Margetuximab Plus Chemotherapy vs Trastuzumab Plus Chemotherapy in the Treatment of HER2+ Metastatic Breast Cancer

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 (PgR) positive or negative.
• •Have received at least 2 prior lines of anti-HER2 directed therapy in the metastatic setting, or in case of having received (neo)adjuvant pertuzumab, at least 1 prior line of anti-HER2 directed therapy in the metastatic setting. In either case, patients must have received prior treatment with pertuzumab, in the (neo)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 overall 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 14 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.
• •Infusion sub-study prior therapy requirements: Same as above, except:
• •Must have received 4 or more prior lines or therapy in the metastatic setting
• •Must have received prior trastuzumab, pertuzumab, and T-DM1