The Role of Regional Therapies for in-Transit Melanoma in the Era of Improved Systemic Options

Liposomal Phenylephrine Nanoparticles Enhance the Antitumor Activity of Intratumoral Chemotherapy in a Preclinical Model of Melanoma

Intratumoral injection of anticancer agents has limited efficacy and is not routinely used for most cancers. In this study, we aimed to improve the efficacy of intratumoral chemotherapy using a novel approach comprising peri-tumoral injection of sustained-release liposomal nanoparticles containing phenylephrine, which is a potent vasoconstrictor. Using a preclinical model of melanoma, we have previously shown that systemically administered (intravenous) phenylephrine could transiently shunt blood flow to the tumor at the time of drug delivery, which in turn improved antitumor responses. This approach was called dynamic control of tumor-associated vessels. Herein, we used liposomal phenylephrine nanoparticles as a "local" dynamic control strategy for the B16 melanoma. Local dynamic control was shown to increase the retention and exposure time of tumors to intratumorally injected chemotherapy (melphalan). C57BL/6 mice bearing B16 tumors were treated with intratumoral melphalan and peri-tumoral injection of sustained-release liposomal phenylephrine nanoparticles (i.e., the local dynamic control protocol). These mice had statistically significantly improved antitumor responses compared to melphalan alone (p = 0.0011), whereby 58.3% obtained long-term complete clinical response. Our novel approach of local dynamic control demonstrated significantly enhanced antitumor efficacy and is the subject of future clinical trials being designed by our group.

Expression of c-erb-B2 oncoprotein as a neoantigen strategy to repurpose anti-neu antibody therapy in a model of melanoma

In this study, we tested a novel approach of "repurposing" a biomarker typically associated with breast cancer for use in melanoma. HER2/neu is a well characterized biomarker in breast cancer for which effective anti-HER2/neu therapies are readily available. We constructed a lentivirus encoding c-erb-B2 (the animal homolog to HER2/neu). This was used to transfect B16 melanoma in vitro for use in an orthotopic preclinical mouse model, which resulted in expression of c-erb-B2 as a neoantigen target for anti-c-erb-B2 monoclonal antibody (7.16.4). The c-erb-B2-expressing melanoma was designated B16/neu. 7.16.4 produced statistically significant in vivo anti-tumor responses against B16/neu. This effect was mediated by NK-cell antibody-dependent cell-mediated cytotoxicity. To further model human melanoma (which expresses <5% HER2/neu), our c-erb-B2 encoding lentivirus was used to inoculate naïve (wild-type) B16 tumors in vivo, resulting in successful c-erb-B2 expression. When combined with 7.16.4, anti-tumor responses were again demonstrated where approximately 40% of mice treated with c-erb-B2 lentivirus and 7.16.4 achieved complete clinical response and long-term survival. For the first time, we demonstrated a novel strategy to repurpose c-erb-B2 as a neoantigen target for melanoma. Our findings are particularly significant in the contemporary setting where newer anti-HER2/neu antibody-drug candidates have shown increased efficacy.

Management of In-Transit Metastases

PURPOSE OF REVIEW

The purpose of this study is to discuss the current knowledge and future perspectives regarding the treatment options for in-transit metastases (ITM), along with the optimal algorithms for patients presenting with this adverse manifestation of melanoma.

RECENT FINDINGS

In addition to procedures historically accepted for the management of ITM, encompassing surgery and regional techniques, novel medications in the form of immune checkpoint inhibitors (ICI) and targeted therapies now represent standard options, allowing for the possibility of combined approaches, with an expanding role of systemic therapies. Melanoma in-transit metastases consist of intralymphatic neoplastic implants distributed between the primary site and the regional nodal basin, within the subepidermal and dermal lymphatics. Distinct risk factors may influence the development of ITM, and the clinical presentation can be highly heterogeneous, enhancing the complexity of the management of ITM. Surgical resection, when feasible, continues to represent a standard approach for patients with curative intent. Patients with extensive or unresectable disease may also benefit from regional approaches that include isolated limb perfusion or infusion, electrochemotherapy, and a wide variety of intralesional therapies. Over the past decade, regimens with ICI and BRAF/MEK inhibitors dramatically expanded the benefit of systemic treatments for patients with melanoma, both in the adjuvant setting and for those with advanced disease, and the combination of these modalities with regional treatments, as well as neoadjuvant approaches, may represent the future for the treatment of patients with ITM.

