Renal toxicity with liposomal doxorubicin in metastatic breast cancer.

There is no preferred treatment option for metastatic breast cancer; therefore, treatment should provide palliation, prolong survival, control symptoms, and improve quality of life. Liposomal doxorubicin formulations have been shown to have less alopecia, nausea, vomiting, and myelosuppression than traditional doxorubicin, but more skin toxicities and infusion reactions. Prolonged use of liposomal doxorubicin may be associated with unrecognized or less well-defined toxicities. We report a case of acute kidney injury and progressively worsening chronic kidney disease necessitating dialysis in a patient who received prolonged therapy with liposomal doxorubicin for treatment of metastatic breast cancer. This case report should give caution to providers considering prolonged use of liposomal doxorubicin in the metastatic breast cancer setting as we observed sustained renal toxicity, long past the cessation of treatment.

HER-2/neu vaccine-primed autologous T-cell infusions for the treatment of advanced stage HER-2/neu expressing cancers.

This phase I study evaluated the feasibility of expanding HER-2/neu (HER2) vaccine-primed peripheral blood T-cells ex vivo and assessed the safety of T-cell infusions. Eight patients with HER2(+) treatment refractory metastatic cancers were enrolled. T-cells could be expanded to predefined parameters in seven patients (88%). Ninety-two percent of adverse events were grade 1 or 2. Three of seven patients developed infusion-related inflammatory reactions at their disease sites. HER2-specific T-cells significantly increased in vivo compared to pre-infusion levels (p = 0.010) and persisted in 4/6 patients (66%) over 70 days after the first infusion. Partial clinical responses were observed in 43% of patients. Levels of T-regulatory cells in peripheral blood prior to infusion (p < 0.001), the level of HER2-specific T-cells in vivo (p = 0.030), and development of diverse clonal T-cell populations (p < 0.001) were associated with response. The generation of HER2 vaccine-primed autologous T-cells for therapeutic infusion is feasible and well tolerated. This approach provides a foundation for the application of T-cell therapy to additional solid tumor types.

Safety and Outcomes of a Plasmid DNA Vaccine Encoding the ERBB2 Intracellular Domain in Patients With Advanced-Stage ERBB2-Positive Breast Cancer: A Phase 1 Nonrandomized Clinical Trial.

Importance: High levels of ERBB2 (formerly HER2)-specific type 1 T cells in the peripheral blood are associated with favorable clinical outcomes after trastuzumab therapy; however, only a minority of patients develop measurable ERBB2 immunity after treatment. Vaccines designed to increase ERBB2-specific T-helper cells could induce ERBB2 immunity in a majority of patients. Objective: To determine the safety and immunogenicity of 3 doses (10, 100, and 500 µg) of a plasmid-based vaccine encoding the ERBB2 intracellular domain (ICD). Design, Setting, and Participants: Single-arm phase 1 trial including 66 patients with advanced-stage ERBB2-positive breast cancer treated in an academic medical center between 2001 and 2010 with 10-year postvaccine toxicity assessments. Data analysis was performed over 2 periods: January 2012 to March 2013 and July 2021 to August 2022. Interventions: Patients were sequentially enrolled to the 3 dose arms. The vaccine was administered intradermally once a month with soluble granulocyte-macrophage colony-stimulating factor as an adjuvant for 3 immunizations. Toxicity evaluations occurred at set intervals and yearly. Peripheral blood mononuclear cells were collected for evaluation of immunity. Biopsy of vaccine sites at weeks 16 and 36 measured DNA persistence. Main Outcomes and Measures: Safety was graded by Common Terminology Criteria for Adverse Events, version 3.0, and ERBB2 ICD immune responses were measured by interferon-γ enzyme-linked immunosorbent spot. Secondary objectives determined if vaccine dose was associated with immunity and evaluated persistence of plasmid DNA at the vaccine site. Results: A total of 66 patients (median [range] age, 51 [34-77] years) were enrolled. The majority of vaccine-related toxic effects were grade 1 and 2 and not significantly different between dose arms. Patients in arm 2 (100 µg) and arm 3 (500 µg) had higher magnitude ERBB2 ICD type 1 immune responses at most time points than arm 1 (10 µg) (arm 2 compared with arm 1, coefficient, 181 [95% CI, 60-303]; P = .003; arm 3 compared with arm 1, coefficient, 233 [95% CI, 102-363]; P < .001) after adjusting for baseline factors. ERBB2 ICD immunity at time points after the end of immunizations was significantly lower on average in patients with DNA persistence at week 16 compared with those without persistence. The highest vaccine dose was associated with the greatest incidence of persistent DNA at the injection site. Conclusions and Relevance: In this phase 1 nonrandomized clinical trial, immunization with the 100-µg dose of the ERBB2 ICD plasmid-based vaccine was associated with generation of ERBB2-specific type 1 T cells in most patients with ERBB2-expressing breast cancer, and it is currently being evaluated in randomized phase 2 trials. Trial Registration: ClinicalTrials.gov Identifier: NCT00436254.

