Elizabeth Fitzpatrick

HER-2 pulsed dendritic cell vaccine can eliminate HER-2 expression and impact ductal carcinoma in situ.

HER‐2/neu overexpression plays a critical role in breast cancer development, and its expression in ductal carcinoma in situ (DCIS) is associated with development of invasive breast cancer. A vaccine targeting HER‐2/neu expression in DCIS may initiate immunity against invasive cancer.

A novel dendritic cell-based immunization approach for the induction of durable Th1-polarized anti-HER-2/neu responses in women with early breast cancer

Twenty-seven patients with HER-2/neu overexpressing ductal carcinoma in situ of the breast were enrolled in a neoadjuvant immunization trial for safety and immunogenicity of DC1-polarized dendritic cells (DC1) pulsed with 6 HER-2/neu promiscuous major histocompatibility complex class II-binding peptides and 2 additional human leukocyte antigen (HLA)-A2.1 class I-binding peptides. DC1 were generated with interferon-&ggr; and a special clinical-grade bacterial endotoxin (lipopolysaccharide) and administered directly into groin lymph nodes 4 times at weekly intervals before scheduled surgical resection of ductal carcinoma in situ. Patients were monitored for the induction of new or enhanced antipeptide reactivity by interferon-&ggr; ELISPOT and enzyme-linked immunosorbentassays performed on Th cells obtained from peripheral blood or excised sentinel lymph nodes. Responses by cytotoxic T lymphocyte against HLA-A2.1-binding peptides were measured using peptide-pulsed T2 target cells or HER-2/neu-expressing or nonexpressing tumor cell lines. DC1 showed surface phenotype indistinct from “gold standard” inflammatory cocktail-activated DC, but displayed a number of distinguishing functional characteristics including the secretion of soluble factors and enhanced “killer DC” capacity against tumor cells in vitro. Postimmunization, we observed sensitization of Th cells to at least 1 class II peptide in 22 of 25 (88%; 95% exact confidence interval, 68.8%-97.5%) evaluable patients, whereas 11 of 13 (84.6%; 95% exact confidence interval, 64%-99.8%) HLA-A2.1 patients were successfully sensitized to class I peptides. Perhaps most importantly, anti-HER-2/neu peptide responses were observed up to 52-month postimmunization. These data show that even in the presence of early breast cancer such DC1 are potent inducers of durable type I-polarized immunity, suggesting potential clinical value for development of cancer immunotherapy.

Progressive loss of anti-HER2 CD4+ T-helper type 1 response in breast tumorigenesis and the potential for immune restoration

Genomic profiling has identified several molecular oncodrivers in breast tumorigenesis. A thorough understanding of endogenous immune responses to these oncodrivers may provide insights into immune interventions for breast cancer (BC). We investigated systemic anti-HER2/neu CD4+ T-helper type-1 (Th1) responses in HER2-driven breast tumorigenesis. A highly significant stepwise Th1 response loss extending from healthy donors (HD), through HER2pos-DCIS, and ultimately to early stage HER2pos-invasive BC patients was detected by IFNγ ELISPOT. The anti-HER2 Th1 deficit was not attributable to host-level T-cell anergy, loss of immune competence, or increase in immunosuppressive phenotypes (Treg/MDSCs), but rather associated with a functional shift in IFNγ:IL-10-producing phenotypes. HER2high, but not HER2low, BC cells expressing IFNγ/TNF-α receptors were susceptible to Th1 cytokine-mediated apoptosis in vitro, which could be significantly rescued by neutralizing IFNγ and TNF-α, suggesting that abrogation of HER2-specific Th1 may reflect a mechanism of immune evasion in HER2-driven tumorigenesis. While largely unaffected by cytotoxic or HER2-targeted (trastuzumab) therapies, depressed Th1 responses in HER2pos-BC patients were significantly restored following HER2-pulsed dendritic cell (DC) vaccinations, suggesting that this Th1 defect is not “fixed” and can be corrected by immunologic interventions. Importantly, preserved anti-HER2 Th1 responses were associated with pathologic complete response to neoadjuvant trastuzumab/chemotherapy, while depressed responses were observed in patients incurring locoregional/systemic recurrence following trastuzumab/chemotherapy. Monitoring anti-HER2 Th1 reactivity following HER2-directed therapies may identify vulnerable subgroups at risk of clinicopathologic failure. In such patients, combinations of existing HER2-targeted therapies with strategies to boost anti-HER2 CD4+ Th1 immunity may decrease the risk of recurrence and thus warrant further investigation.

