Hydroxychloroquine in Metastatic Estrogen Receptor-Positive Breast Cancer Progressing on Hormonal Therapy

Inclusion Criteria

• •1. Patients ≥ 18 years of age with histologically confirmed, metastatic ER + breast cancer with clinical progression of disease (including radiographically stable disease with at least 50% increment of an elevated tumor marker by two measurements at least 2 weeks apart (this particular tumor marker will be used for disease status assessment in the study) on current hormonal therapy with PFS for at least 3 months.
• •2. Karnofsky Performance Status (KPS) ≥70% and a life expectancy \>3 months.
• •3. Participants must have at least one target visceral lesion that allows for evaluation of tumor response or in the case of bone-only metastases, patients need to have a positive imaging study such as bone scan, magnetic resonance imaging (MRI) or positron emission tomography-computed tomography (PET-CT) or CT, and an elevated tumor marker at least twice as high as upper limit.
• •4. Absolute neutrophil count \> 1500 mm3, platelet count ≥ 80×109 L, hemoglobin ≥ 8.5 g/dL
• •5. Creatinine clearance ≥ 30 mL/min, total bilirubin ≤ 2 mg/dL, AST/ALT ≤ 3 times the upper limit of normal range
• •6. No remaining grade 2 or higher toxicity from prior cancer therapies unless judged to be clinically insignificant by the Principal Investigator
• •7. At least two (2) weeks from prior major surgery
• •8. Willingness to provide permission to biopsy one of the lesions if applicable before the study (All the patients are encouraged to have post-therapy biopsy upon progression of disease, but it is optional) as well as blood samples for pertinent laboratory studies
• •9. Women of child-bearing potential (i.e., women who are pre-menopausal or not surgically sterile) must be willing to use an acceptable non-hormonal contraceptive method (abstinence, or double barrier method) for the duration of the study and for 30 days following the last dose of study drug, and must have a negative urine or serum pregnancy test within 2 weeks prior to beginning treatment on this trial -