Use of the anti-idiotype antibody vaccine TriAb after autologous stem cell transplantation in patients with metastatic breast cancer

Fetal and Neonatal Illnesses Caused or Influenced by Maternal Transplacental IgG and/or Therapeutic Antibodies Applied During Pregnancy

The human fetus is protected by the mother’s antibodies. At the end of the pregnancy, the concentration of maternal antibodies is higher in the cord blood, than in the maternal circulation. Simultaneously, the immune system of the fetus begins to work and from the second trimester, fetal IgM is produced by the fetal immune system specific to microorganisms and antigens passing the maternal-fetal barrier. The same time the fetal immune system has to cope and develop tolerance and T_REG cells to the maternal microchimeric cells, latent virus-carrier maternal cells and microorganisms transported through the maternal-fetal barrier.

The maternal phenotypic inheritance may hide risks for the newborn, too. Antibody mediated enhancement results in dengue shock syndrome in the first 8 month of age of the baby.

A series of pathologic maternal antibodies may elicit neonatal illnesses upon birth usually recovering during the first months of the life of the offspring. Certain antibodies, however, may impair the fetal or neonatal tissues or organs resulting prolonged recovery or initiating prolonged pathological processes of the children.

The importance of maternal anti-idiotypic antibodies are believed to prime the fetal immune system with epitopes of etiologic agents infected the mother during her whole life before pregnancy and delivery.

The chemotherapeutical and biological substances used for the therapy of the mother will be transcytosed into the fetal body during the last two trimesters of pregnancy. The long series of the therapeutic monoclonal antibodies and conjugates has not been tested systematically yet. The available data are summarised in this chapter.

The innate immunity plays an important role in fetal defence. The concentration of interferon is relative high in the placenta. This is probably one reason, why the therapeutic interferon treatment of the mother does not impair the fetal development.

Posttransplantation vaccination: concepts today and on the horizon

Allogeneic hematopoietic stem cell transplantation (allogeneic HSCT) remains a curative treatment for hematological malignancies resistant to other treatment approaches through the unique GVL effect. However, relapse remains a major cause of treatment failure after allogeneic HSCT for patients with high-risk hematological malignancies. Further improvements in exploiting the GVL effect to prevent relapse in high-risk leukemias while minimizing toxicity have focused on the use of targeted antileukemic immunotherapy. These strategies include methods to boost the GVL effect with leukemia vaccines or the adoptive transfer of leukemia-specific lymphocytes. Vaccines can be classified as those against defined antigens such as minor histocompatibility antigens (mHags) or leukemia-associated antigens (PR1, WT1, and BCR-ABL) and those that have broad "antileukemic" activity such as engineered irradiated leukemia cells or leukemia-derived dendritic cells (DCs). The unique posttransplantation milieu, which is characterized by lymphopenia, regulatory T-cell depletion, and the release of growth factors, provides a unique opportunity for effective antitumor immunotherapy and augmenting specific GVL responses. This review focuses on approaches to enhancimg the GVL response by combining allogeneic HSCT with vaccination.

New T cell epitopes identified from an anti-idiotypic antibody mimicking ovarian cancer associated antigen

Anti-idiotype (Id) antibodies can be used to induce specific cellular immune responses against tumor antigens, but the mechanism of antigenicity is not always clear. We previously reported an anti-Id antibody, 6B11, which mimics human ovarian cancer associated antigen OC166-9. To explore the molecular basis of cellular immune response induced by 6B11, a panel of peptides derived from complementarity determining region (CDR) of 6B11 were synthesized. After a series of immunologic experiments, we found that the light chain CDR3 peptide and heavy chain CDR3 peptide were the MHC class I and class II epitopes of 6B11, respectively. The combination of MHC class I and class II epitopes is more effective than 6B11 in inducing specific cellular immune response against ovarian cancer. Our study provided the structural basis of antigenicity of 6B11. The identification of antigen-specific T cell eptitopes in 6B11 should facilitate the design of epitope-based vaccine against human ovarian cancer.

