Treatment Of Metastatic Melanoma Research Articles

Abstract 2902: CA-4948 (emavusertib) improves treatment response of preclinical metastatic brain melanoma to anti-PD-1 immune checkpoint blockade

Abstract Background: Although recent advances in immunotherapy for metastatic melanoma have transformed the treatment paradigm for a disease that once carried a grim prognosis, nearly 50% of patients fail to reach a complete response to immune checkpoint blockade (ICB) due to multiple mechanisms of tumor-induced immune resistance. These challenges are amplified in the CNS tumor microenvironment (TME) where metastatic brain melanoma (MBM) demonstrates diminished clinical benefit to ICB treatment. A deeper understanding of these mechanisms are required to improve therapeutic response to ICB for these patients. Our group has previously identified that aberrant activation of the myddosomal cascade through downstream interleukin (IL)-1 receptor-associated kinase (IRAK-4) signaling results in chronic stimulation of MAPK and NF-κB in MBM. Further investigation reveals myddosome signaling emanates in large part from the TME, resulting in reflexive immune suppression. CA-4948 (emavusertib), a small molecule inhibitor of IRAK-4, is capable of reaching therapeutic dose levels in the brain where it demonstrates on-target inhibition of this pathway. These data highlight a unique therapeutic opportunity where selective inhibition of immune-suppressive signaling via targeted IRAK-4 blockade may sensitize MBM to anti-PD-1 ICB. Methods Multispectral imaging of patient MBM samples were analyzed for myddosome expression in the TME. Melanoma preclinical models, including both primary site (cutaneous) and metastatic brain disease, were evaluated for tumor burden and survival in response to CA-4948 treatment alone and in combination with anti-PD-1 ICB. Immunological responses of tumor to treatment were evaluated in two transgenic reporter models, CCR2RFPCX3CR1GFP and IFNγIRES-EYFP, to determine both the distribution and activation of infiltrating immune cells. Tumor-associated myeloid cells were assessed for phenotypic markers by multiparameter flow cytometry. Results Myddosome signaling was found to be elevated in tumor-associated immune cells in patient MBM specimens. Treatment of preclinical melanoma with CA-4948 combined with anti-PD-1 ICB resulted in significantly reduced tumor growth and improved survival in three independent models. CA-4948 treatment was associated with reduced tumor recruitment of peripherally derived tumor-associated macrophages, as well as increased lymphocyte infiltration and improved pro-inflammatory signaling measured by increased IFNγ expression in the combinatorial setting. Conclusion Targeted inhibition of IRAK-4 with CA-4948 improves immune surveillance and activation in preclinical models when combined with anti-PD-1 ICB, resulting in reduced tumor growth and increased survival. Thus, CA-4948 may be an effective adjuvant treatment strategy alongside anti-PD-1 ICB for the treatment of metastatic melanoma. Citation Format: Christina A. von Roemeling, Bently P. Doonan, Amanda M. Acevedo, Jeet A. Patel, Savannah L. Carpenter, Alisha Bhatia, Reinhard W. von Roemeling, Jamison Hoffman, Maureen Lane, Duane A. Mitchell. CA-4948 (emavusertib) improves treatment response of preclinical metastatic brain melanoma to anti-PD-1 immune checkpoint blockade [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 2902.

Melanoma-Modern Treatment for Metastatic Melanoma.

Traditional chemotherapy has been ineffective in the treatment of metastatic melanoma. Until the use of checkpoint inhibitors, patients had very limited survival. Since the original US Food and Drug Administration approval of ipilimumab over a decade ago, the armamentarium of immunotherapeutic agents has expanded to include programmed cell death protein 1 and lymphocyte activation gene 3 antibodies, requiring a nuanced approach to the selection of frontline treatments, managing patients through recurrence and progression, and determining length of therapy. Herein, we review the existing evidence supporting current standard immunotherapy regimens and discuss the clinical decision-making involved in treating patients with metastatic melanoma with checkpoint inhibitors.

Upregulation of IL4-induced gene 1 enzyme by B2 cells during melanoma progression impairs their antitumor properties.

