Autologous hapten-modified melanoma vaccine as postsurgical adjuvant treatment after resection of nodal metastases

Novel dendritic cell-based vaccination in late stage melanoma

Dendritic cells (DCs) are professional antigen-presenting cells (APCs) that play an important role in stimulating an immune response of both CD4(+) T helper cells and CD8(+) cytotoxic T lymphocytes (CTLs). As such, DCs have been studied extensively in cancer immunotherapy for their capability to induce a specific anti-tumor response when loaded with tumor antigens. However, when the most relevant antigens of a tumor remain to be identified, alternative approaches are required. Formation of a dentritoma, a fused DC and tumor cells hybrid, is one strategy. Although initial studies of these hybrid cells are promising, several limitations interfere with its clinical and commercial application. Here we present early experience in clinical trials and an alternative approach to manufacturing this DC/tumor cell hybrid for use in the treatment of late stage and metastatic melanoma.

Development of a potent melanoma vaccine capable of stimulating CD8(+) T-cells independently of dendritic cells in a mouse model

At present, there are no vaccines approved for the prevention or treatment of malignant melanoma, despite the amount of time and resources that has been invested. In this study, we aimed to develop a self-contained vaccine capable of directly stimulating anticancer CD8(+) T-cell immune responses. To achieve this, three whole-cell melanoma vaccines were developed expressing 4-1BBL or B7.1 T-cell co-stimulatory molecules individually or in combination. The ability of engineered vaccine cell lines to stimulate potent anticancer immune responses in C57BL/6 mice was assessed. Mice vaccinated with cells overexpressing both 4-1BBL and B7.1 (B16-F10-4-1BBL-B7.1-IFNγ/β anticancer vaccine) displayed the greatest increases in CD8(+) T-cell populations (1.9-fold increase versus control within spleens), which were efficiently activated following antigenic stimulation, resulting in a 10.7-fold increase in cancer cell cytotoxicity relative to control. The enhanced immune responses in B16-F10-4-1BBL-B7.1-IFNγ/β-vaccinated mice translated into highly efficient rejection of live tumour burdens and conferred long-term protection against repeated tumour challenges, which were likely due to enhanced effector memory T-cell populations. Similar results were observed when dendritic cell (DC)-deficient LTα(-/-) mice were treated with the B16-F10-4-1BBL-B7.1-IFNγ/β anticancer vaccine, suggesting that the vaccine can directly stimulate CD8(+) T-cell responses in the context of severely reduced DCs. This study shows that the B16-F10-4-1BBL-B7.1-IFNγ/β anticancer vaccine acted as a highly effective antigen-presenting cell and is likely to be able to directly stimulate CD8(+) T-cells, without requiring co-stimulatory signals from either CD4(+) T-cells or DCs, and warrants translation of this technology into the clinical setting.

New concepts of biomarkers and clinical outcomes for therapeutic cancer vaccines in clinical trials

Aim: This study aimed to derive meaningful parameters for immune monitoring during cancer vaccine development by analysis of the literature. Methods: This retrospective study was based on analysis of clinical trials registered at ClinicalTrials.gov and published data available on PubMed. Results: The most common sample evaluated in immune monitoring was peripheral blood. All trials employed ELISA for detecting a humoral immune response; however, cellular immune assays were not used across trials. Most cellular immune assays failed to correlate with clinical outcome, although results of other methods did. Conclusion: Standardization of the cellular immune assays across trials is important for predicting the effects of therapeutic cancer vaccines when considering the reliability and characteristics of the methods. Currently, assays mostly target detection of T-cell function, such as proliferation and cytokine release; however, T-cell phenotype analysis in peripheral blood and/or tumor sites may also be considered in the future.

Hapten-induced contact hypersensitivity, autoimmune reactions, and tumor regression: plausibility of mediating antitumor immunity

Haptens are small molecule irritants that bind to proteins and elicit an immune response. Haptens have been commonly used to study allergic contact dermatitis (ACD) using animal contact hypersensitivity (CHS) models. However, extensive research into contact hypersensitivity has offered a confusing and intriguing mechanism of allergic reactions occurring in the skin. The abilities of haptens to induce such reactions have been frequently utilized to study the mechanisms of inflammatory bowel disease (IBD) to induce autoimmune-like responses such as autoimmune hemolytic anemia and to elicit viral wart and tumor regression. Hapten-induced tumor regression has been studied since the mid-1900s and relies on four major concepts: (1) ex vivo haptenation, (2) in situ haptenation, (3) epifocal hapten application, and (4) antigen-hapten conjugate injection. Each of these approaches elicits unique responses in mice and humans. The present review attempts to provide a critical appraisal of the hapten-mediated tumor treatments and offers insights for future development of the field.

Immunological monitoring of anticancer vaccines in clinical trials

Therapeutic anticancer vaccines operate by eliciting or enhancing an immune response that specifically targets tumor-associated antigens. Although intense efforts have been made for developing clinically useful anticancer vaccines, only a few Phase III clinical trials testing this immunotherapeutic strategy have achieved their primary endpoint. Here, we report the results of a retrospective research aimed at clarifying the design of previously completed Phase II/III clinical trials testing therapeutic anticancer vaccines and at assessing the value of immunological monitoring in this setting. We identified 17 anticancer vaccines that have been investigated in the context of a completed Phase II/III clinical trial. The immune response of patients receiving anticancer vaccination was assessed for only 8 of these products (in 15 distinct studies) in the attempt to identify a correlation with clinical outcome. Of these studies, 13 were supported by a statistical correlation study (Log-rank test), and no less than 12 identified a positive correlation between vaccine-elicited immune responses and disease outcome. Six trials also performed a Cox proportional hazards analysis, invariably demonstrating that vaccine-elicited immune responses have a positive prognostic value. However, despite these positive results in the course of early clinical development, most therapeutic vaccines tested so far failed to provide any clinical benefit to cancer patients in Phase II/III studies. Our research indicates that evaluating the immunological profile of patients at enrollment might constitute a key approach often neglected in these studies. Such an immunological monitoring should be based not only on peripheral blood samples but also on bioptic specimens, whenever possible. The evaluation of the immunological profile of cancer patients enrolled in early clinical trials will allow for the identification of individuals who have the highest chances to benefit from anticancer vaccination, thus favoring the rational design of Phase II and Phase III studies. This approach will undoubtedly accelerate the clinical development of therapeutic anticancer vaccines.

