Sathibalan Ponniah

Combined Clinical Trial Results of a HER2/neu (E75) Vaccine for the Prevention of Recurrence in High-Risk Breast Cancer Patients: U.S. Military Cancer Institute Clinical Trials Group Study I-01 and I-02

Purpose: E75 is an immunogenic peptide from the HER2/neu protein, which is overexpressed in many breast cancer patients. We have conducted two overlapping E75 vaccine trials to prevent recurrence in node-positive (NP) and node-negative (NN) breast cancer patients. Experimental Design: E75 (HER2/neu 369-377) + granulocyte macrophage colony-stimulating factor was given intradermally to previously treated, disease-free NP breast cancer patients in a dose escalation safety trial and to NN breast cancer patients in a dose optimization study. Local and systemic toxicity was monitored. Immunologic responses were assessed using in vitro assays and in vivo delayed-type hypersensitivity responses. Clinical recurrences were documented. Results: One hundred and eighty-six patients were enrolled in the two studies (NP, 95; NN, 91). Human leucocyte antigen A2 (HLA-A2) and HLA-A3 patients were vaccinated (n = 101), whereas all others (n = 85) were followed prospectively as controls. Toxicities were minimal, and a dose-dependent immunologic response to the vaccine was shown. Planned primary analysis revealed a recurrence rate of 5.6% in vaccinated patients compared with 14.2% in the controls (P = 0.04) at a median of 20 months follow-up. As vaccine-specific immunity waned over time, the difference in recurrence lost significance at 26 months median follow-up (8.3% versus 14.8%); however, a significant difference in the pattern of recurrence persisted. Conclusions: E75 is safe and effective in raising a dose-dependent HER2/neu immunity in HLA-A2 and HLA-A3 NP and NN breast cancer patients. More importantly, E75 may reduce recurrences in disease-free, conventionally treated, high-risk breast cancer patients. These findings warrant a prospective, randomized phase III trial of the E75 vaccine with periodic booster to prevent breast cancer recurrences.

Clinical trial results of the HER-2/neu (E75) vaccine to prevent breast cancer recurrence in high-risk patients: from US Military Cancer Institute Clinical Trials Group Study I-01 and I-02.

The authors conducted exploratory phase 1‐2 clinical trials vaccinating breast cancer patients with E75, a human leukocyte antigen (HLA) A2/A3–restricted HER‐2/neu (HER2) peptide, and granulocyte‐macrophage colony‐stimulating factor. The vaccine is given as adjuvant therapy to prevent disease recurrence. They previously reported that the vaccine is safe and effective in stimulating expansion of E75‐specific cytotoxic T cells. Here, they report 24‐month landmark analyses of disease‐free survival (DFS).

Final report of the phase I/II clinical trial of the E75 (nelipepimut-S) vaccine with booster inoculations to prevent disease recurrence in high-risk breast cancer patients

