Recombinant, tumour-derived idiotype vaccination for indolent B cell non-Hodgkin’s lymphomas: a focus on FavId™

Cancer vaccines: the next immunotherapy frontier

After several decades, therapeutic cancer vaccines now show signs of efficacy and potential to help patients resistant to other standard-of-care immunotherapies, but they have yet to realize their full potential and expand the oncologic armamentarium. Here, we classify cancer vaccines by what is known of the included antigens, which tumors express those antigens and where the antigens colocalize with antigen-presenting cells, thus delineating predefined vaccines (shared or personalized) and anonymous vaccines (ex vivo or in situ). To expedite clinical development, we highlight the need for accurate immune monitoring of early trials to acknowledge failures and advance the most promising vaccines.

Multi-Omics Integration-Based Prioritisation of Competing Endogenous RNA Regulation Networks in Small Cell Lung Cancer: Molecular Characteristics and Drug Candidates

Background

The competing endogenous RNA (ceRNA) network-mediated regulatory mechanisms in small cell lung cancer (SCLC) remain largely unknown. This study aimed to integrate multi-omics profiles, including the transcriptome, regulome, genome and pharmacogenome profiles, to elucidate prioritised ceRNA characteristics, pathways and drug candidates in SCLC.

Method

We determined the plasma messenger RNA (mRNA), microRNA (miRNA), long noncoding RNA (lncRNA) and circular RNA (circRNA) expression levels using whole-transcriptome sequencing technology in our SCLC plasma cohort. Significantly expressed plasma mRNAs were then overlapped with the Gene Expression Omnibus (GEO) tissue mRNA data (GSE 40275, SCLC tissue cohort). Next, we applied a multistep multi-omics (transcriptome, regulome, genome and pharmacogenome) integration analysis to first construct the network and then to identify the lncRNA/circRNA-miRNA-mRNA ceRNA characteristics, genomic alterations, pathways and drug candidates in SCLC.

Results

The multi-omics integration-based prioritisation of SCLC ceRNA regulatory networks consisted of downregulated mRNAs (CSF3R/GAA), lncRNAs (AC005005.4-201/DLX6-AS1-201/NEAT1-203) and circRNAs (hsa_HLA-B_1/hsa_VEGFC_8) as well as upregulated miRNAs (hsa-miR-4525/hsa-miR-6747-3p). lncRNAs (lncRNA-AC005005.4-201 and NEAT1-203) and circRNAs (circRNA-hsa_HLA-B_1 and hsa_VEGFC_8) may regulate the inhibited effects of hsa-miR-6747-3p for CSF3R expression in SCLC, while lncRNA-DLX6-AS1-201 or circRNA-hsa_HLA-B_1 may neutralise the negative regulation of hsa-miR-4525 for GAA in SCLC. CSF3R and GAA were present in the genomic alteration, and further identified as targets of FavId and Trastuzumab deruxtecan, respectively. In the SCLC-associated pathway analysis, CSF3R was involved in the autophagy pathways, while GAA was involved in the glucose metabolism pathways.

Conclusions

We identified potential lncRNA/cirRNA-miRNA-mRNA ceRNA regulatory mechanisms, pathways and promising drug candidates in SCLC, providing novel potential diagnostics and therapeutic targets in SCLC.

Maleimide conjugation markedly enhances the immunogenicity of both human and murine idiotype-KLH vaccines

The collection of epitopes present within the variable regions of the tumor-specific clonal immunoglobulin expressed by B cell lymphomas (idiotype, Id) can serve as a target for active immunotherapy. Traditionally, tumor-derived Id protein is chemically conjugated to the immunogenic foreign carrier protein keyhole limpet hemocyanin (KLH) using glutaraldehyde to serve as a therapeutic vaccine. While this approach offered promising results for some patients treated in early clinical trials, glutaraldehyde Id-KLH vaccines have failed to induce immune and clinical responses in many vaccinated subjects. We recently described an alternative conjugation method employing maleimide-sulfhydryl chemistry that significantly increased the therapeutic efficacy of Id-KLH vaccines in three different murine B cell lymphoma models, with protection mediated by either CD8(+) T cells or antibodies. We now define in detail the methods and parameters critical for enhancing the in vivo immunogenicity of human as well as murine Id-KLH conjugate vaccines. Optimal conditions for Id sulfhydryl pre-reduction were determined, and maleimide Id-KLH conjugates maintained stability and potency even after prolonged storage. Field flow fractionation analysis of Id-KLH particle size revealed that maleimide conjugates were far more uniform in size than glutaraldehyde conjugates. Under increasingly stringent conditions, maleimide Id-KLH vaccines maintained superior efficacy over glutaraldehyde Id-KLH in treating established, disseminated murine lymphoma. More importantly, human maleimide Id-KLH conjugates were consistently superior to glutaraldehyde Id-KLH conjugates in inducing Id-specific antibody and T cell responses. The described methods should be easily adaptable to the production of clinical grade vaccines for human trials in B cell malignancies.