Cancer stem cell antigen-based vaccines: the preferred strategy for active specific immunotherapy of metastatic melanoma?

INTRODUCTION

There are now two chemotherapy agents, one tyrosine kinase inhibitor and three immunotherapy products approved for the treatment of metastatic melanoma, but an unmet need persists because these options are toxic and of limited therapeutic benefit. Active specific immunotherapy with therapeutic vaccines could be a useful addition to the therapeutic armamentarium, especially in patients whose tumor burden has been reduced by other treatment modalities.

AREAS COVERED

This article reviews various sources of melanoma antigens, such as peptides, gangliosides, autologous tumor and cancer stem cells including allogeneic and autologous cell lines. The advantages and disadvantages of various antigen sources and allogeneic and autologous approaches are discussed with an emphasis on the theoretical benefits of immunizing against cancer stem cells. The results from published randomized trials testing the benefit of various vaccine approaches are summarized, as well as promising results from three Phase II trials (one randomized) of patient-specific stem cell antigen-based products.

EXPERT OPINION

Immune responses directed toward the unique neoantigens and stem cell antigens expressed on continuously proliferating, self-renewing, autologous tumor cells could potentially overcome the limitations inherent in these other antigen-based approaches, that to date, have yielded disappointing results in randomized trials.

Interleukin 6 mediates production of interleukin 10 in metastatic melanoma

We previously reported that substantial amounts of IL-10, an immunomodulatory cytokine, are produced by cell suspensions of fresh human metastatic melanoma tissues. Production diminished with continuous culturing of cells, which suggests a pivotal interactive role between melanoma cells and the tumor microenvironment. In this study, we found that the culture media obtained from LPS-stimulated peripheral blood mononuclear cells induced IL-10 production by metastatic melanoma cells. Of the multiple cytokines present in the conditioned culture media, IL-6 was identified as the inducer of IL-10 production. A neutralizing antibody against IL-6 completely blocked the conditioned medium-induced IL-10 production. Metastatic melanoma cells that constitutively produce low amount of IL-10 increased IL-10 production in response to recombinant human IL-6 in a dose-dependent fashion. The response to exogenously added IL-6 was less significant in melanoma cells that produced high amounts of IL-6, probably due to pre-existing autocrine stimulation of IL-10 by endogenous IL-6. On the other hand, metastatic melanoma cells that do not constitutively produce IL-10 protein did not respond to exogenous IL-6. In IL-6-responsive melanoma cells, IL-6 increased STAT3 phosphorylation and inhibition of STAT3 signaling using siRNA or inhibitors for JAKs diminished IL-6-induced IL-10 production. In addition, inhibition of MEK and PI3K, but not mTOR, interfered with IL-10 production. Taken together, the data suggest that blocking of these signals leading to IL-10 production is a potential strategy to enhance an anti-melanoma immune response in metastatic melanoma.

Serum CEACAM1 Correlates with Disease Progression and Survival in Malignant Melanoma Patients

The search for melanoma biomarkers is crucial, as the incidence of melanoma continues to rise. We have previously demonstrated that serum CEACAM1 (sCEACAM1) is secreted from melanoma cells and correlates with disease progression in metastatic melanoma patients. Here, we have used a different cohort of melanoma patients with regional or metastatic disease (N = 49), treated with autologous vaccination. By monitoring sCEACAM1 in serum samples obtained prior to and after vaccination, we show that sCEACAM1 correlates with disease state, overall survival, and S100B. The trend of change in sCEACAM1 following vaccination (increase/decrease) inversely correlates with overall survival. DTH skin test is used to evaluate patients' anti-melanoma immune response and to predict response to vaccination. Importantly, sCEACAM1 had a stronger prognostic value than that of DTH, and when sCEACAM1 decreased following treatment, this was the dominant predictor of increased survival. Collectively, our results point out the relevance of sCEACAM1 in monitoring melanoma patients.

Combined treatment of uveal melanoma liver metastases

Uveal melanoma (UM) is the most prevalent intraocular malignant tumor in the Western world. The prognosis of survival in the presence of metastatic disease is 2-7 months, depending on the treatment applied.

This article presents a case of metastatic UM with successful complex treatment of liver metastases.

A 49-year old female, underwent removal of the right eyeball in 1996 due to a histologically confirmed uveal melanoma. After 11 years, CT revealed a mass in the left kidney and multiple metastases in the liver. After left nephrectomy, 6 chemotherapy courses with dacarbazine were performed. The increasing liver metastases were observed. Additional 4 intraarterial (i/a) chemotherapy courses were administered using cisplatin, doxorubicin, fluorouracil, and interferon alfa. After few courses increase in CTC Grade 4 liver transaminases was seen. A partial response was observed, and in December 2008 the patient underwent surgery removing all liver metastases by 7 wedge or atypical resections. All margins were tumor-free. 21 months after liver resections and 14 years since diagnosis, the patient is alive without evidence of disease.

Successful treatment of metastatic uveal melanoma was due to a timely application of a combination of several treatment methods and good prognostic factors of the patient.

Biology of human cutaneous melanoma

A review of the natural behavior of cutaneous melanoma, clinical and pathological factors, prognostic indicators, some basic research and the present and possible futuristic strategies in the management of this disease are presented. While surgery remains to be the most effective therapeutic approach in the management of early primary lesions, there is no standard adjuvant therapy after surgical resection, or for metastatic disease.

