic medications before enrollment in once daily (QD) treatment groups.

Reporting Groups

	Description
Febuxostat 80 mg QD	Febuxostat 80 mg, orally, once daily for up to 52 weeks.
Febuxostat 120 mg QD	Febuxostat 120 mg, orally, once daily for up to 52 weeks.
Allopurinol 300 mg QD	Allopurinol 300 mg, orally, once daily for up to 52 weeks.

Participant Flow:   Overall Study

	Febuxostat 80 mg QD	Febuxostat 120 mg QD	Allopurinol 300 mg QD
STARTED	256	251	253
COMPLETED	168	153	187
NOT COMPLETED	88	98	66
Lost to Follow-up	25	18	21
Adverse Event	16	23	8
Gout Flare	10	28	9
Personal Reason(s)	19	13	13
Other	11	14	14
Protocol Violation	7	2	1

Reporting Groups

	Description
Febuxostat 80 mg QD	Febuxostat 80 mg, orally, once daily for up to 52 weeks.
Febuxostat 120 mg QD	Febuxostat 120 mg, orally, once daily for up to 52 weeks.
Allopurinol 300 mg QD	Allopurinol 300 mg, orally, once daily for up to 52 weeks.

Baseline Measures

	Febuxostat 80 mg QD	Febuxostat 120 mg QD	Allopurinol 300 mg QD	Total
Number of Participants   [units: participants]	256	251	253	760
Age, Customized   [units: subjects]
<45 years	75	71	84	230
45 years to <65 years	140	133	125	398
≥65 years	41	47	44	132
Age   [units: years] Mean ± Standard Deviation	51.8  ± 11.69	52.0  ± 12.12	51.6  ± 12.63	51.8  ± 12.13
Gender   [units: subjects]
Female	13	8	10	31
Male	243	243	243	729
Body Mass Index   [units: subjects]
<18.5 kilogram per meter² (kg/m²)	0	0	0	0
18.5 kg/m² to <25 kg/m²	15	12	7	34
25 kg/m² to <30 kg/m²	75	87	89	251
≥30 kg/m²	166	152	154	472
missing	0	0	3	3
Calculated Creatinine Clearance [1] [units: subjects]
<50 milliliters per minute (mL/min)	13	8	13	34
50 mL/min to <80 mL/min	77	90	68	235
80 mL/min to <120 mL/min	138	130	140	408
≥120 mL/min	28	23	29	80
missing	0	0	3	3
Presence of Primary Palpable Tophus   [units: subjects]
Yes	52	53	46	151
No, but other tophi present	1	2	3	6
No and no other tophi present	203	196	204	603
Race/Ethnicity   [units: subjects]
White	193	199	195	587
Black or African American	24	20	18	62
Hispanic	22	17	19	58
Asian	10	9	6	25
Other	7	6	15	28

1.  Primary:

Percentage of Subjects With the Last 3 Serum Urate Levels <6.0 Milligrams Per Deciliter (mg/dL)   [ Time Frame: Last 3 Visits (up to 52 weeks) ]

2.  Secondary:

Percentage of Subjects With Serum Urate <6.0 mg/dL at Week 28 Visit   [ Time Frame: Week 28 ]

3.  Secondary:

Percentage of Subjects With Serum Urate <6.0 mg/dL at Week 52 Visit   [ Time Frame: Week 52 ]

4.  Secondary:

Percentage of Subjects With Serum Urate <6.0 mg/dL at Final Visit   [ Time Frame: Final Visit (up to 52 weeks) ]

5.  Secondary:

Percent Change From Baseline in Serum Urate Levels at Week 28.   [ Time Frame: Baseline and Week 28 ]

6.  Secondary:

Percent Change From Baseline in Serum Urate Levels at Week 52.   [ Time Frame: Baseline and Week 52 ]

7.  Secondary:

Percent Change From Baseline in Serum Urate Levels at Final Visit   [ Time Frame: Baseline and Final Visit (up to 52 weeks) ]

8.  Secondary:

Percent Change From Baseline in Tophus Size at Week 28, as Determined by Physical Measurement, in Subjects With a Palpable Primary Tophus at Screening.   [ Time Frame: Baseline and Week 28 ]

9.  Secondary:

Percent Change From Baseline in Tophus Size at Week 52, as Determined by Physical Measurement, in Subjects With a Palpable Primary Tophus at Screening.   [ Time Frame: Baseline and Week 52 ]

10.  Secondary:

Percent Change From Baseline in Tophus Size at Final Visit, as Determined by Physical Measurement, in Subjects With a Palpable Primary Tophus at Screening.   [ Time Frame: Baseline and Final Visit (up to 52 weeks) ]

11.  Secondary:

Change From Baseline in Total Number of Tophi at Week 28 in Subjects With Palpable Tophi at Screening.   [ Time Frame: Baseline and Week 28 ]

12.  Secondary:

Change From Baseline in Total Number of Tophi at Week 52 in Subjects With Palpable Tophi at Screening.   [ Time Frame: Baseline and Week 52 ]

13.  Secondary:

Change From Baseline in Total Number of Tophi at Final Visit in Subjects With Palpable Tophi at Screening.   [ Time Frame: Baseline and Final Visit (up to 52 weeks) ]

14.  Secondary:

Percentage of Subjects Requiring Treatment for Gout Flares Between Weeks 8 and 52.   [ Time Frame: Weeks 8 through 52 ]