If we build it they will come: targeting the immune response to breast cancer.

Historically, breast cancer tumors have been considered immunologically quiescent, with the majority of tumors demonstrating low lymphocyte infiltration, low mutational burden, and modest objective response rates to anti-PD-1/PD-L1 monotherapy. Tumor and immunologic profiling has shed light on potential mechanisms of immune evasion in breast cancer, as well as unique aspects of the tumor microenvironment (TME). These include elements associated with antigen processing and presentation as well as immunosuppressive elements, which may be targeted therapeutically. Examples of such therapeutic strategies include efforts to (1) expand effector T-cells, natural killer (NK) cells and immunostimulatory dendritic cells (DCs), (2) improve antigen presentation, and (3) decrease inhibitory cytokines, tumor-associated M2 macrophages, regulatory T- and B-cells and myeloid derived suppressor cells (MDSCs). The goal of these approaches is to alter the TME, thereby making breast tumors more responsive to immunotherapy. In this review, we summarize key developments in our understanding of antitumor immunity in breast cancer, as well as emerging therapeutic modalities that may leverage that understanding to overcome immunologic resistance

Cancer vaccines: Enhanced immunogenic modulation through therapeutic combinations

Therapeutic cancer vaccines have gained significant popularity in recent years as new approaches for specific oncologic indications emerge. Three therapeutic cancer vaccines are FDA approved and one is currently approved by the EMA as monotherapy with modest treatment effects. Combining therapeutic cancer vaccines with other treatment modalities like radiotherapy (RT), hormone therapy, immunotherapy, and/or chemotherapy have been investigated as a means to enhance immune response and treatment efficacy. There is growing preclinical and clinical data that combination of checkpoint inhibitors and vaccines can induce immunogenic intensification with favorable outcomes. Additionally, novel methods for identifying targetable neoantigens hold promise for personalized vaccine development. In this article, we review the rationale for various therapeutic combinations, clinical trial experiences, and future directions. We also highlight the most promising developments that could lead to approval of novel therapeutic cancer vaccines

Living with Advanced Breast Cancer: A Descriptive Analysis of Survivorship Strategies

Survivors of advanced breast cancer (ABC), also known as metavivors, are often left with fewer treatment options in the landscape of a cure culture. Metavivors have unique psychosocial and physical needs distinct from patients with early-stage breast cancer. This analysis delves into side effects commonly experienced by patients with ABC, such as fatigue, anxiety, and cardiotoxicity; how these side effects impact caregiver support, financial toxicity, emotional strain, and spiritual and emotional distress; as well as current strategies for mitigation, including nutrition, exercise, and participation in clinical research. Overall, this analysis is a mandate for additional research to explore novel treatments and implement strategies to maintain and improve patients’ quality of life

Phase I Trial of a Modified Vaccinia Ankara Priming Vaccine Followed by a Fowlpox Virus Boosting Vaccine Modified to Express Brachyury and Costimulatory Molecules in Advanced Solid Tumors

Lessons Learned Modified vaccinia Ankara-Bavarian Nordic (MVA-BN)-Brachyury followed by fowlpox virus-BN-Brachyury was well tolerated upon administration to patients with advanced cancer. Sixty-three percent of patients developed CD4+ and/or CD8+ T-cell responses to brachyury after vaccination. BN-Brachyury vaccine also induced T-cell responses against CEA and MUC1, which are cascade antigens, that is, antigens not encoded in the vaccines. Background Brachyury, a transcription factor, plays an integral role in the epithelial-mesenchymal transition, metastasis, and tumor resistance to chemotherapy. It is expressed in many tumor types, and rarely in normal tissues, making it an ideal immunologic target. Bavarian Nordic (BN)-Brachyury consists of vaccination with modified vaccinia Ankara (MVA) priming followed by fowlpox virus (FPV) boosting, each encoding transgenes for brachyury and costimulatory molecules. Methods Patients with metastatic solid tumors were treated with two monthly doses of MVA-brachyury s.c., 8 x 10(8) infectious units (IU), followed by FPV-brachyury s.c., 1 x 10(9) IU, for six monthly doses and then every 3 months for up to 2 years. The primary objective was to determine safety and tolerability. Results Eleven patients were enrolled from March 2018 to July 2018 (one patient was nonevaluable). No dose-limiting toxicities were observed. The most common treatment-related adverse event was grade 1/2 injection-site reaction observed in all patients. Best overall response was stable disease in six patients, and the 6-month progression-free survival rate was 50%. T cells against brachyury and cascade antigens CEA and MUC1 were detected in the majority of patients. Conclusion BN-Brachyury vaccine is well tolerated and induces immune responses to brachyury and cascade antigens and demonstrates some evidence of clinical benefit

Abstract OT1-08-01: A phase Ib trial of sequential combinations of BN-brachyury, entinostat, ado-trastuzumab emtansine (T-DM1) and bintrafusp alfa (M7824) in advanced stage breast cancer (BrEAsT)