A Phase I/II Trial of HER2 Vaccine-Primed Autologous T-Cell Infusions in Patients with Treatment Refractory HER2-Overexpressing Breast Cancer.

PURPOSE: High levels of type I T cells are needed for tumor eradication. We evaluated whether the HER2-specific vaccine-primed T cells are readily expanded ex vivo to achieve levels needed for therapeutic infusion. PATIENTS AND METHODS: Phase I/II nonrandomized trial of escalating doses of ex vivo-expanded HER2-specific T cells after in vivo priming with a multiple peptide-based HER2 intracellular domain (ICD) vaccine. Vaccines were given weekly for a total of three immunizations. Two weeks after the third vaccine, patients underwent leukapheresis for T-cell expansion, then received three escalating cell doses over 7- to 10-day intervals. Booster vaccines were administered after the T-cell infusions. The primary objective was safety. The secondary objectives included extent and persistence of HER2-specific T cells, development of epitope spreading, and clinical response. Patients received a CT scan prior to enrollment and 1 month after the last T-cell infusion. RESULTS: Nineteen patients received T-cell infusions. Treatment was well tolerated. One month after the last T-cell infusion, 82% of patients had significantly augmented T cells to at least one of the immunizing epitopes and 81% of patients demonstrated enhanced intramolecular epitope spreading compared with baseline (P < 0.05). There were no complete responses, one partial response (6%), and eight patients with stable disease (47%), for a disease control rate of 53%. The median survival for those with progressive disease was 20.5 months and for responders (PR+SD) was 45.0 months. CONCLUSIONS: Adoptive transfer of HER2 vaccine-primed T cells was feasible, was associated with minimal toxicity, and resulted in an increased overall survival in responding patients. See related commentary by Crosby et al., p. 3256.

Common adjuvant breast cancer therapies do not inhibit cancer vaccine induced T cell immunity.

Cancer vaccines may have the most potential for clinical impact when used in the adjuvant setting when tumor burden is at its lowest. Application of cancer vaccines in the adjuvant setting, however, requires integration of immunization with more standard cytotoxic or cytostatic therapies. Common adjuvant therapies for breast cancer patients, i.e. trastuzumab, bisphosphonates and hormonal agents are often administered over several years requiring concurrent administration of these drugs with active immunization. We questioned whether these common adjuvant therapies would impact a patient's ability to develop tumor specific immunity with vaccination. Immune parameters from 36 subjects were evaluated. We determined these adjuvant therapies have no impact on the ability to develop an immune response specific for HER-2/neu peptides (P>0.1) nor do they have an impact on the magnitude of T cell immunity developed with concurrent vaccination (P>0.1). This is the first report to show that the use of trastuzumab, bisphosphonates and hormonal therapy concurrent with cancer vaccine administration have no impact on either the generation or the magnitude of vaccine induced immunity.

Level of HER-2/neu protein expression in breast cancer may affect the development of endogenous HER-2/neu-specific immunity.

