Randomized Trial of an Allogeneic Melanoma Lysate Vaccine With Low-Dose Interferon Alfa-2b Compared With High-Dose Interferon Alfa-2b for Resected Stage III Cutaneous Melanoma

Stem Cell Origin of Cancer: Clinical Implications for Cancer Immunity and Immunotherapy

A simple way to understand the immune system is to separate the self from non-self. If it is self, the immune system tolerates and spares. If it is non-self, the immune system attacks and destroys. Consequently, if cancer has a stem cell origin and is a stem cell disease, we have a serious problem and a major dilemma with immunotherapy. Because many refractory cancers are more self than non-self, immunotherapy may become an uphill battle and pyrrhic victory in cancer care. In this article, we elucidate cancer immunity. We demonstrate for whom, with what, as well as when and how to apply immunotherapy in cancer care. We illustrate that a stem cell theory of cancer affects our perspectives and narratives of cancer. Without a pertinent theory about cancer's origin and nature, we may unwittingly perform misdirected cancer research and prescribe misguided cancer treatments. In the ongoing saga of immunotherapy, we are at a critical juncture. Because of the allure and promises of immunotherapy, we will be treating more patients not immediately threatened by their cancer. They may have more to lose than to gain, if we have a misconception and if we are on a wrong mission with immunotherapy. According to the stem cell theory of cancer, we should be careful with immunotherapy. When we do not know or realize that cancer originates from a stem cell and has stem-ness capabilities, we may cause more harm than good in some patients and fail to separate the truth from the myth about immunotherapy in cancer care.

Comparison of efficacy and tolerability of adjuvant therapy for resected high-risk stage III-IV cutaneous melanoma: a systemic review and Bayesian network meta-analysis

Background

Although immune checkpoint inhibitors (ICIs) and targeted therapies have been widely used as adjuvant treatment for resected melanoma, the optimal therapy remains controversial. Therefore, we conducted this updated network meta-analysis (NMA) to assess the efficacy and tolerability of adjuvant therapies for cutaneous melanoma.

Methods

PubMed, Embase, Cochrane library, and Web of Science were systematically searched for relevant literatures published in the last 30 years. Disease-free survival (DFS), overall survival (OS), and serious adverse events were considered as the efficacy and tolerability outcomes.

Results

In all, 27 randomized controlled trials (RCTs) including 16,709 stage III-IV melanoma patients were enrolled in this NMA. For BRAF wild-type melanoma, our analysis showed that both nivolumab and pembrolizumab demonstrated significantly better DFS and tolerability than ipilimumab (10 mg/kg). Nivolumab, pembrolizumab, ipilimumab (3 mg/kg), and ipilimumab (10 mg/kg) all appeared to be effective in prolonging OS, but no therapy demonstrated significantly better OS than ipilimumab (10 mg/kg). Nivolumab + ipilimumab showed the best DFS, but did not appear to be effective in improving OS and ranked only seventh in tolerability. Vaccines and granulocyte-macrophage colony-stimulating factor therapies were well tolerated, but all failed to improve the DFS or OS in stage III melanoma patients. In terms of BRAF mutation-positive melanoma, ICIs (nivolumab + ipilimumab, nivolumab, pembrolizumab, ipilimumab; 10 mg/kg) exhibited comparable efficacy to dabrafenib + trametinib, and all these therapies showed significantly better DFS than placebo.

Conclusion

Considering efficacy and tolerability, nivolumab and pembrolizumab seem to be preferable adjuvant therapies for patients with stage III-IV melanoma. For BRAF mutation-positive patients, more RCTs are still required to determine which is better between ICIs and targeted therapy.

Antitumor Peptide-Based Vaccine in the Limelight

The success of the immune checkpoint blockade has provided a proof of concept that immune cells are capable of attacking tumors in the clinic. However, clinical benefit is only observed in less than 20% of the patients due to the non-specific activation of immune cells by the immune checkpoint blockade. Developing tumor-specific immune responses is a challenging task that can be achieved by targeting tumor antigens to generate tumor-specific T-cell responses. The recent advancements in peptide-based immunotherapy have encouraged clinicians and patients who are struggling with cancer that is otherwise non-treatable with current therapeutics. By selecting appropriate epitopes from tumor antigens with suitable adjuvants, peptides can elicit robust antitumor responses in both mice and humans. Although recent experimental data and clinical trials suggest the potency of tumor reduction by peptide-based vaccines, earlier clinical trials based on the inadequate hypothesis have misled that peptide vaccines are not efficient in eliminating tumor cells. In this review, we highlighted the recent evidence that supports the rationale of peptide-based antitumor vaccines. We also discussed the strategies to select the optimal epitope for vaccines and the mechanism of how adjuvants increase the efficacy of this promising approach to treat cancer.

