Ana María Vázquez

An Anti-Idiotype Vaccine Elicits a Specific Response to N -Glycolyl Sialic Acid Residues of Glycoconjugates in Melanoma Patients

We generated the 1E10 γ-type anti-idiotype mAb (Ab2) specific to an Ab1 mAb able to react specifically with N-glycolyl-containing gangliosides and with Ags expressed on human melanoma and breast carcinoma cells. This Ab2 mAb induced an Ab response in animal models sharing immunochemically defined idiotopes with the Ab1. The treatment of tumor-bearing mice with 1E10 mAb induced a strong antitumor activity. A clinical trial was conducted in 20 patients with advanced malignant melanoma. Patients were treated with six intradermal injections of aluminum hydroxide-precipitated 1E10 anti-Id mAb given at 2-wk intervals. Sixteen of the 17 patients who received at least four doses of the anti-Id vaccine develop Ab3 Abs capable of inhibiting Ab2 binding to Ab1 (Ab3Id+). In contrast to the incapacity of 1E10 mAb to generate Ab3 Abs with the same antigenic specificity as the Ab1 mAb in mice, a very specific and strong Ab3 response against N-glycolyl-containing gangliosides was induced in 16 patients (Ab3Ag+). No evidence of serious or unexpected adverse effects has been observed in this clinical trial. 1E10 anti-Id vaccine was safe, well tolerated, and immunologically effective, with most patients being able to generate a specific immune response against 1E10 and Neu-glycolyl-GM3 ganglioside.

A Mouse IgG1 Monoclonal Antibody Specific for N-Glycolyl GM3 Ganglioside Recognized Breast and Melanoma Tumors

14F7 murine monoclonal antibody (MAb) is an IgG1 immunoglobulin that is generated by immunizing Balb/c mice with GM3(NeuGc) ganglioside hydrophobically conjugated with human very-low-density lipoproteins and in the presence of Freunds adjuvants. 14F7 MAb binds specifically to GM3(NeuGc), whereas neither N-glycolyl or N-acetyl gangliosides, nor a sulfated glycolipid, are recognized as assessed by enzyme-linked immunosorbent assay or immunostaining on thin layer chromatograms. Immunohistochemical studies in fresh tumor tissues showed that 14F7 MAb strongly recognized in antigen expressed in human breast and melanoma tumors.

Characterization of the Antibody Response against NeuGcGM3 Ganglioside Elicited in Non-Small Cell Lung Cancer Patients Immunized with an Anti-Idiotype Antibody

1E10 mAb is an anti-Id murine mAb (Ab2 mAb) specific for an Ab1 mAb that reacts with NeuGc-containing gangliosides, sulfatides, and Ags expressed in some human tumors. In preclinical studies, this Ab2 Ab was able to mimic NeuGc-containing gangliosides only in animals lacking expression of these Ags in normal tissues. In this study, we report on the immune responses elicited in 20 non-small cell lung cancer patients treated with 1 mg of aluminum hydroxide-precipitated 1E10 mAb. In the hyperimmune sera from 16 of 20 patients, a strong specific Ab response of both IgM and IgG isotypes against NeuGcGM3 ganglioside was observed. Patient immune sera were able to induce complement-independent cell death of NeuGcGM3-expressing X63 murine myeloma target cells. Significant immunoreactivity to NeuGcGM3 was still detected after the complete abrogation of the reactivity against 1E10 mAb by the adsorption of patient sera with this Ab. We hypothesize that Id−Ag+ Abs could reflect the activation of an autologous idiotypic cascade into the patients. Both Id+Ag+ and Id−Ag+ fractions were separated by affinity chromatography and characterized. Although IgG isotype Abs were found in both fractions, IgM isotype Abs were found only in the Id−Ag+ fraction. Both Id+Ag+ and Id−Ag+ Abs were able to specifically recognize and induce cell death in NeuGcGM3-expressing X63 myeloma target cells. Patients that developed IgG and/or IgM Abs against NeuGcGM3 showed longer median survival times.