B cells present in human cutaneous melanoma have been associated with protective or detrimental effects on disease progression according to their phenotype. By using the RET model of spontaneous melanoma and adoptive transfer of B16 melanoma cells, we show that immature and follicular B2 (B2-FO) cells exert a protective effect on melanoma progression by promoting the generation of effector memory T cells and limiting the recruitment of polymorphonuclear myeloid-derived suppressor cells. Unfortunately, this beneficial effect progressively wanes as a consequence of enhanced expression of the IL4-induced gene 1 (IL4I1) enzyme by immature B cells and B2-FO cells. Endogenous IL4I1 selectively decreases CXCR5 expression in splenic immature B cells, subverting their trafficking to primary tumors and enhancing the production of IL-10 by B2 cells, thereby promoting an immunosuppressive microenvironment. Accordingly, B2 cells from RET IL4I1KO mice more efficiently controlled B16 melanoma growth than B2 cells from IL4I1-competent RET mice. Collectively, immature B cells and B2-FO cells are key actors in the control of melanoma growth, but their mobility and functions are differently impaired by IL4I1 overexpression during melanoma progression. Thus, our present data strongly urge us to associate an IL4I1 antagonist with current immunotherapy to improve the treatment of metastatic melanoma.

Immunoembolization for the Treatment of Uveal Melanoma Hepatic Metastases.

Uveal melanoma is the most common primary intraocular tumor in adults. Approximately 50% of patients develop metastatic disease despite successful treatment of the primary eye tumor. The liver is the most common site of metastatic disease occurring in more than 90% of patients. Clinical prognosis is dependent on the ability to control the growth of liver tumors. Locoregional therapies play an important role in stabilizing liver metastases, prolonging survival for patients with metastatic uveal melanoma. As overall survival is prolonged, the development of extrahepatic disease becomes more common. Immunoembolization, a form of liver-directed therapy, not only focuses on treating hepatic metastases by stimulating the local immune system to suppress the growth of liver tumors, but it potentially generates a systemic immune response delaying the growth of extrahepatic metastases as well. The following article discusses immunoembolization for the treatment of metastatic uveal melanoma including the rationale, mechanism of action, indications, contraindications, outcomes, and associated toxicities.

Targeting CD20-expressing malignant melanoma cells augments BRAF inhibitor killing.

Mutant BRAF targeted therapies remain a standard of care for the treatment of metastatic malignant melanoma (MM); however, high initial response rates are tempered by the persistence of residual MM cells that eventually lead to disease recurrence and mortality. As MM recurrence during targeted therapy can present with the simultaneous occurrence of multiple tumour nodules at the original body sites, we hypothesized the presence of an intrinsically resistant MM cell subpopulation. To identify an MM cell subpopulation that is intrinsically resistant to targeted therapy and possibly responsible for MM recurrence. Using melanoma cell lines, we defined culture conditions for the reproducible three-dimensional growth of melanospheres to investigate putative cancer stem cell populations. We undertook RNA sequencing and bioinformatic analysis to characterize cell populations between adherent and nonadherent culture, and cells expressing or not expressing CD20. Furthermore, we defined an in vitro assay to evaluate the killing of melanoma cancer stem cells as a therapeutic test using combination therapies targeting driver mutation and CD20. We described the culture conditions that promote MM cells to form melanospheres with a reproducible colony-forming efficiency rate of 0.3-1.3%. RNA sequencing of melanosphere vs. conventional MM cell cultures (n = 6), irrespective of the BRAF mutation status, showed that melanosphere formation was associated with growth and differentiation transcriptional signatures resembling MM tumours. Importantly, melanosphere formation also led to the emergence of a CD20+ MM cell subpopulation, similar to that observed in primary human MM tumours. CD20+ MM cells were resistant to BRAF inhibitor therapy and, consistent with this finding, demonstrated a Forkhead box protein M1 transcriptomic profile (n = 6). Combining BRAF inhibitor and anti-CD20 antibody treatment led to the additional killing of previously resistant CD20+ BRAF mutant MM cells. In patients with MM that harbour a CD20+ subpopulation, combined therapy with BRAF inhibitor and anti-CD20 antibody could potentially kill residual MM cells and prevent disease recurrence.

Cutaneous type IV hypersensitivity reaction following tebentafusp treatment for uveal melanoma.

Tebentafusp is a bispecific protein that recently underwent FDA approval for the treatment of metastatic uveal melanoma that functions by redirecting cytotoxic T cells to glycoprotein-100, a protein highly expressed in melanoma. Although clinical trials have demonstrated that rashes are common in the first few days of treatment, little is known about skin reactions that develop later in the treatment course. Herein, we describe a type IV hypersensitivity reaction and vitiligo-like depigmentation that developed six weeks into treatment and discuss the possible mechanisms underlying these reactions. The type IV hypersensitivity reaction resolved without intervention within seven weeks of onset, suggesting that tebentafusp can be safely continued in select patients who develop this cutaneous reaction.

