Vinorelbine With Trastuzumab Emtansine in Pre-Treated HER2-Positive Metastatic Breast Cancer

This is a Phase I/II, single arm, open-label clinical trial designed to establish the recommended phase II dose (RP2D) of vinorelbine with a fixed dose of trastuzumab emtansine. The study will also evaluate the safety and efficacy of the RP2D in patients with human epidermal growth factor receptor 2 (HER2)-positive metastatic, locally advanced, or unresectable breast cancer. The study will be opened to accrual at the University of Miami Sylvester Comprehensive Cancer Center (SCCC) main campus and constituent satellite sites, Deerfield Beach and Plantation. This phase I/II study will have a total of 50 enrolled patients, taking into account 10% drop-out in the phase II follow-up. The duration anticipated to enroll all study subjects in Phase I/II is 2 years. The estimated duration for the Investigators to complete this study (Phase I/II) is 4.5 to 5 years. For the phase I portion, standard 3+3 dose escalation/de-escalation design will be applied. Approximately 15 to 21 patients will be needed to establish the recommended phase II dose (RP2D). For the phase II portion of the study, up to 35 patients will be treated at the RP2D (MTD) including 6 patients treated at RP2D in phase I. Patients may remain on treatment with the combination until disease progression or unmanageable toxicity. Tumor assessments will be conducted every 6 weeks (±7 days) to week 18. Thereafter, these assessments will be done every 12 weeks (±7 days). These will shall occur regardless of dose delays or dose interruptions, until Investigator-assessed progressive disease (PD), or death, whichever occurs first. More frequent tumor assessments may be performed as clinically indicated, at the discretion of the treating Investigator. For the phase II portion of the study - patients who discontinue treatment for reasons other than PD will continue to have required tumor assessments completed until PD or the initiation of a new therapy. Once patients have progressed, they will be followed for survival approximately every 3 months for at least 3 years. Subsequent anti-cancer therapies will be documented until study completion. Patients who are discontinued from study treatment will return for the Study Treatment Discontinuation Visit approximately 30 days (±7 days) after the last dose of study treatment.