Sulfhydryl-based tumor antigen-carrier protein conjugates stimulate superior antitumor immunity against B cell lymphomas

Therapeutic vaccination of B cell lymphoma patients with tumor-specific Ig (idiotype, or Id) chemically coupled to the immunogenic foreign carrier protein keyhole limpet hemocyanin (KLH) using glutaraldehyde has shown promising results in early clinical trials, and phase III trials are underway. However, glutaraldehyde Id-KLH vaccines fail to elicit anti-Id immune and clinical responses in many patients, possibly because glutaraldehyde reacts with lysine, cysteine, tyrosine, and histidine residues, damaging critical immunogenic epitopes. A sulfhydryl-based tumor Ag-carrier protein conjugation system using maleimide chemistry was used to enhance the efficacy of Id-KLH vaccines. Maleimide Id-KLH conjugates eradicated A20 lymphoma from most tumor-bearing mice, whereas glutaraldehyde Id-KLH had little efficacy. Maleimide Id-KLH elicited tumor-specific IgG Abs and T cells, with CD8(+) T cells being the major effectors of antilymphoma immunity. Maleimide Id-KLH vaccines also demonstrated superior efficacy in 38C13 and BCL-1 lymphoma models, where Abs were shown to be critical for protection. Importantly, standard glutaraldehyde Id-KLH conjugation procedures could result in "overconjugation" of the tumor Ag, leading to decreased efficacy, whereas the heterobifunctional maleimide-based conjugation yielded potent vaccine product regardless of conjugation duration. Under lysosomal processing conditions, the Id-carrier protein linkage was cleavable only after maleimide conjugation. Maleimide KLH conjugation was easily performed with human Igs analogous to those used in Id-KLH clinical trials. These data support the evaluation of sulfhydryl-based Id-KLH vaccines in lymphoma clinical trials and possibly the use of tumor Ag-carrier protein vaccines for other cancers.

Enhanced immune stimulation by a therapeutic lymphoma tumor antigen vaccine produced in insect cells involves mannose receptor targeting to antigen presenting cells

Therapeutic vaccination of lymphoma patients with tumor-specific immunoglobulin (idiotype, Id) coupled to the carrier protein keyhole limpet hemocyanin (Id-KLH) is undergoing clinical investigation, and methods to improve the immunogenicity of these and other protein tumor antigen vaccines are being sought. Id proteins can be produced via tumor-myeloma hybridomas or recombinant methods in mammalian, bacteria, or insect cells. We now demonstrate that terminal mannose residues, characteristic of recombinant proteins produced in insect cells, yield Id proteins with significantly enhanced immunostimulatory properties compared to Id proteins derived from mammalian cells. Recombinant baculovirus-infected insect cell-derived Id showed higher binding to and activation of human dendritic cells mediated by mannose receptors. In vivo, insect cell-derived Id elicited higher levels of tumor-specific CD8+ cytotoxic T lymphocyte (CTL) and improved eradication of pre-established murine lymphoma. Insect cell and mammalian Id generated similar levels of tumor-specific antibodies, showing no impairment in antibody responses to native tumor antigen despite the glycoslylation differences in the immunogen. Combining insect cell production and maleimide-based KLH conjugation offered the highest levels of anti-tumor immunity. Our data comparing sources of recombinant Id protein tumor antigens used in therapeutic cancer vaccines demonstrate that insect cell-derived antigens can offer several immunologic advantages over proteins derived from mammalian sources.

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.

