Cytokine-enhanced vaccine and suicide gene therapy as surgery adjuvant treatments for spontaneous canine melanoma: 9 years of follow-up

Cancer Immunotherapy

The enhanced understanding of immunology experienced over the last 5 decades afforded through the tools of molecular biology has recently translated into cancer immunotherapy becoming one of the most exciting and rapidly expanding fields. Human cancer immunotherapy is now recognized as one of the pillars of treatment alongside surgery, radiation, and chemotherapy. The field of veterinary cancer immunotherapy has also rapidly advanced in the last decade with a handful of commercially available products and a plethora of investigational cancer immunotherapies, which will hopefully expand our veterinary oncology treatment toolkit over time.

Suicide gene therapy by canine mesenchymal stem cell transduced with thymidine kinase in a u-87 glioblastoma murine model: Secretory profile and antitumor activity

The role played by certain domestic species such as dogs as a translational model in comparative oncology shows great interest to develop new therapeutic strategies in brain tumors. Gliomas are a therapeutic challenge that represents the most common form of malignant primary brain tumors in humans and the second most common form in dogs. Gene-directed enzyme/prodrug therapy using adipose mesenchymal stem cells (Ad-MSCs) expressing the herpes simplex virus thymidine kinase (TK) has proven to be a promising alternative in glioblastoma therapy, through its capacity to migrate and home to the tumor and delivering local cytotoxicity avoiding other systemic administration. In this study, we demonstrate the possibility for canine Ad-MSCs (cAd-MSCs) to be genetically engineered efficiently with a lentiviral vector to express TK (TK-cAd-MSCs) and in combination with ganciclovir (GCV) prodrug demonstrated its potential antitumor efficacy in vitro and in vivo in a mice model with the human glioblastoma cell line U87. TK-cAd-MSCs maintained cell proliferation, karyotype stability, and MSCs phenotype. Genetic modification significantly affects its secretory profile, both the analyzed soluble factors and exosomes. TK-cAd-MSCs showed a high secretory profile of some active antitumor immune response cytokines and a threefold increase in the amount of secreted exosomes, with changes in their protein cargo. We also found that the prodrug protein is not released directly into the culture medium by TK-cAd-MSCs. We believe that our work provides new perspectives for glioblastoma gene therapy in dogs and a better understanding of this therapy in view of its possible implantation in humans.

Canine Melanoma Immunology and Immunotherapy: Relevance of Translational Research

In veterinary oncology, canine melanoma is still a fatal disease for which innovative and long-lasting curative treatments are urgently required. Considering the similarities between canine and human melanoma and the clinical revolution that immunotherapy has instigated in the treatment of human melanoma patients, special attention must be paid to advancements in tumor immunology research in the veterinary field. Herein, we aim to discuss the most relevant knowledge on the immune landscape of canine melanoma and the most promising immunotherapeutic approaches under investigation. Particular attention will be dedicated to anti-cancer vaccination, and, especially, to the encouraging clinical results that we have obtained with DNA vaccines directed against chondroitin sulfate proteoglycan 4 (CSPG4), which is an appealing tumor-associated antigen with a key oncogenic role in both canine and human melanoma. In parallel with advances in therapeutic options, progress in the identification of easily accessible biomarkers to improve the diagnosis and the prognosis of melanoma should be sought, with circulating small extracellular vesicles emerging as strategically relevant players. Translational advances in melanoma management, whether achieved in the human or veterinary fields, may drive improvements with mutual clinical benefits for both human and canine patients; this is where the strength of comparative oncology lies.

Adenoviral CD40 Ligand Immunotherapy in 32 Canine Malignant Melanomas-Long-Term Follow Up

Malignant melanoma is a serious disease in both humans and dogs, and the high metastatic potential results in poor prognosis for many patients. Its similarities with human melanoma make spontaneous canine melanoma an excellent model for comparative studies of novel therapies and tumor biology. Gene therapy using adenoviruses encoding the immunostimulatory gene CD40L (AdCD40L) has shown promise in initial clinical trials enrolling human patients with various malignancies including melanoma. We report a study of local AdCD40L treatment in 32 cases of canine melanoma (23 oral, 5 cutaneous, 3 ungual and 1 conjunctival). Eight patients were World Health Organization (WHO) stage I, 9 were stage II, 12 stage III, and 3 stage IV. One to six intratumoral injections of AdCD40L were given every seven days, combined with cytoreductive surgery in 20 cases and only immunotherapy in 12 cases. Tumor tissue was infiltrated with T and B lymphocytes after treatment, suggesting immune stimulation. The best overall response based on result of immunotherapy included 7 complete responses, 5 partial responses, 5 stable and 2 progressive disease statuses according to the World Health Organization response criteria. Median survival was 285 days (range 20–3435 d). Our results suggest that local AdCD40L therapy is safe and could have beneficial effects in dogs, supporting further treatment development. Clinical translation to human patients is ongoing.

