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AB0496 Tumor necrosis factor (TNF)-inhibitor dose escalation in rheumatoid arthritis (RA) patients in a united states (US) pharmacy benefits management (PBM) setting
  1. S.W. Blume1,
  2. K.M. Fox2,
  3. G. Joseph3,
  4. C.-C. Chuang1,
  5. J. Thomas3,
  6. S.R. Gandra3
  1. 1United BioSource Corp., Bethesda, MD
  2. 2Strategic Healthcare Solutions, LLC, Monkton, MD
  3. 3Amgen Inc., Thousand Oaks, CA, United States


Background In the US, Pharmacy Benefits Management (PBM) companies act as third-party administrators who manage prescription benefits for health insurance companies and self-insured entities. Research in commercial health plans has shown higher rates of dose increases with some TNF-inhibitors than others, but the impact of dose escalation in a PBM setting that may have more intensive cost management is not clear.

Objectives This study investigated multiple measures of dose escalation among RA patients who were either initiating or continuing treatment with TNF-inhibitor therapy with etanercept (ETN) and adalimumab (ADA) in a PBM setting.

Methods A retrospective study using integrated pharmacy and medical claims from the Medco database was conducted; Medco is one of the largest PBMs in the US. Adult (age 18-64 yrs) RA patients with a pharmacy claim for ETN or ADA therapy between 2007 and 2009, continuous enrollment in the Medco PBM for ≥6 months before and ≥12 months after first (index) claim, ≥12 months persistence (no switching or ≥60 day gap in TNF-inhibitor therapy), and who started at ≥ the recommended label dose were eligible. Patients were excluded if they had other conditions that were also treated with TNF-inhibitors (e.g. psoriasis) or other conditions where TNF-inhibitors use was not prudent (e.g. cancer). Patients were classified as new patients if they had no claim for a TNF-inhibitor in the 6 months prior to index TNF-inhibitor date; otherwise, they were classified as continuing patients. Dose escalation was defined as: 1) average weekly dose ≥110% of recommended label dose; 2) average subsequent dose ≥130% of starting dose; 3) last dose ≥110% of starting dose; 4) two or more consecutive instances of dose ≥130% of starting dose; or 5) any instance where dose increase connoted additional syringe or vial use. Differences in proportions of dose escalators were evaluated using chi-square tests.

Results Data from 1,260 ETN and 852 ADA patients with RA were analyzed. Across all measures of dose escalation, patients on ETN had a significantly lower rate of dose escalation (P<0.001) than patients on ADA (Table).

Conclusions Several different measures of evaluating dose escalations were applied to data from a PBM setting that represented real-world use of TNF-inhibitors. Each method consistently showed that RA patients, both new and continuing on ETN, had significantly lower rates of dose escalation than patients on ADA.

This study was sponsored by Immunex, a wholly owned subsidiary of Amgen Inc. and by Wyeth, which was acquired by Pfizer Inc.

Disclosure of Interest S. Blume Consultant for: Amgen Inc., K. Fox Consultant for: Amgen Inc., G. Joseph Shareholder of: Amgen Inc., Employee of: Amgen Inc., C.-C. Chuang Consultant for: Amgen Inc., J. Thomas Shareholder of: Amgen Inc., Employee of: Amgen Inc., S. Gandra Shareholder of: Amgen Inc., Employee of: Amgen Inc.

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