Disparities in the Receipt of Systemic Treatment in Metastatic Melanoma.

In 2011, immunotherapy and targeted therapy revolutionized melanoma treatment. However, inequities in their use may limit the benefits seen by certain patients. We performed a retrospective review of patients in the National Cancer Database for patients with stage IV melanoma from 2 time periods: 2004-2010 and 2016-2020, distinguishing between those who received systemic therapy and those who did not. We investigated the rates and factors associated with treatment omission. We employed Kaplan-Meier analysis to explore the impact of treatment on overall survival. A total of 19,961 patients met the inclusion criteria: 7621 patients were diagnosed in 2004-2010 and 12,340 patients in 2016-2020, of whom 54.9% and 28.3% did not receive systemic treatment, respectively. The rate of "no treatment" has decreased to a plateau of ∼25% in 2020. Median overall survival was improved with treatment in both time periods (2004-2010: 8.8 vs. 5.6mo [ P <0.05]; and 2016-2020: 25.9 vs. 4.3mo [ P <0.05]). Nonmedical factors associated with the omission of treatment in both periods included low socioeconomic status, Medicaid or no health insurance, and treatment at low-volume centers. In the period from 2016 to 2020, patients treated at nonacademic programs were also less likely to receive treatment. Systemic therapies significantly improve survival for patients with metastatic melanoma, but significant disparities exist with their receipt. Local efforts are needed to ensure all patients benefit from these revolutionary treatments.

Evaluation of ABT-751, a novel anti-mitotic agent able to overcome multi-drug resistance, in melanoma cells

PurposeDrug efflux transporter associated multi-drug resistance (MDR) is a potential limitation in the use of taxane chemotherapies for the treatment of metastatic melanoma. ABT-751 is an orally bioavailable microtubule-binding agent capable of overcoming MDR and proposed as an alternative to taxane-based therapies.MethodsThis study compares ABT-751 to taxanes in vitro, utilizing seven melanoma cell line models, publicly available gene expression and drug sensitivity databases, a lung cancer cell line model of MDR drug efflux transporter overexpression (DLKP-A), and drug efflux transporter ATPase assays.ResultsMelanoma cell lines exhibit a low but variable protein and RNA expression of drug efflux transporters P-gp, BCRP, and MDR3. Expression of P-gp and MDR3 correlates with sensitivity to taxanes, but not to ABT-751. The anti-proliferative IC50 profile of ABT-751 was higher than the taxanes docetaxel and paclitaxel in the melanoma cell line panel, but fell within clinically achievable parameters. ABT-751 IC50 was not impacted by P-gp-overexpression in DKLP-A cells, which display strong resistance to the P-gp substrate taxanes compared to DLKP parental controls. The addition of ABT-751 to paclitaxel treatment significantly decreased cell proliferation, suggesting some reversal of MDR. ATPase activity assays suggest that ABT-751 is a potential BCRP substrate, with the ability to inhibit P-gp ATPase activity.ConclusionOur study confirms that ABT-751 is active against melanoma cell lines and models of MDR at physiologically relevant concentrations, it inhibits P-gp ATPase activity, and it may be a BCRP and/or MDR3 substrate. ABT-751 warrants further investigation alone or in tandem with other drug efflux transporter inhibitors for hard-to-treat MDR melanoma.

Relatlimab: a novel drug targeting immune checkpoint LAG-3 in melanoma therapy.

Relatlimab is a type of human immunoglobulin G4 monoclonal blocking antibody. It is the world's first Lymphocyte-Activation Gene-3 (LAG-3) inhibitor and the third immune checkpoint inhibitor with clinical application, following PD-1 and CTLA-4. Relatlimab can bind to the LAG-3 receptor which blocks the interaction between LAG-3 and its ligand to reduce LAG-3 pathway-mediated immunosuppression and promote T-cell proliferation, inducing tumor cell death. On 18 March 2022, the U.S. FDA approved the fixed-dose combination of relatlimab developed by Bristol Myers Squibb with nivolumab, under the brand name Opdualag for the treatment of unresectable or metastatic melanoma in adult and pediatric patients aged 12 and older. This study comprehensively describes the mechanism of action and clinical trials of relatlimab and a brief overview of immune checkpoint drugs currently used for the treatment of melanoma.

