T-Cell Therapy for Advanced Breast Cancer

Inclusion Criteria: * Patients aged ≥18 years with metastatic breast cancer * Karnofsky performance status ≥70% * Patients with breast cancer that is pathologically confirmed at MSKCC (pathology from outside institutions is acceptable for the screening phase of the protocol) and defined by the following: * HER2 negative (in cases of mixed HER2 results, the most recent pathology results considered reflective of the active cancer will be considered) * Previously treated with at least 1 chemotherapy regimen for metastatic disease and documented progression * Expression of mesothelin must be confirmed by meeting 1 of the following criteria: * Mesothelin expression (\>10% of the tumor expressing mesothelin) by IHC * Elevated serum SMRP levels (\>1.0 nM/L) * Presence of measurable or evaluable disease * Chemotherapy, targeted therapy (such as a tyrosine kinase inhibitor), or radiotherapy must have been completed at least 14 days before administration of T-cells. Prior immunotherapy with checkpoint blockade (i.e., PD1 inhibitor, PDL1 inhibitor, or CTL4-antagonist or similar agent) must have been completed more than 1 month before the T-cell infusion. \*Chemotherapy must have been completed at least 7 days prior to leukapheresis * Any major operation must have occurred at least 28 days before study enrollment. * All acute toxic effects of any previous radiotherapy, chemotherapy, or surgical procedures must have resolved to grade 1 or lower according to CTCAE * Lab requi…