Proliferation index and pseudoprogression as predictors of the therapeutic efficacy of suicide gene therapy for canine melanoma

In our veterinary clinical trials, the combination of systemic immunotherapy with local herpes simplex virus thymidine kinase/ganciclovir suicide gene (SG) treatment induced tumor pseudoprogression as part of a strong local antitumor response. This phenomenon could be owing to tumor inflammation, increased vascular permeability and to different tumor growth rates before, during and after SG therapy. The proliferation index (PI: the fraction of viable cells in S, G2/M, and hyperdiploid phases) would reflect the in-vivo and in-vitro proportion of proliferating melanoma cells in the absence of treatment (PIB) or in response to SG (PISG). The extent of in-vivo and in-vitro melanoma cells responses to SG exhibited a reverse correlation with PIB and a direct correlation with PISG. Then, the final SG outcome depended on the balance between PIB-dependent 'regrowth resistance' versus 'regrowth sensitivity' to SG treatment. In all the cell lines derived from canine tumors presenting partial responses to SG treatment, PISG prevailed over PIB. Conversely, as more aggressive was the tumor (greater PIB of the cell line), the more the balance displacement towards 'regrowth resistance' over SG 'regrowth sensitivity'. All these parameters could have a prognostic value for SG treatment response and provide a glimpse at the clinical benefit of this therapy.

Particulate mediators of the bystander effect linked to suicide and interferon-β transgene expression in melanoma cells

In the context of comparative oncology, melanoma cells derived from companion animal tumors are good models for optimizing and predicting their in vivo response to therapeutic strategies. Here, we report that human, canine, and feline melanoma cells driven to death by bleomycin, interferon-β gene, or herpes simplex virus thymidine kinase/ganciclovir suicide gene (SG) treatment significantly increased their internal granularity. This fact correlated with the release of a heterogeneous collection of nano- and micro-sized granules as revealed by transmission electron microscopy. While killing lipofected cells, the expressed transgenes and their derived products were incorporated into these granules that were isolated by differential centrifugation. These particulate factors (PFs) were able to transfer, in a dose- and time-dependent manner, appreciable levels of therapeutic genes, related proteins, and drugs. Thus, when recipient cells of SG-carrying PFs were exposed to ganciclovir, this prodrug was efficiently activated, eliminating them. These PFs kept the functionality of their cargo, even after being subjected to adverse conditions, such as the presence of DNase, freezing, or heating. Since our in vitro system did not include any of the immune mechanisms that could provide additional antitumor activity, the chemo-gene treatments amplified by these delivery bags of therapeutic agents offer a great clinical potential.

Combination of cytokine-enhanced vaccine and chemo-gene therapy as surgery adjuvant treatments for spontaneous canine melanoma

After 6 years of follow-up treating 364 canine melanoma patients, we present here results about the proof-of-concept, safety, and efficacy of a new surgery adjuvant combined gene therapy. The adjuvant treatment (AT) group was divided in three arms as follows: (i) complete surgery plus vaccine (CS-V), (ii) complete surgery plus combined treatment (CS-CT), and (iii) partial surgery plus combined treatment (PS-CT). Besides the genetic vaccines composed by tumor extracts and lipoplexes carrying human interleukin-2 and granulocyte-macrophage colony-stimulating factor genes, the patients were subjected to combined treatment received in the post-surgical bed injections of lipid-complexed thymidine kinase suicide gene plus ganciclovir and canine interferon-β gene plus bleomycin. As compared with surgery-only treated controls (So), CS-CT and CS-V treatments significantly increased the fraction of local disease-free (from 20 to 89 and 74%) and distant metastases-free patients (M0: from 45 to 87 and 84%). Although less effective than CS arms, PS-CT arm demonstrated a significantly improved control of metastatic disease (M0: 80%) compared with So (M0: 44%). In addition, AT produced a significant 9.3- (CS-CT), 6.5- (CS-V), and 5.4-fold (PS-CT) increase of overall survival as compared with their respective So controls. In general terms, the AT changed a lethal disease into a chronic disease where 70% of CS-CT, 51% of CS-V, and 14% of PS-CT patients died of melanoma unrelated causes. These surgery adjuvant treatments delayed or prevented post-surgical recurrence and distant metastasis, and improved disease-free and overall survival while maintaining quality of life. These successful outcomes encourage assaying a similar scheme for human melanoma.