Anti-HER2 CD4+ T-helper type 1 response is a novel immune correlate to pathologic response following neoadjuvant therapy in HER2-positive breast cancer

IntroductionA progressive loss of circulating anti-human epidermal growth factor receptor-2/neu (HER2) CD4+ T-helper type 1 (Th1) immune responses is observed in HER2pos-invasive breast cancer (IBC) patients relative to healthy controls. Pathologic complete response (pCR) following neoadjuvant trastuzumab and chemotherapy (T + C) is associated with decreased recurrence and improved prognosis. We examined differences in anti-HER2 Th1 responses between pCR and non-pCR patients to identify modifiable immune correlates to pathologic response following neoadjuvant T + C.MethodsAnti-HER2 Th1 responses in 87 HER2pos-IBC patients were examined using peripheral blood mononuclear cells pulsed with 6 HER2-derived class II peptides via IFN-γ ELISPOT. Th1 response metrics were anti-HER2 responsivity, repertoire (number of reactive peptides), and cumulative response across 6 peptides (spot-forming cells [SFC]/106 cells). Anti-HER2 Th1 responses of non-pCR patients (n = 4) receiving adjuvant HER2-pulsed type 1-polarized dendritic cell (DC1) vaccination were analyzed pre- and post-immunization.ResultsDepressed anti-HER2 Th1 responses observed in treatment-naïve HER2pos-IBC patients (n = 22) did not improve globally in T + C-treated HER2pos-IBC patients (n = 65). Compared with adjuvant T + C receipt, neoadjuvant T + C — utilized in 61.5 % — was associated with higher anti-HER2 Th1 repertoire (p = 0.048). While pCR (n = 16) and non-pCR (n = 24) patients did not differ substantially in demographic/clinical characteristics, pCR patients demonstrated dramatically higher anti-HER2 Th1 responsivity (94 % vs. 33 %, p = 0.0002), repertoire (3.3 vs. 0.3 peptides, p < 0.0001), and cumulative response (148.2 vs. 22.4 SFC/106, p < 0.0001) versus non-pCR patients. After controlling for potential confounders, anti-HER2 Th1 responsivity remained independently associated with pathologic response (odds ratio 8.82, p = 0.016). This IFN-γ+ immune disparity was mediated by anti-HER2 CD4+T-bet+IFN-γ+ (i.e., Th1) — not CD4+GATA-3+IFN-γ+ (i.e., Th2) — phenotypes, and not attributable to non-pCR patients’ immune incompetence, host-level T-cell anergy, or increased immunosuppressive populations. In recruited non-pCR patients, anti-HER2 Th1 repertoire (3.7 vs. 0.5, p = 0.014) and cumulative response (192.3 vs. 33.9 SFC/106, p = 0.014) improved significantly following HER2-pulsed DC1 vaccination.ConclusionsAnti-HER2 CD4+ Th1 response is a novel immune correlate to pathologic response following neoadjuvant T + C. In non-pCR patients, depressed Th1 responses are not immunologically “fixed” and can be restored with HER2-directed Th1 immune interventions. In such high-risk patients, combining HER2-targeted therapies with strategies to boost anti-HER2 Th1 immunity may improve outcomes and mitigate recurrence.

Dendritic Cell Vaccination Enhances Immune Responses and Induces Regression of HER2pos DCIS Independent of Route: Results of Randomized Selection Design Trial.

Purpose: Vaccination with HER2 peptide-pulsed DC1s stimulates a HER2-specific T-cell response. This randomized trial aimed to establish safety and evaluate immune and clinical responses to vaccination via intralesional (IL), intranodal (IN), or both intralesional and intranodal (ILN) injection. Experimental Design: Fifty-four HER2pos patients [42 pure ductal carcinoma in situ (DCIS), 12 early invasive breast cancer (IBC)] were enrolled in a neoadjuvant HER2 peptide-pulsed DC1 vaccine trial. Patients were randomized to IL (n = 19), IN (n = 19), or ILN (n = 16) injection. Immune responses were measured in peripheral blood and sentinel lymph nodes by ELISPOT or in vitro sensitization assay. Pathologic response was assessed in resected surgical specimens. Results: Vaccination by all injection routes was well tolerated. There was no significant difference in immune response rates by vaccination route (IL 84.2% vs. IN 89.5% vs. ILN 66.7%; P = 0.30). The pathologic complete response (pCR) rate was higher in DCIS patients compared with IBC patients (28.6% vs. 8.3%). DCIS patients who achieved pCR (n = 12) and who did not achieve pCR (n = 30) had similar peripheral blood anti-HER2 immune responses. All patients who achieved pCR had an anti-HER2 CD4 immune response in the sentinel lymph node, and the quantified response was higher by response repertoire (P = 0.03) and cumulative response (P = 0.04). Conclusions: Anti-HER2 DC1 vaccination is a safe and immunogenic treatment to induce tumor-specific T-cell responses in HER2pos patients; immune and clinical responses were similar independent of vaccination route. The immune response in the sentinel lymph nodes, rather than in the peripheral blood, may serve as an endpoint more reflective of antitumor activity. Clin Cancer Res; 23(12); 2961–71. ©2016 AACR.

