New Classification System for Gout Could Become FDA Standard

A new evidence-based classification system for gout has been shown to outperform the current gold standard, which could lead to an updated protocol.

The current classification system lacks sensitivity and was created before advanced imaging was an option. An international team led by researchers from Boston University School of Medicine (BUSM), however, believe that they have developed a better system, saying that it could become the new US Food and Drug Administration (FDA) standard as well as help evaluate gout drugs in clinical trials.

Multiple steps were taken to develop the gout classification system, as explained in both Annals of the Rheumatic Disease and Arthritis & Rheumatology. The authors conducted a literature review of advanced imaging, a study where they found the presence of monosodium urate (MSU) crystals to be the gold standard for gout classification, and a scientific analysis to detail the current criteria for the condition.

The entry criterion for the new system is for at least one occurrence of peripheral joint or bursal swelling, pain, or tenderness. It goes on to look at clinical (pattern of joint and bursa involvement), laboratory (serum urate levels), and imaging (ultrasound or computed tomography) to classify gout. One notable difference from current strategies is that this system takes into account “negative scoring for the absence of certain parameters,” a statement from BUSM specified.

“The implications of this new classification are significant as it provides a means for clinical researchers to use validated criteria for enrollment of subjects with gout into studies,” said lead investigator Tuhina Neogi, MD, PhD. “This is particularly important for clinical trials which will use these criteria moving forward, and it is anticipated that these will become the standard expected by the FDA and EMA when evaluating gout clinical trials.”

When compared to the existing criteria, the investigators found that the new system was superior. It was 92% sufficient in sensitivity and 89% in specificity.

“The new classification criteria, developed using a data-driven and decision analytic approach, have excellent performance characteristics and incorporate current state-of-the-art evidence regarding gout,” the authors concluded.