Anti-TNF re-induction is as effective, simpler, and cheaper compared with dose interval shortening for secondary loss of response in Crohn's disease

Background and Aims: The optimal duration of dose-intensified therapy following secondary loss of response [LOR] to anti-tumour necrosis factor [TNF] therapy remains unclear. Anti-TNF re-induction involves a finite period of intensified therapy and may be a cost-effective means of re-capturing response. This study aimed to compare the efficacy, durability, and cost of anti-TNF re-induction and dose interval shortening [DIS] for secondary LOR in Crohn's disease [CD]. Methods: This was a retrospective observational study in CD patients who developed secondary LOR to maintenance anti-TNF therapy, requiring subsequent re-induction and/or DIS. The primary outcome was treatment failure within 12 months. Secondary outcomes included factors associated with time to failure, disease activity, and incremental anti-TNF costs. Results: Of 423 patients with CD on anti-TNF therapy, 80 [19%] developed secondary LOR, with 33 and 55 patients undergoing subsequent anti-TNF re-induction and DIS, respectively. There was no significant difference in the incidence of treatment failure at 12 months following re-induction and DIS, respectively [p = 0.27]. Factors predictive of a longer time to failure included a higher baseline serum albumin, male sex, and thiopurine co-therapy [each p < 0.05], whereas higher baseline faecal calprotectin was associated with shorter time to failure. There was no significant difference in clinical remission or objective disease activity across both groups. The median incremental cost of re-induction and DIS was AUD 4 838 and AUD 13 190, respectively. Conclusions: In patients with CD who develop secondary LOR, re-induction may represent an effective and less expensive first-line strategy, reserving dose intensification strategies such as DIS for non-responders.