Non-Operative Options for Loco-regional Melanoma

Malignant melanoma is the 5th most common cancer and stage IV melanoma accounts for approximately 4% of new melanoma diagnoses in the United States. The prognosis for regionally advanced disease is poor, but there have been numerous recent advances in the medical management of melanoma in-transit metastases. The goal of this paper is to review currently accepted treatment options for in-transit metastases and introduce emerging therapies. Therapies to be discussed include limb perfusion and infusion, immunotherapy, checkpoint inhibitors, and radiation therapy.

Combination Treatment of Topical Imiquimod Plus Anti-PD-1 Antibody Exerts Significantly Potent Antitumor Effect

The exact mechanisms of the imiquimod (IMQ)-induced antitumor effect have not been fully understood. Although both topical IMQ treatment and anti-PD-1 antibody may be used for primary skin lesions or skin metastases of various cancers, the efficacy of each monotherapy for these lesions is insufficient. Using a murine tumor model and human samples, we aimed to elucidate the detailed mechanisms of the IMQ-induced antitumor effect and analyzed the antitumor effect of combination therapy of topical IMQ plus anti-PD-1 antibody. Topical IMQ significantly suppressed the tumor growth of MC38 in wildtype mice. IMQ upregulated interferon γ (IFN-γ) expression in CD8⁺ T cells in both the lymph nodes and the tumor, and the antitumor effect was abolished in both Rag1-deficient mice and IFN-γ-deficient mice, indicating that IFN-γ produced by CD8⁺ T cells play a crucial role in the IMQ-induced antitumor effect. IMQ also upregulated PD-1 expression in T cells as well as PD-L1/PD-L2 expression in myeloid cells, suggesting that IMQ induces not only T-cell activation but also T-cell exhaustion by enhanced PD-1 inhibitory signaling. Combination therapy of topical IMQ plus anti-PD-1 antibody exerted a significantly potent antitumor effect when compared with each single therapy, indicating that the combination therapy is a promising therapy for the skin lesions of various cancers.

Advances in the discovery and development of melanoma drug therapies

INTRODUCTION

Therapeutic strategies for melanoma have evolved significantly over the last decade shifting from cytotoxic chemotherapies like dacarbazine to targeted therapies and immunotherapies including immune checkpoint inhibitors. These new drug therapies have improved overall as well as progression-free survival, lowering the mortality of this cancer for melanoma patients with advanced disease. Newer strategies incorporate combination therapies that harness synergies between mechanisms of anticancer efficacy as well as help overcome resistance issues of monotherapies, which remain a challenge.

AREAS COVERED

This review looks at each class of drug therapy for melanoma and provides an overview of the preclinical mechanism of action, the clinical efficacy data, and their applications in combination therapy regimens. NCCN treatment guidelines, safety, toxicity, and immune-related adverse events are also described as well as a note on cost.

EXPERT OPINION

Numerous ongoing trials continue to evaluate the role of novel therapies and combinations for this challenging disease and understanding their mechanism of action, risks, benefits, and treatment guidelines can help care providers and patients have a more comprehensive and tailored discussion of treatment options and expectations.

In-transit metastatic cutaneous melanoma: current management and future directions

Management of in-transit melanoma encompasses a variety of possible treatment pathways and modalities. Depending on the location of disease, number of lesions, burden of disease and patient preference and characteristics, some treatments may be more beneficial than others. After full body radiographic staging is performed to rule out metastatic disease, curative therapy may be performed through surgical excision, intraarterial regional perfusion and infusion therapies, intralesional injections, systemic therapies or various combinations of any of these. While wide excision is limited in indication to superficial lesions that are few in number, the other listed therapies may be effective in treating unresectable disease. Where intraarterial perfusion based therapies have been shown to successfully treat extremity disease, injectable therapies can be used in lesions of the head and neck. Although systemic therapies for in-transit melanoma have limited specific data to support their primary use for in-transit disease, there are patients who may not be eligible for any of the other options, and current clinical trials are exploring the use of concurrent and sequential use of regional and systemic therapies with early results suggesting a synergistic benefit for oncologic response and outcomes.

pH-Responsive Nanostructures Based on Surface Active Fatty Acid-Protic Ionic Liquids for Imiquimod Delivery in Skin Cancer Topical Therapy