A Bayesian network meta-analysis of comparison of cancer therapeutic vaccines for melanoma

Several approaches to active immunotherapy for melanoma, including peptide-based vaccines (PVs), autologous tumour cell vaccines (TCVs), allogeneic TCVs and autologous dendritic cell vaccines (DCVs), have been investigated in clinical trials. However, comprehensive evidence comparing these interventions remains unavailable. The objective of this study was to expand previous work to compare and rank the immunotherapeutic strategies for melanoma in terms of overall survival and toxic effects with a Bayesian network meta-analysis. Methodologically, we performed a network meta-analysis of head-to-head randomized controlled trials comparing and ranking cancer vaccine approaches for patients with melanoma. PubMed, MEDLINE, Embase, the Cochrane Central Register of Controlled Trials, the WHO International Clinical Trials Registry Platform and ClinicalTrials.gov were searched up to 31 July 2020. We estimated summary hazard ratios for death and risk ratios for toxicity. The effects of the underlying prognostic variable on survival benefits were examined by meta-regression. We performed subgroup analysis for the outcomes based on metastatic categories. Overall, we identified 4776 citations, of which 15 head-to-head randomized controlled trials (3162 participants) were included in the analysis. In terms of efficacy, allogeneic tumour cell vaccines plus immunotherapy adjuvants, peptide-based vaccines plus immunotherapy adjuvants and standard therapy were more effective than peptide vaccines. The proportion of women was inversely associated with mortality risk. For safety, all treatments were inferior to allogeneic tumour cell vaccines except for allogeneic tumour cell vaccines plus chemotherapy. Peptide vaccines plus immunotherapy adjuvants led to an increased risk of adverse events compared to allogeneic tumour cell vaccines plus immunotherapy adjuvants. These results suggest that allogeneic TCV and autologous DCV are better than standard therapy. PV plus immune modulators are the most effective strategy among all comparable strategies but is associated with increased toxicity. Any combination regimens for cancer therapeutic vaccines need to be balanced between risk and benefit profiles.

Systemic adjuvant therapy for adult patients at high risk for recurrent melanoma: A systematic review

Cutaneous melanoma is typically treated with wide local excision and, when appropriate, a sentinel node biopsy. Many patients are cured with this approach but for patients who have cancers with high risk features there is a significant risk of local and distant relapse and death. Interferon-based adjuvant therapy was recommended in the past but had modest results with significant toxicity. Recently, new therapies (immune checkpoint inhibitors and targeted therapies) have been found to be effective in the treatment of patients with metastatic melanoma and many of these therapies have been evaluated and found to be effective in the adjuvant treatment of high risk patients with melanoma. This systematic review of adjuvant therapies for cutaneous and mucosal melanoma was conducted for Ontario Health (Cancer Care Ontario) as the basis of a clinical practice guideline to address the question of whether patients with completely resected melanoma should be considered for adjuvant systemic therapy and which adjuvant therapy should be used.

Vaccine Strategies to Improve Anti-cancer Cellular Immune Responses

More than many other fields in medicine, cancer vaccine development has been plagued by a wide gap between the massive amounts of highly encouraging preclinical data on one hand, and the disappointing clinical results on the other. It is clear now that traditional approaches from the infectious diseases' vaccine field cannot be borrowed as such to treat cancer. This review highlights some of the strategies developed to improve vaccine formulations for oncology, including research into more powerful or “smarter” adjuvants to elicit anti-tumoral cellular immune responses. As an illustration of the difficulties in translating smart preclinical strategies into real benefit for the cancer patient, the difficult road of vaccine development in lung cancer is given as example. Finally, an outline is provided of the combinatorial strategies that leverage the increasing knowledge on tumor-associated immune suppressive networks. Indeed, combining with drugs that target the dominant immunosuppressive pathway in a given tumor promises to unlock the true power of cancer vaccines and potentially offer long-term protection from disease relapse.

An Update on Randomized Clinical Trials in Melanoma

Despite many advances in the treatment of melanoma, it still continues to be a disease that affects many people. Fortunately, there have been a multitude of randomized trials that have refined the treatment of this prevalent disease. From 1975 to 2000, there were 154 prospective randomized trials on the treatment of local, regional, and metastatic melanoma. From 2001 to now, additional randomized trials have focused on the role of surgery, adjuvants to surgery, and treatment of metastatic disease. The results of the practice-changing trials are summarized in this review.

Challenges faced when identifying patients for combination immunotherapy

In 1996, Jim Allison demonstrated that blocking the immune regulatory molecule CTLA-4 with anit-CTLA4 antibody led to enhance tumor responses in mice. It would take an additional 15 years for human studies to confirm the potency and clinical efficacy of anti-CTLA4, ultimately leading to US FDA approval of the first checkpoint inhibitor, ipilimumab. Now with a plethora of immune-modulating agents demonstrating single agent safety and benefit across many tumor types, investigation on the optimal combination of immune-based therapies has begun in earnest. While there are many challenges, a central one is how to select which combination for which patient is the best. Here we review the current approaches that a practitioner can use to achieve this therapeutic goal.

Twenty-five years of type I interferon-based treatment: a critical analysis of its therapeutic use

The clinical exploitation of type I interferon (IFN) as an antiviral and antineoplastic agent is based on the properties originally attributed to this cytokine family, with schedules reflecting only their antiviral and antiproliferative activities. Nevertheless, type I IFN has emerged as a central activator of the innate immunity. As current schedules of treatment for chronic hepatitis C and for hematological and solid tumors, based on the continuous administration of recombinant type I IFN or pegylated formulations, disregard viral resistance, host genetic variants predicting treatment outcome and mechanisms of refractoriness, new administration schedules, the combination of type I IFN with new drugs and the increased monitoring of patients' susceptibility to type I IFN are expected to provide a new life to this valuable cytokine.