Whole tumor cell vaccine with irradiated S180 cells as adjuvant

Whole tumor cell vaccines have been widely studied and remain promising cancer immunotherapies. In the present study, we discovered that vaccination with irradiated mouse sarcoma S180 tumor cells stimulated robust antitumor immunity to autologous tumor cells in both syngenic and allogenic mice. The antitumor activity requires both T and B cells, but not NK cells. When a mouse lung carcinoma (TC-1) whole tumor cell vaccine was combined with the S180 vaccine, the antitumor immunity against live TC-1 tumor cells is significantly enhanced compared to a TC-1 whole cell vaccine alone. This antitumor immunity not only prevents live tumor challenge but also eradicates existing tumor cells. A similar phenomenon was also observed when S180 vaccine was combined with LL2 Lewis lung carcinoma tumor cells. Therefore, S180 vaccine may serve as an adjuvant for other whole tumor cell vaccines.

Translational research in melanoma

Current treatment of malignant melanoma exemplifies not only the need for translational research but also many of the challenges of moving from bench to bedside. Melanoma remains unique among solid tumors in that its treatment primarily is surgical. Radiation is of limited benefit, and chemotherapy has been disappointing in both the adjuvant and metastatic settings. This leaves clinicians with few options for reducing the chance of recurrence after surgery and for treating unresectable disease. With this in mind, there has been a fervent attempt to identify novel approaches to melanoma therapy and translate them into clinical use.

Vaccine therapy for melanoma: current status and future directions

A vaccine is typically defined as any preparation used as a preventive inoculation to confer immunity against a specific disease. Vaccines for infectious diseases are highly effective, acting by inducing antigen-specific immunity that prevents subsequent infection. Unfortunately, the success of vaccines in infectious diseases has not been mirrored in oncology. This failure is the result of several challenges facing cancer vaccines, including the conceptual shift from disease prevention to disease treatment, tumor-induced immunosuppression and other mechanisms of immune escape, the similarity between tumor antigens and self antigens to which the patient is tolerant, unfavorable effector-to-target ratios in patients with established tumors, and financial and regulatory issues. Despite this, cancer remains a promising target for vaccine therapy. Melanoma in particular is known for its inherent immunogenicity on the basis of many anecdotal reports of spontaneous immune-based tumor regression, and thus has been the focus of immunotherapeutic approaches. Rare but significant vaccine-induced clinical regression of melanoma has spurred intensive investigations to augment vaccine efficacy. This review explores the many vaccine strategies that have been clinically tested for the treatment of melanoma and considers future approaches of cancer immunotherapy.

Patient-Specific Vaccines Derived from Autologous Tumor Cell Lines as Active Specific Immunotherapy: Results of Exploratory Phase I/II Trials in Patients with Metastatic Melanoma

Seventy-four (74) patients with metastatic melanoma were treated with patient-specific vaccines derived from autologous tumor cell lines. Cryopreserved irradiated tumor cells were injected weekly for 3 weeks, then monthly for 5 months. At a median follow up >6 years, the median event-free survival (EFS) was 4.5 months, with 13 patients alive and progression free 6-12 years later. Median overall survival (OS) was 20.5 months, with 29% 5-year OS. Tumor response rate was 9% among the 35 patients with evaluable disease who received at least 3 injections. Better survival was observed for patients who had minimal rather than clinically evident metastatic disease at the time vaccine therapy was initiated (5-yr OS 47% vs. 13%; p < 0.0001), received granulocyte-macrophage colony-stimulating factor and/or interferon gamma as an adjuvant (5-yr EFS 26% vs. 0%; p < 0.0001) or received an average of <7 million cells for each of the first 3 injections, compared to those who received 7-11.9 million or >12 million cells per injection (5-yr EFS OS 35% vs. 24%; p = 0.041 and p = 0.034). There was a trend toward better EFS for those who had a positive delayed type hypersensitivity (DTH) reaction to an intradermal injection of 1 million irradiated tumor cells at baseline, or converted to positive after 3 injections, compared to those whose DTH remained negative (5-yr EFS 39% vs. 18%; p = 0.159). This treatment approach is feasible, produces minimal toxicity, and is associated with longterm survival in a significant proportion of patients.

Immunotherapy of melanoma: a critical review of current concepts and future strategies

Advanced melanoma is a devastating disease with a very poor overall prognosis. There are only two agents that are approved by the FDA for use in patients with metastatic melanoma: dacarbazine and IL-2. Both agents have an overall response rate well below 20%, with only rare long-term responders noted. Metastatic melanoma is known to be one of the most resistant cancers to a plethora of treatment modalities, such as single-agent and combination chemotherapy, chemoimmunotherapy and immunotherapy with a host of immune stimulators. Indeed, researchers worldwide have recognized the lack of effective therapies and have refocused their efforts on developing novel and cutting-edge strategies of treatment. This is based on an improved understanding of the complex interactions that occur within the tumor microenvironment, and the central role that the host immune system plays in the surveillance of cancer. This review summarizes the recent results of novel immunotherapeutic regimens and focuses on cutting-edge modalities of treatment that encompass new lines of thinking in the war against cancer and, in particular, melanoma.

Malignant melanoma in the 21st century, part 2: staging, prognosis, and treatment

Critical to the clinical management of a patient with malignant melanoma is an understanding of its natural history. As with most malignant disorders, prognosis is highly dependent on the clinical stage (extent of tumor burden) at the time of diagnosis. The patient's clinical stage at diagnosis dictates selection of therapy. We review the state of the art in melanoma staging, prognosis, and therapy. Substantial progress has been made in this regard during the past 2 decades. This progress is primarily reflected in the development of sentinel lymph node biopsies as a means of reducing the morbidity associated with regional lymph node dissection, increased understanding of the role of neoangiogenesis in the natural history of melanoma and its potential as a treatment target, and emergence of innovative multimodal therapeutic strategies, resulting in significant objective response rates in a disease commonly believed to be drug resistant. Although much work remains to be done to improve the survival of patients with melanoma, clinically meaningful results seem within reach.

