Anti-drug antibodies against TNF-inhibitors and implementation of monitoring routine in health care

Purpose and goal

In this project we enabled rheumatologist to test their infliximab treated RA patients for drug level and anti-drug antibodies (ADA). We show that only 20% of the treated patients had an optimal drug level. Half of them had suboptimal levels, of which in part was due to that the immune system had reacted against the drug and they had developed ADA. In addition, we saw that 20% had too high levels of drug and these patients need an adjustment of the dose. These results will help in optimizing the efficacy of the treatment by identifying patients where the immune system has reacted against the drug.

Expected results and effects

The project is going to generate two manuscripts. One will summarize the results from the pilot study and include data on risk factors for ADA. The second will describe the occurrence of ADA in clinical routine, a comparison of the methods used and how the results should be interpreted to optimize treatment, by identifying those that develop tolerance against the drug. Data generated in the project will be connected to the patients through an add-on module in the patient register for future follow-up.

Planned approach and implementation

A pilot study with samples from a clinical trial stored in the biobank gave interesting results that was followed-up with samples directly from the clinics in Stockholm, Lund and Gothenburg, by using the ELISA method. The majority of the patients had a suboptimal levels of the drug explained by the development of ADA. With a method for identification of immune complexes we could show that ADA could be found in some of the patients not able to analyze with ELISA for ADA. We can thus now identify all patients in which the immune system has reacted against the drug.