Abstract 4639: Spherical nucleic acids induce an antitumor immune response against triple-negative breast cancer

Author(s):  
Lisa E. Cole ◽  
Dai Horiuchi ◽  
Chad A. Mirkin
eLife ◽  
2021 ◽  
Vol 10 ◽  
Author(s):  
Fernanda I Staquicini ◽  
Amin Hajitou ◽  
Wouter HP Driessen ◽  
Bettina Proneth ◽  
Marina Cardó-Vila ◽  
...  

Triple-negative breast cancer (TNBC) is an aggressive tumor with limited treatment options and poor prognosis. We applied the in vivo phage display technology to isolate peptides homing to the immunosuppressive cellular microenvironment of TNBC as a strategy for non-malignant target discovery. We identified a cyclic peptide (CSSTRESAC) that specifically binds to a vitamin D receptor, protein disulfide-isomerase A3 (PDIA3) expressed on the cell surface of tumor-associated macrophages (TAM), and targets breast cancer in syngeneic TNBC, non-TNBC xenograft, and transgenic mouse models. Systemic administration of CSSTRESAC to TNBC-bearing mice shifted the cytokine profile toward an antitumor immune response and delayed tumor growth. Moreover, CSSTRESAC enabled ligand-directed theranostic delivery to tumors and a mathematical model confirmed our experimental findings. Finally, in silico analysis showed PDIA3-expressing TAM in TNBC patients. This work uncovers a functional interplay between a cell surface vitamin D receptor in TAM and antitumor immune response that could be therapeutically exploited.


2017 ◽  
Vol 35 (15_suppl) ◽  
pp. 1100-1100
Author(s):  
Ishita Choudhary ◽  
Sergey Klimov ◽  
Padmashree C.G. Rida ◽  
Angela Ogden ◽  
Andrew R. Green ◽  
...  

1100 Background: Recent studies show strong correlation between tumor infiltrating lymphocytes (TILs) and triple-negative breast cancer (TNBC) patient survival. CD8+ T cells serve as a favorable prognostic marker for TNBC. In addition, other cells such as CD4+ T cells, macrophages, B cells, and Tregs also infiltrate tumors. In this study, we delineate a strong relationship between the cycling kinetics of proliferating cells in TNBCs and antitumor immune response. Methods: A multi-institutional study performed by our group has previously shown that KAMS (Ki67-Adjusted Mitotic Score) provides a measure of the cycling kinetics of proliferating tumor cells and robustly stratifies TNBC patients into slow cycling (low KAMS) cyclophosphamide-methotrexate-fluorouracil (CMF)-responsive and fast cycling (high KAMS) CMF-resistant subgroups. In this study, we reviewed clinical data from 124 CMF-treated TNBC patients from Nottingham Hospital and sought correlations between cycling kinetics (High/Low KAMS) and tumor infiltrating immune cells. Results: We found that slow cycling TNBCs had higher mean expression of tumor infiltrating immune cells than fast cycling TNBCs. Intratumoral CD68 (p = 0.003), CD3 (p = 0.006), CD20 (p = 0.01), FOXP3 (p = 0.01), and total numbers of intratumoral and stromal CD68 (p = 0.01) and CD3 (p = 0.03) expressing cells were found to be significantly higher in low KAMS tumors than in high KAMS tumors. Of these biomarkers, CD68 was significantly associated with patients’ breast cancer-specific survival (BCSS): (a) low KAMS, high CD68 TNBCs had better BCSS than low KAMS, low CD68 (p = 0.01) TNBCs, and (b) high KAMS, low CD68 cases had better BCSS than high KAMS, high CD68 cases. Conclusions: Our observation that there are more TILs in slow cycling TNBCs suggests that there may be a dynamic cross-regulation between cycling kinetics and antitumor immune response. From our surprising observation that CD68 exerts polar roles in low/high KAMS subgroups, we propose that distinctions in M1 and M2 macrophage subsets in slow and fast cycling TNBCs may correlate with distinct outcomes. In addition, metabolic competition between tumor and immune cells may determine the level and function of TILs.


