Abstract No : 1040
Abstract Type : Poster Discussion Session
Indication : Her2 Positive Breast Cancer
Intervention : margetuximab (M) + Ctx
Company : MacroGenics
Technology : Monoclonal Antibody
Investigator chemotherapy choices and results by chemotherapy are shown in the table. Subjects receiving Eri and Gem had the lowest PFS hazards ratios (HRs), favoring M over T, although no statistical significance of individual chemotherapy subgroups was seen. There was variable toxicity among Ctx subgroups, and fewer subjects receiving Cap had Ctx related Grade 3 or higher (.=Gr 3) AEs. In this unblinded study, more subjects on M than T in all subgroups discontinued Ctx while continuing study antibody.
In combination with chemotherapy in pretreated HER2+ MBC, M improved PFS over T. Safety was manageable in all Ctx subgroups. Differences among HRs for chemotherapy subgroups may be driven by selection bias and/or sensitivity differences.