For topical treatment of skin cancer, the design of pH-responsive nanocarriers able to selectively release the drug in the tumor acidic microenvironment represents a reliable option for targeted delivery. In this context, a series of newly synthesized surface-active fatty acid-protic ionic liquids (FA-PILs), based on tetramethylguanidinium cation and different natural hydrophobic fatty acid carboxylates, have been investigated with the aim of developing a pH-sensitive nanostructured drug delivery system for cutaneous administration in the skin cancer therapy. The capability of FA-PILs to arrange in micelles when combined with each other and with the non-ionic surfactant d-α-Tocopherol polyethylene glycol succinate (vitamin E TPGS) as well as their ability to solubilize imiquimod, an immuno-stimulant drug used for the treatment of skin cancerous lesions, have been demonstrated. The FA-PILs-TPGS mixed micelles showed pH-sensitivity, suggesting that the acidic environment of cancer cells can trigger nanostructures’ swelling and collapse with consequent rapid release of imiquimod and drug cytotoxic potential enhancement. The in vitro permeation/penetration study showed that the micellar formulation produced effective imiquimod concentrations into the skin exposed to acid environment, representing a potential efficacious and selective drug delivery system able to trigger the drug release in the tumor tissues, at lower and less irritating drug concentrations.

Dynamic control of tumor vasculature improves antitumor responses in a regional model of melanoma

Despite advances in therapy for melanoma, heterogeneous responses with limited durability represent a major gap in treatment outcomes. The purpose of this study was to determine whether alteration in tumor blood flow could augment drug delivery and improve antitumor responses in a regional model of melanoma. This approach to altering tumor blood flow was termed "dynamic control." Dynamic control of tumor vessels in C57BL/6 mice bearing B16 melanoma was performed using volume expansion (saline bolus) followed by phenylephrine. Intravital microscopy (IVM) was used to observe changes directly in real time. Our approach restored blood flow in non-functional tumor vessels. It also resulted in increased chemotherapy (melphalan) activity, as measured by formation of DNA adducts. The combination of dynamic control and melphalan resulted in superior outcomes compared to melphalan alone (median time to event 40.0 vs 25.0 days, respectively, p = 0.041). Moreover, 25% (3/12) of the mice treated with the combination approach showed complete tumor response. Importantly, dynamic control plus melphalan did not result in increased adverse events. In summary, we showed that dynamic control was feasible, directly observable, and augmented antitumor responses in a regional model of melanoma. Early clinical trials to determine the translational feasibility of dynamic control are ongoing.

Improved durable responses regardless of age following cytoreduction and "no-tourniquet" hyperthermic isolated limb chemotherapy for in transit melanoma of the extremity

BACKGROUND

In-transit metastatic melanoma of the extremity is a clinically aggressive disease. For patients with disease confined to the limb, regional chemotherapy remains an effective option. However, no studies thus far have included cytoreduction or perfusion/infusion without using a limb tourniquet as part of the operative procedure. We hypothesize that combining cytoreduction with no-tourniquet HILP/HILI is safe in patients of all ages and results in durable responses.

METHODS

A retrospective analysis was performed of a prospectively collected database of patients with in-transit malignant melanoma who underwent cytoreduction and HILP/HILI between 2013 and 2017. The primary endpoint was RECIST response at 3-12 months. Secondary endpoints included length of hospital stay, adverse effects, overall survival, and time to recurrence. A subgroup analysis was performed in patients ≥80 years old.

RESULTS

HILP patients had significantly higher disease burdens than HILI patients. Complete response rates for HILP and HILI were 95% and 75%, respectively at 3 months and 47% and 50%, respectively at 1 year (50% for patients >80) with 100% 1-year survival rates for both HILP and HILI patients. Three-year survival rates were 57% (HILP), 52% (HILI) and 68% (patients >80 years old). The average length of stay for all patients was 3.6 ± 1.4 days.

CONCLUSION

Combining cytoreduction with no-tourniquet HILP/HILI for in-transit metastatic melanoma of the extremity resulted in 100% survival regardless of age at 1 year and 68% 3-year survival in patients over 80 without any increase in adverse events.

Intralesional PV-10 for the treatment of in-transit melanoma metastases-Results of a prospective, non-randomized, single center study

Background

Patients with in‐transit melanoma metastases frequently experience high rates of recurrence, limited overall survival and reduced quality of life. After promising results within a Phase II, multi‐center study, PV‐10 treatment was continued at our institution for patients with in‐transit disease.