Single agent vs combination immunotherapy in advanced melanoma: a review of the evidence.

The aim of this review is to outline the current landscape of advanced melanoma treatment options, provide insights on selecting combination therapies within different clinical scenarios, capture clinical relevance of anti-programmed cell death protein 1 (PD-1) monotherapy, and explore the unmet needs with immune check-point inhibitors (ICI) in advanced melanoma. ICI based treatment consisted of single agent ICI or dual combination ICI-ICI is the standard of care of front-line treatment of metastatic or unresectable melanoma. PD-1 inhibitors (Pembrolizumab and Nivolumab) improved progression free survival (PFS) and overall survival (OS) compared to chemotherapy and cytotoxic T-lymphocyte associated protein 4 (CTLA-4) inhibitors (Ipilimumab and Tremelimumab). The dual ICI combination (Nivolumab and Ipilimumab) provided profound and durable responses better than monotherapy, and the longest overall survival ever achieved in advanced disease, including in patients with murine sarcoma viral oncogene homolog B (BRAF)-mutated disease, but at the cost of a high risk of severe toxicity. The new dual blockage of LAG-3 and PD-1 (Nivolumab-Relatlimab) emerges as a valid option with promising efficacy outcomes and a favourable toxicity profile. Mature survival data is still needed to capture the real benefit. These new plethora of options pose new challenges not only for optimal treatment sequencing strategies but especially for management of adverse effects, endorsing the need to integrate a holistic and personalized approach for patient care.

Metastatic melanoma of the gallbladder

??????????? ??????? ????? ???? SUMMARY Introduction. Malignant melanoma (MM) is a tumor of the melanocytes and is one of the most aggressive tumors. In most cases, the first symptoms appear in the metastatic phase of the disease. In clinical practice, malignant melanoma very rarely metastasizes to the gallbladder. Modern diagnostic methods include 18F-fluorodeoxyglucose positron emission tomography, new computed tomography protocols, new nuclear magnetic resonance for melanoma protocols, and contrast-enhanced ultrasound. The article aims to emphasize the necessity of radical surgical treatment of metastatic melanoma of the gallbladder. Case report. We present a rare case of metastatic malignant melanoma of the gallbladder, which was treated with cholecystectomy and radical surgical excision of all metastatic lesions. Conclusion. All patients with a positive anamnesis for malignant melanoma require to be checked for the spread of the disease to the gallbladder and subsequent surgical treatment.

Focused ultrasound ablation of melanoma with boiling histotripsy yields abscopal tumor control and antigen-dependent dendritic cell activation.

Background: Boiling histotripsy (BH), a mechanical focused ultrasound ablation strategy, can elicit intriguing signatures of anti-tumor immunity. However, the influence of BH on dendritic cell function is unknown, compromising our ability to optimally combine BH with immunotherapies to control metastatic disease. Methods: BH was applied using a sparse scan (1 mm spacing between sonications) protocol to B16F10-ZsGreen melanoma in bilateral and unilateral settings. Ipsilateral and contralateral tumor growth was measured. Flow cytometry was used to track ZsGreen antigen and assess how BH drives dendritic cell behavior. Results: BH monotherapy elicited ipsilateral and abscopal tumor control in this highly aggressive model. Tumor antigen presence in immune cells in the tumor-draining lymph nodes (TDLNs) was ~3-fold greater at 24h after BH, but this abated by 96h. B cells, macrophages, monocytes, granulocytes, and both conventional dendritic cell subsets (i.e. cDC1s and cDC2s) acquired markedly more antigen with BH. BH drove activation of both cDC subsets, with activation being dependent upon tumor antigen acquisition. Our data also suggest that BH-liberated tumor antigen is complexed with damage-associated molecular patterns (DAMPs) and that cDCs do not traffic to the TDLN with antigen. Rather, they acquire antigen as it flows through afferent lymph vessels into the TDLN. Conclusion: When applied with a sparse scan protocol, BH monotherapy elicits abscopal melanoma control and shapes dendritic cell function through several previously unappreciated mechanisms. These results offer new insight into how to best combine BH with immunotherapies for the treatment of metastatic melanoma.