Long-term clinical outcome of melanoma patients treated with messenger RNA-electroporated dendritic cell therapy following complete resection of metastases

PURPOSE

Melanoma patients with a high risk of recurrence may benefit from immunotherapy with mRNA-electroporated autologous monocyte-derived dendritic cells (DCs). Further benefit may be found in combining DC-therapy with interferon alfa-2b.

PATIENTS AND METHODS

The long-term clinical outcome of AJCC stage III/IV melanoma patients who had no evidence of disease at the time of treatment with autologous mRNA-electroporated DCs in a single-center pilot clinical trial was analyzed. Antigen loading was accomplished by co-electroporation of mRNA encoding a fusion protein between MAGE-A1, -A3, -C2, Tyrosinase, MelanA/MART-1, or gp100, and an HLA class II-targeting sequence. DCs were administered by 4-6 bi-weekly intradermal injections. IFN-α-2b (5 MIU TIW) was initiated either at recurrence (cohort 1), concomitant with DCs (cohorts 2 and 3), or following the fourth DC administration (cohort 4).

RESULTS

Thirty melanoma patients were recruited between April 2006 and June 2009. DC-related adverse events included grade 2 local injection site reactions in all patients, grade 2 fever and flu-like symptoms in one patient, and skin depigmentation in seven patients. After a median follow-up of over 6 years, the median relapse-free survival is 22 months (95% CI 12-32 months). Twelve patients have died. The median overall survival has not been reached; the 2-year and 4-year survival rates are 93 and 70%, respectively.

CONCLUSIONS

Adjuvant therapy following the resection of melanoma metastases with autologous mRNA-electroporated DCs, combined with interferon alfa-2b, is tolerable and results in encouraging long-term overall survival rates justifying further evaluation in a randomized clinical trial.

Interferon alpha for the adjuvant treatment of cutaneous melanoma

BACKGROUND

Interferon alpha is the only agent approved for the postoperative adjuvant treatment of high-risk cutaneous melanoma. However, the survival advantage associated with this treatment is unclear, especially in terms of overall survival. Thus, adjuvant interferon is not universally considered a gold standard treatment by all oncologists.

OBJECTIVES

To assess the disease-free survival and overall survival effects of interferon alpha as adjuvant treatment for people with high-risk cutaneous melanoma.

SEARCH METHODS

We searched the following databases up to August 2012: the Cochrane Skin Group Specialised Register, CENTRAL in The Cochrane Library (2012, issue 8), MEDLINE (from 2005), EMBASE (from 2010), AMED (from 1985), and LILACS (from 1982). We also searched trials databases in 2011, and proceedings of the ASCO annual meeting from 2000 to 2011. We checked the reference lists of selected articles for further references to relevant trials.

SELECTION CRITERIA

We included only randomised controlled trials (RCTs) comparing interferon alpha to observation (or any other treatment) for the postoperative (adjuvant) treatment of patients with high-risk skin melanoma, that is, people with regional lymph node metastasis (American Joint Committee on Cancer (AJCC) TNM (tumour, lymph node, metastasis) stage III) undergoing radical lymph node dissection, or people without nodal disease but with primary tumour thickness greater than 1 mm (AJCC TNM stage II).

DATA COLLECTION AND ANALYSIS

Two authors extracted data, and a third author independently verified the extracted data. The main outcome measure was the hazard ratio (HR), which is the ratio of the risk of the event occurring in the treatment arm (adjuvant interferon) compared to the control arm (no adjuvant interferon). The survival data were either entered directly into Review Manager (RevMan) or extrapolated from Kaplan-Meier plots and then entered into RevMan. Based on the presence of between-study heterogeneity, we applied a fixed-effect or random-effects model for calculating the pooled estimates of treatment efficacy.

MAIN RESULTS

Eighteen RCTs enrolling a total of 10,499 participants were eligible for the review. The results from 17 of 18 of these RCTs, published between 1995 and 2011, were suitable for meta-analysis and allowed us to quantify the therapeutic efficacy of interferon in terms of disease-free survival (17 trials) and overall survival (15 trials). Adjuvant interferon was associated with significantly improved disease-free survival (HR (hazard ratio) = 0.83; 95% CI (confidence interval) 0.78 to 0.87, P value < 0.00001) and overall survival (HR = 0.91; 95% CI 0.85 to 0.97; P value = 0.003). We detected no significant between-study heterogeneity (disease-free survival: I² statistic = 16%, Q-test P value = 0.27; overall survival: I² statistic = 6%; Q-test P value = 0.38).Considering that the 5-year overall survival rate for TNM stage II-III cutaneous melanoma is 60%, the number needed to treat (NNT) is 35 participants (95% CI = 21 to 108 participants) in order to prevent 1 death. The results of subgroup analysis failed to answer the question of whether some treatment features (i.e. dosage, duration) might have an impact on interferon efficacy or whether some participant subgroups (i.e. with or without lymph node positivity) might benefit differently from interferon adjuvant treatment.Grade 3 and 4 toxicity was observed in a minority of participants: In some trials, no-one had fever or fatigue of Grade 3 severity, but in other trials, up to 8% had fever and up to 23% had fatigue of Grade 3 severity. Less than 1% of participants had fever and fatigue of Grade 4 severity. Although it impaired quality of life, toxicity disappeared after treatment discontinuation.