BACKGROUND E75 (nelipepimut-S) is a human leukocyte antigen (HLA)-A2/A3-restricted immunogenic peptide derived from the HER2 protein. We have conducted phase I/II clinical trials vaccinating breast cancer patients with nelipepimut-S and granulocyte-macrophage colony-stimulating factor (GM-CSF) in the adjuvant setting to prevent disease recurrence. All patients have completed 60 months follow-up, and here, we report the final analyses. PATIENTS AND METHODS The studies were conducted as dose escalation/schedule optimization trials enrolling node-positive and high-risk node-negative patients with tumors expressing any degree of HER2 (immunohistochemistry 1-3+). HLA-A2/3+ patients were vaccinated; others were followed prospectively as controls. Local and systemic toxicity was monitored. Clinical recurrences were documented, and disease-free survival (DFS) was analyzed by Kaplan-Meier curves; groups were compared using log-rank tests. RESULTS Of 195 enrolled patients, 187 were assessable: 108 (57.8%) in the vaccinated group (VG) and 79 (42.2%) in the control group (CG). The groups were well matched for clinicopathologic characteristics. Toxicities were minimal. Five-year DFS was 89.7% in the VG versus 80.2% in the CG (P = 0.08). Due to trial design, 65% of patients received less than the optimal vaccine dose. Five-year DFS was 94.6% in optimally dosed patients (P = 0.05 versus the CG) and 87.1% in suboptimally dosed patients. A voluntary booster program was initiated, and among the 21 patients that were optimally boosted, there was only one recurrence (DFS = 95.2%). CONCLUSION The E75 vaccine is safe and appears to have clinical efficacy. A phase III trial evaluating the optimal dose and including booster inoculations has been initiated. CLINICAL TRIALS NCT00841399, NCT00584789.BACKGROUND E75 (nelipepimut-S) is a human leukocyte antigen (HLA)-A2/A3-restricted immunogenic peptide derived from the HER2 protein. We have conducted phase I/II clinical trials vaccinating breast cancer patients with nelipepimut-S and granulocyte-macrophage colony-stimulating factor (GM-CSF) in the adjuvant setting to prevent disease recurrence. All patients have completed 60 months follow-up, and here, we report the final analyses. PATIENTS AND METHODS The studies were conducted as dose escalation/schedule optimization trials enrolling node-positive and high-risk node-negative patients with tumors expressing any degree of HER2 (immunohistochemistry 1-3+). HLA-A2/3+ patients were vaccinated; others were followed prospectively as controls. Local and systemic toxicity was monitored. Clinical recurrences were documented, and disease-free survival (DFS) was analyzed by Kaplan-Meier curves; groups were compared using log-rank tests. RESULTS Of 195 enrolled patients, 187 were assessable: 108 (57.8%) in the vaccinated group (VG) and 79 (42.2%) in the control group (CG). The groups were well matched for clinicopathologic characteristics. Toxicities were minimal. Five-year DFS was 89.7% in the VG versus 80.2% in the CG (P = 0.08). Due to trial design, 65% of patients received less than the optimal vaccine dose. Five-year DFS was 94.6% in optimally dosed patients (P = 0.05 versus the CG) and 87.1% in suboptimally dosed patients. A voluntary booster program was initiated, and among the 21 patients that were optimally boosted, there was only one recurrence (DFS = 95.2%). CONCLUSION The E75 vaccine is safe and appears to have clinical efficacy. A phase III trial evaluating the optimal dose and including booster inoculations has been initiated. CLINICAL TRIALS NCT00841399, NCT00584789.

Results of the First Phase I Clinical Trial of the Novel Ii-Key Hybrid Preventive HER-2/neu Peptide (AE37) Vaccine

PURPOSE HER-2/neu is overexpressed in breast cancer and is the source of immunogenic peptides. CD4(+) T-helper peptides for HER-2/neu are being evaluated in vaccine trials. The addition of Ii-Key, a four-amino-acid LRMK modification, increases vaccine potency when compared with unmodified class II epitopes. We present the results of the first human phase I trial of the Ii-Key hybrid HER-2/neu peptide (AE37) vaccine in disease-free, node-negative breast cancer patients. PATIENTS AND METHODS The dose escalation trial included five dose groups, to determine safety and optimal dose of the hybrid peptide (100 microg, 500 microg, 1,000 microg) and granulocyte-macrophage colony-stimulating factor (GM-CSF; range, 0 to 250 microg). In the event of significant local toxicity, GM-CSF (or peptide in absence of GM-CSF) was reduced by 50%. Immunologic response was monitored by delayed-type hypersensitivity and [(3)H]thymidine proliferative assays for both the hybrid AE37 (LRMK-positive HER-2/neu:776-790) and AE36 (unmodified HER-2/neu:776-790). RESULTS All 15 patients completed the trial with no grade 3 to 5 toxicities. Dose reductions occurred in 47% of patients. In the second group (peptide, 500 microg; GM-CSF, 250 microg), all patients required dose reductions, prompting peptide-only inoculations in the third group. The vaccine induced dose-dependent immunologic responses in vitro and in vivo to AE37, as well as AE36. CONCLUSION The hybrid AE37 vaccine seems safe and well tolerated with minimal toxicity if properly dosed. AE37 is capable of eliciting HER-2/neu-specific immune responses, even without the use of an adjuvant. This trial represents the first human experience with the Ii-Key modification, and to our knowledge, AE37 is the first peptide vaccine to show potency in the absence of an immunoadjuvant.