Abstract Immune checkpoint blockade (ICB) monotherapy has produced limited benefit in breast cancer (BC) with response rates (RR) ranging from 5 to 23%. Combination ICB improved RR and progression free survival (PFS) resulting in atezolizumab + nab-paclitaxel receiving FDA accelerated approval for programmed cell death ligand 1 (PD-L1) positive, triple negative breast cancers (TNBC). BC has historically been considered immunologically quiet with most having a low mutational burden, low PD-L1 expression, defective antigen presentation machinery, and immuosuppressive signals in the tumor microenvironment (TME). An approach using a combination of immuno-oncology (IO) agents including ICB, immunomodulators and vaccines may shift the TME to allow for improved antigen presentation, the release of immunostimulatory cytokines, more immunogenic cell death and increased PD-L1 expression. The transcription factor brachyury plays an important role in breast tumor plasticity. High brachyury expression is associated with treatment resistance and a worse prognosis. Entinostat is a histone deacetylase inhibitor that has activity in multiple breast cancer subtypes. Preclinical data demonstrates entinostat upregulates MHC, enhances immune-mediated lysis and upregulates PD-L1 expression through epigenetic modification. Bintrafusp alfa is a bifunctional protein composed of the extracellular domain of the TGF-βRII receptor (TGF-β“trap”) fused to a human IgG1. Preclinical data shows bintrafusp alpha treatment increases T-cell trafficking, antigen-specific CD8+ T-cell lysis and NK cell activation. Monotherapy clinical studies with these agents have produced modest results in solid tumors, including BC. Preclinical data evaluating combinations of these agents shows a reduction in in tumor size, improved antigen-specific T-cell responses, reduced regulatory T cells, increased CD8+T-cells, and increased PD-L1 expression. We propose the stepwise addition of BN-Brachyury, Bintrafusp alfa, T-DM1 and Entinostat in advanced BC. This phase Ib study will assess efficacy and safety of the regimen and has three cohorts: Cohort 1(TNBC) will receive BN-Brachyury + Bintrafusp alfa. Cohort 2 (HER2+) will receive T-DM1 + BN-Brachyury + Bintrafusp alfa +/- entinostat. After safety is established in Cohort 2, patients in Cohort 3 (HER2+) will be assigned to receive T-DM1 + BN-Brachyury + Bintrafusp alfa +/- entinostat. Responses are evaluated every 2 cycles (6 weeks). Patients in Cohorts 2 and 3 will undergo research biopsies -baseline and after 2 cycles to evaluate changes within TME. Peripheral immune responses will be evaluated at selected time points. All patients must have measurable disease and HER2+ patients must have biopsiable disease. >1 prior treatment is required. Asymptomatic or brain metastases treated > 6 weeks are allowed. Well controlled HIV, HBV or treated HCV is allowed. Exclusion criteria include symptomatic brain metastases or clinically significant bleeding (<3 months from study entry). Co-primary objectives are RR and safety. Secondary objectives include PFS and changes in tumor infiltrating lymphocytes (Cohorts 2 and 3). Exploratory analyses include changes in immune cells and cytokines in the peripheral blood. Analyses performed will be descriptive, reporting the outcome measure for each treatment arm indicated along with two-tailed 80% and 95% confidence intervals. All cohorts employ a safety assessment in the initial 6 patients and a Simon minimax 2-stage design for clinical efficacy. We plan to recruit 51 patients: 13 patients with TNBC, 38 patients with HER2+BC. This trial will open Fall 2019 at the National Institutes of Health (Bethesda, MD). For more information contact the PI, [email protected]. Citation Format: Margaret E Gatti-Mays, Claudia Palena, Sofia R Gameiro, Renee N Donahue, Caroline Jochems, Seth Steinberg, Stan Lipkowitz, Alexandra Zimmer, Deneise Francis, Julius Strauss, Houssein Abdul Sater, Lisa Cordes, Jason Redman, Fatima Karzai, Marijo Bilusic, Ravi A Madan, James L Gulley, Jeffrey Schlom. A phase Ib trial of sequential combinations of BN-brachyury, entinostat, ado-trastuzumab emtansine (T-DM1) and bintrafusp alfa (M7824) in advanced stage breast cancer (BrEAsT) [abstract]. In: Proceedings of the 2019 San Antonio Breast Cancer Symposium; 2019 Dec 10-14; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2020;80(4 Suppl):Abstract nr OT1-08-01

A Phase I Trial Using a Multitargeted Recombinant Adenovirus 5 (CEA/MUC1/Brachyury)-Based Immunotherapy Vaccine Regimen in Patients with Advanced Cancer