The treatment of melanoma with an emphasis on immunotherapeutic strategies

Melanoma continues to be one of the most difficult to treat of all solid tumors. Many new advances have been made in the surgical management of melanoma, including new guidelines for margins of excision, as well as sentinel node biopsy for the diagnosis of lymph node micrometastases. The search continues for an effective adjuvant melanoma treatment that can prevent local and distant recurrences. Melanoma is one of the most immunogenic of all tumors, and several clinical trials testing the immunotherapy of melanoma have been conducted, including trials in interferon, interleukin-2, and melanoma vaccines. Here we discuss many of the recent clinical trials in the surgical management of melanoma, in addition to the advances that have been made in the field of immunotherapy. A new second-generation melanoma vaccine, DC-MelVac (patent # 11221/5), has recently been granted FDA approval for Phase I clinical trials and will be introduced in this review.

Evaluation of Immunotherapy in the Treatment of Melanoma

These data show that the extraordinary potency of the immune system can be harnessed to control or destroy melanoma. The proven impact has been limited for patients who have melanoma, but has been dramatic and lasting in selected groups. Recent improvements in understanding of immunology, including mechanisms regulating immune responses and methods of tumor cell escape, are already yielding improved clinical outcomes and potential avenues for extending benefits to more patients. Thus, although the full potential of this treatment modality has yet to be realized, the vanguard of the "treatment of tomorrow" has clearly arrived.

Therapeutic vaccines for melanoma: current status

Considerable clinical research is focused on improving systemic treatments for melanoma. Unfortunately, the disease is generally resistant to standard chemotherapy, and surgical excision remains the best treatment option whenever possible. However, complete spontaneous regression of melanoma has been observed in some patients, a phenomenon thought to be mediated by the immune system. This has stimulated attempts to manipulate the immune system for therapeutic purposes. Vaccination is a form of active specific immunotherapy, such that the response against the tumor is actively generated by the patient's immune system, and is directed against a particular cellular target or specific membrane antigen. Numerous approaches to vaccination for melanoma have been investigated, and have become more complex as our understanding of anti-tumor immunity has increased. Vaccines have been shown to induce measurable immunologic responses that may be correlated with improved clinical outcomes in patients with melanoma. Large phase III clinical trials using peptide, ganglioside, and whole-cell tumor antigens are ongoing. Although anti-tumor vaccination has shown promising results in patients with melanoma, to date no vaccine has been approved for routine therapy of melanoma. Recently, a phase III trial evaluating the Canvaxin whole-cell vaccine in stage IV melanoma was halted because of a low likelihood of significant benefit. However, a larger phase III trial for patients with stage III disease was continued and results are awaited with interest.

Melanoma treatment update

Except for high-dose interferon as adjuvant therapy in stage III disease, little success has emerged over the last 20 years for metastatic melanoma. Recent advances in melanoma biology suggest that disarming oncogenic mechanisms in melanoma may be an attractive approach to therapy. For instance, sustained expression of Bcl2 has been associated with an increased resistance to apoptosis, and recently, anti-sense-mediated reduction of Bcl2 levels was shown to chemosensitize patients to dacarbazine, dimethyl triazino imidazole carboxomide, or DTIC. Likewise, the identification of activating mutations in the RAS signaling pathway, including the NRAS and BRAF genes, opens up new therapeutic options for RAS and RAF inhibitors. A more thorough understanding of melanoma biology and tumor immunology will undoubtedly yield new promise for patients with advanced disease.

In vivo targeting of vaccinating tumor cells to antigen-presenting cells by a gene therapy method with adenovirus containing the α1,3galactosyltransferase gene

Poor uptake by antigen-presenting cells (APC) is a major reason for low immunogenicity of autologous tumor vaccines. This immunogenicity may be increased by exploiting the natural anti-Gal antibody that is present in humans as approximately 1% of circulating IgG. Anti-Gal binds to alpha-gal epitopes (Galalpha1-3Galbeta1-4GlcNAc-R) on vaccinating tumor cells and opsonizes them for effective uptake by APC. This epitope is synthesized in human tumor cells by transduction with AdalphaGT- a replication deficient adenovirus containing the alpha1,3galactosyltransferase (alpha1,3GT) gene. Protection against tumors by immunization with AdalphaGT-transduced tumor cells was studied in alpha1,3GT knockout (KO) mice, challenged with the highly tumorigenic BL6 melanoma cells. These mice lack alpha-gal epitopes and can produce anti-Gal. Immunization of KO mice with AdalphaGT-transduced BL6 cells protects many of the mice against challenge with live BL6 cells lacking alpha-gal epitopes. Immunization with AdalphaGT transduced autologous tumor cells may serve as adjuvant immunotherapy delivered after completion of standard therapy. This method may complement another gene therapy method in which GM-CSF-secreting vaccinating tumor cells recruit APC to vaccination sites. Anti-Gal-opsonized vaccinating tumor cells will be effectively internalized by GM-CSF recruited APC and transported to draining lymph nodes for processing and presentation of tumor antigens. Alternatively, injection of AdalphaGT directly into solid tumor masses of cancer patients may result in anti-Gal-mediated destruction of the transduced tumor cells in a manner similar to xenograft rejection. The subsequent uptake of anti-Gal-opsonized tumor membranes by APC results in their effective transportation to lymph nodes where processed tumor antigens may elicit a protective antitumor immune response.

Melanoma vaccines

Melanoma vaccines offer new hope to patients with metastatic melanoma, although convincing survival advantages have yet to be reported. This review outlines the progress made in this exciting field of research and looks ahead to the future.

