Patients receive ivermectin orally (PO) once daily (QD) on days 1-3, 8-10, and 15-17. Cycles repeat every 21 days in the absence of disease progression or unacceptable toxicity. Patients also receive balstilimab intravenously (IV) over 30 minutes on day 1. Treatment repeats every 21 days for up to 35 cycles in the absence of disease progression or unacceptable toxicity.~After completion of study treatment, patients are followed up for 90 days and then periodically thereafter.
This phase II trial studies the side effects and best dose of ivermectin in combination with balstilimab and to see how well they they work in shrinking tumors in patients with triple negative breast cancer that has spread to other places in the body (metastatic). Immunotherapy with monoclonal antibodies, such as balstilimab, may help the body's immune system attack the cancer, and may interfere with the ability of tumor cells to grow and spread. Ivermectin may help block the formation of growths that may become cancer. Giving ivermectin with balstilimab may increase the effect of balstilimab in shrinking tumors in patients with triple negative breast cancer. The secondary objectives of the study include evaluating the following efficacy outcomes: objective response rate (ORR), progression free survival (PFS), overall survival (OS), duration of response (DOR), clinical benefit rate (CBR), and patients' quality of life (QOL) by European Organization for Research and Treatment of Cancer (EORTC) Quality of Life Questionnaire Core 30 (QLQ-C30).