We questioned whether the incidence or magnitude of the humoral or cellular immune response to the self-tumor antigen HER-2/neu is influenced by the level of HER-2/neu protein overexpression as defined by immunohistochemical staining of tumors in breast cancer patients. We obtained peripheral blood from 104 women with stage II, III, and IV pathologically confirmed HER-2/neu-overexpressing breast cancer. Patients were categorized with +1 (n = 14), +2 (n = 20), or +3 (n = 70) HER-2/neu overexpression by institutional pathologic report. Circulating antibodies to HER-2/neu were evaluated using ELISA. T-cell responses to HER-2/neu were measured using an antigen-specific tritiated thymidine incorporation assay. Eighty-two percent of subjects with HER-2/neu antibodies were +3 overexpressors compared with 18% +2 overexpressors and 0% +1 overexpressors, a highly significant difference (P < 0.001), and there were significant differences in the magnitude of the HER-2/neu-specific antibodies between groups with varying HER-2/neu protein expression (P = 0.022). In addition, 65% of subjects with HER-2/neu-specific T cells were +3 overexpressors compared with 16% +2 overexpressors and 19% +1 overexpressors (P = 0.001). Data presented here indicate that endogenous HER-2/neu-specific humoral and T-cell immunity is greater in patients with +3 protein overexpression in their tumors than in patients with lower levels of HER-2/neu expression. Overexpression of a self-tumor-associated protein is a potential mechanism by which immunogenicity is enhanced and may aid in the identification of biologically relevant proteins to target for immune-based molecular cancer therapies.

Tumor antigen-specific T-cell expansion is greatly facilitated by in vivo priming.

PURPOSE: Adoptive T-cell therapy is a promising strategy for the treatment of patients with established tumors but is often limited to specific cancers where tumor-infiltrating lymphocytes, the source of T cells for ex vivo culture, can be obtained. In this study, we evaluated the feasibility of expanding HER-2/neu-specific T cells derived from peripheral blood ex vivo following in vivo priming with a HER-2/neu peptide vaccine. EXPERIMENTAL DESIGN: Peripheral blood mononuclear cells from cytomegalovirus (CMV)-seronegative and CMV-seropositive donors as well as HER-2/neu-positive cancer patients who had or had not been vaccinated with a HER-2/neu peptide-based vaccine was used as a source of T lymphocytes. Antigen-specific T-cell lines were generated by in vitro stimulation with antigen followed by nonspecific expansion on CD3/CD28 beads. The ability to expand antigen-specific T cells was assessed using IFN-gamma and granzyme B enzyme-linked immunosorbent spot. The phenotype of the resultant T-cell lines was evaluated by flow cytometry, including the presence of FOXP3-expressing CD4(+) T cells. RESULTS: The frequencies of CMV-specific T cells generated from CMV(+) donors were >11-fold higher than the frequencies from CMV(-) donors (P = 0.001), with 22-fold increase of total number of CD3(+) T cells. The frequencies of HER-2/neu-specific T cells generated from the primed patients were >25-fold higher than the frequencies from unvaccinated patients (P = 0.006), with an average of a 19-fold increase of total number of CD3(+) T cells. Using peripheral blood as the source of T cells did not result in concurrent expansion of FOXP3(+)CD4(+) regulatory T cells despite the use of interleukin-2 in in vitro culture. Both CD4(+) and CD8(+) HER-2/neu-specific T cells could be expanded. The extent of ex vivo expansion correlated with the magnitude of immunity achieved during immunization (P = 0.008). CONCLUSION: Tumor-specific T cells can be efficiently expanded from the peripheral blood ex vivo following in vivo priming with a vaccine. This approach provides an effective method to generate tumor-specific polyclonal T cells for therapeutic use that could be applied to cancer patients with any tumor type.

Recognition of breast cancer cells by CD8+ cytotoxic T-cell clones specific for NY-BR-1.

Immunotherapy for breast cancer using cytotoxic T cells (CTL) is hindered by the lack of well-characterized breast cancer antigens that are expressed in most breast tumor cells and recognized by CD8+ CTL. A recently described breast tissue differentiation antigen, NY-BR-1, is expressed in >80% breast tumors and elicits a humoral response in a subset of breast cancer patients. To identify potential NY-BR-1 epitopes that are recognized by CTL, CD8+ T cells were stimulated in vitro with autologous dendritic cells pulsed with NY-BR-1 peptides that were predicted to bind to HLA-A2. In multiple normal female donors and breast cancer patients, specific CD8+ CTL responses were detected by enzyme-linked immunospot assay against several NY-BR-1 peptides after two cycles of stimulation. CD8+ CTL clones against three NY-BR-1 epitopes were isolated and recognized peptide-pulsed target cells with high avidity. T-cell clones specific for one of the NY-BR-1 epitopes (p904) also recognized breast tumor cells expressing NY-BR-1, NY-BR-1(-) cells transfected with a cDNA encoding the NY-BR-1 protein, and autologous dendritic cells pulsed with opsonized NY-BR-1+ breast tumor cells. Taken together, these results show that the p904 epitope derived from NY-BR-1 is efficiently processed and presented endogenously and identify NY-BR-1 as a promising target for T-cell-based immunotherapy for breast cancer.