Listeriolysin O is an improved protein carrier for lymphoma immunoglobulin idiotype and provides systemic protection against 38C13 lymphoma

Follicular lymphoma (FL) is a disease that responds to current treatment regimens; however, patients in general relapse with increasingly refractory disease. Idiotype-based vaccines are currently under trial for the treatment of FL. These vaccines comprise the patient's BCR idiotype (Id) as the tumor antigen conjugated to the protein carrier Keyhole Limpet Hemocyanin (KLH); however, other protein carriers may enhance the immune response to the lymphoma Id. In this study we investigated whether an alternate carrier, Listeriolysin O (LLO), would amplify the immune response to Id protein and provide better protection against challenge by 38C13 murine lymphoma. The Id-LLO vaccine compared favorably against Id-KLH in tumor-protection studies and both vaccines provided systemic immunity against 38C13 lymphoma. However, the immune response to the two conjugates was different in that Id-LLO induced a more powerful Th1 response characterized by high titer IgG2a anti-Id antibodies after one immunization and the presence of CD4 cells secreting IFN-gamma. In vivo studies demonstrated that immune serum contributed to the anti-lymphoma efficacy seen following Id-LLO immunization. Interestingly, Id-LLO immunized mice, when challenged twice with 38C13 lymphoma provided better protection against challenge by the BCR loss variant 38C13-V2, suggesting that Id-LLO immunized mice have more potential to develop epitope spreading than Id-KLH. In conclusion, Id-LLO compared favorably against Id-KLH in its anti-lymphoma efficacy. Furthermore, Id-LLO induced a more potent humoral and cell-mediated immune response and promoted epitope spreading after lymphoma challenge. Thus, anti-Id vaccines incorporating LLO may be a better therapeutic option for treatment of B-cell lymphoma.

Lessons from randomized phase III studies with active cancer immunotherapies--outcomes from the 2006 meeting of the Cancer Vaccine Consortium (CVC)

After years of effort to develop active cancer immunotherapies, seven candidate products achieved promising results in phase I/II studies that triggered phase III randomized studies. One candidate to date has received an approvable letter from the United States Food and Drug Administration (FDA), defining a clear path to licensure for sipuleucel-T (Provenge, Dendreon) within the next couple of years. The other phase III studies failed to achieve statistical criteria for some or all of the critical endpoints. Yet, there is widespread recognition that using a patient's own immune system to target and destroy cancer cells may offer an effective biological therapy with less toxicity than presently available anti-cancer therapies, and several candidates are still being evaluated in clinical studies. This review summarizes the lessons learned from these case studies, evaluates scientific, study design, and business factors that can affect study outcomes, identifies common challenges faced by sponsors developing these innovative therapies, and provides considerations for future study designs that may increase the likelihood of success.

Therapeutic lymphoma vaccines: importance of T-cell immunity

The unique antigenic determinants, termed idiotype, of the immunoglobulin expressed on a given B-cell malignancy can serve as a tumor-specific antigen for active immunotherapy. Administration of autologous tumor-derived idiotype protein conjugated to a carrier protein, keyhole limpet hemocyanin, together with granulocyte-macrophage colony-stimulating factor to follicular lymphoma patients in complete clinical remission was associated with induction of tumor-specific cellular and humoral immunity, molecular remissions, and prolonged disease-free survival. Idiotype vaccination in patients with mantle cell lymphoma following rituximab-containing chemotherapy induced tumor-specific T-cell immunity in the absence of B cells, suggesting that vaccines may be used in combination with rituximab. Three double-blind, randomized, Phase III idiotype vaccine trials are currently ongoing to definitively determine the clinical benefit of idiotype-keyhole limpet hemocyanin plus granulocyte-macrophage colony-stimulating factor vaccination in patients with lymphoma. Results from early clinical trials with idiotype vaccines suggested that both humoral and cellular immune responses may be independently associated with tumor regression and improved progression-free survival. With the increased use of rituximab for the treatment of follicular lymphoma and other B-cell non-Hodgkin's lymphomas, further improvement in the potency of the vaccines would require strategies to enhance T-cell responses, as rituximab depletes normal B cells and impairs the generation of antibody responses.

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.

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.

