gout dose response study

Conditions: Hyperuricemia

Summary: to compare the proportion of subjects whose serum urate (sua) level is \< 6.0 mg/dl after 28 days of dosing by treatment group.


Eligibility criteria:
inclusion criteria: * male or post-menopausal or surgically sterile female. * 18 - 75 years of age. * hyperuricemic (i.e., screening sua ≥8 mg/dl). * meets criteria for the diagnosis of gout as per the american rheumatism association (ara) criteria for the classification of acute arthritis of primary gout. * willing and able to give informed consent and adhere to visit/protocol schedules (informed consent must be given before the first study procedure is performed). * subjects entering the optional extension period must have successfully completed the double-blind treatment period and follow-up period within approximately 4 months and must not have experienced any serious adverse events considered possibly related to study drug. exclusion criteria: * classified as an overproducer of urine urate (cur \> 6.0 ml/min/1.73 m2 24- hour urine). * consumes more than 14 drinks of alcohol per week (e.g., 1 drink = 5 oz \[150 ml\] of wine, 12 oz \[360 ml\] of beer, or 1.5 oz \[45 ml\] of hard liquor). * history or suspicion of drug abuse. * documented history of or suspicion of kidney stones. * history of rheumatoid arthritis or other autoimmune disease. * confirmed (positive serology to hiv1 and hiv 2) or suspected hiv infection. * positive serology to hcv antibodies (abs), and/or hepatitis b surface antigen (hbsag). * history of malignancy, except treated non-melanomatous skin cancer or cervical dysplasia. * history of cardiac abnormalities, including abnormal and clinically relevant ecg changes such as bradycardia (sinus rate \ 120 msec, symptomatic or asymptomatic arrhythmias with the exception of sinus arrhythmia, evidence of ventricular pre-excitation, frequent palpitations or syncopal episodes, heart failure, hypokalemia, family history of long qt syndrome, and/or family history of sudden death in an otherwise healthy individual between the ages of 1 and 30 years. * any condition predisposing them to qt prolongation including pathological q-wave (defined as q-wave \>40 msec or depth \> 0.4-0.5 mv). * any use of a concomitant medication that prolong the qt/qtc interval within the 14 days prior to baseline (day 0) * qt interval corrected for heart rate according to fridericia (qtcf) \> 450 msec at screening or pre-dose at baseline (day 0) * uncontrolled hypertension (above 150/95) * inadequate renal function * hemoglobin \< 10 g/dl (males) or \< 9 g/dl (females) * alanine aminotransferase (alt) or aspartate aminotransferase (ast) \> 2.5 x upper limit of normal (uln) * gamma glutamyl transferase (ggt) \> 3 x uln * active peptic ulcer disease requiring treatment * history of xanthinuria, active liver disease, or hepatic dysfunction. * requires therapy with any other urate-lowering medication, other than the study medication. * requires long-term use of salicylates; diuretics; azathioprine; mercaptopurine; theophylline; intravenous colchicine; cyclosporine; cyclophosphamide; pyrazinamide; sulfamethoxazole; or trimethoprim * taking medications known as enzyme inducers * receiving a strong or moderate inhibitor of cyp3a4 or a p-gp inhibitor within 1 month prior to study drug dosing * gout flare at screening that is resolved for less than one week prior to the first treatment with study medication (exclusive of chronic synovitis/ arthritis) * female of childbearing potential * received an investigational medication within 4 weeks prior to study medication administration * previously participated in a clinical study involving rdea806 or rdea594. * known hypersensitivity or allergy to rdea594 or colchicine or any components in their formulations. * body mass index (bmi) \>40 kg/m2. * taking greater than 1000 mg/day of vitamin c. * any other medical or psychological condition, which in the opinion of the investigator and/or medical monitor, might create undue risk to the subject or interfere with the subject's ability to comply with the protocol requirements, or to complete the study. * inadequate renal function after completing the double-blind treatment period prior to entering extension period. * requiring treatment with prohibited medications noted in exclusion criteria numbers 20-23 after completing the double-blind treatment period prior to entering the extension period. * clinically relevant medical event as determined by the investigator in consultation with medical monitor prior to entering the extension period.