Phase I-II Study of Interferon-gamma in Patients With HER-2 Positive Breast Cancer

Phase 1: IFN-γ 50 or 75 mcg/m\^2 SQ x 3 days/week for 12 weeks. Phase 2: IFN-γ at Recommended Phase II Dose (RP2D) subcutaneously (SQ) x 3 days/week, for 12 weeks.

Phase 1 and Phase 2: Paclitaxel 80 mg/m\^2/week, for 12 weeks.

Phase 1 and Phase 2: Trastuzumab 8 mg/kg intravenous (IV) loading dose on cycle 1/day 1 (C1D1), followed by 6 mg/kg on subsequent cycles every 3 weeks, for 12 weeks.

Phase 1 and Phase 2: Pertuzumab 840 mg IV loading dose on C1D1, followed by 420 mg on subsequent cycles every 3 weeks, for 12 weeks.

Phase 2: Participants will be assessed for surgery following the fourth cycle of study therapy (or earlier if study treatment is cancelled due to unmanageable side effects).