2020 ◽  
Vol 117 (30) ◽  
pp. 17543-17550 ◽  
Author(s):  
Cassandra E. Callmann ◽  
Lisa E. Cole ◽  
Caroline D. Kusmierz ◽  
Ziyin Huang ◽  
Dai Horiuchi ◽  
...  

Highly heterogenous cancers, such as triple-negative breast cancer (TNBC), remain challenging immunotherapeutic targets. Herein, we describe the synthesis and evaluation of immunotherapeutic liposomal spherical nucleic acids (SNAs) for TNBC therapy. The SNAs comprise immunostimulatory oligonucleotides (CpG-1826) as adjuvants and encapsulate lysates derived from TNBC cell lines as antigens. The resulting nanostructures (Lys-SNAs) enhance the codelivery of adjuvant and antigen to immune cells when compared to simple mixtures of lysates with linear oligonucleotides both in vitro and in vivo, and reduce tumor growth relative to simple mixtures of lysate and CpG-1826 (Lys-Mix) in both Py230 and Py8119 orthotopic syngeneic mouse models of TNBC. Furthermore, oxidizing TNBC cells prior to lysis and incorporation into SNAs (OxLys-SNAs) significantly increases the activation of dendritic cells relative to their nonoxidized counterparts. When administered peritumorally in vivo in the EMT6 mouse mammary carcinoma model, OxLys-SNAs significantly increase the population of cytotoxic CD8+ T cells and simultaneously decrease the population of myeloid derived suppressor cells (MDSCs) within the tumor microenvironment, when compared with Lys-SNAs and simple mixtures of oxidized lysates with CpG-1826. Importantly, animals administered OxLys-SNAs exhibit significant antitumor activity and prolonged survival relative to all other treatment groups, and resist tumor rechallenge. Together, these results show that the way lysates are processed and packaged has a profound impact on their immunogenicity and therapeutic efficacy. Moreover, this work points toward the potential of oxidized tumor cell lysate-loaded SNAs as a potent class of immunotherapeutics for cancers lacking common therapeutic targets.


2021 ◽  
Vol 9 (Suppl 3) ◽  
pp. A644-A644
Author(s):  
Anita Mehta ◽  
Madeline Townsend ◽  
Madisson Oliwa ◽  
Patrice Lee ◽  
Nicholas Saccomano ◽  
...  

BackgroundPoly(ADP-ribose) polymerase inhibitors (PARPi) have improved the outcomes of BRCA-associated breast cancer; however, treatment responses are often not durable. Our preclinical studies demonstrated that PARPi activates the cGAS/STING pathway and recruitment of anti-tumor CD8+ T-cells that are required for tumor clearance [1]. These studies contributed to development of clinical trials testing PARPi plus immune checkpoint blockade (ICB). Unfortunately, early phase trials of PARPi + ICB have not yet suggested efficacy will be superior to PARPi monotherapy. Lack of demonstrated clinical synergy between PARPi + ICB underscores the need to study the tumor microenvironment (TME) during PARPi therapy to identify optimal strategies to enhance T-cell activation. We recently showed that PARPi induces CSF-1R+ suppressive tumor associated macrophages (TAMs) that restrict antitumor immune responses, contributing to PARPi resistance [2]. Removing TAMs with anti-CSF-1R therapy in combination with PARPi significantly enhanced overall survival (OS) compared to PARPi monotherapy in preclinical models [2]. Here, we investigate how modulating TAMs can enhance PARPi + ICB.MethodsMice bearing BRCA1-deficient TNBC (K14-Cre;Brca1f/f;p53f/f) tumors were treated for 98 days with PARPi (Talazoparib) ± small molecule inhibitor of CSF-1R (ARRAY-382; CSF-1Ri) ± anti-PD-1 and then followed for survival. Flow cytometry was employed to elucidate changes in the TME after treatment.ResultsPARPi conferred a significant survival advantage over vehicle treated mice (median OS 33 v. 14 days; p=0.0034) and 2/8 PARPi-treated mice experienced complete tumor clearance at day 98. PARPi + CSF-1Ri treated mice (median OS 140 days) remarkably cleared 7/10 tumors by day 98. The addition of anti-PD-1 to PARPi did not enhance OS compared to PARPi monotherapy. The triple combination of anti-PD-1 + PARPi + CSF-1Ri has not yet significantly enhanced the median OS compared to PARPi + CSF-1Ri (ongoing; 168 v. 140 days); nor did it increase clearance of tumor by day 98 (7/10). However, the triple combination led to superior long term tumor clearance. At day 161 the triple combination exhibited 5/10 tumor free mice compared to 2/10 treated with PARPi + CSF-1Ri. To elucidate how CSR-1Ri enhanced PARPi + ICB responses, flow cytometry was performed and revealed increased expression of the co-stimulatory molecule CD80, reduced tissue resident macrophages (CX3CR1+) and lower CSF-1R expression compared to PARPi + ICB.ConclusionsThese data suggest that targeting immunosuppressive macrophages may induce a favorable anti-tumor immune response and enhance responses to PARPi plus ICB. We are currently evaluating the adaptive immune response in this context.ReferencesPantelidou, C., et al., PARP inhibitor efficacy depends on CD8+ T cell recruitment via intratumoral STING pathway activation in BRCA-deficient models of triple-negative breast cancer. Cancer Discovery, 2019: p. CD-18-1218.Mehta, A.K., et al., Targeting immunosuppressive macrophages overcomes PARP inhibitor resistance in BRCA1-associated triple-negative breast cancer. Nat Cancer, 2021. 2(1): p. 66–82.