Novel lncRNA Gm33149 modulates metastatic heterogeneity in melanoma by regulating the miR-5623-3p/Wnt axis via exosomal transfer.

The high mortality rate associated with melanoma primarily results from metastasis and recurrence. However, the precise mechanisms driving these processes remain poorly understood. Intercellular communication between cancer cells and non-cancer cells significantly influences the tumor microenvironment and plays a crucial role in metastasis. Therefore, our current study aims to investigate the role and mechanism of long non-coding RNAs (lncRNAs) in regulating the interaction between melanoma cancer stem cells (CSCs) and non-CSCs during the metastatic colonization process. This study has characterized a novel lncRNA called Gm33149. Importantly, we provide evidence for the first time that Gm33149, originating from highly metastatic melanoma stem cells (OL-SD), can be packaged into exosomes and transferred to low-metastatic nonstem cells (OL). Once internalized by OL cells, Gm33149 exerts its function through a competitive endogenous RNA mechanism (ceRNA) involving miR-5623-3p. Specifically, Gm33149 competitively binds to miR-5623-3p, thereby activating the Wnt signaling pathway and promoting the acquisition of a more aggressive metastatic phenotype by OL cells. In summary, our findings suggest that targeting lncRNA Gm33149 within extracellular vesicles could potentially serve as a therapeutic strategy for the treatment of metastatic melanoma. Schematic representation of the mechanisms underlying the pro-metastatic activity of lncRNA Gm33149 mediated by exosomal transfer. The figure illustrates the key mechanisms involved in the pro-metastatic activity of lncRNA Gm33149 through exosomal transfer. Melanoma stem cells (OLSD) release exosomes containing lncRNA Gm33149. These exosomes are taken up by non-stem melanoma cells (OL), delivering lncRNA Gm33149 to the recipient cells. Within OL cells, lncRNA Gm33149 functions as a competitive endogenous RNA (ceRNA), sequestering miR-5623-3p. This sequestration prevents miR-5623-3p from binding to its target genes, thereby activating the Wnt signaling pathway. The activated Wnt signaling pathway enhances the migration, invasion, and metastatic colonization capabilities of OL cells. The transfer of lncRNA Gm33149 via exosomes contributes to OL cells acquiring "metastatic competency" while promoting their metastatic colonization. These findings underscore the importance of lncRNA Gm33149 in intercellular communication and the metastatic progression of melanoma.

News in immunotherapy for metastatic melanoma: prolgolimab in clinical practice (authors' experience)

The incidence of skin melanoma is growing globally and in Russia. Also, the proportion of patients with advanced skin melanoma prevails. Introduction into clinical practice of a novel group of immunological drugs (anti-CTLA4 and anti-PD-1) for metastatic melanoma increased the time to disease progression and patients' life expectancy. Prolgolimab is a PD-1 inhibitor, a new domestic drug that is effective and safe in treating metastatic melanoma. The article presents authors' experience with prolgolimab. When used in the first-line treatment of metastatic melanoma, this drug achieved long-term stabilization of the disease. The drug showed good tolerability, including in patients with severe comorbidity.

Quality by Design Galvanized development of resveratrol loaded PLGA nanoparticles: In vitro and Ex vivo evaluation for the non-invasive treatment of metastatic melanoma

Melanoma is a lethal form of skin cancer, which progresses with poor prognosis. The melanoma tumors are highly metastatic in nature, which often leads to tumorigenesis in lungs and brain tissues. Invasion and migration are mainly responsible for poor 5-year survival rate of ∼32 % after diagnosis of melanoma. The limitations of conventional melanoma therapy include insufficient drug accumulation in tumor due to distal nature of the tumor, and chemoresistance. Resveratrol (RES) is a TGF-β and WNT/β-catenin inhibitor reported to suppress cancer cell proliferation, invasion, and migration. Therefore, we developed RES-loaded poly(lactic-co-glycolic acid) (PLGA) nanoparticles (RES-PLGA-NPs), and embedded within the carbopol hydrogel to achieve site-specific delivery of resveratrol to melanoma cells. During development stage, we employed quality by design (QbD) approach to understand the process parameters. Consequently, we observed 1.26-fold reduction in IC50 for RES-PLGA-NPs compared to unformulated RES. Scratch assay demonstrated the ability of RES and RES-PLGA-NPs to inhibit the migratory properties of melanoma (B16–F10) cells. Further, cell cycle analysis demonstrated that RES and RES-PLGA-NPs arrested cell cycle progression in G2/M phase. Based on these studies we concluded that RES-PLGA-NPs offered enhanced therapeutic effect by inhibiting cell cycle progression, proliferation and invasion of metastatic melanoma cells. Therefore, delivery of RES via nanoparticulate delivery system may have immense potential for metastatic melanoma treatment.

