Therapeutic drug monitoring sustains disease control during infliximab maintenance
Proactive therapeutic drug monitoring sustained disease control without disease worsening among patients with immune-mediated inflammatory diseases undergoing infliximab maintenance therapy, according to study results.
“Proactive therapeutic drug monitoring (TDM), an individualized treatment strategy based on scheduled assessments of serum drug levels and antidrug antibodies, has been proposed to improve long-term efficacy of tumor necrosis factor inhibitors by optimizing drug concentrations and facilitating early detection of antidrug antibodies,” Silje Watterdal Syversen, MD, PhD, of the division of rheumatology and research at Diakonhjemmet Hospital in Oslo, Norway, and colleagues wrote in JAMA. “However, due to lack of data from randomized clinical trials, treatment recommendations differ with respect to the use of proactive TDM during maintenance therapy with TNF inhibitors.”
In a randomized, parallel-group, open-label clinical trial, researchers aimed to compare treatment efficacy during infliximab maintenance between proactive TDM and standard care without TDM. Of 458 patients (mean age, 44.8 years; 49.8% women) with immune-mediated inflammatory diseases, 228 patients underwent proactive TDM with infliximab dose and interval adjustments based on scheduled algorithmic monitoring and 230 patients underwent standard infliximab therapy without drug and antibody level monitoring. They defined the primary outcome as sustained disease control without disease worsening during the 52-week study period.
According to assessment, researchers observed the primary outcome among 73.6% of patients in the TDM group compared with 55.9% of patients in the standard therapy group; the estimated adjusted difference favored TDM (17.6%; 95% CI, 9-26.2). Compared with the TDM group, the estimated HR for disease worsening in the standard therapy group was 2.1 (95% CI, 1.5-2.9). Researchers noted adverse events among 60% of patients in the TDM group and 63% of patients in standard therapy group.
“Among patients with immune-mediated inflammatory diseases undergoing maintenance therapy with infliximab, proactive TDM was more effective than treatment without TDM in sustaining disease control without disease worsening,” Syversen and colleagues concluded. “Further research is needed to compare proactive TDM with reactive TDM, to assess the effects on long-term disease complications and to evaluate the cost-effectiveness of this approach.”