Cost-effectiveness of drug monitoring of anti-TNF therapy in inflammatory bowel disease and rheumatoid arthritis: a systematic review.

BACKGROUND: Therapeutic drug monitoring (TDM) of anti-TNF is increasingly used to manage inflammatory bowel diseases (IBD) and rheumatoid arthritis (RA). The cost-effectiveness of this strategy is debated.

METHODS: All studies comparing the cost-effectiveness of a TDM-based strategy and an empirical dose management of anti-TNF in IBD or RA were screened. Studies were identified through the MEDLINE electronic database (up to July 2016), and annual international meeting abstracts were also manually reviewed.

RESULTS: Seven studies were included: two randomized controlled trials (RCTs) enrolling 332 patients [247 Crohn's disease (CD) and 85 ulcerative colitis (UC)] and five modeling approaches. Four studies included only CD patients, one included both CD and UC patients, and two included only RA patients. Three studies compared the cost-effectiveness of the two strategies in patients with secondary infliximab (IFX) failure (dose-escalation strategy), one in patients in remission on optimized IFX (de-escalation strategy), one in patients starting adalimumab, and two in patients with clinical response to maintenance anti-TNF therapy. The two RCTs demonstrated that a TDM strategy led to major cost savings, ranging from 28 to 34 %. The three modeling approaches with regard to CD patients demonstrated cost savings ranging from $5396 over a 1-year period to €13,130 per patient at 5 years of follow-up. A TDM strategy also led to major cost savings in the two modeling approaches in RA patients.

CONCLUSIONS: Available evidence indicates that a TDM strategy leads to major cost savings related to anti-TNF therapy in both IBD and RA patients, with no negative impact on efficacy.