Methodology

An open‐label, non‐randomized, prospective study was performed at the Princess Alexandra Hospital, Queensland, Australia. Patients were treated with PV‐10 in accordance with the treatment protocol established during a previous Phase II study. The primary outcome was the complete response of treated lesions.

Results

Forty‐five patients were enrolled over a total of 82 treatment episodes from July 2008 to December 2015. With sequential PV‐10 treatments the complete response rate was 42% and overall response rate 87% on an intention to treat analysis. The median follow‐up duration was 22 months and the median overall survival was 25 months from first PV‐10 treatment. Having fewer than 15 metastases at the time of treatment was associated with a complete response (P = 0.03).

Conclusions

Intralesional PV‐10 provided rapid lesion‐specific ablation of melanoma metastases with well‐tolerated local effects and minimal systemic adverse events. This therapy should be considered for patients with multiple accessible deposits within the spectrum of low to moderate disease volume.

Do you know your guidelines? Diagnosis and management of cutaneous head and neck melanoma

The following article is the next installment of the series "Do You Know Your Guidelines?" presented by the Education Committee of the American Head and Neck Society. Guidelines for the prevention, diagnosis, workup, and management of cutaneous melanoma are reviewed in an evidence-based fashion.

MicroRNA-21 antisense oligonucleotide improves the sensitivity of A375 human melanoma cell to Cisplatin: An in vitro study

This study explored Cisplatin resistance effect of microRNA-21 (miR-21) antisense oligonucleotide (AS-ODN) in human melanoma A375 cell. AS-ODN was transfected in melanoma A375 cells and Cisplatin-resistant cell line A375/CDDP, and divided into the AS-ODN, nonsense oligonucleotide (NS-ODN) and normal groups. Cell ultrastructure changes were observed through transmission electron microscope. MiR-21 AS-ODN could be tested cell growth effect in different time periods by trypan blue exclusion. MiR-21 mRNA expression change was detected by quantitative fluorescence PCR. Cell apoptosis, cycle distribution and miR-21 AS-ODN effect on proliferation and Cisplatin sensitivity were tested by flow cytometry, MTT assay, TUNEL, and Clonogenic assay. Cell apoptosis was observed after transfection 24 h with the AS-ODN group, while the NS-ODN and normal group cells had no apoptotic symptoms; Compared with the normal group, the AS-ODN group began to show obvious cell growth inhibition effect after transfection 24 h lasting 72 h (all P < 0.05), but the NS-ODN group had no significant difference (P > 0.05). miR-21 mRNA expression in the AS-ODN group was obviously decreased with rising apoptosis rate (all P < 0.05) and there was no significant difference in the NS-ODN group (P > 0.05). MiR-21 AS-ODN could remarkably increase A375 cell and A375/CDDP cell sensitivity to Cisplatin (P < 0.05), while A375 cell sensitivity to Cisplatin between the NS-ODN group and the normal group had no difference. MiR-21 AS-ODN decreased IC₅₀ and increased Cisplatin sensitivity for A375 cells and A375/CDDP cells, which would be a new target of melanoma treatment.

Preclinical Validation of a Single-Treatment Infusion Modality That Can Eradicate Extremity Melanomas

Isolated limb perfusion (ILP) with the chemotherapeutic agent melphalan is an effective treatment option for extremity in-transit melanoma but is toxic and technically challenging to deliver locoregionally. CBL0137 is an experimental clinical drug with broad anticancer activity in animal models, owing to its ability to bind DNA in a nongenotoxic manner and inactivate the FACT chromatin modulator essential for tumor cell viability. Here, we report that CBL0137 delivered by ILP in a murine melanoma model is as efficacious as melphalan, displaying antitumor activity at doses corresponding to only a fraction of the systemic MTD of CBL0137. The ability to bind DNA quickly combined with a favorable safety profile made it possible to substitute CBL0137 in the ILP protocol, using an intra-arterial infusion method, to safely achieve effective tumor suppression. Our findings of a preclinical proof of concept for CBL0137 and its administration via intra-arterial infusion as a superior treatment compared with melphalan ILP allows for locoregional treatment anywhere a catheter can be placed. Cancer Res; 76(22); 6620-30. ©2016 AACR.