Uveal Melanoma: Comprehensive Review of Its Pathophysiology, Diagnosis, Treatment, and Future Perspectives

Uveal melanoma (UM) is the most common intraocular malignancy in adults. Recent advances highlight the role of tumor-derived extracellular vesicles (TEV) and circulating hybrid cells (CHC) in UM tumorigenesis. Bridged with liquid biopsies, a novel technology that has shown incredible performance in detecting cancer cells or products derived from tumors in bodily fluids, it can significantly impact disease management and outcome. The aim of this comprehensive literature review is to provide a summary of current knowledge and ongoing advances in posterior UM pathophysiology, diagnosis, and treatment. The first section of the manuscript discusses the complex and intricate role of TEVs and CHCs. The second part of this review delves into the epidemiology, etiology and risk factors, clinical presentation, and prognosis of UM. Third, current diagnostic methods, ensued by novel diagnostic tools for the early detection of UM, such as liquid biopsies and artificial intelligence-based technologies, are of paramount importance in this review. The fundamental principles, limits, and challenges associated with these diagnostic tools, as well as their potential as a tracker for disease progression, are discussed. Finally, a summary of current treatment modalities is provided, followed by an overview of ongoing preclinical and clinical research studies to provide further insights on potential biomolecular pathway alterations and therapeutic targets for the management of UM. This review is thus an important resource for all healthcare professionals, clinicians, and researchers working in the field of ocular oncology.

Management of Uveal Melanoma: Updated Cancer Care Alberta Clinical Practice Guideline

OBJECTIVE

The purpose of this guideline update is to reassess and update recommendations in the prior guideline from 2016 on the appropriate management of patients with uveal melanoma.

METHODS

In 2021, a multidisciplinary working group from the Provincial Cutaneous Tumour Team, Cancer Care Alberta, Alberta Health Services was convened to update the guideline. A comprehensive review of new research evidence in PubMed as well as new clinical practice guidelines from prominent oncology groups informed the update. An enhancement in methodology included adding levels of evidence and strength of recommendations. The updated guideline was circulated to all members of the Provincial Cutaneous Tumour Team for review and endorsement.

RESULTS

New and modified recommendations address provider training requirements, diagnostic imaging for the detection of metastases, neo-adjuvant pre-enucleation radiotherapy, intravitreal anti-vascular endothelial growth factor agents for radiation retinopathy, genetic prognostic testing, surveillance following definitive local therapy, and systemic therapy for patients with metastatic uveal melanoma.

DISCUSSION

The recommendations represent evidence-based standards of care agreed to by a large multidisciplinary group of healthcare professionals.

Novel Prognostic Immunohistochemical Markers in Uveal Melanoma-Literature Review

Simple Summary

The following study provides an overview of the English-language literature on the search for new prognostic factors for uveal melanoma. Uveal melanoma is the most common primary intraocular tumor in adults, and although it is a relatively rare disease, it poses a significant health problem. About half of the patients develop distant metastases, and unfortunately there are currently no effective treatments for the disease at such an advanced stage. The search for new prognostic factors is important to understand the biology of the disease and to be able to monitor patients more effectively. At the same time, it creates an opportunity to find new therapeutic targets. We focused our attention on immunohistochemical research because it is a widely used method, relatively cheap, technically simple, and gives reproducible results. The analysis of this study will enable other researchers to verify their research plans and may also be a source of inspiration for creating new ones.

Abstract

Uveal melanoma is the most common primary intraocular neoplasm in adults. As there are currently no effective methods of treating the disease in the metastatic stage, there is a need to search for new prognostic factors that would enable a reliable assessment of the patient’s condition and constitute a possible therapeutic target. In this review, we have prepared the results of English-language studies on new prognostic factors determined with immunohistochemical methods. We found 64 articles in which the expression of various proteins was associated in a statistically significant manner with the histopathological and clinical prognostic factors identified by AJCC. The results of our work clearly show that the biology of uveal melanoma is extraordinarily complex. Numerous studies have shed new light on the complexity of the processes involved in the development of this cancer. Moreover, a careful analysis of the expression of individual proteins may allow the identification of homogeneous groups of patients requiring different treatment regimens.

