Patients with Gout Treated with Febuxostat Compared with Those Treated with Allopurinol

Atlanta—Patients with gout treated with febuxostat are younger, have more comorbidities and higher mean baseline serum uric acid (sUA) levels, use more healthcare resources, and incur higher costs compared with patients treated with allopurinol.

This is the conclusion of a study presented in a poster at the AMCP meeting. The poster was titled Characteristics of Gout Patients Initiating Febuxostat in a Large US Managed Care Population. For the past 40 years, allopurinol has been the mainstay of treatment for hyperuricemia. In 2009, the US Food and Drug Administration approved febuxostat for the treatment of hyperuricemia. In the retrospective study, researchers used 2009-2010 medical and pharmacy claims and outpatient laboratory data from commercial and Medicare Advantage health plan members with gout to identify baseline demographic, clinical characteristics, healthcare resource utilization, and costs among patients receiving febuxostat compared to allopurinol. Overall, 5880 patients received allopurinol (300 mg) and 451 received febuxostat (40 mg and 80 mg).

Patients included in the study had ≥1 medical claims with a diagnosis of gout, ≥1 fill for either allopurinol or febuxostat between February 2009 and March 2010, continuous enrollment in the health plan for ≥6 months prior to the index date, 18 years of age, no evidence of cancer, ≥1 sUA lab result, and index dose within the recommended dose range. The study found that patients treated with febuxostat were significantly younger than those treated with allopurinol (55.4 vs 57.0 years, P=.004); the allopurinol cohort had a significantly lower percentage of patients <75 years of age (4.6% vs 9.3%, P<.01). Patients treated with febuxostat also had significantly more comorbid conditions at baseline than those treated with allopurinol, including gout and other crystal arthopathies (89.46% vs 67.13%, P<.001), hypertension (71.08% vs 66.23%, P=.03), nontraumatic joint disorders (55.38% vs 37.03%, P<.001), other µconnective tissue disease (39.69% vs 29.66%, P<.001), diseases of the urinary system (38.34% vs 28.54%, P<.001), other nutritional, endocrine, and metabolic disorders (19.28% vs 15.59%, P=.04), other skin disorders (17.94% vs 14.20%, P=.03), diseases of arteries, arterioles, and capillaries (16.59% vs 13.08%, P=.03), anemia (15.70% vs 11.78%, P=.01), and thyroid disorders (13.45% vs 10.34%, P=.04).

Of the patients with available preindex laboratory sUA values (69.2% of febuxostat patients and 41.6% of allopurinol patients), those taking febuxostat had a significantly higher mean baseline sUA value than those taking allopurinol (8.5 vs 7.8 mg/dL, P<.001). Febuxostat-treated patients also had significantly higher healthcare utilization than those treated with allopurinol, including emergency department (23.50% vs 17.09%, P<.001) and office visits (98.9% vs 93.6%, P<.001) as well as gout-related office visits (54.8% vs 37.3%, P<.001) and gout-related outpatient visits (15.1% vs 7.8%, P<.001) during the baseline period. Overall, febuxostat patients had significantly higher total healthcare costs (P=.02), medical costs (P=.04), and pharmacy costs (P=.05) compared with those taking allopurinol. Limitations of the study include limitations of the data used (diagnosis codes may be incorrect, prescription claims may not prove actual medication use) as well as the specific analysis of the data on patients in stable managed care settings that may not be able to be generalized to other populations.

This study was supported by Takeda Pharmaceuticals International, Inc.