Lessons Learned Concurrent ETBX-011, ETBX-051, and ETBX-061 can be safely administered to patients with advanced cancer. All patients developed CD4(+) and/or CD8(+) T-cell responses after vaccination to at least one tumor-associated antigen (TAA) encoded by the vaccine; 5/6 patients (83%) developed MUC1-specific T cells, 4/6 (67%) developed CEA-specific T cells, and 3/6 (50%) developed brachyury-specific T cells. The presence of adenovirus 5-neutralizing antibodies did not prevent the generation of TAA-specific T cells. Background A novel adenovirus-based vaccine targeting three human tumor-associated antigens-CEA, MUC1, and brachyury-has demonstrated antitumor cytolytic T-cell responses in preclinical animal models of cancer. Methods This open-label, phase I trial evaluated concurrent administration of three therapeutic vaccines (ETBX-011 = CEA, ETBX-051 = MUC1, and ETBX-061 = brachyury). All three vaccines used the same modified adenovirus 5 (Ad5) vector backbone and were administered at a single dose level (DL) of 5 x 10(11) viral particles (VP) per vector. The vaccine regimen consisting of all three vaccines was given every 3 weeks for three doses then every 8 weeks for up to 1 year. Clinical and immune responses were evaluated. Results Ten patients enrolled on trial (DL1 = 6 with 4 in the DL1 expansion cohort). All treatment-related adverse events were temporary, self-limiting, grade 1/2 and included injection site reactions and flu-like symptoms. Antigen-specific T cells to MUC1, CEA, and/or brachyury were generated in all patients. There was no evidence of antigenic competition. The administration of the vaccine regimen produced stable disease as the best clinical response. Conclusion Concurrent ETBX-011, ETBX-051, and ETBX-061 can be safely administered to patients with advanced cancer. Further studies of the vaccine regimen in combination with other agents, including immune checkpoint blockade, are planned

A Phase I Single-Arm Study of Biweekly NHS-IL12 in Patients With Metastatic Solid Tumors

NHS-IL12 is a first-in-class, recombinant fusion protein composed of the human monoclonal antibody NHS76 (binds exposed DNA/histones at sites of intratumoral necrosis) fused to 2 IL-12 heterodimers. The maximum tolerated dose (MTD) and recommended phase II dose (RP2D) of NHS-IL12 monotherapy given subcutaneously (SC) every 4 weeks was previously reported. The study was expanded to include a high-exposure cohort with NHS-IL12 SC every 2 weeks (q2w). This single-arm, phase I trial evaluated NHS-IL12 12 µg/kg SC q2w or 16.8µg/kg SC q2w in patients with metastatic solid tumors. The primary endpoint was safety. Using a 3+3 design, 13 patients with advanced cancer were enrolled and 12 were dose-limiting toxicity (DLT) evaluable. There was 1 DLT (Grade 3 aspartate transaminase/alanine transaminase [AST/ALT] elevation). Other grade 3 toxicities included: flu-like symptoms 1/13 (8%), decreased absolute lymphocyte count (ALC) 1/13 (8%), decreased white blood cell count (WBC) 1/13 (8%), but most adverse events reported were low grade and self-limiting grade. Fifty percent of evaluable patients (6/12) experienced stable disease (SD) with 42% (5/12) developing progressive disease (PD) at the first restaging. Biweekly NHS-IL12 was well tolerated in this small phase I study. Additional studies incorporating NHS-IL12 with other immunomodulating agents are underway. (ClinicalTrials.gov Identifier: NCT01417546)

Society for Immunotherapy of Cancer (SITC) clinical practice guideline on immunotherapy for the treatment of breast cancer.

Breast cancer has historically been a disease for which immunotherapy was largely unavailable. Recently, the use of immune checkpoint inhibitors (ICIs) in combination with chemotherapy for the treatment of advanced/metastatic triple-negative breast cancer (TNBC) has demonstrated efficacy, including longer progression-free survival and increased overall survival in subsets of patients. Based on clinical benefit in randomized trials, ICIs in combination with chemotherapy for the treatment of some patients with advanced/metastatic TNBC have been approved by the United States (US) Food and Drug Administration (FDA), expanding options for patients. Ongoing questions remain, however, about the optimal chemotherapy backbone for immunotherapy, appropriate biomarker-based selection of patients for treatment, the optimal strategy for immunotherapy treatment in earlier stage disease, and potential use in histological subtypes other than TNBC. To provide guidance to the oncology community on these and other important concerns, the Society for Immunotherapy of Cancer (SITC) convened a multidisciplinary panel of experts to develop a clinical practice guideline (CPG). The expert panel drew upon the published literature as well as their clinical experience to develop recommendations for healthcare professionals on these important aspects of immunotherapeutic treatment for breast cancer, including diagnostic testing, treatment planning, immune-related adverse events (irAEs), and patient quality of life (QOL) considerations. The evidence-based and consensus-based recommendations in this CPG are intended to give guidance to cancer care providers treating patients with breast cancer