A Review of Immunotherapeutic Strategies in Canine Malignant Melanoma

In dogs, melanomas are relatively common tumors and the most common form of oral malignancy. Biological behavior is highly variable, usually aggressive, and frequently metastatic, with reported survival times of three months for oral or mucosal melanomas in advanced disease stages. Classical clinical management remains challenging; thus, novel and more efficacious treatment strategies are needed. Evidence-based medicine supports the role of the immune system to treat neoplastic diseases. Besides, immunotherapy offers the possibility of a precise medicinal approach to treat cancer. In recent years, multiple immunotherapeutic strategies have been developed, and are now recognized as a pillar of treatment. In addition, dogs represent a good model for translational medicine purposes. This review will cover the most relevant immunotherapeutic strategies for the treatment of canine malignant melanoma, divided among five different categories, namely, monoclonal antibodies, nonspecific immunotherapy activated by bacteria, vaccines, gene therapy, and lymphokine-activated killer cell therapy.

A combination of electrochemotherapy, gene electrotransfer of plasmid encoding canine IL-12 and cytoreductive surgery in the treatment of canine oral malignant melanoma

The aim of this study was to evaluate the safety and efficacy of the combination of electrochemotherapy (ECT) with bleomycin and gene electrotransfer (GET) of plasmid encoding canine interleukin 12 (IL-12) for the treatment of canine oral malignant melanoma (OMM). Our focus was to determine the effect of the treatment on achieving local tumor control and stimulation of an antitumor immune response. Nine dogs with histologically confirmed OMM stage I to III were included in a prospective, non-randomized study. The dogs were treated with a combination of cytoreductive surgery, ECT and IL-12 GET, which was repeated up to five times, depending on the clinical response to the treatment, evaluated according to the follow-up protocol (7, 14 and 28 days after, the last treatment). One month after treatment, the objective response (OR) rate was 67% (6/9). Median survival time (MST) was 6 months and, even though the disease progressed in 8/9 patients at the end of the observation period (2 to 22 months), four animals were euthanized due to tumor-unrelated reasons. In addition, we observed a decline in the percentage of regulatory T cells (Treg) in the peripheral blood in the course of the treatment, which could be attributed to a systemic antitumor response to IL-12 GET. The results of this study suggest that a combination of ECT and IL-12 GET may be beneficial for dogs with OMM, especially when other treatment approaches are not acceptable due to their invasiveness or cost.

Combination of Suicide and Cytokine Gene Therapies as Surgery Adjuvant for Canine Mammary Carcinoma

The incidence of canine mammary carcinoma varies with age, breed, and spay status, being among the main tumors appearing in intact female dogs. Thirty-six canine mammary carcinoma patients received injections of canine interferon-β (cIFN-β) and HSV-thymidine kinase/ganciclovir (HSV-tk/GCV) carrying lipoplexes, into the tumor bed, immediately after surgery. Next, they started periodic subcutaneous injections of lipoplexes carrying a human granulocyte-macrophage colony stimulating factor and interleukin-2 mixed with allogeneic mammary carcinoma extracts. This combined strategy was safe and well tolerated. In addition, only two out of 26 patients treated with complete surgery developed a local relapse, and 0 out of 29 stage II and III patients displayed distant metastases, suggesting both local and systemic antitumor activities. The most encouraging result was the long survival times: 22 > 1 year (where 13 > 2 and 4 > 3 years), while maintaining a good quality of life. The preliminary results in five patients presenting with local disease, an additional HSV-tk/GCV plus cIFN-β gene treatment induced local antitumor activity, evidenced by four objective responses (one complete, three partial) and one stable disease. This successful outcome supports further studies to validate this approach not only for canine veterinary patients, but also for translation to human patients.