Anti-idiotype antibodies in cancer treatment

As a cancer immunotherapy tool, idiotypes (Ids) have been used in different ways over the last three decades, depending on the actual human tumor cell target. It all started with passive, monoclonal, anti-Id antibody treatment of B-cell lymphoma, a setting in which results were tantalizing, but logistics unsustainable. It then moved toward the development of anti-Id vaccines for the treatment of the same tumors, a setting in which we have recently provided the first formal proof of principle of clinical benefit associated with the use of a human cancer vaccine. Meanwhile, it also expanded in the direction of exploiting the antigenic mimicry of some Ids with Id-unrelated, tumor-associated antigens for the immunotherapy of a number of solid tumors, a setting in which clinical results are still far from being consolidated. All in all, over the years Id-based immunotherapy has paved the way for a number of seminal therapeutic improvements for cancer patients, including the development of most if not all Id-unrelated monoclonal antibodies that have recently revolutionized the field.

Immunity for tumors and microbes after autotransplantation: if you build it, they will (not) come

Relapses after autologous stem cell transplants for hematopoietic malignancies are frequent and post-transplant infections continue to cause significant post-transplant morbidity and even mortality. The post-transplant period is typically characterized by low lymphocyte counts and impaired immune cell function. Early restoration of immune function may contribute to better disease control and enhance protection from infections. Indeed the attainment of a 'minimal residual disease' status following high-dose therapy makes the early post-transplant period ideal for the introduction of antitumor immunotherapy. Attempts to generate immunity against tumor and microbial antigens after autotransplantation have included vaccinations, T cell infusions (both resting and activated) and combinations of vaccinations and adoptive T cell infusions. One successful strategy for generating robust immune responses against microbial antigens was the combination of pre and post-transplant immunizations along with an early (post-transplant) infusion of in vivo vaccine-primed and ex vivo co-stimulated autologous T cells. Whether this or similar strategies will lead to the generation of effective antitumor immunity is unknown. The lessons gained from efforts to rebuild immune system function in the setting of autotransplantation may also be applicable to the problem of restoring immunity in other immunodeficient groups such as patients with cancer or HIV disease and the elderly.

Using antibodies in tumour immunotherapy

The role of antibodies as therapeutic cancer vaccines includes two distinct approaches, which are summarised in this review, namely anti-idiotypic vaccines and antigen-antibody complex therapies. Bispecific antibodies directed against T cells or antigen-presenting cells are also referenced. The report focuses on theoretical issues, laboratory data on the mechanism of action, examples of humoral and cellular immune induction, and novel therapeutic advances in vaccine development. The biology of antigen processing and recent advances in the field of dendritic cell biology are critical to understanding the potent immune response induction. Future directions include combination therapies to manipulate immune regulatory mechanisms and to enhance clinical effects. Additional applications of antibodies targeting costimulatory or regulatory receptors on antigen-presenting cells and T cells, neutralising immune suppressive cytokines, and depleting T regulatory cells hold promise for future mono- and particularly combination therapies.

Strategies in cancer vaccines development

The recent definition of tumour-specific immunity in cancer patients and the identification of tumour-associated antigens have generated renewed enthusiasm for the application of immune-based therapies for the treatment of malignancies. Recent developments in cancer vaccines have also been based on an improved understanding of the cellular interactions required to induce a specific anti-tumour immune response. Consequently, a number of cancer vaccines have entered clinical trials. Targeting broad-spectrum tumour-associated antigens has emerged as a strategy to lower the risk of tumour escape due to the loss of specific nominal antigen. Amongst the most challenging of tumour-associated antigens to which to target in active specific immunotherapy applications are carbohydrate antigens. As carbohydrates are intrinsically T-cell-independent antigens, more novel approaches are perhaps needed to drive specific-T-cell-dependent immune responses to carbohydrate antigens. In this context peptide mimetics of core structures of tumour-associated carbohydrate antigens might be developed to augment immune responses to these broad-spectrum antigens.

