Determinants of Achieving Serum Urate Goal with Treat-to-Target Urate-Lowering Therapy in Gout

Objective. Using trial data comparing treat-to-target allopurinol and febuxostat in gout, we examined participant characteristics associated with serum urate (SU) goal achievement. Methods. Participants with gout and SU >= 6.8 mg/dL were randomized to allopurinol or febuxostat, titrated during weeks 0 to 24, and maintained weeks 25 to 48. Participants were considered to achieve SU goal if the mean SU from weeks 36, 42, and 48 was <6.0 mg/dL or <5 mg/dL if tophi were present. Possible determinants of treatment response were preselected and included sociodemographics, comorbidities, diuretic use, health-related quality of life (HRQoL), body mass index, and gout measures. Determinants of SU response were assessed using multivariable logistic regression with additional analyses to account for treatment adherence.Results. Of 764 study participants completing week 48, 618 (81%) achieved SU goal. After multivariable adjustment, factors associated with a greater likelihood of SU goal achievement included older age (adjusted odds ratio [aOR] 1.40 per 10 years), higher education (aOR 2.02), and better HRQoL (aOR 1.17 per 0.1 unit). Factors associated with a lower odds of SU goal achievement included non-White race (aORs 0.32-0.47), higher baseline SU (aOR 0.83 per 1 mg/dL), presence of tophi (aOR 0.29), and the use of diuretics (aOR 0.52). Comorbidities including chronic kidney disease, hypertension, diabetes, and cardiovascular disease were not associated with SU goal achievement. Results were not meaningfully changed in analyses accounting for adherence.Conclusions. Several patient-level factors were predictive of SU goal achievement among patients with gout who received treat-to-target urate-lowering therapy (ULT). Approaches that accurately predict individual responses to treat to-target ULT hold promise in facilitating personalized management and improving outcomes in patients with gout.