A Phase 3, Randomized Study of Margetuximab Plus Chemotherapy in the Treatment of Patients of Patients with HER2+ Metastatic Breast Cancer Who Have Received Prior Anti-HER2 Therapies and Require Systemic Treatment

Inclusion Criteria:

Histologically-proven metastatic or locally-advanced relapsed/refractory HER2+ breast cancer based on the most recently available tumor biopsy collected from the patient. Tumors may be estrogen receptor (ER)/progesterone receptor (PR) positive or negative.
Prior treatment with pertuzumab, trastuzumab, and ado-trastuzumab emtansine in the neoadjuvant, adjuvant, or metastatic setting. Prior radiotherapy, hormonal therapies, and other anti-HER2 therapies are allowed.
Prior treatment with at least one, and no more than three, lines of therapy in the metastatic setting. Patients must have progressed on or following, the most recent line of therapy.
Resolution of all chemotherapy or radiation-related toxicities to ≤ Grade 1
Life expectancy ≥ 12 weeks
Acceptable laboratory parameters
Women of childbearing potential must have negative pregnancy test performed within 7 days of randomization and on the first day of treatment. All subjects must agree to use an effective form of contraception for the duration of study treatment and for 7 months after the last dose of study drug
Exclusion Criteria:

Known, untreated brain metastasis. Patients with signs or symptoms of brain metastasis must have a CT or MRI performed within 4 weeks prior to randomization to specifically exclude the presence of radiographically-detected brain metastases
History of uncontrolled seizures within 6 months of randomization
History of prior allogeneic bone marrow, stem-cell, or solid organ transplantation
History of clinically significant cardiovascular disease
Clinically-significant pulmonary compromise, including a requirement for supplemental oxygen use to maintain adequate oxygenation
Any condition that would be a contraindication to receiving trastuzumab as described in the approved local label or a condition that would prevent treatment with the physician's choice of chemotherapy
Phase III
Raul Mena, M.D.
MacroGenics, Inc
Erikan Enyong
  • Disney Family Cancer Center (DFCC)
  • Providence Los Angeles Research Center