Use of the anti-idiotype breast cancer vaccine 11D10 in conjunction with autologous stem cell transplantation in patients with metastatic breast cancer

The results of cytotoxic therapy, including dose-intensive therapy requiring autologous stem cell transplantation (ASCT), have been disappointing in patients with metastatic breast cancer, as almost all patients eventually experience disease progression. There has been a renewed interest in immunotherapeutic strategies in this disease, including evaluation of several breast cancer vaccines. In the current study, we describe the results of a program in which the anti-idiotype breast cancer vaccine 11D10 (TriAb) was administered before and after ASCT in patients with metastatic breast cancer chemosensitive to previous conventional therapy. The toxicity of this approach was acceptable, and idiotype-specific humoral and T-cell proliferative responses were observed in the majority of patients within a few weeks post-ASCT. The actuarial 3-year overall survival rate was 48% (95% CI, 32%-64%), while the progression-free survival rate was 32% (95% CI, 19%-45%). Multivariate analysis identified achievement of a strong antibody and cellular immune response to the vaccine as the only significant prognostic factors for outcome. The ability to reliably produce robust immune responses after ASCT is encouraging. Further studies are required to determine if the immune response mediates an antitumor benefit in these patients.

European approach to antibody-based immunotherapy of melanoma

In the past two decades, the worldwide steadily rising incidence of melanoma, its dismal prognosis when locally advanced or metastatic, and the absence of clinically effective therapeutic options have prompted studies that generated extensive preclinical knowledge on the biology of melanoma cells and their interaction with the host's immune system. As a consequence, among solid tumors, melanoma represents a "model malignancy" to design and apply in the clinic new bioimmunotherapeutic approaches, that are eventually translated to solid tumors of different histotypes. Despite its waxing and waning appeal as a therapeutic strategy, antibody treatment still represents a promising clinical approach to melanoma. Europe is no exception in the clinical interest for antibodies as therapeutic tools in melanoma patients; European researchers have also focused on preclinical issues that may improve current antibody-based therapeutic approaches on the one hand, while providing novel clinical strategies on the other hand.

Antibody-based vaccines for the treatment of melanoma

Malignant melanoma remains a difficult clinical problem. Chemotherapy is not effective and immunotherapy has long been contemplated as the preferred approach to this disease. Extensive passive and active immunotherapy trials have been conducted. Active vaccination with whole cells or defined antigens, administered with a panoply of techniques to increase immunogenicity, has yielded inconsistent results. The development of antibody-based vaccines has allowed vaccination without the need for tumor tissue material or purified antigens. The idiotype network theory originally proposed by Lindemann and by Jerne provided the basis for the development of anti-idiotype (anti-Id) antibody vaccines, which mimic the internal image of the epitope targeted for immunization. Preclinical and phase I clinical data are available for various malignancies. In melanoma, some of the anti-Id vaccines have targeted gangliosides. One of these vaccines, TriGem, has been successful in generating a robust and specific humoral immunity in melanoma patients. Phase II data suggest this anti-Id vaccine has clinical activity.

Effects on fertility of immunizing mice with anti-idiotypic antibodies to porcine zona pellucida antigen

OBJECTIVE

To evaluate the effects on fertility by immunization with anti-idiotypic antibodies to porcine zona pellucida (PZP) antigen.

METHOD

Anti-idiotypic antibodies (Ab(2)) were produced in New Zealand rabbits immunized with 17D3 monoclonal antibodies (mAbs) (IgG, Ab(1)) to PZP antigen. The antisera were first passed through immuno-affinity chromatography column linked to normal mouse IgG so as to remove the antibody bound to normal mouse IgG The passing elute was then purified by immuno-affinity chromatography using 17D3 mAbs to get the Ab(2). Female BALB/c mice, 5-week-old, were grouped and immunized with the Ab(2), PZP antigen, target antigen of the Ab(1) and normal rabbit IgG, respectively. The treated female mice were mated with male BALB/c mice and sacrificed at gestation day 10. Analyses included ELISA measurement of anti-ZP antibody titer, fetal number determination and evaluation of ovarian histomorphology.

