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Appropriate Therapeutic Drug Monitoring of Biologic Agents for Patients With Inflammatory Bowel Diseases



Therapeutic drug monitoring (TDM) is widely available for biologic therapies in patients with inflammatory bowel disease (IBD). We reviewed current data and provided expert opinion regarding the clinical utility of TDM for biologic therapies in IBD.



We used a modified Delphi method to establish consensus. A comprehensive literature review was performed regarding the use of TDM of biologic therapy in IBD and presented to international IBD specialists. Subsequently, 28 statements on the application of TDM in clinical practice were rated on a scale of 1 to 10 (1=strongly disagree and 10=strongly agree) by each of the panellists. Statements were accepted if 80% or more of the participants agreed with a score ≥7. The remaining statements were discussed and revised based on the available evidence followed by a second round of voting.



The panel agreed on 24 (86%) statements. For anti-tumor necrosis factor (anti-TNF) therapies, proactive TDM was found to be appropriate after induction and at least once during maintenance therapy, but this was not the case for the other biologics. Reactive TDM was appropriate for all agents both for primary non-response and secondary loss of response. The panellists also agreed on several statements regarding TDM and appropriate drug and anti-drug antibody (ADA) concentration thresholds for biologics in specific clinical scenarios.



Consensus was achieved towards the utility of TDM of biologics in IBD, particularly anti-TNF therapies. More data are needed especially on non-anti-TNF biologics to further define optimal drug concentration and ADA thresholds as these can vary depending on the therapeutic outcomes assessed.


Papamichael K1, Cheifetz AS2, Melmed GY3, Irving PM4, Casteele NV5, Kozuch PL6, Raffals LE7, Baidoo L8, Bressler B9, Devlin SM10, Jones J11, Kaplan GG10, Sparrow MP12, Velayos FS13, Ullman T14, Siegel CA15.


Clin Gastroenterol Hepatol. 2019 Mar 27. pii: S1542-3565(19)30301-5. doi: 10.1016/j.cgh.2019.03.037. [Epub ahead of print]

Author Information

  1. Beth Israel Deaconess Medical Center, Boston, Massachusetts.

  2. Beth Israel Deaconess Medical Center, Boston, Massachusetts. Electronic address:

  3. Cedars-Sinai Medical Center, Los Angeles, California.

  4. Guy's and St. Thomas' Hospitals, London, United Kingdom.

  5. University of California San Diego, La Jolla, California.

  6. Jefferson University, Philadelphia, Pennsylvania.

  7. Mayo Clinic, Rochester, Minnesota.

  8. Northwestern University Feinberg School of Medicine.

  9. University of British Columbia, Vancouver, Canada.

  10. University of Calgary, Alberta, Canada.

  11. Dalhousie University, Halifax, Canada.

  12. Alfred Hospital, Melbourne, Australia.

  13. University of California San Francisco, San Francisco, California.

  14. Montefiore Medical Center/Albert Einstein College Medicine, Bronx, NY.

  15. Dartmouth-Hitchcock Medical Center, Lebanon, New Hampshire.

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