Abatacept (Orencia®) is a fusion protein produced by recombinant DNA technology in Chinese hamster ovary cells.

Abatacept consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G1 (IgG1).

Abatacept dampens T lymphocyte-dependent antibody responses and inflammation. Experimental studies have shown that it attenuates human T lymphocyte activation, since proliferation and cytokine production (antigen specific TNFα, interferon-γ, and interleukin-2) were decreased. 

Mechanism of action

Abatacept modulates a key costimulatory signal required for full activation of T lymphocytes expressing CD28. Full activation of T lymphocytes requires both recognition of a specific antigen by a T cell receptor and a costimulatory signal, both provided by antigen presenting cells. A major costimulatory pathway involves the binding of CD80 and CD86 molecules on the surface of antigen presenting cells to the CD28 receptor on T lymphocytes. Abatacept specifically binds to CD80 and CD86, thereby selectively inhibiting this costimulatory pathway. 

Clinical use

In Europe, abatacept (Orencia®) is indicated for treatment of:

  • in combination with methotrexate, active rheumatoid arthritis (RA) in adults who respond inadequately to previous therapy
  • highly active and progressive disease in adult rheumatoid arthritis methotrexate-naïve patients
  • in combination with methotrexate, for moderate to severe active polyarticular juvenile idiopathic arthritis in patients of at least 6 years old who respond inadequately to other therapy.

Consult CHMP for details.

What can Sanquin do for you?

We can measure the levels of free drug in the serum; levels of therapeutic antibodies are assessed using validated ELISAs. As we have hands-on experience in these assays, we can provide you with accurate and reproducible test results. 

Send in samples

If you want to use our drug level testing services, fill out this form and send it to us along with 1 ml frozen serum sample per patient.