Research Project
Window of Opportunity Trial of Prospective Low Dose Azacitidine in High-Risk Early-Stage Breast Cancer
- Principal Investigator
- Godoy-Calderon, Maria Jose
- Research Area(s)
- Ongoing Projects
Abstract
Introduction: Hypomethylating agents such as 5-azacitadine (5-aza) derepress transcription of human endogenous retroviral (HERV) genes in several tumor types and may result in expression of immunogenic viral epitopes. Hypomethylating agents may also reverse epigenetic reprogramming of the exhaustion phenotype observed in tumor infiltrating lymphocytes (TILs) Although studied in hematologic malignancies, the role of 5-Aza in solid tumors as an immune response stimulating agent remains underexplored. We hypothesized that 5-aza treatment could better prime an immune response in breast cancers that have typically not demonstrated responses to current immunotherapies (e.g., luminal subtype, hormone receptor positive tumors). We tested this hypothesis in a window of opportunity single-institution clinical trial in patients presenting for initial multidisciplinary curative management of high-risk tumors. Interim analysis of immune responses and safety are presented from this ongoing study. Objectives: The primary objective is to determine the effect of low dose 5-aza therapy on tumor infiltrating lymphocytes (TILs) in patients with high-risk early-stage breast cancer. Correlative objectives include the effects of azacitidine therapy in high-risk subjects on immune response markers. Methods: UICC BRE-04 (NCT04891068) is a pre-op window trial testing low-dose 5-Aza in early-stage high-risk breast cancer. Patients (Age 18-99; ECOG 0-2) were eligible for participation if they were diagnosed with tumor stage T1b-T3 primary invasive breast cancers that are negative for the ER, PR or HER2 receptors (triple negative breast cancer, TNBC) or are ER+ with at least one adverse feature (HER2+, Node +, high-risk gene expression profile, or PR-). The intervention involved 5 continuous days of 5-Aza 50mg/m2 SQ. Following the window treatment, patients underwent standard surgical excision at which time tissue is collected or if patients required a full course of pre-operative systemic therapy, a breast mass biopsy was performed. Pre-treatment and post-window tissues preserved in FFPE were evaluated for the primary outcome of changes in TIL infiltration (quantitative and qualitative) and for HERV gene expression determined by quantitative-PCR. Cytokine concentrations were determined from time-matched plasma specimens. Results: 27 patients have completed the study treatments, and no serious adverse events were observed in any patients. We demonstrated treatment-associated immune remodeling following a short-course of treatment with 5-azacitidine. Significant reduction in CD8⁺ T cell–tumor distance suggests enhanced tumor–immune engagement. Transient increases in monocytes and plasmacytoid dendritic cells indicate early innate immune activation. Cytokine changes (e.g., IL-6, IL-8, MIP-1β) suggest chemokine-driven immune recruitment. The treatment might be promoting enhanced immune cell trafficking to the tumor without systemic T-cell expansion, as evidenced by increased proximity of CD8 T cells to tumor cells. 5-Azacitidine may serve as a priming agent for combination immunotherapy. Future Directions: Validate findings in larger cohorts to confirm spatial immune remodeling and reduce patient heterogeneity. Correlate HERV expression with immune changes (cytokines, pDCs, CD8 proximity) to define mechanistic links. Assess functional state of T cells (activation, exhaustion, cytotoxicity) to determine whether spatial engagement translates to anti-tumor activity. Identify predictive biomarkers of response, including HERV expression signatures and innate immune activation profiles.