Clinical benefit associated with idiotypic vaccination in patients with follicular lymphoma

Developing idiotype vaccines for lymphoma: from preclinical studies to phase III clinical trials

Therapeutic vaccines for B-cell non-Hodgkin lymphoma (NHL) using the clonal tumour immunoglobulin idiotype (Id) have been under development for more than three decades. A major obstacle for rapid progress in the field has been that the Id vaccine is patient-specific and required the generation of a custom-made product. The manufacturing issues were recently overcome by advances in hybridoma and recombinant DNA technology which facilitated the completion of several phase I and II clinical trials. The strong immunogenicity and apparent clinical benefit observed on the early phase studies led to the initiation of three randomized phase III clinical trials that are also nearing completion. This review will focus on the development of Id vaccines before and after the introduction of rituximab for the treatment of B-cell NHL and also discuss potential strategies to enhance the efficacy of active immunotherapy in the future.

Idiotype vaccination in patients with myeloma reduced circulating myeloma cells (CMC)

BACKGROUND

Circulating myeloma cells (CMC), exhibiting the same immunoglobulin heavy-chain gene rearrangements as the plasma cells, are part of the myeloma clone. In this study, we evaluated the effect of idiotype (Id) vaccination on CMC.

PATIENTS AND METHODS

Eleven patients were immunized with the autologous Id in combinations with granulocyte-macrophage colony-stimulating factor and interleukin 12, and followed for CMC by quantitative real-time allele-specific PCR. Id-specific T cells were monitored by proliferation assay, enzyme-linked immunospot (interferon-gamma) assay, and quantitative real-time PCR for cytokines. Regulatory T (T(reg)) cells were analyzed by flow cytometry.

RESULTS

CMC were detected in 9 of 11 patients at start of vaccination. In four patients, CMC declined and two had a complete molecular remission. Further two patients had stable levels of CMC during follow-up, while in three patients CMC progressively increased. Six patients had a vaccine-induced Id-specific T-cell response. A significant correlation was observed between reduced/stable levels of CMC and the Id-specific T cells (P < 0.02). The frequency of T(reg) cells was decreased in immune responders, but increased in immune nonresponders (P < 0.05). No significant change in the serum M-protein concentration was, however, observed in any patient.

CONCLUSION

Id vaccination reduced CMC, which correlated with vaccine-induced Id-specific T cells. Further studies are warranted to analyze the clinical significance of CMC and clinical effects of Id vaccination.

BiovaxID idiotype vaccination: active immunotherapy for follicular lymphoma

Although advanced-stage follicular lymphoma (FL) has been considered incurable with standard therapy, novel strategies that utilize immunotherapy provide opportunities for prolonging disease-free survival. While passive immunotherapy with antibodies targeting the CD20 antigen on B cells has been the most widely applied lymphoma immunotherapy, active immunization with vaccines derived from the immunoglobulin idiotype present on the surface of FL provides an opportunity to induce specific humoral and cellular immune responses to the tumor, and have been demonstrated to produce significant benefits in prolonging disease-free survival. Promoting the benefits of all forms of immunotherapy will likely depend upon improving complete remission rates with initial treatment. BiovaxID, a patient-specific idiotype vaccine, has demonstrated durable remissions when administered to FL patients in first complete remission along with keyhole limpet hemocyanin and granulocyte-macrophage colony-stimulating factor, and is now undergoing evaluation in a pivotal Phase III clinical trial.

Long-term effects of idiotype vaccination on the specific T-cell response in peripheral blood and bone marrow of multiple myeloma patients

OBJECTIVES

To elucidate long-term effects of idiotype (Id) vaccination on Id-specific T cells of multiple myeloma (MM) patients and compare Id-specific T-cell responses of peripheral blood with those of bone marrow (BM).

MATERIALS AND METHODS

Id-specific T-cell responses of peripheral blood mononuclear cells (PBMC) were compared with those of BM mononuclear cells (BMMC) in 10 MM patients vaccinated with the Id protein at a median time of 41 months since the last immunization. The PBMC responses at late follow-up were also compared with those during active immunization. The responses were assessed by a proliferation assay, enzyme-linked immunospot (ELISPOT) (gamma-interferon), cytometric bead array (CBA) for secreted cytokines and quantitative real-time polymerase chain reaction (QRT-PCR) for cytokine gene expression.

RESULTS

At the late testing time, an Id-specific response was detected in PBMC of five patients (ELISPOT, CBA, QRT-PCR) and in BMMC of four patients (CBA, QRT-PCR). A response in both compartments was noted only in three patients. The cytokines gene profile was consistent with a predominance of Th(2) cells [interleukin (IL)-4, IL-5, IL-10]. Comparison of the Id-specific responses of PBMC during active immunization with those at the late follow-up showed that the frequency and magnitude of the responses had decreased significantly by time (proliferation/ELISPOT) (P < 0.02) and shifted at the gene level from a Th(1) to a Th(2) profile (P < 0.05).