Microfluidic development and biological evaluation of targeted therapy-loaded biomimetic nano system to improve the metastatic melanoma treatment

Optimizing current therapies is among next steps in metastatic melanoma (MM) treatment landscape. The innovation of this study is the design of production process by microfluidics of cell membrane (CM)-modified nanoparticles (NPs), as an emerging biomimetic platform that allows for reduced immune clearance, long blood circulation time and improved specific tumor targeting. To achieve melanoma selectivity, direct membrane fusion between synthetic liposomes and CMs extracted from MM cell line was performed by microfluidic sonication approach, then the hybrid liposomes were loaded with cobimetinib (Cob) or lenvatinib (Lenva) targeting agents and challenged against MM cell lines and liver cancer cell line to evaluate homotypic targeting and antitumor efficacy. Characterization studies demonstrated the effective fusion of CM with liposome and the high encapsulation efficiency of both drugs, showing the proficiency of microfluidic-based production. By studying the targeting of melanoma cells by hybrid liposomes versus liposomes, we found that both NPs entered cells through endocytosis, whereas the former showed higher selectivity for MM cells from which CM was extracted, with 8-fold higher cellular uptake than liposomes. Hybrid liposome formulation of Cob and Lenva reduced melanoma cells viability to a greater extent than liposomes and free drug and, notably, showed negligible toxicity as demonstrated by bona fide haemolysis test. The CM-modified NPs presented here have the potential to broaden the choice of therapeutic options in MM treatment.

Abstract IA012: REGN10597: A PD-1-targeted, receptor-masked wild type IL-2 with improved therapeutic window for cancer immunotherapy

Abstract Recombinant IL-2 has been used for the treatment of metastatic melanoma and renal cell carcinoma, and induced complete, durable tumor regression in some patients. ​However, its broader use in cancer immunotherapy has been limited by severe toxicity. Here, we describe the development of REGN10597, a PD-1-targeted, receptor-masked IL-2 immunocytokine with attenuated systemic IL-2 activity but maintained capacity to engage endogenous IL-2Ra on PD-1+ T cells. We will share preclinical data on in vitro characterization as well as in vivo efficacy and toxicity studies of REGN10597. Citation Format: Jiaxi Wu, Nicolin Bloch, Aaron Chang, Ramandeep Bhavsar, Qingqing Wang, Supriya Patel, Vidur Garg, Hassan Shakil, Michael Amatulli, Drew Dudgeon, Yuetian Yan, Shunhai Wang, Willy Ramos, Pamela Krueger, Kristin Vazzana, Alison Crawford, Jacqueline Idun, Corinne Decker, David DiLillo, Samira Chandwani, Tammy Huang, Jessica Kirshner, Chungguang Guo, Lynn Macdonald, Erica Ullman, Aynur Hermann, William Olson, Samuel Davis, John Lin, Eric Smith, Tong Zhang. REGN10597: A PD-1-targeted, receptor-masked wild type IL-2 with improved therapeutic window for cancer immunotherapy [abstract]. In: Proceedings of the AACR-NCI-EORTC Virtual International Conference on Molecular Targets and Cancer Therapeutics; 2023 Oct 11-15; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2023;22(12 Suppl):Abstract nr IA012.

CAR NK Cell Therapy for the Treatment of Metastatic Melanoma: Potential & Prospects.

Melanoma is among the most lethal forms of cancer, accounting for 80% of deaths despite comprising just 5% of skin cancer cases. Treatment options remain limited due to the genetic and epigenetic mechanisms associated with melanoma heterogeneity that underlie the rapid development of secondary drug resistance. For this reason, the development of novel treatments remains paramount to the improvement of patient outcomes. Although the advent of chimeric antigen receptor-expressing T (CAR-T) cell immunotherapies has led to many clinical successes for hematological malignancies, these treatments are limited in their utility by their immune-induced side effects and a high risk of systemic toxicities. CAR natural killer (CAR-NK) cell immunotherapies are a particularly promising alternative to CAR-T cell immunotherapies, as they offer a more favorable safety profile and have the capacity for fine-tuned cytotoxic activity. In this review, the discussion of the prospects and potential of CAR-NK cell immunotherapies touches upon the clinical contexts of melanoma, the immunobiology of NK cells, the immunosuppressive barriers preventing endogenous immune cells from eliminating tumors, and the structure and design of chimeric antigen receptors, then finishes with a series of proposed design innovations that could improve the efficacy CAR-NK cell immunotherapies in future studies.