Therapeutic potential of bleomycin plus suicide or interferon-β gene transfer combination for spontaneous feline and canine melanoma

We originated and characterized melanoma cell lines derived from tumors of two feline and two canine veterinary patients. These lines reestablished the morphology, physiology and cell heterogeneity of their respective parental tumors. We evaluated the cytotoxicity of bleomycin (BLM) alone, or combined with interferon-β (IFN-β) or HSVtk/GCV suicide gene (SG) lipofection on these cells. Although the four animals presented stage III disease (WHO system), SG treated feline tumors displayed stable disease in vivo, while the canine ones exhibited partial response. Their derived cell lines reflected this behavior. Feline were significantly more sensitive than canine cells to IFN-β gene transfer. BLM improved the antitumor effects of both genes. The higher levels of reactive oxygen species (ROS) significantly correlated with membrane and DNA damages, emphasizing ROS intervention in apoptotic and necrotic cell death. After 3 days of BLM alone or combined with gene treatments, the colony forming capacity of two canine and one feline treatments survivor cells almost disappeared. Taken together, these results suggest that the treatments eradicated tumor initiating cells and support the clinical potential of the tested combinations.

Recent clinical trials of cancer immunogene therapy in companion animals

This mini-review presents the results of veterinary clinical trials on immunogene therapy published from 2014 to 2016. A variety of tumors, among them melanoma (canine and equine), mastocytoma (canine), mammary adenocarcinoma (canine) and fibrosarcoma (feline) were treated by using diverse strategies. Non-viral vectors were usually employed to transfer genes of cytokines, suicide enzymes and/or tumor associated antigens. In general terms, minor or no adverse collateral effects were related to these procedures, and treated patients frequently improved their conditions (better quality of life, delayed or suppressed recurrence or metastatic spread, increased survival). Some of these new methodologies have a promising future if applied as adjuvant treatments of standard approaches. The auspicious results, derived from immunogene therapy studies carried out in companion animals, warrant their imperative usage in veterinary clinical oncology. Besides, they provide a strong preclinical basis (safety assays and proofs of concept) for analogous human clinical trials.

The combination of bleomycin with suicide or interferon-β gene transfer is able to efficiently eliminate human melanoma tumor initiating cells

We explored the potential of a chemogene therapy combination to eradicate melanoma tumor initiating cells, key producers of recurrence and metastatic spread. Three new human melanoma cell lines, two obtained from lymph nodes and one from spleen metastasis were established and characterized. They were cultured as monolayers and spheroids and, in both spatial configurations they displayed sensitivity to single treatments with bleomycin (BLM) or human interferon-β (hIFNβ) gene or herpes simplex virus thymidine kinase/ganciclovir suicide gene (SG) lipofection. However, the combination of bleomycin with SG or hIFNβ gene transfer displayed greater antitumor efficacy. The three cell lines exhibited a proliferative behavior consistent with melan A and gp100 melanoma antigens expression, and BRAF V600E mutation. BLM and both genetic treatments increased the fraction of more differentiated and treatment-sensitive cells. Simultaneously, they significantly decreased the sub-population of tumor initiating cells. There was a significant correlation between the cytotoxicity of treatments with BLM and gene transfer and the fraction of cells exhibiting (i) high proliferation index, and (ii) high intracellular levels of reactive oxygen species. Conversely, the fraction of cells surviving to our treatments closely paralleled their (i) colony and (ii) melanosphere forming capacity. A very significant finding was that the combination of BLM with SG or hIFNβ gene almost abrogated the clonogenic capacity of the surviving cells. Altogether, the results presented here suggest that the combined chemo-gene treatments are able to eradicate tumor initiating cells, encouraging further studies aimed to apply this strategy in the clinic.

Progress and problems with the use of suicide genes for targeted cancer therapy

Among various gene therapy methods for cancer, suicide gene therapy attracts a special attention because it allows selective conversion of non-toxic compounds into cytotoxic drugs inside cancer cells. As a result, therapeutic index can be increased significantly by introducing high concentrations of cytotoxic molecules to the tumor environment while minimizing impact on normal tissues. Despite significant success at the preclinical level, no cancer suicide gene therapy protocol has delivered the desirable clinical significance yet. This review gives a critical look at the six main enzyme/prodrug systems that are used in suicide gene therapy of cancer and familiarizes readers with the state-of-the-art research and practices in this field. For each enzyme/prodrug system, the mechanisms of action, protein engineering strategies to enhance enzyme stability/affinity and chemical modification techniques to increase prodrug kinetics and potency are discussed. In each category, major clinical trials that have been performed in the past decade with each enzyme/prodrug system are discussed to highlight the progress to date. Finally, shortcomings are underlined and areas that need improvement in order to produce clinical significance are delineated.

