Prometheus Laboratories announced a new therapeutic drug monitoring test, the ‘Anser UST’ for adult patients with inflammatory bowel disease (IBD) who are being treated with ustekinumab (Stelara; Janssen).

The Anser UST measures serum drug concentrations and antidrug antibody levels from a single serum sample. By measuring drug and antibody concentrations physicians can adapt treatment strategies and guide patients toward more personalized medicine. 

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Researchers examined the accuracy of the test in 19 serum samples from anti-TNF± refractory Crohn’s Disease patients receiving ustekinumab maintenance treatment. Results showed that the serum ustekinumab concentration was associated with clinical response in a real world biologic-experienced CD patient population. Although the researchers did comment that a larger cohort of patients will be needed to determine the optimal cut-offs of serum ustekinumab “that may predict [ustekinumab] responsiveness.”

“The availability of a drug-tolerant assay such as Anser UST represents an important advancement in managing patients with Crohn’s disease,” said William J. Sandborn, MD, Chief, Division of Gastroenterology and Professor of Medicine, UC San Diego, and co-author of the study.

In addition to the ustekinumab test, the Anser portfolio of therapeutic drug monitoring tests includes tests for infliximab (and its biosimilars), adalimumab, and vedolizumab.

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