|Abciximab||Abecarnil||Abetimus Sodium||Abietic Acid||Abikoviromycin|
|Pregnancy cat.||C (U.S.)|
|Legal status||POM (UK), ℞-only (U.S.)|
|(what is this?)|
Abatacept (marketed as Orencia) is a fusion protein composed of the Fc region of the immunoglobulin IgG1 fused to the extracellular domain of CTLA-4. It is a molecule capable of binding with more avidity to CD80 (B7-1) than to CD86 (B7-2). Abatacept is a selective co-stimulation modulator as it inhibits the costimulation of T cells. It was developed by Bristol-Myers Squibb and is licensed in the United States for the treatment of rheumatoid arthritis in the case of inadequate response to anti-TNFα therapy.