Cytokine-Enhanced Vaccine and Interferon-β plus Suicide Gene Therapy as Surgery Adjuvant Treatments for Spontaneous Canine Melanoma

We present here a nonviral immunogene therapy trial for canine malignant melanoma, an aggressive disease displaying significant clinical and histopathological overlapping with human melanoma. As a surgery adjuvant approach, it comprised the co-injection of lipoplexes bearing herpes simplex virus thymidine kinase and canine interferon-β genes at the time of surgery, combined with the periodic administration of a subcutaneous genetic vaccine composed of tumor extracts and lipoplexes carrying the genes of human interleukin-2 and human granulocyte-macrophage colony-stimulating factor. Following complete surgery (CS), the combined treatment (CT) significantly raised the portion of local disease-free canine patients from 11% to 83% and distant metastases-free (M0) from 44% to 89%, as compared with surgery-only-treated controls (ST). Even after partial surgery (PS), CT better controlled the systemic disease (M0: 82%) than ST (M0: 48%). Moreover, compared with ST, CT caused a significant 7-fold (CS) and 4-fold (PS) rise of overall survival, and >17-fold (CS) and >13-fold (PS) rise of metastasis-free survival. The dramatic increase of PS metastasis-free survival (>1321 days) and CS recurrence- and metastasis-free survival (both >2251 days) demonstrated that CT was shifting a rapidly lethal disease into a chronic one. In conclusion, this surgery adjuvant CT was able of significantly delaying or preventing postsurgical recurrence and distant metastasis, increasing disease-free and overall survival, and maintaining the quality of life. The high number of canine patients involved in CT (301) and the extensive follow-up (>6 years) with minimal or absent toxicity warrant the long-term safety and efficacy of this treatment. This successful clinical outcome justifies attempting a similar scheme for human melanoma.

Immunotherapy for canine cancer--is it time to go back to the future?

Over the last 50 years, the significance of the immune system in the development and control of cancer has been much debated. However, recent discoveries provide evidence for a role of immunological mechanisms in the detection and destruction of cancer cells. Forty years ago veterinary oncologists were already investigating the feasibility of treating neoplasia by enhancing anticancer immunity. Unfortunately, this research was hindered by lack of a detailed understanding of cancer immunology, this limited the specificity and success of these early approaches. The great forward strides made in our understanding of onco-immunology in recent years have provided the impetus for a resurgence of interest in anticancer immunotherapy for canine patients. In this article both these initial trials and the exciting novel immunotherapeutics currently in development are reviewed.

The importance of comparative oncology in translational medicine

Human cancer is so complex that in vivo preclinical models are needed if effective therapies are to be developed. Naturally occurring cancers in companion animals are therefore a great resource, as shown by the remarkable growth that comparative oncology has seen over the last 30 years. Cancer has become a leading cause of death in companion animals now that more pets are living long enough to develop the disease. Furthermore, more owners are seeking advanced and novel therapies for their pets as they are very much considered family members. Living in the same environments, pets and humans are often afflicted by the same types of cancer which show similar behavior and, in some species, express the same antigen molecules. The treatment of pet tumors using novel therapies is of compelling translational significance.

Ethics of Cancer Gene Transfer Clinical Research

Translation of cancer gene transfer confronts many familiar-and some distinctive-ethical challenges. In what follows, I survey three major ethical dimensions of cancer gene transfer development. Subheading 1 centers on the ethics of planning, designing, and reporting animal studies. Subheading 2 describes basic elements of human subjects protection as pertaining to cancer gene transfer. In Subheading 3, I describe how cancer gene transfer researchers have obligations to downstream consumers of the evidence they produce.

