Treatment Patterns Of Adalimumab And Infliximab In The Treatment Of Crohn's Disease Over A Three-Year Period: A Canadian Assessment


      A previous study indicated that after one year, the proportion of patients with a dose augmentation was higher with infliximab than with adalimumab. The objective of this study was to analyze, in a real world setting, trends in dose changes over a three-year period


      A retrospective cohort study was conducted using data from the Regie de l'assurance maladie du Quebec (RAMQ) for a randomly selected group of patients with a CD diagnosis, who had initiated (6month washout period) adalimumab or infliximab between February 2008 and March 2011. For adalimumab, dose increase was considered when the dose received exceeded 40mg every other week over at least an 8-week period. For infliximab, dose increase was considered either when the dose was increased or interval between doses was reduced for two periods of 8 weeks after the third injection. Statistical analyses were conducted using chi square test


      The cohort included 1,517 patients (mean age: 33.9 years, 55.4% females). During the study period, 1,004 patients initiated infliximab (28 previously used adalimumab) and 513 patients initiated adalimumab (195 previously used infliximab). After 36 months, 28.2%(275/976) of patients with infliximab and 23.0%(73/318) of patients with adalimumab experienced a dose increase (p<0.05). For the non-naive patient subgroups, dose escalation occurred for 42.9%(12/28) with infliximab and for 27.2%(53/195) with adalimumab (p<0.05). Average annual cost of adalimumab was CDN$26,957 and CDN$18,577 for patients with and without dose escalation, respectively, and CDN$29,504 and CDN$25,449 for infliximab in patients with and without dose escalation, respectively


      Results of this RAMQ database analysis illustrate that, in a real-world setting and over a long period of time, CD patients treated with infliximab had a significantly higher proportion of dose escalation compared with patients treated with adalimumab. In both recommended and adjusted dosing, adalimumab demonstrated significant cost savings over infliximab