Amplifying cancer vaccine responses by modifying pathogenic gene programs in tumor cells

Immunosuppressive factors, such as vascular endothelial growth factor, transforming growth factor-beta, prostaglandin E2, interleukin (IL)-10, and IL-6, are made frequently by cancer cells. These factors, along with others, can inhibit the development and function of tumor-reactive effector T cells and the clinical results of cancer vaccines. Production of these factors by tumor cells is associated with disease progression and may represent an active immune surveillance escape mechanism. However, a number of factors appear to be made directly in response to signaling molecules, such as RAS, AKT, and signal transducer and activator of transcription 3, which are activated as a result of genetic events that occur during oncogenesis. Methods to overcome the negative effects of immunosuppressive factors, which are "hard wired" into gene programs of cancer cells, might then improve the results of cancer vaccines. For example, specific blocking antibodies, which recognize such factors, or kinase inhibitors, which block the signaling pathways that lead to their production, could potentially be used as vaccine adjuvants. The effects of immunosuppressive factors may also be "turned off" by cytokines with tumor suppressor properties. The enhanced clinical and immunological effects of melanoma vaccines observed after the administration of high doses of interferon-alpha2b provide a "proof of principle" in human patients, that agents which counter the gene programs of cancer cells, causing them to intrinsically resist tumor-reactive T cells, may improve significantly the efficacy of cancer vaccines.

Immunopharmacologic analysis of an autologous, hapten-modified human melanoma vaccine

PURPOSE

We have previously reported a clinical trial of a human cancer vaccine consisting of autologous tumor cells modified with the hapten, dinitrophenyl (DNP), in patients with clinical stage III melanoma. Here we present a follow-up report expanded to 214 patients with 5-year follow-up.

PATIENTS AND METHODS

Two hundred fourteen patients with clinical stage III melanoma (117 patients with stage IIIC and 97 patients with stage IIIB) who were melanoma-free after standard lymphadenectomy were treated with multiple intradermal injections of autologous, DNP-modified vaccine mixed with bacille Calmette-Guérin. Four vaccine dosage schedules were tested sequentially, all of which included low-dose cyclophosphamide. Patients were tested for delayed-type hypersensitivity (DTH) to autologous melanoma cells, both DNP-modified and unmodified, and to control materials.

RESULTS

The 5-year overall survival (OS) rate of the 214 patients was 44%. DTH responses to unmodified autologous melanoma were induced in 47% of patients. The OS of this DTH-positive group was double that of DTH-negative patients (59.3% v 29.3%; P <.001). In contrast, positive DTH responses to DNP-modified autologous melanoma cells and to purified protein derivative developed in almost all patients but did not affect OS. Surprisingly, the OS after relapse was also significantly longer in patients who developed positive DTH to unmodified tumor cells (25.2% v 12.3%; P <.001). Finally, the development of DTH was dependent on the schedule of administration of the vaccine, specifically, the timing of an induction dose administered at the beginning of the treatment program.

CONCLUSION

This study underscores the importance of the immunopharmacology of the autologous, DNP-modified vaccine and may be relevant to other cancer vaccine technologies.

Treatment of patients with progressive unresectable metastatic melanoma with a heterologous polyvalent melanoma whole cell vaccine

Unresectable metastatic melanoma has no elective treatment. Neither chemotherapy, intravenous IL-2 nor biochemotherapy clearly improves the overall survival. Recent assays with therapeutic vaccines have been recently yielded promising results. Here, we describe the application, clinical tolerance and antitumoural activity of a heterologous polyvalent melanoma whole cell vaccine in patients with metastatic melanoma. Twenty-eight AJCC stage III/IV melanoma patients with progressive unresectable metastatic disease were treated with our heterologous polyvalent melanoma whole cell vaccine between July 1, 1998 and July 1, 2002. All patients had already been unsuccessfully treated with high doses of IFN-alpha2 and/or polychemotherapy and/or biochemotherapy and/or perfusion of extremities, or could not receive other treatments due to their age or underlying illness. Twenty-three were assessable. The vaccine was constituted by 10 melanoma cell lines, derived from primary, lymph node and metastatic melanomas. Prior to intradermal inoculation, the cells were irradiated and mixed with BCG, and 50% were treated with DNFB. After a median follow-up of 19 months, 26% of patients responded: 3 CR (18, 16+, and 26+ months), 2 PR (8 and 22 months) and 1 MR (36+ months). The median survival of the whole group was 20.2 months. None of the 28 patients initially included in the study presented significant toxicity. This vaccination program had specific antitumoural activity in advanced metastatic melanoma patients and was well tolerated. The clinical responses and the median survival of our group of patients, together with the low toxicity of our polyvalent vaccine, suggest that this approach could be applied to earlier metastatic melanoma patients.

Immunomodulation in cancer therapeutics

Clinical verification is being obtained, with a variety of different therapeutic approaches, for the concept that anticancer treatments based on exploiting the host's own antitumor defense mechanism can be beneficial. Nevertheless, as was seen with both chemotherapeutic and radiation treatments, the benefit of single agent treatments is not great. It is anticipated that, in attempting to realize the maximal potential of anticancer treatments based on exploiting the host's own antitumor defense mechanism, it will be necessary to utilize combination therapies. For medical-ethical reasons, the ability to effectively combine such treatments with ones with proven clinical efficacy should increase the enthusiasm for the initiation of clinical trials. Chemotherapeutic agents may serve this purpose, since, contrary to the generally held tenet that anticancer chemotherapeutic agents are merely immunosuppressive, there is considerable literature describing their ability to augment antitumor host defenses. This review attempts to collate this information derived by numerous investigators employing diverse experimental approaches with a number of the most widely used anticancer chemotherapeutic agents.

