Biological drugs are commonly used to treat chronic inflammatory diseases like rheumatoid arthritis and inflammatory bowel diseases. The most common biological drugs are infliximab, adalimumab, and etanercept. Monitoring drug levels and antibodies against the drugs is important because immunogenicity can lead to loss of treatment efficiency. Clinical studies have shown correlations between low drug levels, high antibody levels, and poor patient responses. Monitoring biological drugs allows for optimization of treatment regimens.

1. MONITORING BIOLOGICALS

4. References… “ Several studies have shown that immunogenicity is associated with allergic reactions and loss of response in a significant number of patients treated with chimeric or human therapeutic antibodies. Monitoring of drug levels as well as of antibodies against therapeutic antibodies may lead to more rational treatment strategies.” Wolbink et al. Curr Op Rheum 2009. “ Secondary response failure is associated with low trough levels of anti-TNF-alpha biologicals and development of antibodies against these drugs. Indeed, trough level assessments of anti-TNF-alpha drugs and measurements of antibodies against these biologicals are among the parameters that best predict the response of individual RA patients” Radstake et al. Ann.Rheum.Dis 2009 “ Assesments of bioavailability and immunogenicity of infliximab may be used to optimize dose regimens and prevent prolonged use of inadequate therapy .” Svenson et al. Rheum 2007. “ We show that determining the immunogenic status of a non responding patient may be important for further decision making and could assist in developing an optimised treatment for the individual patient.” Bartelds et al. Ann.Rheum.Dis 2009

11. PROMONITOR PROMONITOR Optimizes each patient´s therapy Adequate drug level+ no antibody response Decreased drug level + antibody response Low drug level+ significant antibody production Treatment OK Consider increasing dosage or frequency of dosage Consider switching to another drug