Phase I/II Trial of Combined Pegylated Liposomal Doxorubicin and Cyclophosphamide in Metastatic Breast Cancer.

INTRODUCTION: Doxorubicin in combination with cyclophosphamide is active in breast cancer; however, its use in metastatic cancer is limited owing to cardiotoxicity. Pegylated liposomal doxorubicin (PLD) was formulated to decrease the toxicity of conventional doxorubicin. We evaluated the safety and efficacy of PLD with metronomic oral cyclophosphamide. PATIENTS AND METHODS: We conducted a single-arm open-label phase I/II study of PLD and oral cyclophosphamide in patients with metastatic breast cancer. In phase I, 3 escalating doses of PLD were planned (30, 35, and 40 mg/m2) with cyclophosphamide (60 mg/m2 orally daily) to determine the maximum tolerated dose (MTD). In phase II, the MTD of PLD in combination of oral cyclophosphamide was used to assess the primary endpoint of overall clinical response rate and secondary endpoints of progression-free survival, overall survival, and adverse events. RESULTS: Thirty patients were enrolled in the study (n = 6 in phase I and n = 24 in phase II). The MTD of PLD from phase I was 30 mg/m2. The median progression-free and overall survival for the entire cohort were 6.4 months (95% confidence interval, 3.9 months to N/A) and 18.7 months (95% confidence interval, 15.1-31.5 months), respectively. A total of 21 (75%) patients had clinical benefit, including 6 (21%) patients with partial response and 15 (54%) patients with stable disease. The majority of toxicities were uncomplicated myelosuppression, and no infection or febrile neutropenia were noted in any patient. CONCLUSION: PLD in combination with daily oral cyclophosphamide is an active and tolerable regimen in metastatic breast cancer.

Topical Imiquimod Plus Nab-paclitaxel for Breast Cancer Cutaneous Metastases: A Phase 2 Clinical Trial.

IMPORTANCE: Salvage chemotherapy for recurrent chest wall lesions in breast cancer results in response rates of 20% to 30%. Preclinical studies showed significant disease regression could be induced in murine chest wall mammary cancers with a topical toll-like receptor (TLR)-7 agonist, imiquimod. OBJECTIVE: To evaluate the safety and objective response rate (ORR) of imiquimod in combination with systemic albumin bound paclitaxel in treatment-refractory breast cancer of the chest wall. DESIGN, SETTING, AND PARTICPANTS: A single arm phase 2 clinical trial of 15 patients with breast cancer previously treated in an academic medical center setting between 2009 and 2012 for chest wall disease that had recurred. INTERVENTIONS: Imiquimod cream, 5%, was applied topically to a designated target lesion once per day for 4 consecutive days on days 1 through 4, 8 through 11, 15 through 18, and 22 through 25 of a 28-day cycle, for 12 weeks. Albumin bound paclitaxel, 100 mg/m2, was given intravenously on days 1, 8, and 15, and repeated every 28 days over the 12-week period. MAIN OUTCOMES AND MEASURES: The primary endpoint was safety and ORR. Secondary endpoints included the generation of tumor-infiltrating lymphocytes and modulation of immune cell populations. RESULTS: The median age at baseline of the 15 study participants was 54 years (range, 46-92 years). Fourteen patients were evaluable. Combination therapy was associated with low-grade toxic effects. Of 358 adverse events 330 (92%) were grades 1 and 2. Five (36%) patients achieved a compete response and another 5 (36%) were partial responders for an overall response rate of 72% (10 of 14). The response duration was limited. Pretreatment levels of programmed death-1 (PD-1)+ peripheral blood T cells (PD-1+ cluster of differentiation [CD]4+; 95% CI, 2.68-6.63; P < .001 and PD-1+CD8+; 95% CI, 1.13-8.35; P = .01) and monocytic myeloid derived suppressor cells (mMDSC) (95% CI, 3.62-12.74; P = .001) greater than controls predicted suboptimal clinical response. CONCLUSIONS AND RELEVANCE: Chemoimmunomodulation with a TLR-7 agonist and albumin bound paclitaxel is effective in inducing disease regression in treatment-refractory breast cancer chest wall metastases but responses are short-lived. Preexisting levels of cells indicating either T-cell exhaustion or systemic immunosuppression may be markers of selection for responsive patients. TRIAL REGISTRATION: clinicaltrials.gov Identifier: NCT00821964.

