A Dose Finding Phase 1 of Sarilumab Plus Capecitabine in HER2/Neu-Negative Metastatic Breast Cancer and a Single-arm, Historically-controlled Phase 2 Study of Sarilumab Plus Capecitabine in Stage I-III Triple Negative Breast Cancer With High-Risk Residual Disease (EMPOWER)

This study looks to advance a novel and potent strategy to eliminate minimal residual disease (MRD) in triple negative breast cancer (TNBC) present even after multimodal treatment, thereby improving survival and increasing cure rate in this aggressive cancer. Patients with locally advanced TNBC are at high risk of developing lethal metastatic disease within 2 years of diagnosis, especially for those without a pathologic complete response (pCR) after neoadjuvant chemotherapy. The high risk occurs despite surgical excision of the primary tumor and axillary lymph nodes to eliminate residual disease.

The study will consist of two phases, I and II. Phase I will include patients with metastatic TNBC, HER2/neu-negative and hormone resistant breast cancer. A total of 4 doses of sarilumab will be given with the starting dose of 150 mg SQ at 3-weeks cycles given 3 days prior to each of the first 4 of 8 cycles of capecitabine (1000 mg/m2/BID; for 14 days every 21 days). If dose escalation is possible, sarilumab will be administered every 3 weeks at 200 mg SQ for 4 doses. Blood samples will be obtained prior during the course of treatment. Bone marrow samples are optional. Phase II is a single arm study in Stage I to III TNBC with less than a complete pCR after neoadjuvant therapy evaluating the combination of sarilumab with capecitabine (1000mg/m2/BID; for 14 days every 21 days) as compared to historical control patients treated with capecitabine alone. There are 8 cycles of capecitabine. The first 4 cycles will be combined with sarilumab. The Phase II sarilumab dose will be determined by the Phase I best tolerated dose. Blood samples will be obtained prior during the course of treatment. Bone marrow samples are optional. A pilot parallel biological baseline study of standard adjuvant capecitabine in stage I to III TNBC with less than a pCR will be performed. This Arm will be open in parallel with both Phases 1 and 2. Blood samples will be obtained prior during the course of treatment. Bone marrow samples are optional.