AUTHORS' CONCLUSIONS

The results of this meta-analysis support the therapeutic efficacy of adjuvant interferon alpha for the treatment of people with high-risk (AJCC TNM stage II-III) cutaneous melanoma in terms of both disease-free survival and, though to a lower extent, overall survival. Interferon is also valid as a reference treatment in RCTs investigating new therapeutic agents for the adjuvant treatment of this participant population. Further investigation is required to select people who are most likely to benefit from this treatment.

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.

Adjuvant treatment of melanoma

Melanomas represent 4% of all malignant tumors of the skin, yet account for 80% of deaths from skin cancer.While in the early stages patients can be successfully treated with surgical resection, metastatic melanoma prognosis is dismal. Several oncogenes have been identified in melanoma as BRAF, NRAS, c-Kit, and GNA11 GNAQ, each capable of activating MAPK pathway that increases cell proliferation and promotes angiogenesis, although NRAS and c-Kit also activate PI3 kinase pathway, including being more commonly BRAF activated oncogene. The treatment of choice for localised primary cutaneous melanoma is surgery plus lymphadenectomy if regional lymph nodes are involved. The justification for treatment in addition to surgery is based on the poor prognosis for high risk melanomas with a relapse index of 50-80%. Patients included in the high risk group should be assessed for adjuvant treatment with high doses of Interferon- α 2b, as it is the only treatment shown to significantly improve disease free and possibly global survival. In the future we will have to analyze all these therapeutic possibilities on specific targets, probably associated with chemotherapy and/or interferon in the adjuvant treatment, if we want to change the natural history of melanomas.

Cancer microenvironment and cancer vaccine

The cancer microenvironment is constituted of non-transformed host stromal cells such as endothelial cells, fibroblasts, various immune cells, and a complex extra-cellular matrix secreted by both the normal and neoplastic cells embedded in it. The importance of the microenvironment and its potential in cancer therapy is just being established. Among modalities that target the microenvironment, cancer vaccine is a unique strategy which is aimed to elicit specific immunity against components in the microenvironment. Most, if not all, components can be targeted by the vaccines. The most extensively studied are the endothelial cells, fibroblasts and macrophages as well as ECM. Vaccines are in development for each of them. All the vaccines were proved to be effective at providing protective or therapeutic anti-tumor effects in the pre-clinical models. A few of them have been tested in the clinical trials. The mechanisms of the vaccines were mainly related to the cellular immune response such as CD8+ cytotoxic T cells, and in some instances CD4+ Th cells were involved as well. The present review also discussed the hurdles associated with the microenvironment-based vaccines such as the selection of suitable patients with appropriate biomarkers. With the rapid increase of our knowledge in the cancer microenvironment, the proof-of-concept of microenvironment-based cancer vaccines will surely expand our armamentarium against cancer.

Adjuvant therapy: melanoma

With an incidence that is increasing at 2–5% per year, cutaneous melanoma is an international scourge that disproportionately targets young individuals. Despite much research, the treatment of advanced disease is still quite challenging. Immunotherapy with high-dose interferon-α2b or interleukin-2 benefits a select group of patients in the adjuvant and metastatic settings, respectively, with significant attendant toxicity. Advances in the biology of malignant melanoma and the role of immunomodulatory therapy have produced advances that have stunned the field. In this paper, we review the data for the use of interferon-α2b in various dosing ranges, vaccine therapy, and the role of radiotherapy in the adjuvant setting for malignant melanoma. Recent trials in the metastatic setting using anticytoxic T-lymphocyte antigen-4 (anti-CTLA-4) monoclonal antibody therapy and BRAF inhibitor therapy have demonstrated clear benefit with prolongation of survival. Trials investigating combinations of these novel agents with existing immunomodulators are at present underway.

Immunization route dictates cross-priming efficiency and impacts the optimal timing of adjuvant delivery

Delivery of cell-associated antigen represents an important strategy for vaccination. While many experimental models have been developed in order to define the critical parameters for efficient cross-priming, few have utilized quantitative methods that permit the study of the endogenous repertoire. Comparing different strategies of immunization, we report that local delivery of cell-associated antigen results in delayed T cell cross-priming due to the increased time required for antigen capture and presentation. In comparison, delivery of disseminated antigen resulted in rapid T cell priming. Surprisingly, local injection of cell-associated antigen, while slower, resulted in the differentiation of a more robust, polyfunctional, effector response. We also evaluated the combination of cell-associated antigen with poly I:C delivery and observed an immunization route-specific effect regarding the optimal timing of innate immune stimulation. These studies highlight the importance of considering the timing and persistence of antigen presentation, and suggest that intradermal injection with delayed adjuvant delivery is the optimal strategy for achieving CD8⁺ T cell cross-priming.

Melanoma vaccines: developments over the past 10 years

Decades of preclinical evaluation and clinical trials into melanoma vaccines have yielded spectacular progress in our understanding of melanoma antigens and the immune mechanisms of tumor rejection. Key insights and the results of their clinical evaluation are reviewed in this article. Unfortunately, durable clinical benefit following vaccination remains uncommon. Two recent clinical advances that will impact on melanoma vaccine development are trials with inhibitors of CTLA-4 and oncogenic BRAF. Long-term therapeutic control of melanoma will require integration of specific active immunotherapy with these emerging successful therapies from the disparate fields of immune regulation and signal transduction.

