VIB4920 + belatacept

**VIB4920 + belatacept** is an investigational combination consisting of VIB4920 (also known as dazodalibep), a recombinant fusion protein that inhibits T-cell and B-cell interactions by specifically blocking CD40 ligand (CD40L), and belatacept, a fusion protein that inhibits T-cell activation by blocking CD80/CD86 interaction with CD28. VIB4920 is engineered from human tenascin C third fibronectin type III domains fused to human serum albumin and lacks an Fc region, designed to reduce the risk of thromboembolic events seen with earlier CD40L inhibitors. Belatacept is a selective T-cell co-stimulation blocker. The combination is being investigated primarily for transplantation and autoimmune indications, although there is very limited published evidence for their use together as a named combination.