Anti-NeuGcGM3 Antibodies, Actively Elicited by Idiotypic Vaccination in Nonsmall Cell Lung Cancer Patients, Induce Tumor Cell Death by an Oncosis-Like Mechanism

1E10 is a murine anti-idiotypic mAb specific for an idiotypic mAb that reacts with NeuGc-containing gangliosides, sulfatides, and Ags expressed in some human tumors. In melanoma, breast, and lung cancer patients, this anti-idiotypic Ab was able to induce a specific Ab response against N-glycolilated gangliosides, attractive targets for cancer immunotherapy as these glycolipids are not naturally expressed in humans. A clinical study with nonsmall cell lung cancer patients showed encouraging clinical benefits. Immunological studies performed in 20 of these patients suggested a correlation between the induction of Abs against NeuGcGM3 and longer survival times. The induced anti-NeuGcGM3 Abs recognized and directly killed tumor cells expressing the Ag, by a mechanism independent of complement activation. In the present work, we show that this cytotoxicity differs from apoptosis because it is temperature independent, no chromatin condensation or caspase 3 induction are detected, and the DNA fragmentation induced has a different pattern than the one characteristic for apoptosis. It is a very quick process and involves cytosqueleton reorganization. The Abs induce cellular swelling and the formation of big membrane lesions that allow the leakage of cytoplasm and the loss of the cell membrane integrity. All of these characteristics resemble a process of oncotic necrosis. To our knowledge, this is the first report of the active induction in cancer patients of NeuGcGM3-specific Abs able to induce complement independent oncotic necrosis to tumor cells. These results contribute to reinforcing the therapeutic potential of anti-idiotypic vaccines and the importance of NeuGcGM3 ganglioside as antitumor target.

Active immunotherapy with 1E10 anti-idiotype vaccine in patients with small cell lung cancer: report of a phase I trial.

1E10 is an anti-idiotype murine monoclonal antibody (Ab2 MAb) specific to an Ab1 MAb which reacts with NeuGc-containing gangliosides, sulfatides and with antigens expressed in some human tumors. Preparations containing this Ab2 were capable to induce a strong anti-metastatic effect in tumor-bearing mice. We conducted a Phase I clinical trial to evaluate the toxicity and humoral immune response elicited by 1E10 vaccine in patients with small cell lung cancer (SCLC). Eligible patients were those who after received chemotherapy and/or radiotherapy had partial or complete response to treatment. Patients received four biweekly injections with 2 mg of aluminum hydroxide-precipitated 1E10 MAb, then other six doses at 28-day intervals, and later the patients who maintained a good performance status were re-immunized. Six patients with limited-stage disease and three with extensive-stage disease were enrolled in the study. Most of the patients who received at least four doses of 1E10 vaccine developed strong specific antibody responses against 1E10 MAb and NeuGc-GM3 ganglioside. Antibodies able to react with lung carcinoma tissue sections were detected in sera from vaccinated patients. A prolonged survival was observed in several patients treated with the anti-idiotype vaccine. No evidence of serious adverse effects was found.

A Randomized, Multicenter, Placebo-Controlled Clinical Trial of Racotumomab-Alum Vaccine as Switch Maintenance Therapy in Advanced Non–Small Cell Lung Cancer Patients

Purpose: Racotumomab-alum is an anti-idiotype vaccine targeting the NeuGcGM3 tumor-associated ganglioside. This clinical trial was conducted to provide a preliminary estimate of efficacy and safety of racotumomab as switch maintenance for patients with advanced non–small cell lung cancer (NSCLC). Experimental design: Patients with stage IIIb/IV NSCLC who have at least stable disease after first-line chemotherapy were randomized 1:1 to racotumomab-alum (5 immunizations every 2 weeks and re-immunizations every 4 weeks) or placebo. Treatment was administered beyond progressive disease, until severe performance status worsening or toxicity. At progression, only five patients per group received further anticancer therapy. The primary endpoint was overall survival (OS). Results: One-hundred and seventy-six patients were randomized to racotumomab-alum (n = 87) and placebo (n = 89). Median OS was 8.23 and 6.80 months, respectively [HR, 0.63; 95% confidence interval (CI), 0.46–0.87; P = 0.004]. Median progression-free survival (PFS) in vaccinated patients was 5.33 versus 3.90 months for placebo (HR, 0.73; 95% CI 0.53–0.99; P = 0.039). The most common adverse events in the racotumomab-alum arm were burning and pain at the injection site, bone pain, and asthenia. A high antibody response of IgM and IgG isotype against the NeuGcGM3 ganglioside was obtained. Hyperimmune sera were able to specifically recognize and kill the NeuGcGM3-expressing L1210 cell line. Patients who developed anti-NeuGcGM3 antibodies capable to bind and kill ≥30% L1210 cells showed longer median survival times. Conclusions: Switch maintenance with racotumomab-alum is an effective and a well-tolerated treatment option for patients with advanced NSCLC. Clin Cancer Res; 20(14); 3660–71. ©2014 AACR.