Cancer immunotherapy

Cancer immunotherapy consists of approaches that modify the host immune system, and/or the utilization of components of the immune system, as cancer treatment. During the past 25 years, 17 immunologic products have received regulatory approval based on anticancer activity as single agents and/or in combination with chemotherapy. These include the nonspecific immune stimulants BCG and levamisole; the cytokines interferon-α and interleukin-2; the monoclonal antibodies rituximab, ofatumumab, alemtuzumab, trastuzumab, bevacizumab, cetuximab, and panitumumab; the radiolabeled antibodies Y-90 ibritumomab tiuxetan and I-131 tositumomab; the immunotoxins denileukin diftitox and gemtuzumab ozogamicin; nonmyeloablative allogeneic transplants with donor lymphocyte infusions; and the anti-prostate cancer cell-based therapy sipuleucel-T. All but two of these products are still regularly used to treat various B- and T-cell malignancies, and numerous solid tumors, including breast, lung, colorectal, prostate, melanoma, kidney, glioblastoma, bladder, and head and neck. Positive randomized trials have recently been reported for idiotype vaccines in lymphoma and a peptide vaccine in melanoma. The anti-CTLA-4 monoclonal antibody ipilumumab, which blocks regulatory T-cells, is expected to receive regulatory approval in the near future, based on a randomized trial in melanoma. As the fourth modality of cancer treatment, biotherapy/immunotherapy is an increasingly important component of the anticancer armamentarium.

Interferon signaling patterns in peripheral blood lymphocytes may predict clinical outcome after high-dose interferon therapy in melanoma patients

Background

High-dose Interferon (HDI) therapy produces a clinical response and achieves relapse-free survival in 20-33% of patients with operable high risk or metastatic melanoma. However, patients may develop significant side effects frequently necessitating dose reduction or discontinuation of therapy. We recently showed that peripheral blood lymphocytes (PBL) from some melanoma patients have impaired interferon (IFN) signaling which could be restored with high concentrations of IFN. This exploratory study evaluated IFN signaling in PBL of melanoma patients to assess whether the restoration of PBL IFN signaling may predict a beneficial effect for HDI in melanoma patients.

Methods

PBL from 14 melanoma patients harvested on Day 0 and Day 29 of neoadjuvant HDI induction therapy were analyzed using phosflow to assess their interferon signaling patterns through IFN-α induced phosphorylation of STAT1-Y701.

Results

Patients who had a clinical response to HDI showed a lower PBL interferon signaling capacity than non-responders at baseline (Day 0). Additionally, clinical responders and patients with good long-term outcome showed a significant increase in their PBL interferon signaling from Day 0 to Day 29 compared to clinical non-responders and patients that developed metastatic disease. The differences in STAT1 activation from pre- to post- HDI treatment could distinguish between patients who were inclined to have a favorable or unfavorable outcome.

Conclusion

While the sample size is small, these results suggest that interferon signaling patterns in PBL correlate with clinical responses and may predict clinical outcome after HDI in patients with melanoma. A larger confirmatory study is warranted, which may yield a novel approach to select patients for HDI therapy.

Insights into the Role of PAX-3 in the Development of Melanocytes and Melanoma

Melanoma is the deadliest form of skin cancer in the United States with an increasing prevalence. However, the development of melanoma from a melanocyte precursor is still poorly defined. Understanding the molecules responsible for melanoma progression may lead to improved targeted therapy. One potential molecule is the paired box-3 (PAX-3) protein, which has been implicated in the development of melanocytes and malignant melanoma. In melanoma, the expression of PAX-3 is believed to be differentially regulated, and has been linked with malignancies and staging of the disease. The loss of PAX-3 regulation has also been associated with the loss of transforming growth factor-beta (TGF-β) activity, but its effect on PAX-3 in differentiated melanocytes as well as metastatic melanoma remains unclear. Understanding PAX-3 regulation could potentially shift melanoma to a less aggressive and less metastatic disease. This review summarizes our current knowledge on PAX-3 during melanocyte development, its regulation, and its implications in the development of novel chemo-immunotherapeutics against metastatic melanoma.

Immunotherapy using allogeneic squamous cell tumor-dendritic cell fusion hybrids

BACKGROUND

Tumor-associated antigens (TAAs) are known to be immunotherapy targets; thus tumor-sharing TAA may be used as a fusion hybrid partner to confer protection against subsequent tumor challenge.

METHODS

The squamous cell carcinomas (SCCs), SCCVII and B4B8, were used in C3H/HEN mice: SCCVII (H-2(k)) is syngeneic, B4B8 (H-2(d)) is allogeneic. Experiments using tumor alone included hyperimmunization schedule, subdermal and intranodal routes. Mice were challenged 2 weeks later. Fusion hybrids were created from both SCC tumor cell lines and syngeneic dendritic cells (DCs). These were delivered intranodally for immunization, and mice were challenged with tumor 2 weeks later.

