Mark D. Pegram, MD, a professor of medicine at Stanford University Medical Center and the director of the Breast Cancer Program at the Stanford Cancer Institute, discusses a single-arm, open-label, phase II study of MGAH22 (margetuximab) in patients with relapsed or refractory advanced breast cancer whose tumors express HER2 at the 2+ level by immunohistochemistry but lack evidence of HER2
gene amplification by FISH.
Pegram says MGAH22 is part of a new generation of HER2 targeted monoclonal antibodies. MGAH22 was engineered to have a higher affinity for activating FC gamma receptors on immune-effector cells. Pegram describes the agent as a “super trastuzumab”, since it can more readily engage immune-effector cells to elicit antibody-dependent cellular toxicity of HER2-positive tumor targets.
Because of this enhanced immunologic activity of the HER2 antibody, researchers may be able to elicit responses in HER2 “low” metastatic breast cancer, Pegram says.
Before the patients can be enrolled in this trial, which is currently in progress, patients must meet eligibility criteria that must be confirmed in a central reference laboratory.
The trial, which is currently ongoing, will expand to about 40 patients if results are seen in the first 20 patients enrolled in the trial.
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