qs-21 and Breast-Neoplasms

To determine the clinical toxicities and antibody response against sTn and tumor cells expressing sTn following immunization of high-risk breast cancer patients with clustered sTn-KLH [sTn(c)-KLH] conjugate plus QS-21.. Twenty-seven patients with no evidence of disease and with a history of either stage IV no evidence of disease, rising tumor markers, stage II (>or=4 positive axillary nodes), or stage III disease received a total of five injections each during weeks 1, 2, 3, 7, and 19. Immunizations consisted of sTn(c)-KLH conjugate containing 30, 10, 3, or 1 microg sTn(c) plus 100 microg QS-21. Induction of IgM and IgG antibodies against synthetic sTn(c) and natural sTn on ovine submaxillary mucin were measured before and after therapy. Fluorescence-activated cell sorting analyses assessed reactivity of antibodies to LSC and MCF-7 tumor cells.. The most common toxicities were transient local skin reactions at the injection site and mild flu-like symptoms. All patients developed significant IgM and IgG antibody titers against sTn(c). Antibody titers against ovine submaxillary mucin were usually of lower titers. IgM reactivity with LSC tumor cells was observed in 21 patients and with MCF-7 cells in 13 patients. There was minimal IgG reactivity with LSC cells.. Immunization with sTn(c)-KLH conjugate plus QS-21 is well tolerated and immunogenic in high-risk breast cancer patients. Future trials will incorporate sTn(c) as a component of a multiple antigen vaccine.

Topics: Adjuvants, Immunologic; Adult; Antibodies; Breast Neoplasms; Cancer Vaccines; Female; Humans; Immunization; Immunoglobulin M; Male; Middle Aged; Risk; Saponins

Conjugation of antigens to a carrier protein like keyhole limpet hemocyanin (KLH) has proven effective in clinical trials for inducing antibodies against selected tumor antigens. The impact of this approach on T-cell immunity has not been previously tested. We utilized peripheral blood mononuclear cells (PBMC) obtained at leukapheresis from 6 breast cancer patients vaccinated 4 times each with a 106-amino acid-long MUC1 peptide conjugated with KLH plus immune adjuvant QS-21. Proliferation after 6 days of in vitro culture and an interferon gamma ELISPOT assay with and without 6 days of in vitro sensitization with the immunizing antigen were used. Parallel experiments employed the use of the cytokine IL2. Our results indicate that despite a high response to KLH in all patients with precursor frequencies as high as 1/120 peripheral blood lymphocytes and augmentation of proliferation in excess of 200-fold after vaccination, the T-cell response against MUC1 peptide was minimal and inconsistent. The strength and consistency of the vaccine-induced T-cell response against KLH in these patients excludes general immune incompetence and assay insensitivity or inconsistency as explanations for the weak and inconsistent response against MUC1. We conclude that for any report of augmented T-cell responses against MUC1 to be convincing, one or more postimmunization blood samples will be needed to demonstrate augmented MUC1-specific immunity consistently on multiple occasions. Assuming this criteria, convincing induction of T-cell immunity against MUC1 by vaccination has yet to be described.

Topics: Adjuvants, Immunologic; Breast Neoplasms; Cancer Vaccines; Cell Division; Epitopes; Female; Hemocyanins; Humans; Immunity, Cellular; Immunoconjugates; Immunotherapy, Active; Leukocytes, Mononuclear; Lymphocyte Activation; Mucin-1; Peptide Fragments; Saponins; T-Lymphocytes

Human epidermal growth factor receptor 2 (HER2) is overexpressed in a subset of cancers including 25% of breast cancers. Since combination therapy consisting of multiple therapeutic approaches is considered a promising regimen, we examined combination treatment modalities in a xenograft model in Balb/c mice injected with 4T1-HER2 cells. We used HER2/neu-loaded bone marrow-derived dendritic cells (BM-DC's) along with anti-PD-L1 monoclonal antibody in a new combination immunotherapy model.. The combination was composed of an active immunotherapy (i.e. BM-DC-based vaccine) designed to boost the immune response against target antigen and was augmented by using anti-PD-L1 mAb to prevent immune evasion by the xenografted tumors. The vaccine combination was further supported using a QS-21 saponin adjuvant and the immune response was evaluated.. Mice treated with HER2/neu-loaded BM-DCs, combined with QS-21 and anti-PD-L1 mAb had significantly decreased tumor sizes and their splenocytes had enhanced cytotoxic activity, based on the lactate dehydrogenase (LDH) assay, compared to vaccine and adjuvant groups alone. The same vaccination group demonstrated a remarkable increase in IFN-γ secreting CD8+ T-cells analyzed by flow cytometry. ELISA data also revealed a significant increase in the serum anti-HER2 IgG1 response; in addition, there was significant splenocyte proliferation upon stimulation with antigen compared to vaccine and adjuvant groups. Consistently, a significant infiltration of CD4+, CD8+ immune cells in and around the tumors was observed.. Our data suggest that the BM-DC + HER2/neu + QS-21 + anti-PD-L1 vaccine combination paradigm synergistically generates anti-tumor activity and immune responses against HER2 overexpressing breast cancer in mice.

Topics: Adjuvants, Immunologic; Animals; Antineoplastic Agents, Immunological; Breast Neoplasms; Cancer Vaccines; Cell Line, Tumor; Combined Modality Therapy; Dendritic Cells; Female; Humans; Immunotherapy, Active; Male; Mice; Mice, Inbred BALB C; Peptide Fragments; Receptor, ErbB-2; Saponins; Treatment Outcome; Xenograft Model Antitumor Assays

Topics: Amino Acid Sequence; BCG Vaccine; Breast Neoplasms; Clinical Trials, Phase I as Topic; Genetic Vectors; Hemocyanins; Humans; Molecular Sequence Data; Mucin-1; Neoplasms; Saponins; Vaccines, Synthetic; Vaccinia