Neoadjuvant Pembrolizumab + Decitabine Followed by Std Neoadj Chemo for Locally Advanced HER2- Breast Ca

This study is a 2-cohort, open-label, multicenter, phase 2 study of a short course of immunotherapy consisting of sequential decitabine followed by pembrolizumab administered prior to a standard neoadjuvant chemotherapy regimen for patients with locally advanced HER2-negative breast cancer. The primary efficacy objective is to determine if the immunotherapy increases the presence and percentage of tumor and/or stromal area of infiltrating lymphocytes prior to initiation of standard neoadjuvant chemotherapy. At enrollment, patients will be assigned to one of 2 cohorts based on hormone receptor status. * Cohort A - patients with HER2-negative, hormone receptor-negative breast cancer (defined as both ER and PgR with \< 10% positive staining on IHC) Note: before beginning standard neoadjuvant chemotherapy, patients in Cohort A may be reassigned to Cohort A2 to receive extended pembrolizumab as part of new standard neoadjuvant and postoperative adjuvant therapy. * Cohort B - patients with HER2-negative, hormone receptor-positive breast cancer (defined as either ER or PgR with ≥ 10% positive staining on IHC)

NCT Number	NCT02957968
Lead Sponsor	Virginia Commonwealth University Collaborators: Merck Sharp & Dohme LLC, National Cancer Institute (NCI)
Conditions	Breast Adenocarcinoma, Estrogen Receptor- Negative Breast Cancer, Estrogen Receptor-positive Breast Cancer, HER2/Neu Negative, Invasive Breast Carcinoma, Progesterone Receptor Negative, Progesterone Receptor Positive Tumor, Stage II Breast Cancer +5 more
Enrollment	46 participants
Start Date	2017-01-24
Primary Completion	2022-08-04 (estimated)
Study Completion	2027-03-31 (estimated)
Updated on ClinicalTrials.gov	2026-07-01