2017 ◽  
Vol 35 (15_suppl) ◽  
pp. TPS1126-TPS1126 ◽  
Author(s):  
Steven J. Isakoff ◽  
Sara M. Tolaney ◽  
Nadine M. Tung ◽  
Sylvia Adams ◽  
Hatem Hussein Soliman ◽  
...  

TPS1126 Background: Stage 2-3 triple negative breast cancer (TNBC) remains at high risk for recurrence despite modern adjuvant therapy. An important role for the immune system in TNBC has recently emerged. Tumor infiltrating lymphocytes (TILs) are correlated with improved prognosis and several PD-1/PD-L1 checkpoint inhibitors, including Durvalumab (DUR), demonstrated activity in metastatic TNBC. Vaccines are a promising approach to further enhance the immune response in many cancers including TNBC. PVX-410 (PVX) is a novel tetra-peptide vaccine against XBP1 (2 splice variants), CD138 and CS1 that was safe and induced immune responses in a phase 1b study in smoldering myeloma. XBP1 and CD138 are also over-expressed in TNBC. Methods: This Phase 1b multi-center, single arm study will enroll 20 HLA-A2+ female patients (pts) following completion of all adjuvant therapy for stage 2-3 TNBC. Pts will receive 6 doses of 800ug PVX (emulsified in Montanide (SC) and co-administered with Hiltonol (IM)) at 2-week intervals, and 2 doses of DUR 1500mg IV at the 4th and 6th vaccine visits. Eligible pts must be between 1-6 months from completing adjuvant therapy, have no prior autoimmune disease, and have residual disease if neoadjuvant therapy was used. The primary objective is to determine the safety and tolerability of the combination, and the key secondary objective is to determine the immune response to PVX + DUR. If ≤1 pt in the first 6 has a protocol defined dose limiting toxicity within 4 weeks after the first DUR dose, accrual will continue to 20 pts. Immune response will be assessed at baseline, pre-dose 4 PVX/dose 1 DUR, and 4 weeks after completing protocol therapy. Paired data in 20 pts provides 90% power to see a shift of 0.75 standardized units from baseline to 4 weeks post treatment with the signed rank test. Immune response will be determined by a FACs based assay of antigen specific CD3+CD8+ T lymphocyte response and IFN-γ production (intracellular staining) in patient PBMCs. Additional correlative studies, including T-cell PD-1 and tissue PD-L1, XBP1, and CD138, are planned. Currently 4 pts are enrolled. Clinical trial information: NCT02826434.


Author(s):  
AE Gillgrass ◽  
GR Pond ◽  
MN Levine ◽  
TJ Whelan ◽  
JA Hassell ◽  
...  

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