Concurrent SPECT/PET-CT imaging as a method for tracking adoptively transferred T-cells in vivo.

BACKGROUND: The ability of T-cells to traffic to and penetrate tumors impacts the clinical efficacy of T-cell therapy therefore methods to track transferred T-cells in vivo are needed. In this preliminary report, we evaluated the use of concurrent SPECT/PET-CT imaging to monitor the egress of HER-2/neu specific T-cells in a breast cancer patient with extensive bone-only metastatic disease. FINDINGS: Indium (In-111) labeled T-cells demonstrated similar or greater viability than unlabeled T-cells at either a low or high dose of In-111 over a 24-h incubation period in vitro. The function of labeled or unlabeled T-cells was not significantly different (p > 0.05) at either dose. T-cells trafficked to all sites of metastatic disease and infiltrated the tumor as assessed by SPECT imaging. In-111 uptake at 24 h after infusion varied from 3.8 (right proximal humerus) to 6.3 (right sacrum) background corrected counts per pixel and remained elevated at 48 h. Concurrent PET-CT imaging demonstrated a fluorodeoxyglucose flare, measured by increase in tumor site uptake as high as 32 % and at most sites of disease at 48 h. This flare was associated with focal pain after T-cell infusion at metastatic sites. The patient had stable disease for 18 months after completion of T-cell therapy. CONCLUSION: Concurrent SPECT/PET-CT imaging, over a 48-h period after T-cell infusion, provided evidence of T-cell homing to all disease sites as well as a tumor metabolism flare response. This technique may be useful for monitoring T-cell trafficking after autologous as well as chimeric antigen receptor T-cell infusion. TRIAL REGISTRAION: Trial registered at ClinicalTrials.gov registration number NCT00791037, registered 13 November 2008.

Effect of dose on immune response in patients vaccinated with an her-2/neu intracellular domain protein--based vaccine.

PURPOSE: To evaluate the safety of an HER-2/neu intracellular domain (ICD) protein vaccine and to estimate whether vaccine dose impacts immunogenicity. PATIENTS AND METHODS: Twenty-nine patients with HER-2/neu-overexpressing breast or ovarian cancer and with no evidence of disease after standard therapy received a low- (25 microg), intermediate- (150 microg), or high-dose (900 microg) HER-2/neu ICD protein vaccine. The vaccine was administered intradermally, monthly for 6 months, with granulocyte-macrophage colony-stimulating factor as an adjuvant. Toxicity and both cellular and humoral HER-2/neu-specific immunity was evaluated. RESULTS: The vaccine was well tolerated. The majority of patients (89%) developed HER-2/neu ICD-specific T-cell immunity. The dose of vaccine did not predict the magnitude of the T-cell response. The majority of patients (82%) also developed HER-2/neu-specific immunoglobulin G antibody immunity. Vaccine dose did not predict magnitude or avidity of the HER-2/neu-specific humoral immune response. Time to development of detectable HER-2/neu-specific immunity, however, was significantly earlier for the high- versus low-dose vaccine group (P =.003). Over half the patients retained HER-2/neu-specific T-cell immunity 9 to 12 months after immunizations had ended. CONCLUSION: The HER-2/neu ICD protein vaccine was well tolerated and effective in eliciting HER-2/neu-specific T-cell and antibody immunity in the majority of breast and ovarian cancer patients who completed the vaccine regimen. Although the dose of vaccine did not impact the magnitude of T-cell or antibody immunity elicited, patients receiving the highest dose developed HER-2/neu-specific immunity more rapidly than those who received the lowest dose.

