The use of biologics, which are generally made from human and/or animal materials, has significantly changed the management of rheumatoid arthritis over the last decade, becoming the cornerstone treatment for many patients. Because the arsenal of biologics for rheumatoid arthritis includes numerous monoclonal antibodies with various mechanisms of action, it can be challenging to optimize treatments for individuals.

A new review of the medical literature indicates that blood concentrations of biologics can vary from patient to patient and may correlate with therapeutic response. Therefore, the use of a 'one dose fits all' approach, mainly proposed by pharmaceutical companies, needs to be reassessed. In general, individualized doses of biologics should be implemented in clinical practice.

"Since their usage is spreading, the study of factors and covariates that could relevantly influence serum drug concentrations and exposure would be extremely useful to better understand and predict drugs' pharmacokinetic/pharmacodynamic behavior in advance," wrote the authors of the British Journal of Clinical Pharmacology review. "Moreover, the applicability of population pharmacokinetic and pharmacodynamic models in the clinical setting would allow us to select the suitable dose for specific patients at the same time a cost-efficient approach is considered."

Article: Is there potential for Therapeutic Drug Monitoring of Biologic Agents in Rheumatoid Arthritis? C. Bastida, V. Ruíz, M. Pascal, J. Yagüe, R. Sanmartí and D. Soy, British Journal of Clinical Pharmacology, doi: 10.1111/bcp..13192, published online 19 December 2016.