CONCLUSION

Id-specific T-cells may decline overtime and shift toward a Th(2) response and may be found at a similar frequency of patients in blood and BM.

Immunomodulation against leukemias and lymphomas: a realistic future treatment?

Immunotherapy offers the potential for cure of malignancy without the side effects too commonly seen with conventional chemotherapy. The efficacy of allogenic transplantation and monoclonal antibodies in hematological malignancies illustrate this principle and are now part of routine care. Newer cell based and molecular approaches aimed at stimulating cytotoxic activity against host derived tumor associated antigens are able to 'boost' anti-tumor immunity as judged by immunological assays in vitro. Although clinically meaningful responses were originally less evident, more promising results are now being reported. Our growing understanding of tumor immunology provide rationales for further improvements in the field.

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.

Defining the role of immunotherapy and radioimmunotherapy in the treatment of low-grade lymphoma

PURPOSE OF REVIEW

To critically assess recent advances in the treatment of indolent non-Hodgkin lymphoma with a focus on immunologically based therapies.

RECENT FINDINGS

Modern treatment strategies, including monoclonal antibodies targeting lymphoma-associated antigens, radioimmunotherapy, therapeutic vaccination and allogeneic hematopoietic stem cell transplantation, have the potential to profoundly impact clinical outcomes in indolent lymphoma therapy. The results of randomized phase III trials now indicate that the addition of rituximab to combination chemotherapy prolongs progression-free and overall survival compared to chemotherapy alone. It is anticipated that similar improvements in outcomes will be associated with other immunologic strategies.

SUMMARY

Many questions remain unanswered regarding the optimal treatment approach for patients with indolent lymphoma. Randomized phase III trials addressing the key issues in patient management are ongoing. Continued follow-up of treated patients will be required to assess the character and frequency of long-term toxicities, and to provide insights into the best sequencing of treatments. It is likely that combinations of new treatment strategies will have the greatest impact on long-term clinical outcome. New insights into the underlying biology of the indolent lymphomas are anticipated to help guide therapy for individual patients and to provide new therapeutic targets.

Therapeutic vaccine for lymphoma

The unique antigenic determinants (Idiotype [Id]) of the immunoglobulin expressed on a given B-cell malignancy can serve as a tumor-specific antigen for active immunotherapy. Therapeutic vaccines targeting the tumor-specific idiotype have demonstrated promising results against lymphomas in phase I/II studies and are currently being evaluated in phase III randomized trials. Additional vaccine therapies being developed include those based on DNA, dendritic cells, gene-modified tumor cells. It is hoped that immunotherapeutic agents, used in tandem or in combination, may in the future allow effective treatment of lymphoid malignancies and delay or even replace the need for conventional cytotoxic therapies.

Cancer vaccines in old age

The incidence of cancer has increased over the last decade, mainly due to an increase in the elderly population. Vaccine therapy for cancer is less toxic than chemotherapy or radiation and could be, therefore, especially effective in older, more frail cancer patients. However, it has been shown that older individuals do not respond to vaccine therapy as well as younger adults. This has been attributed to T cell unresponsiveness, a phenomenon also observed in cancer patients per se. This review summarizes the current knowledge of T cell unresponsiveness in cancer patients and elderly, the results of cancer vaccination in preclinical models and in clinical trials, and recent data of cancer vaccination at young and old age in preclinical models. Finally, experimental approaches will be proposed how to make cancer vaccines more effective at older age.

Vaccine therapy for B-cell lymphomas: next-generation strategies

Active immunotherapy is a promising approach for the treatment of lymphomas. Immunization with the clonal tumor immunoglobulin, idiotype, expressed on the surface of B-cell malignancies was associated with induction of tumor-specific cellular and humoral immunity, molecular remissions, and prolonged disease-free survival in early clinical trials. Idiotype vaccination was also demonstrated to induce tumor-specific T-cell immunity in the absence of B cells following treatment with rituximab-containing chemotherapy, suggesting that vaccines may be used in combination with rituximab. Three double-blind randomized phase 3 idiotype vaccine trials are currently ongoing to definitively determine the clinical benefit of idiotype vaccination in patients with lymphoma. Novel second-generation lymphoma vaccines are in development to streamline the production of patient-specific cancer vaccines and show encouraging results in preclinical and pilot clinical studies. To enhance the clinical efficacy of active immunotherapy, future clinical trials are likely to use a combination strategy with the lymphoma vaccine to stimulate an antitumor T-cell response and the simultaneous suppression of immune regulatory pathways to augment the induced T-cell response.