CPC-025 Average Duration of Treatment with Different TNF Inhibitors

Abstract

Background Alpha tumour necrosis factor inhibitors (TNF inhibitors) represent an important advance in immune-mediated inflammatory diseases. The first three drugs marketed and most used nowadays within this family are: infliximab, etanercept, and adalimumab. There is no apparent superiority between any of these drugs and it is known they often loss their efficacy over time. Therefore, it could be of interest to find out if any of them (under usual clinical conditions) has a longer period of time without loss of efficacy. Purpose To compare the different treatments with TNF inhibitors, in order to find out which has the longest average duration (in days) before loss of treatment response finally requires a change in the treatment. Materials and Methods All patients who began the treatment with TNF inhibitors between March 2007 and March 2012 and who had a change in treatment were analysed retrospectively with pharmacotherapy management software. Patients who had stopped the treatment after presenting immediate adverse reactions in the first administration were excluded. The mean durations of treatment were compared using the Student’s t-test for unpaired data Results In total 309 patients were analysed. The three TNF inhibitor drugs most used were etanercept (Average duration 574.47 ± 461.51, N = 125), infliximab (Average duration 470.82 ± 469.64, N = 95) and adalimumab (Average duration 454.92 ± 378.89, N = 95). We found a significant difference between etanercept versus adalimumab (P.value = 0.0412), but not in the case of etanercept versus infliximab (P.valour = 0.0997). These results are coincident with Dr. Hetland’s study in 8074 patients (1). They also agree with the study presented by J.A Markenson in 2418 patients (2). However our study results do not resemble those of G. Lapadula’s study (3). Conclusions The average duration of treatment before requiring a change of drug is higher with etanercept than infliximab and adalimumab, but only is statistically significant with adalimumab. These results should be considered in the design of TNF inhibitor prescribing guidelines. No conflict of interest.