A novel proteoliposomal vaccine elicits potent antitumor immunity in mice

Therapeutic vaccination against idiotype is a promising strategy for immunotherapy of B-cell malignancies. Its feasibility, however, is limited by the requirement for a patient-specific product. Here we describe a novel vaccine formulation prepared by simply extracting cell-membrane proteins from lymphoma cells and incorporating them together with IL-2 into proteoliposomes. The vaccine was produced in 24 hours, compared with more labor-intensive and time-consuming hybridoma or recombinant DNA methods. The vaccine elicited T-cell immunity in vivo, as demonstrated by secretion of type 1 cytokines. It protected against tumor challenge at doses of tumor antigen 50 to 100 times lower than that previously observed using either liposomes formulated with IL-2 and secreted lymphoma immunoglobulin or a prototype vaccine consisting of lymphoma immunoglobulin conjugated to keyhole limpet hemocyanin. The increased potency justifies testing similar patient-specific human vaccines prepared using extracts from primary tumor samples.

A novel proteoliposomal vaccine induces antitumor immunity against follicular lymphoma

Clinical studies suggest that treatment with vaccines comprised of idiotype protein may be associated with improved clinical outcome in follicular lymphoma patients. The time-consuming process required to generate patient-specific vaccines is a major limitation, however. Here we report results of a pilot clinical trial with a novel autologous, tumor-derived proteoliposome vaccine formulation that could be rapidly produced within a single day. Vaccination was safe, induced autologous tumor-specific type 1 cytokine responses in 5 out of 10 follicular lymphoma patients, and was associated with induction of a sustained complete response in one patient. Other patients had large tumor burdens and progressed after a median duration of 8 months. These results suggest that further testing of this vaccine formulation, particularly in the setting of minimal disease, is warranted. Furthermore, the proteoliposome formulation may provide a model for vaccine development for other human cancers, for which tumor-associated antigens need not be defined.

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.

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.

Serial cytogenetic alterations resulting in transformation of a low-grade follicular lymphoma to Burkitt lymphoma

Follicular lymphoma (FL) is the most common indolent or low-grade non-Hodgkin lymphoma (NHL). Histologic transformation to high-grade lymphoma, generally to diffuse large B-cell lymphoma, occurs in 25-35% of cases. Although t(14;18), the cytogenetic hallmark of FL, has been found in approximately 85% of these cases, multiple secondary cytogenetic and molecular genetic changes underlie the transformation process. We report the case of a 58-year-old patient who presented with stage IVA, grade 2 FL that subsequently transformed to Burkitt lymphoma. Multiple chromosomal aberrations, including three novel translocations, were observed related to this transformation. Inversion (1)(p36.3q12) and t(3;14;18)(p23;q32;q21) occurred prior to transformation and may have contributed to the transformation process. A t(1;11)(q25;q13) was acquired simultaneously with t(8;22) and, in conjunction with other chromosomal abnormalities, coincided with an extremely aggressive clinical course. The frequent breakage of 1q observed in this case suggests that the region harbors important genomic signals for the transformation of FL.

Humoral immune response and immunoglobulin G Fc receptor genotype are associated with better clinical outcome following idiotype vaccination in follicular lymphoma patients regardless of their response to induction chemotherapy

We have reported that anti-idiotype antibody response and FcgammaRIIIa 158 valine/valine (V/V) genotype both correlate with better outcome in a group of 136 follicular lymphoma patients receiving idiotype vaccination after induction chemotherapy. Here, we examined whether this correlation is related in any way to the chemotherapy response. In patients with complete response (CR), the 5-year progression-free survival (PFS) was 69% for patients with antibody response and/or V/V genotype, while the PFS was only 40% for patients with neither; the median time to progression (TTP) was 10.47 versus 3.46 years (P=.012). In patients with partial response (PR), the 5-year PFS was 57% for patients with antibody response and/or V/V genotype, and 17% for patients with neither; the median TTP was not reached versus 1.31 years (P=.001). This study further confirms the strong association of clinical outcome with antibody response and with the functionally more active form of the Fc receptor in patients receiving idiotype vaccination regardless of their response to induction chemotherapy.

