Personalized immunotherapy for the treatment of non-Hodgkin's lymphoma: a promising approach

Clinical and economic aspects of the use of rituximab in non-Hodgkin's lymphoma

Non-Hodgkin's lymphoma (NHL) consists of a group of neoplasias involving mainly B cells and represents 90% of all lymphomas. The current available therapy is based on chemotherapy associated with the monoclonal antibody rituximab (Mab Thera(r)), which targets the CD20 protein, present in over 80% of NHL mature B cells. Recent clinical reports show a preference for combining the benefits of immunotherapy and adjuvant chemotherapy, thus generating safe and effective alternative treatments. The current review aimed at evaluating various aspects related to the use of rituximab for NHL, highlighting the possible inhibitory mechanisms of cell proliferation, the achieved clinical results, and the expected clinical and economic outcomes of treatments. The results from clinical tests indicate the need for a better understanding of the critical mechanisms of action of this antibody, which may maximize its therapeutic efficacy. This therapy not only represents a viable option to treat most types of NHLs, especially when associated with conventional chemotherapy, but also offers cost-utility and cost-effectiveness advantages.

Conjugation of lymphoma idiotype to CD40 antibody enhances lymphoma vaccine immunogenicity and antitumor effects in mice

Personalized immunotherapy of lymphoma based on tumor idiotype (Id) has shown anti-idiotype humoral immune responses in 40%-50% and cellular immune responses in 50%-75% of follicular lymphoma patients, indicating that this therapy can be clinically successful. We have developed a novel vaccine against lymphoma consisting of an anti-CD40 Ab (ADX40) chemically conjugated to the tumor idiotype A20 and tested it in a murine lymphoma model. BALB/c mice were immunized with 2 doses of immunogen alone or in conjunction with additional adjuvants before tumor challenge. ADX40-Id vaccination resulted in significantly retarded tumor growth and reduced mouse morbidity. Moreover, similar mouse survival was obtained with 2 injections of ADX40-Id as with 8 injections using the standard therapy of keyhole limpet hemocyanin Id + GM-CSF. Co-administration of ADX40-Id with 3-O-deacyl-4'-monophosphoryl lipid A further significantly enhanced vaccine efficacy, resulting in an increased overall survival. Anti-Id-specific Abs were detected at elevated levels after ADX40-Id immunization; however, in vivo depletion of CD4 and/or CD8 T cells before challenge showed that CD8 effector T cells were the major mediators of tumor protection. The results of the present study show that the ADX40-Id conjugate vaccine is a potential candidate as a stand-alone vaccine or in combination with currently licensed adjuvants for lymphoma immunotherapy.

Economic impact of disease progression in follicular non-Hodgkin lymphoma

Using a retrospective claims database, we estimated the economic costs of progression among patients with follicular non-Hodgkin lymphoma (f-NHL) treated in an outpatient community-based setting. Patients with f-NHL who received care between 1 July 2006 and 31 December 2009 were categorized into two cohorts based on whether they experienced progressive disease (PD) or not. Costs per patient per month (PPPM) were compared between patients with PD versus non-PD. Follow-up time was censored at the last entry for disease status or 6 months after the date of remission/stable disease or progression. Of the 1002 patients with f-NHL identified, 268 progressed and 734 did not. The mean overall costs PPPM over the 6-month follow-up period were significantly higher for patients with PD versus non-PD ($3527 vs. $860; difference = $2667; p < 0.001). This cost difference persisted within all resource categories evaluated. Results of this study indicate that therapies which delay progression for patients with f-NHL may result in potential cost savings.

Human granulocyte-macrophage colony-stimulating factor DNA cationic-lipid complexed autologous tumour cell vaccination in the treatment of canine B-cell multicentric lymphoma

This study describes the development of an human granulocyte-macrophage colony-stimulating factor DNA cationic-lipid complexed autologous tumour cell vaccine (hGM-CSF CLDC ATCV) and its implementation, following a chemotherapy treatment protocol, in a randomized, placebo-controlled, double-blinded clinical trial in pet dogs with naturally occurring lymphoma. We hypothesized that the use of this vaccine would result in an antitumour immune response leading to improved first remission duration and overall survival in dogs with B-cell lymphoma when compared with chemotherapy alone. Immune stimulation generated by hGM-CSF CLDC ATCV was assessed by means of surrogate in vivo analysis (delayed-type hypersensitivity [DTH]) as well as an ex vivo cellular assay (lymphocyte proliferation assay). The vaccine approach considered in the current report did not result in clinically improved outcomes. A small measure of immunomodulation was documented by DTH and several modifications to the approach are suggested. This report illustrates the feasibility of clinical trials with vaccine strategies using companion animals with non-Hodgkin's lymphoma.