RESULTS

Only syngeneic tumor given subdermally was able to protect after tumor challenge 2 weeks later. Hyperimmunization schedule did not alter these findings. However, fusion hybrid immunization from both allogeneic and syngeneic SCCs conferred protection after tumor challenge.

CONCLUSIONS

Allogeneic tumor-DC fusion hybrids targeting TAA can protect against subsequent tumor challenge.

Immunotherapy for melanoma: current status and perspectives

Immunotherapy is an important modality in the therapy of patients with malignant melanoma. As our knowledge about this disease continues to expand, so does the immunotherapeutic armamentarium. Nevertheless, successful preclinical models do not always translate into clinically meaningful results. The authors give a comprehensive analysis of most recent advances in the immune anti-melanoma therapy, including interleukins, interferons, other cytokines, adoptive immunotherapy, biochemotherapy, as well as the use of different vaccines. We also present the fundamental concepts behind various immune enhancement strategies, passive immunotherapy, as well as the use of immune adjuvants. This review brings into discussion the results of newer and older clinical trials, as well as potential limitations and drawbacks seen with the utilization of various immune therapies in malignant melanoma. Development of novel therapeutic approaches, along with optimization of existing therapies, continues to hold a great promise in the field of melanoma therapy research. Use of anti-CTLA4 and anti-PD1 antibodies, realization of the importance of co-stimulatory signals, which translated into the use of agonist CD40 monoclonal antibodies, as well as activation of innate immunity through enhanced expression of co-stimulatory molecules on the surface of dendritic cells by TLR agonists are only a few items on the list of recent advances in the treatment of melanoma. The need to engineer better immune interactions and to boost positive feedback loops appear crucial for the future of melanoma therapy, which ultimately resides in our understanding of the complexity of immune responses in this disease.

Tumor vaccines in 2010: need for integration

Induction of tumor-specific immunity is an attractive approach to cancer therapy, however to date every major pivotal trial has resulted in failure. While the phenomena of tumor-mediated immune suppression has been known for decades, only recently have specific molecular pathways been elucidated, and for the first time, rationale means of intervening and observing results of intervention have been developed. In this review we describe major advances in our understanding of tumor escape from immunological pressure and provide some possible therapeutic scenarios for enhancement of efficacy in future cancer vaccine trials.

Interferon alpha adjuvant therapy in patients with high-risk melanoma: a systematic review and meta-analysis

BACKGROUND

Based on previous meta-analyses of randomized controlled trials (RCTs), the use of interferon alpha (IFN-alpha) in the adjuvant setting improves disease-free survival (DFS) in patients with high-risk cutaneous melanoma. However, RCTs have yielded conflicting data on the effect of IFN-alpha on overall survival (OS).

METHODS

We conducted a systematic review and meta-analysis to examine the effect of IFN-alpha on DFS and OS in patients with high-risk cutaneous melanoma. The systematic review was performed by searching MEDLINE, EMBASE, Cancerlit, Cochrane, ISI Web of Science, and ASCO databases. The meta-analysis was performed using time-to-event data from which hazard ratios (HRs) and 95% confidence intervals (CIs) of DFS and OS were estimated. Subgroup and meta-regression analyses to investigate the effect of dose and treatment duration were also performed. Statistical tests were two-sided.

RESULTS

The meta-analysis included 14 RCTs, published between 1990 and 2008, and involved 8122 patients, of which 4362 patients were allocated to the IFN-alpha arm. IFN-alpha alone was compared with observation in 12 of the 14 trials, and 17 comparisons (IFN-alpha vs comparator) were generated in total. IFN-alpha treatment was associated with a statistically significant improvement in DFS in 10 of the 17 comparisons (HR for disease recurrence = 0.82, 95% CI = 0.77 to 0.87; P < .001) and improved OS in four of the 14 comparisons (HR for death = 0.89, 95% CI = 0.83 to 0.96; P = .002). No between-study heterogeneity in either DFS or OS was observed. No optimal IFN-alpha dose and/or treatment duration or a subset of patients more responsive to adjuvant therapy was identified using subgroup analysis and meta-regression.

CONCLUSION

In patients with high-risk cutaneous melanoma, IFN-alpha adjuvant treatment showed statistically significant improvement in both DFS and OS.

Randomized clinical trials in melanoma

The incidence of melanoma is increasing and it is estimated that, in the United States, the lifetime risk of developing melanoma is 1 in 55. There have been many randomized trials that have refined the treatment and minimized the morbidity of the intervention of this prevalent disease. From 1975 to 2000, there were 154 prospective randomized trials on the treatment of local, regional, and metastatic melanoma. Between 2001 and the end of 2008, there were 52 randomized controlled trials relating to the treatment of patients with malignant melanoma. This article reviews the results of the major studies included in the prior article, and provides a detailed description of selected randomized controlled trials performed from 2001 to 2008.

Childhood melanoma

Pediatric melanoma is rare but increasing in incidence. Because early diagnosis and treatment improves prognosis, clinicians need to include it as a possible diagnosis when evaluating a pigmented lesion in a pediatric patient. Some risk factors for melanoma include xeroderma pigmentosum, giant congenital melanocytic nevi, dysplastic nevus syndrome, atypical nevi, many acquired melanocytic nevi, family history of melanoma, and immunosuppression. Definitive treatment is with surgical excision. Adjuvant therapies such as chemotherapy, immunotherapy, and radiation therapy can be used in advanced cases.