An update on the safety of nivolumab for the treatment of advanced melanoma

Introduction: Due to its unique mechanism of action as an immune checkpoint inhibitor, nivolumab has high antitumor activity, but at the same time this mechanism is responsible for immune-related adverse events that may limit patients' safety and therapy continuation.Areas covered: Long-term safety of nivolumab including 5-year follow-up, safety of nivolumab treatment after ipilimumab therapy, safety of nivolumab in challenging subgroups (elderly, patients with brain metastases, patients with autoimmune disorders), safety of nivolumab in with rare melanoma subtypes (including mucosal melanoma), as well as specificity of AEs reported for nivolumab treatment in melanoma patients in comparison to other cancer types and other immunotherapy molecules, and impact of AEs on response rates and PFS on nivolumab treatment are discussed.Expert opinion: Search for biomarkers that would help us to identify patient populations that may suffer from severe nivolumab toxicity could help in selecting patients that should not be treated with this type of therapy. Novel combinations and immunotherapy drugs including use of NKTR-214 (IL-2 pathway), lymphocyte-activation gene 3 (LAG-3), local injections of talimogene laherparepvec (T-VEC), or systemic use of T-cell receptors agonists such as OX40, CD137, ICOS-1, could provide regimens with limited toxicity and higher activity.

The Role of Immune Checkpoint Blockade in Uveal Melanoma

Uveal melanoma (UM) represents the most common intraocular malignancy in adults and accounts for about 5% of all melanomas. Primary disease can be effectively controlled by several local therapy options, but UM has a high potential for metastatic spread, especially to the liver. Despite its clinical and genetic heterogeneity, therapy of metastatic UM has largely been adopted from cutaneous melanoma (CM) with discouraging results until now. The introduction of antibodies targeting CTLA-4 and PD-1 for immune checkpoint blockade (ICB) has revolutionized the field of cancer therapy and has achieved pioneering results in metastatic CM. Thus, expectations were high that patients with metastatic UM would also benefit from these new therapy options. This review provides a comprehensive and up-to-date overview on the role of ICB in UM. We give a summary of UM biology, its clinical features, and how it differs from CM. The results of several studies that have been investigating ICB in metastatic UM are presented. We discuss possible reasons for the lack of efficacy of ICB in UM compared to CM, highlight the pitfalls of ICB in this cancer entity, and explain why other immune-modulating therapies could still be an option for future UM therapies.

Real-World Impact of Immune Checkpoint Inhibitors in Metastatic Uveal Melanoma

Uveal melanoma (UM) is the most common intraocular malignancy in adults and shows a high rate of metastatic spread. As randomized clinical trials with immune checkpoint inhibitors (ICI) have not been performed in patients with metastatic UM, we analyzed the real-world outcomes in a nationwide population-based study. Clinical data of patients with UM were extracted from the Danish Metastatic Melanoma database, a nationwide database containing unselected records of patients diagnosed with metastatic melanoma in Denmark. Survival before (pre-ICI, n = 32) and after (post-ICI, n = 94) the approval of first-line treatment with ICI was analyzed. A partial response to first-line treatment was observed in 7% of patients treated with anti-programmed cell death protein (PD)-1 monotherapy and in 21% with combined anti-cytotoxic T lymphocyte antigen (CTLA)-4 plus anti-PD-1 therapy. Median progression-free survival was 2.5 months for patients treated in the pre-ICI era compared to 3.5 months in the post-ICI era (hazard ratio (HR) 0.43; 95% confidence interval (CI) 0.28–0.67; p < 0.001). The estimated one-year overall survival rate increased from 25.0% to 41.9% and the median overall survival improved from 7.8 months to 10.0 months, respectively (HR 0.52; 95% CI 0.34–0.79; p = 0.003). Thus, the introduction of ICI as first-line treatment appears to have significantly improved the real-world survival of patients with metastatic UM, despite relatively low response rates compared to cutaneous melanoma. With the lack of therapies proven effective in randomized trials, these data support the current treatment with ICI in patients with metastatic UM.