B cell reconstitution after rituximab treatment of lymphoma recapitulates B cell ontogeny

The long-term immunologic effects of B cell depletion with rituximab and the characteristics of the reconstituting B cell pool in lymphoma patients are not well defined, despite the widespread usage of this therapy. Here we report that during the B cell reconstitution phase a majority of the peripheral blood B cells have an immature transitional phenotype (47.8%+/-25.2% vs. 4.4%+/-2.4% for normal controls, p<0.0001), similar to what has been described during the original ontogeny of the immune system and following bone marrow transplantation. Moreover, the recovery of the CD27+ memory B cell pool was delayed compared to normal B cell ontogeny, remaining below normal controls at 1 year post-rituximab (4.4%+/-3% vs. 31%+/-7%, p<0.0001). Expansion of functionally immature B cells and decreased memory B cells may contribute to an immunodeficient state in patients recovering from rituximab mediated B cell depletion, particularly with repeated treatment.

Current controversies in follicular lymphoma

Follicular lymphoma (FL) is characterized by its responsiveness to initial therapy, a pattern of repeated relapses, and a tendency for histologic progression to a process resembling diffuse, large B-cell lymphoma. Treatment decisions are complicated by the many effective options now available including combinations of conventional chemotherapy and monoclonal antibody, radioimmunotherapy, new targeted agents, and autologous and allogeneic stem cell transplantation. For selected patients, "watch and wait" or involved field irradiation may still be the most appropriate strategy. When therapy is required, a combination of rituximab and conventional chemotherapy results in improved outcomes compared to chemotherapy alone. Radioimmunotherapy alone or in combination with chemotherapy is an attractive strategy for patients with relapsed disease and may prove to be appropriate first line therapy. The role of stem cell transplant in FL requires further investigation. Novel agents with varied mechanisms of action continue to be developed. Enrollment of patients into clinical trials designed to address the many unanswered questions in FL is essential to improving clinical outcomes.

Phase II trial of idiotype vaccination in previously treated patients with indolent non-Hodgkin's lymphoma resulting in durable clinical responses

PURPOSE

To evaluate idiotype (Id) vaccination as a single agent in previously treated patients with indolent non-Hodgkin's lymphoma.

PATIENTS AND METHODS

Patients underwent biopsy for determination of their lymphoma-specific Id sequence. Recombinant Id protein was manufactured and covalently linked with keyhole limpet hemocyanin (KLH) to generate Id/KLH. Patients received Id/KLH 1 mg on day 1 subcutaneously, with granulocyte-macrophage colony-stimulating factor 250 mug on days 1 to 4, monthly for 6 months. Booster injections were administered until progression. Both clinical and immune responses were evaluated.

RESULTS

Thirty-two previously treated patients received at least one injection of Id/KLH, and 31 were assessed for efficacy. Responses were observed in four patients (one complete response and three partial responses). Median time to onset of response was 5.9 months (range, 2.3 to 14.1 months). Median duration of response has not been reached but should be at least 19.4 months (range, 10.4 to 27.2+ months). Median time to progression is 13.5 months. The most common adverse events were mild to moderate injection site reactions. Six (67%) of nine patients tested demonstrated a cellular immune response, and four (20%) of 20 patients demonstrated an antibody response against their Id.

CONCLUSION

This trial demonstrates that Id/KLH alone can induce tumor regression and durable objective responses. Further study of Id/KLH is recommended in other settings where efficacy may be further enhanced as in first-line therapy or after cytoreductive therapy.

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

The efficacy of immunotherapeutic strategies for the treatment of lymphoid malignancies has been demonstrated in recent years. In patients with B-cell lymphomas, particularly indolent lymphoma, the use of passive immunotherapy, such as the anti-CD20 monoclonal antibody rituximab, has made an impressive impact on patient outcome. Personalized immunotherapy, a method that triggers the immune system to mount a response against tumor cells, has shown promising results in early clinical trials in hematologic malignancies. This therapeutic modality appears safe, with the most common adverse events being transient, local reactions at the site of injection. Furthermore, personalized immunotherapy has the potential to generate immunologic memory, which could provide prolonged remission. Currently, 3 large phase III studies are evaluating the efficacy and safety of personalized immunotherapy in patients with follicular lymphoma. It is hoped that the results of these studies will lead to the incorporation of this promising approach into the standard treatment of patients with lymphoma.