Immunogenicity of allo-vesicle carrying ERBB2 tumor antigen for dendritic cell-based anti-tumor immunotherapy

Dendritic cells (DCs) are able to orchestrate innate and acquired immunity and can activate and sustain a long-lasting anti-tumor immune response in vivo when used as anti-tumor cell therapy. The selection of the antigen and the choice of its formulation are key points in designing anti-cancer DC-based vaccines. Cell released vesicles/exosomes have been shown to transfer antigens, HLAI/peptide complexes and co-stimulatory molecules to recipient cells. In this study we describe the generation of an allogenic microvesicle cell factory in which the expression of a specific tumor antigen was combined to the expression of co-stimulatory and allogeneic molecules. The DG75 lymphoblastoid cell line was selected as microvesicle producer and transfected with ErbB2, as tumor antigen prototype. The shed microvesicles transferred antigenic components to recipient DCs, increasing their immunogenicity. DC pulsing resulted in cross-presentation of ErbB2 both in HLAI and HLAII compartments, and ErbB2-specific CD8+ T cells from cancer patients were activated by DCs pulsed with vesicle-bound ErbB2. The microvesicle cell factory proposed may represent a source of cell free immunogen to be used for DC-based cancer therapy.

Utility of adjuvant systemic therapy in melanoma

The lack of effective drugs in stage IV melanoma has impacted the effectiveness of adjuvant therapies in stage II/III disease. To date, chemotherapy, immunostimulants and vaccines have been used with minimal success. Interferon (IFN) has shown an effect on relapse-free survival (RFS) in several clinical trials; however, without a clinically significant effect on overall survival (OS). A recently conducted meta-analysis demonstrated prolongation of disease-free survival (DFS) in 7% and OS benefit in 3% of IFN-treated patients when compared with observation-only patients. There were no clear differences for the dose and duration of treatment observed. Observation is still an appropriate control arm in adjuvant clinical trials. Regional differences exist in Europe in the adjuvant use of IFN. In Northwest Europe, IFN is infrequently prescribed. In Central and Mediterranean Europe, dermatologists commonly prescribe low-dose IFN therapy for AJCC stage II and III disease. High-dose IFN regimens are not commonly used. The population of patients that may benefit from IFN needs to be further characterised, potentially by finding biomarkers that can predict response. Such studies are ongoing.

Biologics in dermatologic therapy - an update

Biologics are protein molecules which are used in various diseases to target the specific points in the immunopathogenesis of the diseases. The molecules are produced by recombinant DNA technology. The molecules bind to the specific targets without interfering wtih rest of the pathogenetic pathways. Therefore the so called 'immunosuppressives' have, although, a broader broader spectrum of action on immune system, their side-effects are also equally more. The biologics, because of their spefic action on the immune system, have very little side effects. The biologics which have revolutionized the treatment of various dermatologic diseases have been discussed here.

The antitumor and immunoadjuvant effects of IFN-alpha in combination with recombinant poxvirus vaccines

PURPOSE

IFN-alpha is a pleiotropic cytokine possessing immunomodulatory properties that may improve the efficacy of therapeutic cancer vaccines. The aim of this study was to evaluate the effectiveness and compatibility of combining recombinant IFN-alpha with poxvirus vaccines targeting the human carcinoembryonic antigen (CEA) in murine models of colorectal and pancreatic adenocarcinomas, where CEA is a self-antigen.

EXPERIMENTAL DESIGN

The phenotypic and functional effects of IFN-alpha were evaluated in the draining inguinal lymph nodes of tumor-free mice. We studied the effect of the site of IFN-alpha administration (local versus distal) on antigen-specific immune responses to poxvirus vaccination. Mechanistic studies were conducted to assess the efficacy of IFN-alpha and CEA-directed poxvirus vaccines in tumor-bearing CEA transgenic mice.

RESULTS

We identified a dose and schedule of IFN-alpha that induced a locoregional expansion of the draining inguinal lymph nodes and improved cellular cytotoxicity (natural killer and CD8(+)) and antigen presentation. Suppression of the vaccinia virus was avoided by administering IFN-alpha distal to the site of vaccination. The combination of IFN-alpha and vaccine inhibited tumor growth, improved survival, and elicited CEA-specific CTL responses in mice with CEA(+) adenocarcinomas. In mice with pancreatic tumors, IFN-alpha slowed tumor growth, induced CTL activity, and increased CD8(+) tumor-infiltrating lymphocytes.

CONCLUSIONS

These data suggest that IFN-alpha can be used as a biological response modifier with antigen-directed poxvirus vaccines to yield significant therapeutic antitumor immune responses. This study provides the rationale and mechanistic insights to support a clinical trial of this immunotherapeutic strategy in patients with CEA-expressing carcinomas.

[Skin cancer: what's new in clinical research?]

