Patterns of biologic agent use in older males with inflammatory diseases: an institution-focused, observational post-marketing study.

BACKGROUND: Little investigation has focused on use of biologic agents in elderly patients with rheumatoid arthritis, spondyloarthropathies, inflammatory bowel disease or psoriasis. Furthermore, studies of drugs for autoimmune diseases that do include elderly populations have tended to include a preponderance of female patients.
OBJECTIVE: To evaluate the pattern of biologic agent use in older males with inflammatory diseases, including rheumatoid arthritis, the spondyloarthropathies (ankylosing spondylitis, psoriatic arthritis and reactive arthritis), inflammatory bowel disease and psoriasis.
METHODS: All prescriptions of biologic agents dispensed by a US Department of Veterans Affairs Medical Center pharmacy in Dallas, Texas, USA, between 1 January 1999 and 31 December 2007 were analysed. Comprehensive chart reviews were undertaken on all non-cancer patients treated with six biologic agents (infliximab, etanercept, adalimumab, abatacept, rituximab and anakinra) to determine the tolerability of the medication and rates of stopping or switching each drug.
RESULTS: A total of 428 patients (mean +/- SD age 59 +/- 12 years) with rheumatoid arthritis (49%), spondyloarthropathy (37%), inflammatory bowel disease (7%) or psoriasis (7%) were treated with biologics at some point over the 9-year study period. The mean number of biologics used was highest in patients with spondyloarthropathies (1.5) [p = 0.003], with the mean stop/switch rate for the first biologic agent being lowest in patients with rheumatoid arthritis (47.4%) [p = 0.02]. The mean length of time patients remained on their first biologic agent before stopping or switching was greatest in patients with rheumatoid arthritis (21.1 months) [p = 0.26]. The biologic with the highest rate of continuation was etanercept for all groups except inflammatory bowel disease.
CONCLUSION: This experience with biologic agents in older males with inflammatory diseases revealed that the mean number of agents used when rheumatologists managed rheumatoid arthritis and spondyloarthropathies was higher than when gastroenterology or dermatology specialists treated inflammatory bowel disease and psoriasis. The stop/switch rates were lowest among rheumatoid arthritis patients. Rheumatologists treating rheumatoid arthritis tended to keep patients on the first biologic for a longer period of time before stopping/switching. For those patients who remained on their first biologic agent, etanercept was the most commonly continued drug.