CSPG4 CAR-redirected Cytokine Induced Killer lymphocytes (CIK) as effective cellular immunotherapy for HLA class I defective melanoma

BackgroundEven acknowledging the game-changing results achieved in the treatment of metastatic melanoma with the use of immune checkpoint inhibitors (ICI), a large proportion of patients (40–60%) still fail to respond or relapse due to the development of resistance. Alterations in the expression of Human Leukocyte Antigen class I (HLA-I) molecules are considered to play a major role in clinical resistance to ICI. Cellular immunotherapy with HLA-independent CAR-redirected lymphocytes is a promising alternative in this challenging setting and dedicated translational models are needed.MethodsIn this study, we propose an HLA-independent therapeutic strategy with Cytokine Induced Killer lymphocytes (CIK) genetically engineered with a Chimeric Antigen Receptor (CAR) targeting the tumor antigen CSPG4 as effector mechanism. We investigated the preclinical antitumor activity of CSPG4-CAR.CIK in vitro and in a xenograft murine model focusing on patient-derived melanoma cell lines (Mel) with defective expression of HLA-I molecules.ResultsWe successfully generated CSPG4-CAR.CIK from patients with metastatic melanoma and reported their intense activity in vitro against a panel of CSPG4-expressing patient-derived Mel. The melanoma killing activity was intense, even at very low effector to target ratios, and not influenced by the expression level (high, low, defective) of HLA-I molecules on target cells. Furthermore, CAR.CIK conditioned medium was capable of upregulating the expression of HLA-I molecules on melanoma cells. A comparable immunomodulatory effect was replicated by treatment of Mel cells with exogenous IFN-γ and IFN-α. The antimelanoma activity of CSPG4-CAR.CIK was successfully confirmed in vivo, obtaining a significant tumor growth inhibition of an HLA-defective Mel xenograft in immunodeficient mice.ConclusionsIn this study we reported the intense preclinical activity of CSPG4-CAR.CIK against melanoma, including those with low or defective HLA-I expression. Our findings support CSPG4 as a valuable CAR target in melanoma and provide translational rationale for clinical studies exploring CAR-CIK cellular immunotherapies within the challenging setting of patients not responsive or relapsing to immune checkpoint inhibitors.

H-Scan Discrimination for Tumor Microenvironmental Heterogeneity in Melanoma

Melanoma is a form of malignant skin cancer that exhibits significant inter-tumoral differences in the tumor microenvironment (TME) secondary to genetic mutations. The heterogeneity may be subtle but can complicate the treatment of metastatic melanoma, contributing to a high mortality rate. Therefore, developing an accurate and non-invasive procedure to discriminate microenvironmental heterogeneity to facilitate therapy selection is an important goal. In vivo murine melanoma models that recapitulate human disease using synchronous implanted YUMM 1.7 (Yale University Mouse Melanoma) and YUMMER 1.7 (Yale University Mouse Melanoma Exposed to Radiation) murine melanoma lines were investigated. Mice were treated with antibodies to modulate the immune response and longitudinally scanned with ultrasound (US). US radiofrequency data were processed using the H-scan analysis, attenuation estimation and B-mode processing to extract five US features. The measures were used to compare different TMEs (YUMMER vs. YUMM) and responses to immunomodulatory therapies with CD8 depletion or programmed cell death protein 1 (PD-1) inhibition. Multiparametric analysis produced a combined H-scan parameter, resolving significant differences (i) between untreated YUMMER and YUMM and (ii) between untreated, PD-1-treated and CD8-treated YUMMER. However, more importantly, the B-mode and attenuation measures failed to differentiate YUMMER and YUMM and to monitor treatment responses, indicating that H-scan is required to differentiate subtle differences within the TME. We anticipate that the H-scan analysis could discriminate heterogeneous melanoma metastases and guide diagnosis and treatment selection, potentially reducing the need for invasive biopsies or immunologic procedures.