Every year skin cancer is the subject of many publications. In this review of the recent literature, we selected epidemiological, clinical, and therapeutic data published between October 2006 and September 2007. Some of the studies presented in conferences in 2007 are also mentioned. New epidemiological data have been provided regarding the incidence of different types of skin cancers, the effect of certain risk factors or drug or food protective factors, the overall improvement of survival in melanoma, the epidemiological, clinical, and/or therapeutic particularities of rapidely growing melanomas and thick melanomas, and the relations between sun exposure, skin cancers, and other solid tumors. New prognostic studies in melanoma have improved the evaluation of prognosis in specific situations such as thin melanoma, acrolentiginous melanoma, and melanoma with positive sentinel lymph nodes (depending on the type of positivity) or negative sentinel lymph nodes. Important results on adjuvant interferon in melanoma have been presented. Clinical trials evaluating new therapeutic approaches in stage III and IV melanoma are going on. Several studies confirmed the clinical benefit of adjuvant irradiation on the tumor site in Merkel cell carcinoma. New treatments are being studied or have been approved in refractory forms of cutaneous T-cell lymphoma and in inoperable forms of squamous cell carcinoma and dermatofibrosarcoma protuberans.

Immunotherapy for advanced melanoma

Immunotherapy for melanoma has undergone significant change since the first attempts to treat patients with high dose IL-2. Herein, strategies to boost patient antitumor immunity through vaccination, treatment with agents that augment host immunity, and adoptive cell transfer will be discussed. The first two strategies have yielded only limited clinical success, but adoptive cell transfer therapy, particularly following a lymphodepleting, preconditioning regimen has resulted in objective response rates approaching 50%. For a number of reasons, lymphodepletion appears to be critical for maintenance of circulating antitumor T cells following adoptive cell transfer. Balancing antitumor efficacy, autoimmunity, and reconstitution of a functioning immune system remain challenging and potentially life-threatening issues.

Melanoma vaccines

Over the last century, vaccine studies have demonstrated that the human immune system, with appropriate help, can limit or prevent infection against otherwise lethal pathogens. Encouraged by these results, success in animal models and numerous well-documented reports of immune-mediated melanoma regression in humans, investigators developed melanoma vaccines. However, despite considerable laboratory evidence for vaccine-induced immune responses, clinical responses remain poor. Recent studies have elucidated several mechanisms that hinder or prevent the creation of successful vaccines and suggest novel approaches to overcome these barriers. Unraveling the mechanisms of autoimmunity, dendritic cell activation, regulatory T cells and Toll-like receptors will generate novel vaccines that, when used in conjunction with standard adjuvant therapies, may result in improved clinical outcomes. The objective of this review is to provide an overall summary of recent clinical trials with melanoma vaccines and highlight novel vaccine strategies to evaluate in the near future.

Allogeneic melanoma vaccine expressing alphaGal epitopes induces antitumor immunity to autologous antigens in mice without signs of toxicity

Owing to the absence of alphaGal epitopes in human cells and constant stimulation of the immune system by the symbiotic bacterial flora, humans develop high titers of natural antibodies against these epitopes. It has been demonstrated that syngeneic whole cell vaccines modified to express alphaGal epitopes could be used to generate a potent anticancer vaccine. In this study, we tested whether allogeneic whole cell cancer vaccines modified to express alphaGal epitopes would be effective for the treatment of murine melanoma. The alpha(1,3)galactosyltransferase (alphaGT) knockout mice (H-2) with preexisting subcutaneous and pulmonary tumors [alphaGal B16, H-2] received therapeutic vaccinations with S91M3alphaGal (H-2) whole cell allogeneic vaccines. These mice had better survival and reduced pulmonary metastasis burden compared with control mice treated with S91M3 vaccine cells. Vaccination with S91M3alphaGal-induced cytotoxic CD8 T cells recognizing the syngeneic alphaGal B16 tumors measured by adoptive transfer to recipients bearing pulmonary metastases. The presence of allo-antigens did not dominate the induction of immunity to "cryptic" tumor antigens and had helped in the generation of a more efficient vaccine to treat preexisting tumors when compared with classic autologous vaccines. Vaccination with allogeneic alphaGal vaccines did not induce signs of toxicity including changes in weight, hematology, chemistry, and histopathology of major perfused organs or autoimmunity in long-term murine models for breast, lung, and melanoma. This study established the safety and efficacy data of allogeneic alphaGal whole cell vaccines and constituted the basis for the initiation of human clinical trials to treat human malignancies.

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.

Cancer vaccines: on the threshold of success

BACKGROUND

Cancer vaccines are a unique approach to cancer therapy. They exert an antitumor effect by engaging the host immune response, and have great potential for circumventing the intrinsic drug resistance that limits standard cancer management. Additional advantages of cancer vaccines are exquisite specificity, low toxicity, and the potential for a durable treatment effect due to immunologic memory.

OBJECTIVES

This review aims to consider the promise of cancer vaccines, review the current state of cancer vaccine development, and suggest directions for future research.

METHODS

The scope of this review was defined peer-reviewed information found on Medline, and information found on the Internet about Phase III clinical trials that are ongoing and not yet published.

RESULTS/CONCLUSIONS

Multiple Phase III clinical trials have demonstrated the promise and challenges posed by therapeutic vaccines, and defined the next steps in their clinical development. Determining the optimal integration of cancer vaccines with chemotherapy, radiation, surgery, and biologically targeted therapies, defining predictive biomarkers of immunologic and clinical response, and combining tumor vaccines with new drugs that effectively modulate the antitumor immune response, will ensure that cancer vaccines become part of standard cancer therapy and prevention.