Information for medical professionals and investigators
Biological-derived proteins (biologicals) such as therapeutic antibodies elicit an unwanted antibody response in a substantial number of patients, resulting in a loss of efficacy of treatment. Diagnostic Services introduces new tests for assessment of therapeutic antibodies and their immunogenicity. This enables fine tuning of drug dosage, early switch to other therapeutics and prevention of side-effects.
More and more proteins are used as therapeutic agents. Especially the use of therapeutic antibodies has been very successful. Well-known examples of therapeutics aiming to diminish TNFα levels are etanercept (Enbrel®), adalimumab (Humira®) and infliximab (Remicade®), which are applied for inflammatory diseases such as rheumatoid arthritis, Bechterew’s disease, psoriasis, Crohn’s disease etc. Rituximab (Mabthera®), directed against the CD20-antigen on B-cells and originally developed for treatment of lymphomas, has increasingly been applied for autoimmune diseases. Several other biologicals have been developed for cancer therapy, such as trastuzumab (Herceptin®) for breast cancer treatment.
Most therapeutic antibodies induce an unwanted immune response. The first generation of therapeutic antibodies was of murine origin (figure 1) and the immunogenicity of those antibodies has been studied extensively. Some 90% of patients treated with murine antibodies produced human anti-mouse antibodies (HAMA). Immunogenicity of therapeutic antibodies has been markedly reduced by replacing murine constant regions with human ones, resulting in chimeric antibodies such as infliximab and rituximab. About 50% of the patients treated with chimeric antibodies develop human anti-chimeric antibodies (HACA). Humanization of the variable regions further reduces immunogenicity. However, even fully human antibodies like adalimumab lead to the production of human anti-human antibodies (HAHA) in ca. 20% of treated patients. Antibody responses may also be influenced by patient-related factors such as genetic background, underlying disease, immunomodulating therapy and dosing schedule.
Figure 1. Engineered biologicals and their immunogenicity in humans
The formation of antibodies against various anti-TNFα-antibodies in patients and the clinical relevance thereof has been demonstrated and published by the Sanquin research team (see key publications). In several studies Sanquin and other research groups key publications found a clear relationship between levels of therapeutic antibody, HACA or HAHA production and efficacy of therapy.
- In RA patients treated with adalimumab, a clear correlation was found between antibody levels and therapy efficacy (Bartelds et al, 2007). In a 3-year follow-up, the development of antidrug antibodies was associated with lower adalimumab concentration and lower likelihood of minimal disease activity or clinical remission (Bartelds et al, 2011).
- Likewise, in RA patients treated with infliximab, HACA formation was associated with a reduced response to treatment (Wolbink et al 2006).
- In patients with Bechterew’s disease who were treated with infliximab, a correlation was found between absence of clinical response and the presence of anti-infliximab-antibodies, together with low infliximab trough levels (de Vries et al 2007).
- Besides a decrease in trough levels we found a relationship between antibody formation and adverse effects such as infusion reactions (van de Laken et al 2007) and serum sickness-like clinical reactions (Pijpe et al 2005).
Figure 2. Trough levels of infliximab and antibodies against infliximab in serum and the Disease Activity Score in 28 joints (DAS28) in a rheumatoid arthritis patient treated with infliximab. After initial decrease of disease activity, the patient had a relapse of disease activity that coincided with a decrease in serum trough levels of infliximab and an increase in the anti-infliximab titre. AU= arbitrary units (after Wolbink, 2006).
Diagnostic Services has developed tests to determine levels of biologicals and antibodies directed against biologicals. HAHA and HACA are quantified using validated antigen-binding tests (RIA), while levels of therapeutic antibodies are assessed using validated ELISAs, both on a routine base. Serum samples should be collected just prior to administration of the following drug dose, to prevent complex-formation of biological and antibody, which could lead to false-negative results.
Our standard assay format allows for quick development of new tests. Validated assays and assays in the validation phase can be requested via our request form without prior consent. In case you would like to request a test for an assay in the development phase, please contact Sanquin (firstname.lastname@example.org or * 31 20 512 3449).
For an overview of our current test curriculum, please click for the overview of our biological tests.
Please contact Sanquin to evaluate possibilities for development of tests in which you are interested: email@example.com.
Our standard assay format allows for quick development of new tests. Currently we are developing tests for abatacept, abciximab and omalizumab. To inform yourself on the most recent assays in development, consult our website regularly. Please contact Sanquin to evaluate possibilities for development of tests in which you are interested: firstname.lastname@example.org.
- Good clinical response, adequate levels of biologicals and no antibody formation: continue treatment.
- Limited clinical effect, decreased drug level and a moderate antibody response: consider increasing the dosage or the dosing frequency.
- Absence of positive clinical effect, diminished drug level and a significant antibody production: consider switching to another TNFα-blocking agent.
- No clinical improvement, sufficient serum drug levels and no antibody response: consider switching to a drug that intervenes in other immunological pathways.
Diagnostic Services performs blood testing in the field of immunology and transfusion medicine and advises medical professionals on the test results.
Diagnostic Services complies with the highest levels of quality with dedicated professionals and scientific support.
Our immunogenicity assays are used for routine screening for both academic centers and hospitals in the Netherlands.
As each patient responds to treatment individually, next to the results of biological and antibody levels Sanquin also provides tailor made advice.
We welcome medical professionals and researchers from outside the Netherlands to send us samples.
We can execute assays for levels of biologicals (monoclonal therapeutics) in serum/plasma and quantitatively detect antibodies against these therapeutics.
For further information on batchwise biologicals testing at Sanquin, please contact us via email@example.com.
If you would like to send in serum for Biologicals level testing and/or immunogenicity testing, please complete this request form and send the form along with your sample(s) to the address depicted on the request form.