There is a lot of data supporting the use of therapeutic drug monitoring (TDM) for anti-TNF agents. A recent study (MJ Kim et al. JPGN 2021; 72: 870-876. Therapeutic Drug Monitoring of Adalimumab During Long-term Follow-up in Paediatric Patients With Crohn Disease) adds to this data and supports increased adalimumab (ADL) dosing if below target values.

In this prospective study of 31 pediatric patients with Crohn’s disease, the authors found correlations between ADL values and the endpoints of clinical remission (CR) and mucosal healing (MH). The authors checked TLs at 4 months, 1, 2, and 3 years. Key findings:

• The median trough levels (TLs) of ADL were higher in patients in CR (7.6 ± 3.5 μg/mL) than in patients with active disease (5.1 ± 2.2 μg/mL).
• ADL TLs were significantly higher in patients who achieved MH than in those who did not (14.2 ± 7.6 vs 7.8 ± 5.2 μg/mL). 
• The optimal cut-point for predicting MH at 1 year of ADL treatment was 8.18 μg/mL
• MH was noted in 42% at 4 months and 55% at 1 yr; CR was noted in 90% at 4 months and 84% at 1 yr. ADL treatment was associated with positive effects on growth indicators as well.

The authors discuss TDM for anti-TNF therapy, noting that for infliximab, the AGA recommends values >5 mcg/mL and the ACG >7.5 mcg/mL. There are fewer studies of ADL TDM -prior studies have indicated goals of >5.8, >7.1, >8, and >8.1; thus, this study is in agreement with these prior studies.

My take: This study further supports the value of TDM; better drug levels correlate with better outcomes.

Related blog posts:

• Proactive Therapeutic Drug Monitoring in Pediatric Crohn’s disease -Better Outcomes
• Real World Experience with TDM
• Updated Adalimumab dosing (2021) and Ustekinumab for Refractory Pediatric UC
• Here’s the Proof That Proactive Therapeutic Drug Monitoring Improves Outcomes in Children with Crohn’s Disease
• CCFA 2019 Update: Proactive Therapeutic Drug Monitoring
• Appropriate Proactive Therapeutic Drug Monitoring
• Briefly noted: Induction Infliximab Levels
• Is there good evidence for proactive therapeutic drug monitoring of anti-TNF therapy?
• Is Standard Infliximab Dose Too Low in Pediatrics?
• Can Therapeutic Drug Monitoring with Monotherapy Achieve Similar Results as Combination Therapy for IBD? | gutsandgrowth
• AGA 2017 Guidelines on Therapeutic Monitoriing Proactive drug monitoring: “careful and selective use of proactive TDM could be beneficial, but current evidence for its routine use is limited and its overall benefits remain uncertain”

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