Management Strategies for Febuxostat as Chronic Therapy for Gout

San Francisco—Gout affects as many as 5 million people in the United States and is the most common cause of inflammatory arthritis for men >40 years of age in the US. Traditionally, the goals of treatment for this condition have been to resolve acute gout attacks and prevent future flare-ups and the formation of tophi and kidney stones. In 2009, febuxostat was approved by the FDA as a new treatment option for gout. For insurers and distributors, prior authorizations, step therapy, and drug coverage exclusions can be implemented to contain cost and judiciously distribute more costly medications when less expensive alternatives may be available.

The objective of this study, reported at an AMCP poster session, was to evaluate the effect of utilization management methods on the use of chronic gout treatment. The study was a retrospective claims database analysis that assessed the effect of utilization management methods on the use of chronic gout treatment. Information from MedImpact’s pharmacy claims database, which contains information on claim status and denials of claims, was used.

The poster was titled Impact of Utilization Management Strategies for Febuxostat on the Use of Chronic Gout Therapy.

To be included in the analysis, patients had to be ≥18 years of age and have at least 1 rejected prescription claim for febuxostat between March 1, 2009, and June 30, 2010. Outcome of interest was whether any patient had used any chronic gout medication within 1 month of the rejected febuxostat claim. In addition to febuxostat, chronic gout medications included allopurinol, probenecid, and colchicine/probenecid. Potential covariates included patient characteristics (age, sex, region of residence), clinical characteristics (health status, claims history), and pharmacy benefits.

A total of 1034 patients were included in the study; most were male (73%), 40 to 64 years of age (52%), enrolled in a commercial health maintenance organization (63%), and had hypertension (65%). Of all patients, 31% had preindex claims for allopurinol and 36% had claims for colchicine. During the 6-month preindex period, mean total pharmacy cost per patient was $1390, and mean number of drug claims per patient was 22.6.

Of all patients, 95% had claims that had been rejected due to utilization management, 36% (n=369) of patients had been rejected due to step therapy, 25% (n=259) due to drug coverage, 18% (n=183) due to quantity limits and other limits, and 16% (n=170) due to prior authorization. Among the study population, 46% (n=474) had filled a febuxostat prescription within a month following a rejected claim; 35% (n=364) had not filled any chronic gout prescription within a month of rejection.

The multivariate logistic regression model found that quantity limits and other limits positively influenced the fill of a chronic gout medication compared to a drug coverage rejection (OR, 4.697; P<.0001). Patients who had ≥40 drug claims in the preindex period were 2.7 times as likely to fill a chronic gout agent prescription compared with patients with 0 to 9 claims (OR, 2.71; P=.01).

Patients with a projected febuxostat copayment of $40 to $59 (OR, 0.51; P=.03) or $100 to $149 (OR, 0.41; P=.002) were less likely to fill a chronic gout agent prescription compared with patients who had a projected copayment of $0 to $19. Hypertension was positively associated with the likelihood of filling a chronic gout medication prescription (OR, 1.56; P=.0143). The investigators said the treatment gap in the use of chronic gout medications in the presence of utilization management methods should be addressed when designing benefits for gout treatment.

This study was supported by Takeda Pharmaceuticals America, Inc.