Immunization of cancer patients with HER-2/neu-derived peptides demonstrating high-affinity binding to multiple class II alleles.

PURPOSE: The purpose of this study was to immunize patients with HER-2/neu-overexpressing cancer with a multipeptide vaccine comprised of four class II HER-2/neu peptides that had been identified as the most immunogenic in a previous clinical trial. Furthermore, we questioned whether MHC binding affinity could predict the in vivo immunogenicity of the HER-2/neu helper peptides. EXPERIMENTAL DESIGN: Four putative class II HER-2/neu peptides, which were found to generate detectable specific T-cell responses (stimulation index > 2) in a majority of patients in a previous study, were used to formulate a single vaccine. The multipeptide vaccine was administered intradermally with granulocyte macrophage colony-stimulating factor as an adjuvant. Ten patients with HER-2/neu overexpressing breast or lung cancer were enrolled. HER-2/neu peptide-and protein-specific T cell and antibody immune responses were measured. Competitive inhibition assays were used to analyze the class II HER-2/neu peptides for their binding affinity to 14 common HLA-DR alleles. RESULTS: Twenty-five percent of patients developed HER-2/neu peptide-specific T-cell immunity, and 50% developed HER-2/neu peptide-specific antibody immunity. No patient developed HER-2/neu protein-specific T cell or antibody immunity. The majority of peptides exhibited high binding affinity, in vitro, to >/==" BORDER="0">3 of the 14 DR alleles analyzed. CONCLUSION: The group of peptides used in this study demonstrated high binding affinity to multiple DR alleles suggesting that in vitro binding affinity may be able to predict the in vivo immunogenicity of class II peptides. However, only a minority of patients immunized with the multipeptide vaccine developed HER-2/neu peptide-specific T cell or antibody immunity, and none developed HER-2/neu protein-specific immunity.

Peptide-based vaccines in breast cancer.

Human tumors are immunogenic and tumor-associated proteins that generate immunity in cancer patients have been defined. Many of these proteins are involved in the malignant transformation and play a role in either initiating or maintaining the malignant phenotype. Furthermore, due to technical advances in basic immunology over the last decade we have a better understanding of the immune effector cell phenotypes that are potentially involved in tumor eradication and have developed methods to quantitate and characterize these immune effectors. Breast cancer is an intriguing model tumor to target with active immunization. Dozens of breast cancer antigens have been defined [1]. Although many patients with breast cancer can be rendered free of disease with standard therapy such as surgery, radiation, and chemotherapy, some patients will have their disease recur. However, relapse may not occur for many months to years after definitive treatment giving an extended period of micrometastatic disease that may be amenable to immune eradication or modulation. Peptide based vaccines are one of the most commonly studied vaccine strategies targeting breast cancer.

Recommendations from the iSBTc-SITC/FDA/NCI Workshop on Immunotherapy Biomarkers.

PURPOSE: To facilitate development of innovative immunotherapy approaches, especially for treatment concepts exploiting the potential benefits of personalized therapy, there is a need to develop and validate tools to identify patients who can benefit from immunotherapy. Despite substantial effort, we do not yet know which parameters of antitumor immunity to measure and which assays are optimal for those measurements. EXPERIMENTAL DESIGN: The iSBTc-SITC (International Society for Biological Therapy of Cancer-Society for Immunotherapy of Cancer), FDA (Food and Drug Administration), and NCI (National Cancer Institute) partnered to address these issues for immunotherapy of cancer. Here, we review the major challenges, give examples of approaches and solutions, and present our recommendations. RESULTS AND CONCLUSIONS: Although specific immune parameters and assays are not yet validated, we recommend following standardized (accurate, precise, and reproducible) protocols and use of functional assays for the primary immunologic readouts of a trial; consideration of central laboratories for immune monitoring of large, multi-institutional trials; and standardized testing of several phenotypic and functional potential potency assays specific to any cellular product. When reporting results, the full QA (quality assessment)/QC (quality control) should be conducted and selected examples of truly representative raw data and assay performance characteristics should be included. Finally, to promote broader analysis of multiple aspects of immunity, and gather data on variability, we recommend that in addition to cells and serum, RNA and DNA samples be banked (under standardized conditions) for later testing. We also recommend that sufficient blood be drawn to allow for planned testing of the primary hypothesis being addressed in the trial, and that additional baseline and posttreatment blood is banked for testing novel hypotheses (or generating new hypotheses) that arise in the field.