Safety and efficacy of nivolumab in patients with rare melanoma subtypes who progressed on or after ipilimumab treatment: a single-arm, open-label, phase II study (CheckMate 172)

BACKGROUND

Nivolumab has been widely studied in non-acral cutaneous melanoma; however, limited data are available in other melanoma subtypes. We report outcomes by melanoma subtype in patients who received nivolumab after progression on prior ipilimumab.

PATIENTS AND METHODS

CheckMate 172 was a phase II, single-arm, open-label, multicentre study that evaluated nivolumab in patients with advanced melanoma who progressed on or after ipilimumab. Patients received 3 mg/kg of nivolumab, every 2 weeks for up to 2 years. The primary end-point was incidence of grade ≥3, treatment-related select adverse events (AEs).

RESULTS

Among 1008 treated patients, we report data on patients with non-acral cutaneous melanoma (n = 723 [71.7%]), ocular melanoma (n = 103 [10.2%]), mucosal melanoma (n = 63 [6.3%]), acral cutaneous melanoma (n = 55 [5.5%]) and other melanoma subtypes (n = 64 [6.3%]). There were no meaningful differences in the incidence of grade ≥3, treatment-related select AEs among melanoma subtypes or compared with the total population. No new safety signals emerged. At a minimum follow-up of 18 months, median overall survival was 25.3 months for non-acral cutaneous melanoma and 25.8 months for acral cutaneous melanoma, with 18-month overall survival rates of 57.5% and 59.0%, respectively. Median overall survival was 12.6 months for ocular melanoma and 11.5 months for mucosal melanoma, with 18-month overall survival rates of 34.8% and 31.5%, respectively.

CONCLUSIONS

The safety profile of nivolumab after ipilimumab is similar across melanoma subtypes. Compared with non-acral cutaneous melanoma, patients with acral cutaneous melanoma had similar survival outcomes, whereas those with ocular and mucosal melanoma had lower median overall survival. CLINICALTRIALS.

GOV ID

NCT02156804.

Immunological Backbone of Uveal Melanoma: Is There a Rationale for Immunotherapy?

No standard treatment has been established for metastatic uveal melanoma (mUM). Immunotherapy is commonly used for this disease even though UM has not been included in phase III clinical trials with checkpoint inhibitors. Unfortunately, only a minority of patients obtain a clinical benefit with immunotherapy. The immunological features of mUM were reviewed in order to understand if immunotherapy could still play a role for this disease.

The impact of targeted therapies and immunotherapy in melanoma brain metastases: A systematic review and meta-analysis

BACKGROUND

Targeted therapies (TT), combination immunotherapy (CMI), and monoimmunotherapy (MI) in combination with radiotherapy (CRI) or not are commonly used in patients with melanoma brain metastases, but studies that directly compare these strategies are lacking. The current meta-analysis aimed to better elucidate their activity and efficacy.

METHODS

A systematic search of MEDLINE, Embase, and conference proceedings up to January 2019 was performed to identify trials investigating combination TT, monotargeted TT (mono TT), MI, CMI, and CRI in melanoma brain metastases. The outcomes considered were progression-free survival (PFS), overall survival (OS), and the objective response rate (ORR) as evaluated at both intracranial and extracranial sites. Random effects models were used to compare the different therapeutic strategies.

RESULTS

A total of 15 trials were included that provided 1132 patients for analyses. CMI demonstrated a statistically significant better OS compared with MI (P = .03, P = .05, and P = .03, respectively, at 6 months, 18 months, and 24 months) and combination TT (P = .04 and P = .03, respectively, at 18 months and 24 months). CMI demonstrated a statistically significant better PFS compared with combination TT (P < .001 at 12 months and 18 months), MI (P = .02, P < .02, and P = .05, respectively, at 6 months, 12 months, and 18 months), and mono TT (P < .001 at 6 months, 12 months, and 18 months). The intracranial objective response rate was higher with CMI compared with mono TT (P < .001) and MI (P < .001), whereas there was no difference between CMI and combination TT.

CONCLUSIONS

The results of the current meta-analysis suggested that CMI increases long-term PFS and OS compared with MI and combination TT. Combination TT and CMI are associated with a similar intracranial response rate. The role of systemic therapy in combination with radiotherapy remains to be better elucidated.

