Early observations and pilot data that first suggested a new direction
Urate-lowering therapy (ULT) with allopurinol or febuxostat is the mainstay of gout management, targeting a serum urate level below 6 mg/dL to dissolve crystals and prevent flares. The CARES trial in 2018 raised major safety concerns about febuxostat. Among 6,190 patients with gout and cardiovascular disease, febuxostat was noninferior to allopurinol for composite MACE (HR 1.03; 95% CI 0.87-1.23) but was associated with significantly higher all-cause mortality (HR 1.22; 95% CI 1.01-1.47) and cardiovascular mortality (HR 1.34; 95% CI 1.03-1.73). This led to an FDA boxed warning and restricted febuxostat prescribing.
Landmark RCTs and pivotal trials that established the evidence base
The FAST trial challenged the CARES findings. This European trial randomized 6,128 patients with gout on allopurinol to continue allopurinol or switch to febuxostat. In the primary on-treatment analysis over a median follow-up of ~43 months, febuxostat was noninferior to allopurinol for MACE (adjusted HR 0.85; 95% CI 0.70-1.03). Importantly, all-cause mortality was actually lower with febuxostat (3.8% vs 5.7%; HR 0.75; 95% CI 0.59-0.95), directly contradicting CARES. The difference was attributed to higher CARES dropout rates (57%) and methodology limitations.
Follow-up studies, subgroup analyses, and real-world validation
The contrasting CARES and FAST results prompted re-examination of the febuxostat safety signal. Subsequent meta-analyses and regulatory reviews noted that the CARES trial had a 57% discontinuation rate, and the mortality difference was primarily driven by events after drug discontinuation. The FDA maintained its boxed warning but acknowledged the FAST data. The focus shifted back to the importance of treat-to-target ULT regardless of which agent was used, as achieving target urate levels was the primary determinant of gout outcomes.
Integration into clinical practice guidelines and recommendations
ACR 2020 guidelines strongly recommend allopurinol as first-line ULT for all patients with gout meeting treatment criteria, with dose titration to a serum urate target of <6 mg/dL. Febuxostat is positioned as second-line, particularly for patients who cannot tolerate allopurinol. EULAR 2024 guidelines similarly emphasize treat-to-target with allopurinol first-line and febuxostat as an alternative.
Allopurinol first-line with dose titration to target; febuxostat as alternative; treat-to-target strategy essential
Now
Current standard of care and ongoing research directions
Gout management centers on a treat-to-target approach with allopurinol as first-line ULT, dosed to achieve serum urate below 6 mg/dL. The febuxostat cardiovascular controversy has been partially resolved by the FAST trial, though the FDA boxed warning persists. The primary clinical challenge is the substantial gap between guideline recommendations and real-world practice, where ULT is underutilized, undertitrated, and frequently discontinued prematurely. Emerging therapies targeting urate production or renal excretion through novel mechanisms are in development.
The CARES trial (6,190 patients) raised concerns with higher all-cause mortality (HR 1.22) and CV mortality (HR 1.34) with febuxostat vs allopurinol. However, the FAST trial (6,128 patients) found febuxostat was noninferior for MACE (HR 0.85) and actually had lower all-cause mortality (HR 0.75). The discrepancy is attributed to CARES methodology limitations. Guidelines position febuxostat as second-line for allopurinol intolerance.
What is the treat-to-target approach in gout?+
ACR and EULAR guidelines recommend titrating ULT to achieve a serum urate target below 6 mg/dL. Allopurinol is started at 100 mg/day and increased every 2-4 weeks until the target is reached. Anti-inflammatory prophylaxis (colchicine or low-dose NSAID) is co-prescribed for 3-6 months during ULT initiation to prevent flares.
