Lowering the serum urate target to less than 0.20 mmol/L (<3.6 mg/dL) for patients with erosive gout does not achieve better gout outcomes and leads to more medication use and subsequent side effects, according to findings from a 2-year, double-blind, randomized, controlled trial.
Nicola Dalbeth, MD, of the bone and joint research group, department of medicine, faculty of medical and health sciences at University of Auckland (New Zealand), and coauthors noted that intensive serum urate lowering is difficult to achieve with oral urate-lowering therapy (ULT) and their findings suggest lower is not always better.
Their data, published in Arthritis & Rheumatology, suggest the less-intensive standard target of less than 0.30 mmol/L (<5.4 mg/dL), currently recommended by rheumatology guidelines, is sufficient.
The more intensive target leads to a high medication burden and does not improve bone erosion score in erosive gout, the authors found.
Dr. Angelo Gaffo
Rheumatologist Angelo Gaffo, MD, associate professor of medicine at the University of Alabama at Birmingham, who was not part of the study, said erosion scores are the best way to test outcomes and this study provides support for current gout treatment approaches.
“It is reassuring that the approach of treating to target is a good approach,” Dr. Gaffo said. “The very, very low targets were not better than the [standard target].”
The trial included 104 participants with erosive gout on oral ULT who were randomized either to a serum urate target of less than 0.20 mmol/L or less than 0.30 mmol/L.
Ninety participants completed the study: 44 (85%) in the intensive target group and 46 (88%) in the standard target group. All were included in the primary intention-to-treat analysis. Participants were mostly men with an average age of 61. Average period of disease was 19 years and about half had a gout flare in the 3 months before enrollment in the study.
Fewer in intensive group hit target
The researchers found that serum urate at year 2 was significantly lower in the intensive target group, compared with the level in the standard target group (P = .002), but fewer participants in the intensive group hit their target, compared with those in the standard group (62% vs. 83%; P < .05).
The intensive group also required more medication. Participants in that group needed higher doses of the first-line treatment allopurinol (mean, 746 mg/day vs. 496 mg/day; P < .001). They also used more combination therapy (P = .0004).
Bone erosion scores were slightly better in both groups over 2 years, but there was no between-group difference (P = .20).
Rates of adverse and serious adverse events were similar between the groups.
The authors noted that a previous study has shown that escalating doses of allopurinol to achieve a target lower than 0.36 mmol/L (6.48 mg/dL) can reduce progression of bone erosion in gout.
“However, improved erosion scores were not observed in this study,” the authors noted.
The authors said that emerging data on intensive serum urate lowering “may lead to erosion healing in gout,” particularly with pegloticase (Krystexxa), a treatment that leads to profound reductions in serum urate.
They highlighted a small longitudinal study of patients treated with pegloticase in whom researchers observed the filling in of bone erosions over a year.