Durvalumab and Tremelimumab Before Surgery in Treating Patients With Hormone Receptor Positive, HER2 Negative Stage II-III Breast Cancer

PRIMARY OBJECTIVES: I. To evaluate the feasibility of enrolling patients with hormone receptor positive (HR+)/human epidermal growth factor receptor negative (HER2-) breast cancer onto a trial evaluating investigational agents prior to initiating standard neoadjuvant chemotherapy. II. To evaluate the safety and tolerability of tremelimumab plus durvalumab in patients with HR+/HER2- breast cancer. SECONDARY OBJECTIVES: I. To assess immunologic/molecular responses to tremelimumab and durvalumab in patients with HR+/HER2- breast cancer who receive the combination therapy. EXPLORATORY OBJECTIVES: I. To evaluate the pathologic response in patients with HR+/HER2- breast cancer receiving tremelimumab plus durvalumab prior to initiating standard neoadjuvant chemotherapy. OUTLINE: Patients receive tremelimumab intravenously (IV) over 1 hour and durvalumab IV over 1 hour on day 1. Treatment repeats every 4 weeks for up to 2 courses in the absence of disease progression or unacceptable toxicity. Patients then undergo a biopsy and receive standard of care neoadjuvant chemotherapy before undergoing surgery. After completion of study treatment, patients are followed up until the time of surgery.