More often than as a single agent, venetoclax is prescribed in combination with a monoclonal antibody.

How Do Monoclonal Antibodies Work? 

Monoclonal antibodies are a treatment administered by intravenous infusion (IV). They kill CLL cells by binding to a protein on their surface, signaling the body's immune system to target the cancer cells. 

The surface protein used by monoclonal antibodies for CLL is often CD20. These treatments may also target healthy B-cells that also have CD20. 

The two monoclonal antibodies that are FDA-approved for CLL treatment are obinutuzumab (Gazyva, Genentech) and rituximab (Rituxan, Genentech).