Bryxta 300 Injection Bryxta 300 is an injectable formulation of bevacizumab, a targeted monoclonal antibody used as part of treatment for several types of cancer. It works by blocking VEGF, a signaling protein that promotes the development of new blood vessels around tumors. Limiting this blood-vessel formation can reduce the supply of oxygen and nutrients available to cancer cells. Bryxta 300 is supplied as a 12 mL vial containing 300 mg of bevacizumab and is administered by intravenous infusion under medical supervision.