Interference-Free HER2 ECD as a Serum Biomarker in Breast Cancer

Over-expression of the HER2/neu receptor occurs in 20 to 30 percent of breast tumors and is linked to poorer prognosis. The HER2/neu expression status determines whether or not patient will receive trastuzumab-based treatment. In clinical practice, over-expression of HER2/neu is routinely identified using Immunohistochemistry (IHC) or Fluorescence in Situ Hybridization (FISH), both of which are invasive approaches requiring tissue samples. Serum assays for the Extra Cellular Domain of HER2/neu receptor (HER2 ECD) have been reported but the use is very limited due to serum interference factors (e.g. human anti-animal immunoglobulin antibodies) that lead to false test results and inconsistency with tissue Her2 status. We have developed an ELISA based approach using an MBB buffer to eliminate false results and to obtain more accurate assessment of HER2 ECD levels. Using this refined assay we retroactively measured HER2/neu levels from breast cancer patients and controls. Abnormal HER2 ECD levels were detected in about 32% of invasive breast cancer patients but not in controls or patients with benign diseases. In addition, we also showed that patients with elevated serum HER2 levels appeared to have worse survival regardless of treatments. In a small group of 12 Ductal Carcinoma in situ (DCIS) patients who received HER2/neu peptide vaccination and surgery, only one patient showed constantly rising HER2 levels after treatment and this patient had recurrence of HER2 positive tumor within 5 years. Our studies indicate that once the serum interference issue is resolved, serum HER2 ECD can have potential clinical utility to supplement the tissue based tests.

HER-2 Pulsed Dendritic Cell Vaccine Can Eliminate HER-2 Expression and Impact DCIS

HER‐2/neu overexpression plays a critical role in breast cancer development, and its expression in ductal carcinoma in situ (DCIS) is associated with development of invasive breast cancer. A vaccine targeting HER‐2/neu expression in DCIS may initiate immunity against invasive cancer.

Addition of anti-estrogen therapy to anti-HER2 dendritic cell vaccination improves regional nodal immune response and pathologic complete response rate in patients with ERpos/HER2pos early breast cancer

ABSTRACT HER2-directed therapies are less effective in patients with ERpos compared to ERneg breast cancer, possibly reflecting bidirectional activation between HER2 and estrogen signaling pathways. We investigated dual blockade using anti-HER2 vaccination and anti-estrogen therapy in HER2pos/ERpos early breast cancer patients. In pre-clinical studies of HER2pos breast cancer cell lines, ERpos cells were partially resistant to CD4+ Th1 cytokine-induced metabolic suppression compared with ERneg cells. The addition of anti-estrogen treatment significantly enhanced cytokine sensitivity in ERpos, but not ERneg, cell lines. In two pooled phase-I clinical trials, patients with HER2pos early breast cancer were treated with neoadjuvant anti-HER2 dendritic cell vaccination; HER2pos/ERpos patients were treated with or without concurrent anti-estrogen therapy. The anti-HER2 Th1 immune response measured in the peripheral blood significantly increased following vaccination, but was similar across the three treatment groups (ERneg vaccination alone, ERpos vaccination alone, ERpos vaccination + anti-estrogen therapy). In the sentinel lymph nodes, however, the anti-HER2 Th1 immune response was significantly higher in ERpos patients treated with combination anti-HER2 vaccination plus anti-estrogen therapy compared to those treated with anti-HER2 vaccination alone. Similar rates of pathologic complete response (pCR) were observed in vaccinated ERneg patients and vaccinated ERpos patients treated with concurrent anti-estrogen therapy (31.4% vs. 28.6%); both were significantly higher than the pCR rate in vaccinated ERpos patients who did not receive anti-estrogen therapy (4.0%, p = 0.03). Since pCR portends long-term favorable outcomes, these results support additional clinical investigations using HER2-directed vaccines in combination with anti-estrogen treatments for ERpos/HER2pos DCIS and invasive breast cancer.