Synergistic effect of dendritic cell vaccination and anti-CD20 antibody treatment in the therapy of murine lymphoma

Indolent B-cell lymphomas are characterized by repeated remissions and relapses with most patients eventually dying of the disease. Although combination treatments with chemotherapy and the anti-CD20 antibody rituximab improved duration of remissions and overall survival, the disease is essentially incurable. Thus, novel therapeutic approaches are needed. One such approach is active immunization with dendritic cells (DCs). Given that rituximab depletes patients of normal B cells, optimal vaccination strategies for rituximab-treated patients require induction of effector T cells. We have previously demonstrated in a murine model that idiotype (Id)-keyhole limpet hemocyanin-pulsed DCs induced Id-reactive CD8 T cells and protection against tumor challenge in the absence of anti-Id antibodies. On the basis of these results, we investigated vaccination in a therapeutic model, in which mice carrying advanced tumors of the highly aggressive 38C-13 lymphoma were treated with chemotherapy and anti-CD20 antibodies combined with a DC-based vaccine. As a rule, cytoreduction by cyclophosphamide was required in each regimen of combination treatment, and vaccination with tumor cell-loaded DCs was more effective than vaccination with Id-keyhole limpet hemocyanin-loaded DCs. We demonstrated that under conditions of large primary tumors that had already spread to lymph nodes, when anti-CD20 antibody treatment showed minimal effect and DC vaccination had no effect, synergism between anti-CD20 antibodies and DC vaccines resulted in significant long-term survival that did not involve active antitumor antibody production. Combination treatments including tumor cell-loaded DC vaccines may therefore provide a strategy for enhancing the potency of therapy in rituximab-treated patients.

Dendritic cell-based therapeutic vaccination against myeloma: vaccine formulation determines efficacy against light chain myeloma

Multiple myeloma is an incurable plasma cell malignancy. Immunotherapy in myeloma patients had limited success to date. We have previously demonstrated that dendritic cells (DCs) pulsed with autologous Ig Id induced Id-reactive CD8(+) T cells and protection against a myeloma tumor challenge. In this work, we studied the therapeutic efficacy of chemotherapy combined with different formulations of DC-based vaccines in mice bearing large plasma cell tumors. The comparative study demonstrated that s.c. injection of DCs loaded with Id coupled to keyhole limpet hemocyanin, s.c. injection of DCs loaded with irradiated tumor cells, and intratumoral injection of naive DCs were similarly effective in mediating tumor regression and long-term survival. However, whereas the Id-keyhole limpet hemocyanin-DC vaccine was inefficient against myeloma cells that lost expression of the Ig H chain, intratumoral injection of naive DCs and s.c. injection of DCs loaded with irradiated tumor cells were highly effective against cells producing L chains only. This may be of particular importance for patients with L chain myeloma. Given that T cells respond primarily to peptides derived from H chain CDRs, attempts to treat L chain disease with myeloma protein-pulsed DCs may be futile. Vaccination with tumor cell-loaded DCs may, however, induce an effective antitumor response.

Future of idiotypic vaccination for B-cell lymphoma

During the last three decades, idiotypic vaccination has cleared all the hurdles between preclinical studies and randomized clinical trials, assuming the forerunner role among human therapeutic cancer vaccines. However, over the last few months, the very same Phase III clinical trials that were supposed to consecrate idiotype vaccines as the first such products to reach the market have, one after another, begun failing to achieve their main end points. While their negative outcome had been predicted long ago, it must be underlined that most clinical studies on idiotypic vaccination have shown a substantial correlation between induction of an idiotype-specific immune response and improvement of clinical outcome. Failures of late-stage clinical trials were due to severe pitfalls in their study design and not necessarily to idiotypic vaccination itself. Therefore, it is desirable that dedicated scientists and clinicians persevere until confirming ultimately the clinical benefit of a broadly and readily available idiotype vaccine.