1E10 anti-idiotype vaccine in non-small cell lung cancer: Experience in stage IIIb/IV patients.

Conventional treatment of non-small cell lung cancer (NSCLC) has apparently reached a plateau of effectiveness in improving the survival of the patients. For that reason the search for new therapeutic strategies in this type of tumor is justified. 1E10 is an anti-idiotype murine monoclonal antibody (Ab2 MAb) specific to P3 Ab1 MAb, which reacts with NeuGc-containing gangliosides, sulfatides and with antigens expressed in some tumors, including those from the lung. We report the treatment with aluminum hydroxide-precipitated 1E10 MAb of 34 stage IIIb and 37 stage IV NSCLC patients. These patients were treated with the anti-idiotype vaccine, after received standard chemotherapy and radiotherapy, in a compassionate-use basis study. Patients received five biweekly injections of 1 mg of 1E10/Alum, other 10 doses at 28-day intervals, and later the patients who maintained a good performance status continued to be immunized at this same time interval. No evidence of unexpected or serious adverse effects was reported. The median survival time of the 56 patients who entered the study with partial response or disease stabilization and with a PS 1 after the first line of chemo/radiotherapy, was 11.50 months from starting vaccination. In contrast, the median survival time calculated for patients who started vaccination with progressive disease and/or a PS2 was 6.50 months.

Ganglioside-based vaccines and anti-idiotype antibodies for active immunotherapy against cancer

This review shall present an update in anticancer ganglioside-based immunotherapies, with particular emphasis on molecular vaccines and anti-idiotype mAbs produced by the Center of Molecular Immunology (Havana, Cuba). The project comprises vaccines of N-acetyl or N-glycolylneuraminic acid GM3 ganglioside incorporated into very small proteoliposomes and anti-idiotype antibodies to glycolylated gangliosides. Development of these vaccine preparations from preclinical models of melanoma, breast and lung cancer to human investigation is summarized. A brief discussion on the progress and limitations of present-day clinical trials and future prospects is also included.

In Vivo and In Vitro Anti-Tumor Effect of 14F7 Monoclonal Antibody

The 14F7 monoclonal antibody (MAb) is an IgG(1) antibody that reacts specifically with GM3 (NeuGc) and with tissue sections of human tumors. We demonstrated here that this MAb is agglutinin that specifically agglutinated horse erythrocytes. Additionally, the capacity of 14F7 MAb to mediate cytotoxicity against GM3 (NeuGc)-positive murine myeloma cells, in vitro and in vivo, was evaluated. High concentrations of 14F7 MAb were needed to induce complement-dependent cytotoxicity (CDC) and antibody-dependent cell-mediated cytotoxicity (ADCC) against the murine myeloma cells. The most relevant finding was the ability of this MAb to directly kill the target cells without participation of complement. This cytotoxicity was dependent on the temperature and MAb concentration and the number of the target cells. In vivo, the passive treatment with 14F7 MAb produced a strong anti-tumor activity, similar to the anti-tumoral response obtained with standard chemotherapy treatment.

Detection and Characterization of N-Glycolyated Gangliosides in Wilms Tumor by Immunohistochemistry

Gangliosides are glycolipids present on the cell surface. The N-glycolylated ganglioside NeuGc-GM3 has been described in some neoplasms, such as breast carcinoma and melanoma, but is usually not detected in normal human cells. Our aim was to evaluate the presence of NeuGc-GM3 in Wilms tumor by immunohistochemistry. Postchemotherapy tumors were grouped into different histologic subtypes considering the main preserved component. Formalin-fixed, paraffin-embedded tumor samples were cut into 5-μm sections. The monoclonal antibody 14F7, a mouse IgG1 that specifically recognizes NeuGc-GM3, and a peroxidase-labeled polymer conjugated to secondary antibodies were used. Sections from breast carcinoma were employed as positive controls. Presence of NeuGc-GM3 was evident in 22 of 25 (88%) cases. The staining was stronger in the epithelial component, with a membrane pattern and cytoplasmic diffusion. The stromal component expressed cytoplasmic NeuGc-GM3 in cells with rhabdomyoblastic differentiation. Tubules of adjacent renal tissue were also positive, but no expression of NeuGc-GM3 was detected in nontumoral fetal kidney. Until now, the expression of N-glycolylated gangliosides in pediatric solid tumors has not been investigated. The present study evidenced the expression of NeuGc-GM3 in a high proportion of Wilms tumors, suggesting its potential utility as a specific target of immunotherapy.