Improving survival in patients with high-risk and metastatic melanoma: immunotherapy leads the way

Melanoma is a neoplasm with an incidence in the US that is rising at a rate second only to lung cancer in women. Early stage melanoma is curable, but advanced metastatic melanoma is almost uniformly fatal, even in 2003. The close relationship of melanoma with the immune system has led to a recent resurgence in the investigation of immunotherapy in the treatment of this disease. The two most widely investigated immunotherapy drugs for melanoma are interferon (IFN)-alpha and interleukin-2 (IL-2). The role of IFNalpha-2b in the adjuvant therapy of patients with localized melanoma at high risk for relapse has recently been established by the results of three large randomized trials conducted by the US Intergroup; all three trials demonstrated an improvement in relapse-free survival and two in overall survival. Recombinant IL-2 (rIL-2) has an overall response rate of 15-20% in metastatic melanoma and is capable of producing complete and durable remissions in about 6% of patients treated. Based upon these data, the US FDA has recently approved the use of high-dose bolus administration of rIL-2 for the therapy of patients with metastatic melanoma. Results of combination chemotherapy and immunotherapy regimens containing rIL-2 and IFNalpha (biochemotherapy) are promising, but conclusions regarding an advantage for this therapy in terms of survival must await the completion of ongoing randomized trials. The use of therapeutic vaccines is an ongoing area of research, and clinical trials of several types of vaccines (whole cell, carbohydrate, peptide) are being conducted in patients with intermediate and late-stage melanoma. In the setting of adjuvant therapy, to date, no vaccine has demonstrated a survival benefit in comparison with either observation or IFNalpha. Vaccines are also being tested in patients with metastatic melanoma to determine their immune effects and to define their activity in combination with other immunotherapeutic agents such as IL-2 or IFNalpha.

Expression of alpha-gal epitopes on ovarian carcinoma membranes to be used as a novel autologous tumor vaccine

OBJECTIVE

Poor presentation of tumor-associated antigens (TAA) to the immune system remains a major obstacle to effective anti-tumor vaccine therapy. The aim of this study is to demonstrate the feasibility of producing a novel autologous tumor vaccine from ovarian carcinoma that is expected to have increased immunogenicity. The strategy is based on the ability of the anti-Gal IgG antibody (a natural antibody comprising 1% of IgG in humans) to target tumor membranes expressing alpha-gal epitopes (Galalpha1-3Galbeta1-4GlcNAc-R) to antigen-presenting cells (APC).

STUDY DESIGN

Freshly obtained ovarian carcinoma tumors are homogenized, washed, and incubated with a mixture of neuraminidase, recombinant alpha1,3 galactosyltransferase (ralpha1,3GT) and uridine diphosphate galactose (UDP-Gal) to synthesize alpha-gal epitopes on carbohydrate chains of glycoproteins of these membranes. Subsequently, the processed membranes are analyzed for expression of alpha-gal epitopes and for the binding of anti-Gal.

RESULTS

Incubation of 3 g of ovarian carcinoma membranes, from five different patients, at 100 mg/ml, mixed together with ralpha1,3GT (50 microg/ml), neuraminidase (1 mU/ml), and UDP-Gal (2 mM), resulted in the effective synthesis of alpha-gal epitopes to the extent of approximately 2 x 10(11) epitopes/mg of tumor membranes. As a result of this de novo expression of alpha-gal epitopes, the tumor membranes readily bound purified anti-Gal antibody, as well as anti-Gal in autologous serum.

CONCLUSIONS

The method described in this study is very effective in the synthesis of many alpha-gal epitopes on tumor membranes obtained from ovarian carcinoma. These novel epitopes readily bind the naturally occurring anti-Gal antibody. This technique of opsonization of alpha-gal-modified autologous tumor membranes carrying TAA is expected to increase effective uptake of the vaccine by APC, which is key to successful anti-tumor vaccination.

Durable complete clinical responses in a phase I/II trial using an autologous melanoma cell/dendritic cell vaccine

Advanced metastatic melanoma is incurable by standard treatments, but occasionally responds to immunotherapy. Recent trials using dendritic cells (DC) as a cellular adjuvant have concentrated on defined peptides as the source of antigens, and rely on foreign proteins as a source of help to generate a cell-mediated immune response. This approach limits patient accrual, because currently defined, non-mutated epitopes are restricted by a small number of human leucocyte antigens. It also fails to take advantage of mutated epitopes peculiar to the patient's own tumour, and of CD4+ T lymphocytes as potential effectors of anti-tumour immunity. We therefore sought to determine whether a fully autologous DC vaccine is feasible, and of therapeutic benefit. Patients with American Joint Cancer Committee stage IV melanoma were treated with a fully autologous immunotherapy consisting of monocyte-derived DC, matured after culture with irradiated tumour cells. Of 19 patients enrolled into the trial, sufficient tumour was available to make treatments for 17. Of these, 12 received a complete priming phase of six cycles of either 0.9x10(6) or 5x10(6) DC/intradermal injection, at 2-weekly intervals. Where possible, treatment continued with the lower dose at 6-weekly intervals. The remaining five patients could not complete priming, due to progressive disease. Three of the 12 patients who completed priming have durable complete responses (average duration 35 months+), three had partial responses, and the remaining six had progressive disease (WHO criteria). Disease regression was not correlated with dose or with the development of delayed type hypersensitivity responses to intradermal challenge with irradiated, autologous tumour. However, plasma S-100B levels prior to the commencement of treatment correlated with objective clinical response ( P=0.05) and survival (log rank P<0.001). The treatment had minimal side-effects and was well tolerated by all patients. Mature, monocyte-derived DC preparations exposed to appropriate tumour antigen sources can be reliably produced for patients with advanced metastatic melanoma, and in a subset of those patients with lower volume disease their repeated administration results in durable complete responses.

Tumor vaccines: a role in preventing recurrence in melanoma?