Economic burden of follicular non-Hodgkin's lymphoma

Follicular non-Hodgkin's lymphoma (FNHL), a slow-growing cancer of the immune system, constitutes about 15-30% of all incident non-Hodgkin's lymphoma in developed countries. Its incidence is rising worldwide. Patients can live many years, but FNHL is considered incurable. We systematically reviewed the English-language MEDLINE-indexed and non-indexed economic literature published in the past 10 years on FNHL, identifying 23 primary economic studies. The economic burden of FNHL is significant, but available data are generally limited to retrospective considerations of hospital-based direct treatment costs, with little information available regarding societal cost of illness. Most direct cost information originates from the US, with one estimate of $US36 000 for the per-patient incremental cost of FNHL care during the first year following diagnosis. The most studied treatment is rituximab, which may offer similar overall costs to fludarabine considering higher resource use with fludarabine complications. Nearly all cost-effectiveness models identified by this review evaluated rituximab for relapsed/refractory FNHL responding to chemotherapy induction. Rituximab is supported as a cost-effective addition to standard chemotherapy by two models in the UK and one in the US, as maintenance therapy instead of stem-cell transplant by one UK model, and as maintenance therapy instead of observation alone by one model each in France, Spain and Canada. The UK National Institute for Health and Clinical Excellence updated guidance on rituximab in February 2008, concluding that it is cost effective when added to induction chemotherapy, and when used as maintenance therapy. No studies of per-patient or national indirect costs of illness were identified, with the only study of indirect costs a Canadian survey documenting lost work productivity. Across all study types identified by our review, the most common focus was on the direct costs of rituximab. As new treatments for FNHL come to market, more real-life cost data are imperative to calculate their relative cost effectiveness.

Idiotype vaccine strategies for improving outcomes in follicular lymphoma

BACKGROUND

Follicular lymphoma (FL) is a common indolent lymphoma associated with a relapsing course. Preclinical models and clinical studies demonstrate that immunizing FL patients against their own tumor idiotype induces humoral and cellular immunity and supresses tumor growth.

METHODS

We review idiotype vaccine strategies that have been tested in FL patients in frontline and relapsed settings to examine the safety and efficacy of this approach.

RESULTS

Several Phase II trials of recombinant or hybridoma-produced vaccines or vaccines combined with other immunotherapy demonstrate cellular and humoral anti-idiotype responses and clinical responses, indicating that idiotype vaccines provide promise for improving FL outcomes.

CONCLUSION

These strategies are now being evaluated in Phase III trials but have yet to demonstrate clear advantages in progression-free survival.

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.

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.

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.

BiovaxID: a personalized therapeutic cancer vaccine for non-Hodgkin's lymphoma

The clonal immunoglobulin molecule, idiotype (ID), expressed on the surface of B-cell malignancies can function as a tumor-specific antigen. BiovaxID is a patient-specific therapeutic cancer vaccine composed of the tumor idiotype conjugated to a carrier protein, keyhole limpet hemocyanin (KLH). In a Phase II clinical trial, administration of ID-KLH vaccine together with granulocyte-macrophage colony-stimulating factor to follicular lymphoma patients in complete remission induced tumor-specific cellular and humoral immunity and molecular remissions, and was associated with prolonged disease-free survival. A randomized, double-blind, Phase III clinical trial is ongoing to definitively determine the clinical benefit of BiovaxID plus granulocyte-macrophage colony-stimulating factor vaccination in patients with follicular lymphoma.

Novel approaches to the immunotherapy of B-cell malignancies: An update

Immunotherapy of cancer includes both active and adoptive, or passive, forms of immunization to target and eradicate malignant B cells in the host. Advances in the understanding of immunology and tumor-cell evasion of the host immune system, coupled with improved technologies to manipulate immune effectors and tumors, have led to a wide array of novel therapies for B-cell malignancies. As a result, investigators have proposed and tested numerous vaccine strategies able to elicit immune responses to tumor antigens. Furthermore, novel approaches to B-cell-targeted antibody therapies hold promise in advancing this line of treatment, and efficient gene transfer technologies have enabled investigators to manipulate immune effector cells to enhance antitumor activity. Significantly, an increasing number of these novel immune-based therapies are being applied to the clinical setting. Whether findings from these clinical trials, in combination with further preclinical studies, will ultimately translate into improved survival of patients with B-cell malignancies remains to be seen.