Clinical trials of immunogene therapy for spontaneous tumors in companion animals

Despite the important progress obtained in the treatment of some pets' malignancies, new treatments need to be developed. Being critical in cancer control and progression, the immune system's appropriate modulation may provide effective therapeutic options. In this review we summarize the outcomes of published immunogene therapy veterinary clinical trials reported by many research centers. A variety of tumors such as canine melanoma, soft tissue sarcomas, osteosarcoma and lymphoma, feline fibrosarcoma, and equine melanoma were subjected to different treatment approaches. Both viral and mainly nonviral vectors were used to deliver gene products as cytokines, xenogeneic tumor associated antigens, specific ligands, and proapoptotic regulatory factors. In some cases autologous, allogenic, or xenogeneic transgenic cytokine producing cells were assayed. In general terms, minor or no adverse collateral effects appeared during this kind of therapies and treated patients usually displayed a better course of the disease (longer survival, delayed or suppressed recurrence or metastatic spread, and improvement of the quality of life). This suggests the utility of these methodologies as standard adjuvant treatments. The encouraging outcomes obtained in companion animals support their ready application in veterinary clinical oncology and serve as preclinical proof of concept and safety assay for future human gene therapy trials.

Immunotherapy in veterinary oncology

Tumor immunology and immunotherapy is one of the most exciting and rapidly expanding fields. The immune system is divided into 2 primary components: the innate immune response and the highly specific, but more slowly developing, adaptive or acquired immune response. Immune responses are separated by whether they are induced by exposure to a foreign antigen (active response) or transferred through serum or lymphocytes from an immunized individual (passive response). The ideal cancer immunotherapy agent should discriminate between cancer and normal cells (specificity), be potent enough to kill small or large numbers of tumor cells (sensitivity), and prevent recurrence of a tumor (durability).

Suicide plus immune gene therapy prevents post-surgical local relapse and increases overall survival in an aggressive mouse melanoma setting

In an aggressive B16-F10 murine melanoma model, we evaluated the effectiveness and antitumor mechanisms triggered by a surgery adjuvant treatment that combined a local suicide gene therapy (SG) with a subcutaneous genetic vaccine (Vx) composed of B16-F10 cell extracts and lipoplexes carrying the genes of human interleukin-2 and murine granulocyte and macrophage colony stimulating factor. Pre-surgical SG treatment, neither alone nor combined with Vx was able to slow down the fast evolution of this tumor. After surgery, both SG and SG + Vx treatments, significantly prevented (in 50% of mice) or delayed (in the remaining 50%) post-surgical recurrence, as well as significantly prolonged recurrence-free (SG and SG + Vx) and overall median survival (SG + Vx). The treatment induced the generation of a pseudocapsule wrapping and separating the tumor from surrounding host tissue. Both, SG and the subcutaneous Vx, induced this envelope that was absent in the control group. On the other hand, PET scan imaging of the SG + Vx group suggested the development of an effective systemic immunostimulation that enhanced (18)FDG accrual in the thymus, spleen and vertebral column. When combined with surgery, direct intralesional injection of suicide gene plus distal subcutaneous genetic vaccine displayed efficacy and systemic antitumor immune response without host toxicity. This suggests the potential value of the assayed approach for clinical purposes.

A snapshot of gene therapy in Latin America

Gene therapy attempts the insertion and expression of exogenous genetic material in cells for therapeutic purposes. Conceived in the 1960s, gene therapy reached its first clinical trial at the end of the 1980s and by December 2013 around 600 genuine open clinical trials of gene therapy were registered at NIH Clinical Trials Database. Here, we summarize the current efforts towards the development of gene therapy in Latin America. Our survey shows that the number of scientists involved in the development of gene therapy and DNA vaccines in Latin America is still very low. Higher levels of investment in this technology are necessary to boost the advancement of innovation and intellectual property in this field in a way that would ease both the social and financial burden of various medical conditions in Latin America.

Gene therapy for advanced melanoma: selective targeting and therapeutic nucleic acids

Despite recent advances, the treatment of malignant melanoma still results in the relapse of the disease, and second line treatment mostly fails due to the occurrence of resistance. A wide range of mutations are known to prevent effective treatment with chemotherapeutic drugs. Hence, approaches with biopharmaceuticals including proteins, like antibodies or cytokines, are applied. As an alternative, regimens with therapeutically active nucleic acids offer the possibility for highly selective cancer treatment whilst avoiding unwanted and toxic side effects. This paper gives a brief introduction into the mechanism of this devastating disease, discusses the shortcoming of current therapy approaches, and pinpoints anchor points which could be harnessed for therapeutic intervention with nucleic acids. We bring the delivery of nucleic acid nanopharmaceutics into perspective as a novel antimelanoma therapeutic approach and discuss the possibilities for melanoma specific targeting. The latest reports on preclinical and already clinical application of nucleic acids in melanoma are discussed.