Novel strategy to identify MHC class II-promiscuous CD4+ peptides from tumor antigens for utilization in vaccination

Meeting abstracts Although cytotoxic CD8 T lymphocytes (CTL) were historically considered primary effectors of antitumor immunity, solely boosting CTL responses with CD8 vaccines in various tumor types has yielded unpredictable clinical results, possibly because CTLs function suboptimally without

Abstract 1308: Depressed anti-HER2 CD4 Th1 responses correlate with residual disease following neoadjuvant therapy in HER2+ breast cancer patients and can be restored by dendritic cell vaccination

Proceedings: AACR 106th Annual Meeting 2015; April 18-22, 2015; Philadelphia, PA BACKGROUND: We have previously demonstrated a loss of anti-HER2 CD4 T-helper type 1 responses (Th1resp) in HER2+ invasive breast cancer (IBC) pts relative to healthy donors. Compared with pathologic complete response (pCR) after neoadjuvant trastuzumab/chemotherapy (T/C), residual disease at surgery (<pCR) portends a worse prognosis. We investigated differences in anti-HER2 Th1resp between pCR and <pCR pts following neoadjuvant T/C, and impact of HER2-pulsed dendritic cell (DC) vaccination in <pCR pts. METHOD: Th1resp were generated from PBMCs pulsed with 6 HER2 class II peptides by measuring IFN-γ production via ELISPOT, and compared between HER2+ IBC groups. Th1resp metrics were anti-HER2 responsivity, no. of reactive peptides (repertoire), and cumulative response across 6 peptides (spots/10^6 cells). Th1resp of <pCR IBC pts (n = 4) receiving adjuvant HER2-pulsed type 1-polarized DC (DC1) vaccination were analyzed pre-/post-immunization. RESULTS: The study comprised 85 pts. The diminished anti-HER2 Th1resp in treatment-naive HER2+ IBC pts (n = 21) - assessed by responsivity, repertoire, or cumulative response - did not improve globally in T/C-treated IBC pts (n = 64). Within this T/C-treated cohort, neoadjuvant T/C receipt (60.9%) was associated with higher repertoire (1.5 vs 0.7; p = 0.04), but not responsivity or cumulative response, compared with adjuvant T/C. <pCR (n = 23) and pCR (n = 16) cohorts did not differ by age, menopausal status, race, BMI, comorbidity, or stage at diagnosis; however, pCR pts were more likely to have ER- tumors (69% vs 30%, p = 0.03). <pCR pts demonstrated dramatically lower anti-HER2 responsivity (30% vs 94%, p<0.001), repertoire (0.3 vs 3.3 peptides, p<0.001), and cumulative response (24.6 vs 148.2, p<0.001) compared with pCR pts. This disparity was not attributable to <pCR pts’ immune incompetence or increase in suppressive (Treg/MDSC) populations, but associated with shifts in IFNγ:IL10-producing Th phenotypes. Four pts in the residual disease cohort were recruited to our adjuvant HER2-pulsed DC1 vaccination trial, receiving 6 weekly injections followed by booster doses. Evaluable anti-HER2 Th1resp at 3 month post-vaccination (prior to 1st booster dose) indicated significantly restored repertoire (3.0 post vs 0.5 pre, p = 0.003) and cumulative response (152.5 vs 33.7; p = 0.03). CONCLUSION: Beyond the known association between ER status and pathologic response following neoadjuvant T/C in HER2+ breast cancer, we identify a novel correlation between <pCR and depressed anti-HER2 CD4 Th1resp. Even in these heavily pre-treated pts, this Th1 deficit is not “fixed” and can be restored by HER2-pulsed DC1 vaccination. Given the worse prognosis in <pCR pts, combinations of existing HER2-targeted therapies with strategies to boost anti-HER2 Th1 immunity may decrease the risk of recurrence. Note: This abstract was not presented at the meeting. Citation Format: Jashodeep Datta, Erik Berk, Shuwen Xu, Elizabeth Fitzpatrick, Lea Lowenfeld, Noah Goodman, David Lewis, Robert E. Roses, Angela DeMichele, Brian J. Czerniecki. Depressed anti-HER2 CD4 Th1 responses correlate with residual disease following neoadjuvant therapy in HER2+ breast cancer patients and can be restored by dendritic cell vaccination. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 1308. doi:10.1158/1538-7445.AM2015-1308