The Impact of HER2/neu Expression Level on Response to the E75 Vaccine: From U.S. Military Cancer Institute Clinical Trials Group Study I-01 and I-02

Purpose: HER2/neu, a source of immunogenic peptides, is expressed in >75% of breast cancer patients. We have conducted clinical trials with the HER2/neu E75 peptide vaccine in breast cancer patients with varying levels of HER2/neu expression. Vaccine response based on HER2/neu expression level was analyzed. Experimental Design: Patients were stratified by HER2/neu expression. Low expressors (n = 100) were defined as HER2/neu immunohistochemistry (IHC) 1+ to 2+ or fluorescence in situ hybridization < 2.0. Overexpressors (n = 51) were defined as IHC 3+ or fluorescence in situ hybridization ≥ 2.0. Additional analyses were done stratifying by IHC status (0-3+). Standard clinocopathlogic factors, immunologic response (in vivo delayed-type hypersensitivity reactions; ex vivo human leukocyte antigen A2:immunoglobulin G dimer assay), and clinical responses (recurrence; mortality) were assessed. Results: Low-expressor (control, 44; vaccinated, 56) versus overexpressor patients (control, 22; vaccinated, 29) were assessed. Low expressors, overexpressors, and most IHC-status vaccinated groups responded immunologically. Vaccinated low-expressor patients had larger maximum immunologic responses compared with overexpressor patients (P = 0.04), and vaccinated IHC 1+ patients had increased long-term immune response (P = 0.08). More importantly, compared with controls, low-expressor patients had a mortality reduction (P = 0.08). The largest decrease in mortality was seen in IHC 1+ patients (P = 0.05). In addition, a subset of overexpressor patients (n = 7) received trastuzumab before vaccination, and this combination seems safe and immunologically beneficial. Conclusions: Most patients with various levels of HER2/neu expression responded immunologically and seemed to benefit from vaccination. The low expressors, specifically IHC 1+ patients, had more robust immunologic responses and may derive the greatest clinical benefit from the E75 vaccine.

Phase I Clinical Trial of a HER-2/neu Peptide (E75) Vaccine for the Prevention of Prostate-Specific Antigen Recurrence in High-Risk Prostate Cancer Patients

Purpose: The E75 peptide is an immunogenic peptide from the HER-2/neu protein that is substantially expressed in prostate cancer. We are conducting a clinical trial of an E75/granulocyte macrophage colony-stimulating factor vaccine to prevent post-prostatectomy prostate-specific antigen (PSA) recurrences in high-risk prostate cancer (HRPC) patients. Experimental Design: Prostate cancer patients at high risk for recurrence were prospectively evaluated and identified by the validated Center for Prostate Disease Research (CPDR)/CaPSURE high-risk equation. From these high-risk equation patients, 27 HER-2/neu-expressing prostate cancer patients were enrolled. HLA-A2+ patients (n = 17) were vaccinated, whereas HLA-A2− patients (n = 10) were followed as clinical controls. Local/systemic toxicities, immunologic responses, and time to recurrence were measured. Results: This vaccine is safe with only minor toxicities observed. Additionally, the vaccine is immunogenic with all patients showing both in vivo and in vitro phenotypic and functional immune responses, although variable. HLA-A2+ patients were found to have larger tumors, higher postoperative Gleason scores, and more high-risk CPDR scores than HLA-A2− patients. Despite these differences, disease-free survival was not different between the vaccinated HLA-A2+ patients and the HLA-A2− controls at a median follow up of 23 months. Three of the four vaccinated patients that recurred had rising PSAs at the initiation of the trial. Ex vivo phenotypic assays were predictive of recurrences and correlated in general with functional assays. Conclusions: The E75 vaccine strategy is safe and effective in eliciting an immune response against the HER-2/neu protein in HRPC patients and may be useful as a preventive strategy against disease recurrence. Vaccination in response to a rising PSA may be too late.

