FREED (Febuxostat for Cerebral and CaRdiorenovascular Events PrEvEntion StuDy) results showed that febuxostat significantly reduced the levels and effects of serum uric acid in patients 65 years of age and older with hyperuricemia (gout) as compared with allopurinol, the standard treatment, with lifestyle modification. Febuxostat is a non-purine-selective inhibitor of xanthine oxidase, which is needed for uric acid production. It is a more potent reducer of uric acid levels than allopurinol, Dr. Kojima said.
Hyperuricemia may lead to the development and progression of chronic kidney disease and renal failure, along with coronary artery disease, hypertension, stroke, and death. Recurrence of urate deposition-related disease, Dr. Kojima said, can be prevented with the use of anti-hyperuricemic drugs. In gout patients with cardiovascular disease in the CARES (Cardiovascular Safety of Febuxostat and Allopurinol in Patients with Gout and Cardiovascular Morbidities) trial, all-cause mortality and cardiovascular mortality were higher with febuxostat than with allopurinol. With the cause of the higher event rates remaining unclear, the FREED study was conducted to further compare events with febuxostat and conventional treatment in this population.
FREED, a multicenter Japanese, prospective, randomized, open-label, blinded endpoint study, included 1,070 elderly patients (mean age, 69 years) with hyperuricemia who were at risk for cardiorenovascular disease. They were randomized to 36 months of febuxostat or conventional therapy. In both groups, the dose of febuxostat or allopurinol was adjusted to avoid a serum uric acid level of less than 2 mg/dL. In the non-febuxostat group, the use of allopurinol 100 mg was considered if serum uric acid was elevated. Hyperuricemia was defined by serum uric acid levels > 7.0 to ≤ 9.0 mg/dL. All participants had one or more cerebral, cardiovascular or renal disease risk factors, which included active hypertension, type-2 diabetes, renal disorder (eGFR ≥ 30 to < 60 mL/min/1.73 m2) or a history of cerebrocardiovascular disease occurring > 3 months prior to enrollment. The primary composite endpoint was comprised of cerebral or cardiorenal vascular disease death, new or recurring cerebrovascular disease, new or recurring non-fatal coronary artery disease, cardiac failure requiring hospitalization, arteriosclerotic disease requiring treatment, renal impairment, new atrial fibrillation, or death due to other causes.
The average dose of febuxostat at the end of the study was 29 mg daily. In the standard therapy arm, 27% of patients received allopurinol 100 mg. Average serum uric acid levels reached 4.4 mg/dL in the febuxostat group and 6.7 mg/dL in the group not receiving febuxostat.
The primary outcome was significantly reduced in the febuxostat group at 23% versus 29% (HR, 0.75; 95% CI, 0.59–0.95; P =0.017). Renal impairment, the most frequent event, occurred at rates of 16.2% and 20.5% in the febuxostat and standard treatment arms, respectively (P = 0.041). Analysis also showed direct correlations between rising serum uric acid levels and risk for primary outcome events. A composite of hard endpoints (death due to any cause, cerebrovascular disease, or non-fatal coronary artery disease) was not significantly reduced with febuxostat, however (HR, 0.861; P = 0.6).
At 24.6% and 25% in the febuxostat and non-febuxostat arms, respectively, adverse event rates were similar between groups.
“Uric acid level lowering by febuxostat provides clinical benefit for prevention of cerebral, cardiovascular, and renal events in elderly patients with hyperuricemia,” Dr. Kojima concluded.
Speaking about FREED results at an ESC press briefing, Kunihiko Matsui, MD, of Kumamoto University, Japan, stated: “Febuxostat has greater renoprotective effect, however, cardiovascular protection may not be expected compared with renal protection.”