Patients presenting with thick primary melanomas or those with regional nodal metastases have a high risk of recurrence after surgery alone. Chemotherapy has limited efficacy in the adjuvant setting, and while the use of high-dose interferon in the adjuvant setting has been reported to improve survival, treatment with interferon is not without significant cost and toxicity. Mounting evidence suggests a prominent role for the immune system in the natural history of melanoma, and the clinical success of interferon highlights the potential for immunotherapy to prevent recurrence. Many researchers hope to use melanoma vaccines to reduce recurrence without significant toxicity, and many different vaccine strategies are under investigation. Peptide vaccines attempt to induce immunity to melanoma MHC-restricted peptide antigens by delivering the peptide to the patient along with an immune adjuvant meant to induce inflammation and stimulate immunity. While peptide vaccines have advantages with regard to cost and feasibility, it is still unclear whether highly purified peptides will stimulate an adequate immune response. An alternative approach is the use of cellular vaccines. Autologous cellular vaccines present all biologically relevant antigens to the immune system, but this is limited to individuals with sufficient tumor to prepare a vaccine. Allogeneic cellular vaccines are based on the fact that melanoma-associated antigens are shared among a large number of patients, so a vaccine prepared from a cultured cell line could stimulate an anti-tumor immune response in many patients. Allogeneic vaccines are available for all patients, and can be standardized, preserved and distributed in a manner akin to any other therapeutic agent. Because of this, they are more readily available for evaluation in large trials, and there are two major allogeneic vaccines presently being evaluated as an adjuvant therapy for melanoma. Several additional approaches to vaccine therapies are being investigated including among others ganglioside vaccines, viral oncolysates, cytokine gene-modified tumor cell vaccines, dendritic cell vaccines, anti-idiotype antibodies and DNA vaccines. While there appears to be tremendous potential for vaccines, it must be remembered that there has been significant interest in immunotherapy for melanoma for over 50 years and, to date, no large prospective, randomized trial has shown a survival benefit.

Immunotherapy of malignant melanoma

Several areas of immunotherapeutic research may ultimately improve the effectiveness of active specific immunotherapy for melanoma and other malignancies. Identification of the most relevant tumor antigens will continue to be a vital component of vaccine design. Optimizing delivery of these antigens by use of adjuvants, dendritic cells, or heat shock proteins will enhance the immunogenicity of vaccines. The use of DNA vaccines to deliver nucleotides that encode relevant antigens and immunologic molecules, such as costimulatory molecules, and the use of targeted therapy with immunocytokines have yielded promising results in animal studies. Finally, cutting-edge techniques such as quantitative polymerase chain reaction and gene/protein microarrays will be used to monitor the response to a vaccine and thereby guide management decisions. Although IFN-alpha 2b is the only FDA-approved adjuvant treatment for AJCC stage IIB/III melanoma, recent data failed to show a benefit in overall survival. For patients with AJCC stage IV melanoma, chemotherapy with dacarbazine is currently the standard of care, with modest response rates of 15% to 20%. The encouraging response rates and low toxicities that were reported in phase I/III trials suggest that active immunotherapy may prove to be the most effective adjuvant therapy. At present, there are no FDA-approved cancer vaccines for malignant melanoma, and the results of ongoing randomized phase III clinical trials are greatly anticipated.

Diagnosis and management of high-risk and metastatic melanoma

OBJECTIVES

To identify treatment modalities and corresponding nursing implications for the high-risk and metastatic melanoma patient.

DATA SOURCES

Texbooks, research articles, and professional experience.

CONCLUSIONS

Recent advances in the field of melanoma include identification of prognostic factors, refinement of surgical techniques, and identification of effective adjuvant therapy. Novel therapies are currently under investigation.

IMPLICATIONS FOR NURSING PRACTICE

Nurses play a vital role in the treatment of melanoma patients through education regarding their disease and treatment options, patient identification for clinical trials, and intensive monitoring and management for treatment-related side effects.

Adjuvant therapy for high-risk primary and resected metastatic melanoma

Patients with thick, primary melanoma and regional lymph-node metastases are at moderate to high risk of recurrence and death, despite apparent complete surgical removal. Immune responses can be demonstrated against melanoma and this has prompted the conduct of a number of randomized trials of immunotherapy. Several trials have been completed and show minimal benefit in prolonging survival or recurrence from melanoma. Similarly, a large number of trials has been conducted to test the efficacy of alpha-2-interferon (IFN-alpha2) in therapy. Clear benefit in recurrence-free survival was shown in several trials, however there is a lack of convincing evidence of an effect on overall survival. Several trials of vaccine and IFN-alpha2 therapy are still in progress and their results are awaited with great interest. The use of high-dose IFN-alpha2 therapy remains a contentious subject, however available evidence suggests the standard of care remains good surgical management.

Noninterferon-based adjuvant therapy for high-risk melanoma

High-dose interferon is the only treatment approved by the FDA for adjuvant therapy of melanoma. However, its efficacy in this setting is questionable and its administration is associated with considerable toxicity. Many new agents are being tested clinically that hold the promise of greater efficacy and less toxicity but none of these have yet shown efficacy in controlled trials. These include biologics such as vaccines, cytokines, monoclonal antibodies, gene transfer, cellular therapies and angiogenesis inhibitors as well as chemotherapy combinations.

Vaccines for melanoma

Melanoma vaccines are now an accepted but still experimental treatment for patients who have been rendered clinically free of disease by surgical resection but are at high risk of recurrence and in selected patients with advanced but still limited disease. In general, there seems to be a correlation between the ability of melanoma vaccines to stimulate antimelanoma cellular or antibody immune responses and improved clinical outcome. Accordingly, a number of strategies are now being pursued to improve the clinical effectiveness of this first generation of vaccines by improving their ability to stimulate antimelanoma immunity. To establish the true effectiveness of vaccines in the treatment of malignant melanoma, several large, prospectively randomized phase III studies are currently being conducted.

TCR rearrangement in lymphocytes infiltrating melanoma metastases after administration of autologous dinitrophenyl-modified vaccine

Administration of a vaccine consisting of autologous melanoma cells modified with a hapten, dinitrophenyl (DNP), induces T cell infiltration of metastatic sites. We have reported an analysis of these infiltrating T cells, indicating that certain TCR-Vbeta gene segments are greatly overexpressed. In this study, we investigate the rearrangement of the TCR-Vbeta as well as the junctional diversity in T cells infiltrating melanoma metastases following treatment with DNP vaccine. In 19 of 26 control specimens, V-D-J length analysis showed the expected polyclonal patterns. In contrast, postvaccine tumors from 9 of 10 patients showed dominant peaks of V-D-J junction size in one or more Vbeta families. Dominant peaks were seen most frequently in six Vbeta families (Vbeta7, 12, 13, 14, 16, and 23) and were never seen in seven others. Further analysis of the oligoclonal Vbeta products showed dominant peaks in the J region as well. Of particular interest was the finding that Vbeta and Jbeta peaks were similar in inflamed metastases obtained at different times or from different sites from the same patient. Although 6 of 10 patients expressed HLA-A1, there was no common pattern of TCR rearrangements among them. Finally, the amplified PCR products from seven of these specimens were cloned and sequenced and the amino acid sequence of the complementarity-determining region 3 was deduced. In six of seven specimens, the same complementarity-determining region 3 sequence was repeated in at least two clones and in five of seven in at least three clones. Our study indicates that DNP vaccine induces the expansion of particular T cell clones that may be agents of its antitumor effects.