Concurrent trastuzumab and HER2/neu-specific vaccination in patients with metastatic breast cancer.

PURPOSE: The primary objectives of this phase I/II study were to evaluate the safety and immunogenicity of combination therapy consisting of concurrent trastuzumab and human epidermal growth factor receptor 2 (HER2)/neu-specific vaccination in patients with HER2/neu-overexpressing metastatic breast cancer. PATIENTS AND METHODS: Twenty-two patients with stage IV HER2/neu-positive breast cancer receiving trastuzumab therapy were vaccinated with an HER2/neu T-helper peptide-based vaccine. Toxicity was graded according to National Cancer Institute criteria, and antigen specific T-cell immunity was assessed by interferon gamma enzyme-linked immunosorbent spot assay. Data on progression-free and overall survival were collected. RESULTS: Concurrent trastuzumab and HER2/neu vaccinations were well tolerated, with 15% of patients experiencing an asymptomatic decline in left ventricular ejection fraction below the normal range during combination therapy. Although many patients had pre-existing immunity specific for HER2/neu and other breast cancer antigens while treated with trastuzumab alone, that immunity could be significantly boosted and maintained with vaccination. Epitope spreading within HER2/neu and to additional tumor-related proteins was stimulated by immunization, and the magnitude of the T-cell response generated was significantly inversely correlated with serum transforming growth factor beta levels. At a median follow-up of 36 months from the first vaccine, the median overall survival in the study population has not been reached. CONCLUSION: Combination therapy with trastuzumab and a HER2/neu vaccine is associated with minimal toxicity and results in prolonged, robust, antigen-specific immune responses in treated patients.

CD4 regulatory T cells in human cancer pathogenesis.

Over the past decade, there has been an accelerated understanding of immune regulatory mechanisms. Peripheral immune regulation is linked to a collection of specialized regulatory cells of the CD4(+) T cell lineage (i.e., CD4(+) Tregs). This collection consists of Tregs that are either thymically derived (i.e., natural) or peripherally induced. Tregs are important for controlling potentially autoreactive immune effectors and immunity to foreign organisms and molecules. Their importance in maintaining immune homeostasis and the overall health of an organism is clear. However, Tregs may also be involved in the pathogenesis of malignancies as now compelling evidence shows that tumors induce or recruit CD4(+) Tregs to block immune priming and antitumor effectors. Efforts are underway to develop approaches that specifically inhibit the function of tumor-associated Tregs which could lead to an increased capability of the body's immune system to respond to tumors but without off-target immune-related pathologies (i.e., autoimmune disease). In this review, the biology of human CD4(+) Tregs is discussed along with their involvement in malignancies and emerging strategies to block their function.

Kinetics of tumor-specific T-cell response development after active immunization in patients with HER-2/neu overexpressing cancers.

The ability of a cancer vaccine to elicit a specific measurable T-cell response is increasingly being used to prioritize immunization strategies for therapeutic development. Knowing the optimal time during a vaccine regimen to measure the development of tumor-specific immunity would greatly facilitate the assessment of T-cell responses. The purpose of this study was to overview the kinetics of HER-2/neu-specific T-cell immunity evolution during and after the administration of HER-2/neu peptide-based vaccination in the adjuvant setting. Furthermore, we questioned whether the presence of preexistent HER-2/neu T-cell immunity or the timing of immunity development over the course of active immunization influenced the intensity of the elicited HER-2/neu-specific T-cell immunity. Our findings demonstrate that maximal tumor-specific immune responses may occur toward the end of the vaccination regimen or even after the scheduled vaccines have been completed. Additionally, the presence of tumor antigen-specific immunity prior to vaccination is associated with greater magnitude immune responses.