RESULTS

The Ab(2) appeared as a single protein band by SDS-PAGE. Shown by a competitive inhibition ELISA, the Ab(2) specifically bound to the variable region of the 17D3 Ab(1). Compared with controls, the female mice immunized with Ab(2) showed a decreased pregnancy rate and a statistically significant reduction in fetal numbers. Histological examination of ovaries demonstrated that Ab(2) exposure interfered less with follicular development than did exposure to PZP.

CONCLUSION

Immunization of female mice with Ab(2) to PZP mAbs suppresses fertility and fetal numbers with minimal ovarian pathology.

Blood stem cell transplantation for breast cancer: new approaches using pre- peri- post-transplant immunotherapy

Autologous peripheral blood stem cell transplantation (auto-PBSCT) after high dose chemotherapy is usually offered to breast cancer patients carrying a high risk of relapse or having chemosensitive metastatic disease. Whether progression free and overall survival of such patients is improved after auto-PBSCT compared to conventional chemotherapy is a matter of debate. Currently available results of randomised trials could not uniformly prove or disprove auto-PBSCT being advantageous. Yet such studies have not employed any manipulation of the stem cell graft or any post-transplant immunomodulation exploiting the unique immunological environment for tumour eradication which exists only after auto-PBSCT. Preliminary data have discussed the ex vivo and in vivo generation of cytotoxic effector cells employing IL-2 and/or IFN-alpha/gamma in the auto-PBSCT setting. Other cytokines such as IL-12, IL-15 and prolactin have likewise been considered. Several anticancer vaccine protocols after auto-PBSCT are ongoing using monovalent vaccines or anti-idiotypic antibodies. Polyvalent anticancer vaccines, cytokine secreting tumour cells, tumour pulsed or hybridised dendritic cells (DC) enhanced with cytokines are studied. Monoclonal antibodies (mAb) could assist: unlabelled for pretransplant exvivo purging, post-transplant for enhancing antibody-dependent cell mediated cytotoxicity (ADCC) or radioimmunoconjugated as an additive cytotoxic part of the conditioning regimen. Autologous graft versus host induction and allogeneic stem cell transplantation (probably with non-myeloablative conditioning followed by donor lymphocyte infusions) are other approaches. Evaluation of successful combinations, optimal dosages and appropriate timing schedules is the subject of future investigations. Since breast cancer patients belong to countless subgroups, a large number of protocols need to be addressed in order to avoid over treatment and prevent relapse.

Interim analysis of the use of the anti-idiotype breast cancer vaccine 11D10 (TriAb) in conjunction with autologous stem cell transplantation in patients with metastatic breast cancer

The anti-idiotype monoclonal antibody breast cancer vaccine 11D10 (TriAb) was administered before and after autologous stem cell transplantation (ASCT) in 45 patients with metastatic breast cancer whose disease was responsive to conventional chemotherapy. Evidence of a positive anti-anti-idiotype antibody (Ab3) humoral response was noted at a median of 1.76 months post-ASCT (range, before ASCT-6 months) with this strategy. Maximal Ab3 levels and idiotype-specific T-cell proliferative responses were observed at a median of 3 and 4 months, respectively, after ASCT. The achievement of rapid immune responses after ASCT, during a known period of decreased immunoresponsiveness, opens the possibility of an additional antitumor effect at a time when the tumor burden is relatively small. Moreover, in this interim analysis, patients with the most vigorous humoral and cellular immune responses had a significant improvement in progression-free survival. Further follow-up and evaluation of this approach is warranted.