Results of the first phase 1 clinical trial of the HER-2/neu peptide (GP2) vaccine in disease-free breast cancer patients: United States Military Cancer Institute Clinical Trials Group Study I-04

HER‐2/neu, overexpressed in breast cancer, is a source of immunogenic peptides that include GP2 and E75. Phase 2 testing of E75 as an adjuvant vaccine has suggested a clinical benefit. GP2, derived from the transmembrane portion of HER‐2/neu, has differing binding characteristics and may be more immunogenic than E75. Results of the first phase 1 trial of GP2 peptide vaccine are presented.

Evaluation of the HER2/neu-derived peptide GP2 for use in a peptide-based breast cancer vaccine trial†‡

E75 and GP2 are human leukocyte antigen (HLA)‐A2‐restricted immunogenic peptides derived from the HER2/neu protein. In a E75 peptide‐based vaccine trial, preexisting immunity and epitope spreading to GP2 was detected. The purpose of this study was to further investigate GP2 for potential use in vaccination strategies. Importantly, a naturally occurring polymorphism (I → V at position 2, 2VGP2) associated with increased breast cancer risk was addressed.

Optimal dose and schedule of an HER-2/neu (E75) peptide vaccine to prevent breast cancer recurrence: from US Military Cancer Institute Clinical Trials Group Study I-01 and I-02.

E75, a HER‐2/neu‐derived peptide, was administered as a preventive vaccine with granulocyte‐macrophage–colony‐stimulating factor (GM‐CSF) in disease‐free lymph node‐positive (NP) and lymph node‐negative (NN) breast cancer (BCa) patients. The optimal biologic dose (OBD) was determined based on toxicity and immunologic response.

Evaluation of the CD107 cytotoxicity assay for the detection of cytolytic CD8+ cells recognizing HER2/neu vaccine peptides

SummaryThe recently reported FACS-based CD107 assay has been used in human HIV and CMV antigen models as well as in the ex vivo analysis of tumor cytolytic T cells in a melanoma model by a single group. The purpose of our study was to validate this assay and to use it in previously untested viral and tumor antigen models. Specifically, we investigated the use of the novel CD107 cytotoxicity assay in the detection of influenza and HER2/neu tumor-specific cytolytic CD8+ T cells. CD8+ T cells from HLA-A2+ healthy donors were stimulated with autologous dendritic cells pulsed with FluM or the HER2/neu peptides, E75 or GP2. These CD8+ T cells were then tested in cytotoxicity assays at varying effector:target (E:T) ratios against T2 targets. Cytotoxicity was measured by detection of CD107a and b on the surface of CD8+ T cells. An E:T of 1:5 was found to optimize the resulting percentage of CD8+CD107+ T cells. E75- and GP2-stimulated CD8+ T cells were then tested in cytotoxicity assays with MCF-7 (HER2/neu+HLA-A2+) and AU565 (HER2/neu+HLA-A2-) tumor cells. Cytotoxicity was measured by both the CD107 assay and the 51Cr release assay. Results of cytotoxicity were then correlated between these two assays. In representative experiments, the CD107 assay identified average specific increases for E75- and GP2-stimulated cells of 4.26 and 3.57%, respectively. These results correlated favorably with cytotoxicity as measured by the traditional 51Cr assay. These findings confirm preliminary reports of the CD107 assay and suggest its usefulness for monitoring cancer trials.