Intermediate- and high-risk melanoma

Intermediate and high risk for recurrence melanoma comprise a unique subset of patients with surgically treatable melanoma for whom cure is possible but relapse and distant metastases likely. Strategies to improve the prognosis for such patients with effective adjuvant therapies are critical. In recent randomized trials conducted by the cooperative groups in the United States of patients at high risk for recurrence (patients with thick primary melanomas and those with regional lymph node metastases) administered adjuvant therapy with high-dose interferon alfa-2b (HDI), relapse-free survival and overall survival rates improved significantly. Research efforts in this area continue to assess the role of intermediate-dose interferon, but there is no convincing evidence of success of the lower-dose regimens, despite the reduction in toxicity. For a subset of patients at highest risk (two or more involved lymph nodes), a regimen of therapy for metastatic stage IV melanoma (interleukin-2 based biochemotherapy) is being compared with HDI in an ongoing phase III trial. For intermediate-risk melanoma, no effective adjuvant therapy is available. For such patients, enrollment in ongoing clinical trials assessing the role of shorter courses of HDI or vaccines should be encouraged.

Autologous cell vaccine as a post operative adjuvant treatment for high-risk melanoma patients (AJCC stages III and IV). The new American Joint Committee on Cancer

This study evaluates the overall survival and disease free survival of melanoma patients that were treated with an autologous melanoma cell vaccine, administered as a post-operative adjuvant. Included are 43 patients with totally resected metastatic melanoma (28-AJCC stage III, 15-AJCC stage IV), with a median follow up of 34 months (6-62). The treatment consisted of eight doses of a vaccine made of 10-25x10(6) autologous melanoma cells either released from the surgical specimen or grown in cell cultures. Tumour cells were conjugated with hapten dinitrophenyl, mixed with Bacille Calmette Guérin and irradiated to 110 Gy. Both disease free survival and overall survival were found to be correlated with intensity of evolving delayed type hypersensitivity to subcutaneous injection of unmodified melanoma cells. Patients with a delayed type hypersensitivity reaction of > or =10 mm had a median disease free survival of 17 months (mean 35 months) and a mean overall survival of 63 months (median not reached). In contrast, patients with a negative or weak delayed type hypersensitivity had a median disease free survival of 9 months (relative risk of recurrence=4.5, P=0.001), and a median overall survival of 16 months (relative risk of death=15, P=0.001). Stage III patients with a positive delayed type hypersensitivity reaction had an improved disease free survival of 16 months and a mean overall survival of 38 months, whereas patients with a negative delayed type hypersensitivity had a median disease free survival of 7 months (relative risk=4.5, P=0.02) and a median overall survival of 16 months (relative risk=9.5, P=0.005). The adjuvant administration of autologous melanoma vaccine was associated with improved disease-free and overall survival to selected patients who successfully attained anti-melanoma reactivity as detected by positive delayed type hypersensitivity reactions to unmodified melanoma cells.

Variability in glucose transporter-1 levels and hexokinase activity in human melanoma

Melanoma exhibits heterogeneous growth patterns and widely varying sensitivities to multiple treatment modalities. This variability may reflect intrinsic genetic differences in factors giving rise to altered metabolism. Glucose is the primary energy source of tumours, including melanoma, and glucose transporter isoform 1 (Glut-1) and hexokinase are key rate-limiting factors in glucose metabolism. The levels of Glut-1 and total hexokinase activity were measured in 31 melanoma biopsies to determine the extent of tumour-to-tumour variability in these parameters. Relative Glut-1 levels were determined by Western immunoblot analysis using human anti-Glut-1 rabbit polyclonal antibody, and hexokinase activity was measured in the same samples by an enzymatic assay monitoring the reduction in the oxidized form of nicotinamide adenine dinucleotide phosphate (NADP+) (in nmol NADP+ reduced/min per mg protein). All melanomas were from patients who had received no therapy prior to surgery. Immediately after excision, tumour biopsies were disaggregated to single cells by collagenase and DNase and frozen in liquid nitrogen. Thirty human melanomas exhibited a 22-fold variation in levels of Glut-1 and 29 exhibited a nine-fold variation in total cellular hexokinase activity. Glut-1 levels and hexokinase activity were not correlated with one another. The broad range in Glut-1 levels and hexokinase activity observed between melanomas suggests that these glycolytic rate-limiting parameters that influence the rate of glucose metabolism may contribute to the variability in melanoma response to treatment modalities.

Tumour cell-based vaccines for the treatment of melanoma

Melanoma is generally resistant to chemotherapy and radiation therapy. Its unique immunological properties lend support to developing innovative new therapies via manipulation of the patient's own immune system. The use of whole-cell-based tumour vaccines, including autologous, whole-cell allogeneic and cytokine gene-modified vaccines, as well as tumour lysate vaccines, for active specific immunotherapy of melanoma, is discussed in detail with regard to rationale and available clinical data. Although phase II data on the use of melanoma vaccine in the adjuvant setting show promise, there is no randomised phase III trial demonstrating the efficacy of active specific immunotherapy for melanoma. The coming years will bring the results of several pivotal multicentre phase III trials testing the clinical utility of active specific immunotherapy in the management of melanoma.