T cell receptor sequencing of activated CD8 T cells in the blood identifies tumor-infiltrating clones that expand after PD-1 therapy and radiation in a melanoma patient

PD-1-targeted therapy has dramatically changed advanced cancer treatment. However, many questions remain, including specificity of T cells activated by PD-1 therapy and how peripheral blood analysis correlates to effects at tumor sites. In this study, we utilized TCR sequencing to dissect the composition of peripheral blood CD8 T cells activated upon therapy, comparing it with tumor-infiltrating lymphocytes. We report on a nonagenarian melanoma patient who showed a prominent increase in peripheral blood Ki-67 + CD8 T cells following brain stereotactic radiation and anti-PD-1 immunotherapy. Proliferating CD8 T cells exhibited an effector-like phenotype with expression of CD38, HLA-DR and Granzyme B, as well as expression of the positive costimulatory molecules CD28 and CD27. TCR sequencing of peripheral blood CD8 T cells revealed a highly oligoclonal repertoire at baseline with one clonotype accounting for 30%. However, the majority of dominant clones-including a previously identified cytomegalovirus-reactive clone-did not expand following treatment. In contrast, expanding clones were present at low frequencies in the peripheral blood but were enriched in a previously resected liver metastasis. The patient has so far remained recurrence-free for 36 months, and several CD8 T cell clones that expanded after treatment were maintained at elevated levels for at least 8 months. Our data show that even in a nonagenarian individual with oligoclonal expansion of CD8 T cells, we can identify activation of tumor-infiltrating CD8 T cell clones in peripheral blood following anti-PD-1-based immunotherapies.

Patterns of disease control and survival in patients with melanoma brain metastases undergoing immune-checkpoint blockade

OBJECTIVES

Immune-checkpoint blockers (ICBs) significantly prolong overall survival (OS) in patients with advanced melanoma. Limited data are available on the efficacy and clinical benefit in patients with melanoma brain metastases (MBMs). The aim of this study was to determine whether ICB is active in an unselected cohort treated of patients with known brain metastases and if disease control correlates with the survival.

METHODS

A total of 385 patients with metastatic malignant melanoma treated with ICB as monotherapy between 2005 and 2017 in two tertiary referral centres were included. Patient records were searched for the development of brain metastases. Demographic and clinical data of all patients were collected retrospectively.

RESULTS

We identified 177 patients with MBM who received ICBs (ipilimumab, nivolumab, pembrolizumab). Patients with and without brain metastases received similar ICB regimens. Prognosis was inferior in patients with brain metastases; patients with >1 brain metastasis showed even poorer survival. For extracranial (ec) metastases, disease control was associated with improved survival. However, when comparing patients with intracranial (ic) disease control during immunotherapy to patients with ic disease progression, no difference in OS could be observed.

CONCLUSIONS

In our study, ec disease control was the dominant predictive factor for OS in both patients with or without melanoma brain metastases. These data indicate that clinical trials in melanoma patients with brain metastases should address end-points such as symptom control, quality of life or OS in addition to ic response rates.

Targeted therapy of brain metastases: latest evidence and clinical implications

Brain metastases (BM) occur in 20-40% of patients with cancer and 60-75% of patients with BM become symptomatic. Due to an aging population and advances in the treatment of primary cancers, patients are living longer and are more likely to experience complications from BM. The diagnosis of BM drastically worsens long-term survival rates, with multiple metastases being a poor prognostic factor. Until recently, the mainstay of treatment consisted of stereotactic radiosurgery (SRS), surgical resection, whole brain radiation therapy (WBRT), or a combination of these modalities. Systemic chemotherapy has been felt largely ineffective in the treatment of BM due to the presence of the blood-brain barrier (BBB), which includes efflux pumps on brain capillaries. Over the past decade however, researchers have identified therapeutic agents that are able to cross the BBB. These findings could make a multimodality treatment approach possible, consisting of surgery, radiation, immunotherapy, and targeted therapy, which could lead to better disease control in this patient population and prolong survival. In this review, we discuss present evidence on available targeted therapies and their role in the treatment of BM from primary tumors with the highest prevalence of central nervous system (CNS) involvement, specifically non-small cell lung cancer (NSCLC), breast cancer melanoma, and renal cell carcinoma.