Tuesday, Ardea Biosciences, Inc. (RDEA) said results from the first dosing group of a one-week drug-combination study of its lead product candidate RDEA594 and febuxostat indicate that the combination therapy produced 20% better results in hyperuricemia and gout patients, compared to single agent therapy. The company said these results show that this combination may be able to reduce tophaceous gout similar to intravenous therapy.
After one week of dosing as monotherapy, both RDEA594 and febuxostat produced a mean reduction in serum urate of 40% from baseline. When administered in combination for seven days, the two agents produced a mean reduction in serum urate of 60% from baseline, Ardea said in a statement.
Gout is a painful form of arthritis that is caused by abnormally elevated levels of uric acid in the blood stream due to under-excretion of uric acid. RDEA594 is a selective inhibitor of URAT1, which is a transporter in the kidney that regulates uric acid excretion from the body. Febuxostat is indicated for the treatment of hyperuricemia and gout, and is marketed under the brand name Uloric by Takeda Pharmaceutical Company (TKPHF.PK) and Adenuric by Ipsen SA.
John Sundy MD, PhD, associate professor of medicine at Duke University Medical Center and a member of Ardea's scientific advisory board, said, "The substantial reduction in serum uric acid observed when RDEA594 and febuxostat are co-administered indicate that these two oral agents with complementary mechanisms may be able to accelerate improvement in tophaceous gout compared to single agent therapy. I look forward to studying this combination in patients with advanced disease."
Barry Quart, chief executive officer of Ardea, said, "Similar reductions in serum urate produced when RDEA594 and febuxostat were administered alone, and the substantial reduction produced when these agents were administered in combination supports our strategy to develop RDEA594 as both monotherapy and in combination with xanthine oxidase inhibitors, such as febuxostat or allopurinol. With the dramatic reduction in serum uric acid observed when RDEA594 and febuxostat are administered in combination, together these agents may be able to produce reductions in tophaceous gout previously achieved only with intravenous therapy."
The randomized, placebo-controlled study was conducted in normal healthy volunteers with baseline serum urate levels of greater than 5 mg/dL. The study was designed to evaluate the potential for pharmacokinetic drug interactions, as well as the serum urate-lowering effect, safety and tolerability of escalating doses of RDEA594, administered once-daily in combination with 40 mg febuxostat.
In the first two periods of the initial dosing group, 18 subjects received either 200 mg of RDEA594 once daily or matching placebo for seven days or 40 mg of febuxostat once daily for seven days, and then the combination of the two regimens for seven days. The combination of RDEA594 and febuxostat in this first dosing group was well tolerated and no pharmacokinetic drug interactions were observed, the company said.
During the study, no clinically-relevant adverse effects or laboratory abnormalities were observed during administration of RDEA594. Two subjects experienced grade two increases in a liver enzyme while receiving febuxostat alone.
Based on these positive results, Ardea has initiated a second dosing group evaluating 400 mg of RDEA594 once daily in combination with 40 mg of febuxostat once daily. In addition to this study, RDEA594 is currently being administered in a Phase 2b single-agent dose-response study evaluating the safety and urate-lowering effects of 200, 400, and 600 mg of RDEA594, a Phase 2b study evaluating RDEA594 as an add-on to allopurinol in patients that do not respond adequately to allopurinol alone, and a study in gout patients with renal impairment.
RDEA is gaining $0.24 or 1.78%, and is trading at $13.70 on the Nasdaq.
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