Cost of Biologics per Treated Patient across Immune-mediated Inflammatory Disease Indications in a Pharmacy Benefit Management Setting: A Retrospective Cohort Study

PurposePharmacy benefits management companies have emerged as the national standard for the management of prescription drugs in the United States. The objective of this study was to estimate the annual costs per treated patient of 8 biologics indicated for select immune-mediated inflammatory diseases: moderate to severe rheumatoid arthritis, moderate to severe plaque psoriasis, active psoriatic arthritis, and/or active ankylosing spondylitis.MethodsUsing the Medco pharmacy benefits-management database, data from patients aged 18 to 63 years with ≥1 claim for abatacept, adalimumab, certolizumab, etanercept, golimumab, infliximab, rituximab, or ustekinumab, dated between January 1, 2008 and August 31, 2011, were collected. Eligible patients were continuously enrolled for ≥180 days before and 360 days after the date of the first biologic claim (index date), and had ≥1 claim associated with a diagnosis of rheumatoid arthritis, moderate to severe plaque psoriasis, active psoriatic arthritis, and/or active ankylosing spondylitis in the 180 days before or 30 days after the index date. The annual total costs per treated patient were calculated as the total dose of the index biologic and all other biologics for which there was a claim in the postindex period, multiplied by the wholesale acquisition cost as of October 1, 2013, plus the costs associated with administrations (calculated as number of infusions multiplied by the 2013 Medicare Physician Fee Schedule costs).FindingsWithin the study population (N = 8306; 5356 (64.5%) women, 2950 men (35.5%), average age: 42.3 years (SD: 10.0)), the most commonly used biologics were etanercept (43.1%), adalimumab (31.0%), and infliximab (17.0%), which accounted for 91.1% of all biologic prescriptions. Total costs per treated patient across indications were as follows: adalimumab, $23,427 to $26,304; infliximab, $22,824 to $28,907; and etanercept, $21,468 to $27,748, whereas abatacept, certolizumab, golimumab, rituximab, and ustekinumab were associated with a larger range: $17,017 to $41,888.ImplicationsThe present study provides insight into the prescribing patterns and cost differences among 8 biologic agents used for the treatment of immune-mediated inflammatory diseases. This information may prove useful when designing a pharmacy benefits-management formulary.