Belatacept is a fusion protein

Fusion protein

Fusion proteins or chimeric proteins are proteins created through the joining of two or more genes which originally coded for separate proteins. Translation of this fusion gene results in a single polypeptide with functional properties derived from each of the original proteins...

 composed of the Fc fragment of a human IgG1 immunoglobulin linked to the extracellular domain of CTLA-4

CTLA-4

CTLA4 also known as CD152 is a protein that plays an important regulatory role in the immune system...

, which is a molecule crucial for T-cell costimulation, selectively blocking the process of T-cell activation. It is intended to provide extended graft

Medical grafting

Grafting refers to a surgical procedure to move tissue from one site to another on the body, or from another person, without bringing its own blood supply with it. Instead, a new blood supply grows in after it is placed. A similar technique where tissue is transferred with the blood supply intact...

 survival while limiting the toxicity generated by standard immune suppressing regimens, such as calcineurin inhibitors. It differs from abatacept

Abatacept

Abatacept is a fusion protein composed of an immunoglobulin fused to the extracellular domain of CTLA-4, a molecule capable of binding B7. Abatacept is a selective costimulation modulator as it inhibits the costimulation of T cells...

 (Orencia) by only 2 amino acids.

Belatacept was developed by Bristol-Myers-Squibb and approved by the U.S. Food and Drug Administration

Food and Drug Administration

The Food and Drug Administration is an agency of the United States Department of Health and Human Services, one of the United States federal executive departments...

on June 15, 2011.