OBJECTIVES: Golimumab is a 50 milligram (mg), once monthly, injected anti-tumor necrosis factor alpha therapy for treatment of rheumatoid arthritis, ankylosing spondylitis and psoriatic arthritis.  This study calculated expected costs of annual golimumab therapy based upon observed dosing patterns within a SPP population during the first 16 months of golimumab availability.  METHODS: Pharmacy and corresponding eNAVIGATORTM patient care management data were collected by Diplomat Specialty Pharmacy, Flint, MI for adult patients with a golimumab prescription between 4/24/2009 and 8/24/2010.  Data were analyzed statistically and are reported as n, %, mean±standard deviation (SD) and median. Costs were modeled in US dollars using the wholesale acquisition cost (WAC; effective 6/9/2010) of $1,731.48 per 50 mg. RESULTS: The study included 89 patients. The majority were female (65%); age >45 years (69%); and reported prior biologic use (56%).  A 50 mg golimumab dose was dispensed in 100% of patients and 100% of all doses.  The mean (±SD) interval between golimumab doses was 32.0 ±14.1 days and the median was 28 days. The mean golimumab dosing interval in patients reporting biologic use prior to golimumab initiation was 32.9±15.9 days (mean±SD) and was similar to the mean dosing interval observed in patients reporting no biologic use prior to golimumab initiation (mean±SD: 31.1±12.1 days; p=0.15; NS).  Based upon modeling of these early observations, the average golimumab patient will utilize approximately 11.4 doses of golimumab annually at a cost of $19,739 (WAC).   CONCLUSIONS: In this SPP population, all patients received 50 mg of golimumab. The mean and median times between distribution of golimumab doses were 32 days and 28 days, respectively.  Based upon the dosing and distribution patterns observed, the estimated average annual per patient cost of golimumab would be $19,739. Golimumab utilization may be similar for patients regardless of prior use of biologic therapies.