Ocular melanoma: what's new?

Poor Response to Checkpoint Immunotherapy in Uveal Melanoma Highlights the Persistent Need for Innovative Regional Therapy Approaches to Manage Liver Metastases

Uveal melanoma is a cancer that develops from melanocytes in the posterior uveal tract. Metastatic uveal melanoma is an extremely rare disease that has a poor long-term prognosis, limited treatment options and a strong predilection for liver metastasis. Median overall survival has been reported to be 6 months and 1 year mortality of 80%. Traditional chemotherapy used in cutaneous melanoma is ineffective in uveal cases. Surgical resection and ablation is the preferred therapy for liver metastasis but is often not feasible due to extent of disease. In this review, we will explore treatment options for liver metastases from uveal melanoma, with a focus on isolated hepatic perfusion (IHP). IHP offers an aggressive regional therapy approach that can be used in bulky unresectable disease and allows high-dose chemotherapy with melphalan to be delivered directly to the liver without systemic effects. Long-term median overall survival has been reported to be as high as 27 months. We will also highlight the poor responses associated with checkpoint inhibitors, including an overview of the biological rationale driving this lack of immunotherapy effect for this disease. The persistent failure of traditional treatments and immunotherapy suggest an ongoing need for regional surgical approaches such as IHP in this disease.

High prevalence of serum IgG antibodies reacting to specific mimotopes of BK polyomavirus, a human oncogenic polyomavirus, in patients affected by uveal melanoma

The uveal melanoma (UM) is the most common human intraocular tumor. The BK polyomavirus (BKPyV) is a small DNA tumor virus whose footprints have been detected in different human cancers. BKPyV has oncogenic potential. Indeed, BKPyV, when inoculated into experimental animals, induces tumors of different histotypes, whereas in vitro, it transforms mammalian cells, including human cells from distinct tissues. In this investigation, the association between UM and BKPyV was studied employing indirect enzyme-linked immunosorbent assays (ELISAs) using synthetic peptides that mimic BKPyV viral capsid 1 (VP1) antigens. Indirect ELISAs were used to detect serum IgG antibodies against this polyomavirus with oncogenic potential in samples from patients with UM and controls, represented by healthy subjects (HS). It was found that serum samples from patients with UM had a higher prevalence of BKPyV antibodies, 85% (51/60), compared with that detected in HS1, 62% (54/87), and HS2, 57% (68/120). The different prevalence of BKPyV antibodies detected in UM versus the two control groups, HS1 and HS2, is statistically significant (p < 0.005). Our immunologic data suggest a significantly higher prevalence of antibodies against BKPyV VP1 epitopes in serum samples from patients with UM compared with HS. These results indicate an association between UM and BKPyV, suggesting that this small DNA tumor virus may be a cofactor in the UM onset or progression.

Dual inhibition of protein kinase C and p53-MDM2 or PKC and mTORC1 are novel efficient therapeutic approaches for uveal melanoma

Uveal melanoma (UM) is the most common cancer of the eye in adults. Many UM patients develop metastases for which no curative treatment has been identified. Novel therapeutic approaches are therefore urgently needed. UM is characterized by mutations in the genes GNAQ and GNA11 which activate the PKC pathway, leading to the use of PKC inhibitors as a rational strategy to treat UM tumors. Encouraging clinical activity has been noted in UM patients treated with PKC inhibitors. However, it is likely that curative treatment regimens will require a combination of targeted therapeutic agents. Employing a large panel of UM patient-derived xenograft models (PDXs), several PKC inhibitor-based combinations were tested in vivo using the PKC inhibitor AEB071. The most promising approaches were further investigated in vitro using our unique panel of UM cell lines. When combined with AEB071, the two agents CGM097 (p53-MDM2 inhibitor) and RAD001 (mTORC1 inhibitor) demonstrated greater activity than single agents, with tumor regression observed in several UM PDXs. Follow-up studies in UM cell lines on these two drug associations confirmed their combination activity and ability to induce cell death. While no effective treatment currently exists for metastatic uveal melanoma, we have discovered using our unique panel of preclinical models that combinations between PKC/mTOR inhibitors and PKC/p53-MDM2 inhibitors are two novel and very effective therapeutic approaches for this disease. Together, our study reveals that combining PKC and p53-MDM2 or mTORC1 inhibitors may provide significant clinical benefit for UM patients.

Phase II Trial of Bevacizumab in Combination With Temozolomide as First-Line Treatment in Patients With Metastatic Uveal Melanoma

BACKGROUND

In experimental models, bevacizumab suppressed in vitro growth and in vivo hepatic metastasis of ocular melanoma cells. Additional preclinical data suggested a potential benefit when combining bevacizumab with dacarbazine.

METHODS

This noncomparative phase II study evaluated a combination of bevacizumab (10 mg/kg on days 8 and 22) with temozolomide (150 mg/m(2) on days 1-7 and 15-21) in 36 patients with metastatic uveal melanoma (MUM). The primary endpoint was the progression-free rate (PFR) at 6 months. Using a modified 2-step Fleming plan, at least 10 of 35 patients were required to support a predefined PFR at 6 months of 40%. Secondary objectives were progression-free survival (PFS), overall survival (OS), and safety; liver perfusion computed tomography (CT) for response imaging; and impact of VEGF-A gene polymorphisms on bevacizumab pharmacodynamics.

RESULTS

First- and second-step analyses revealed nonprogression at 6 months in 3 of 17 and 8 of 35 patients, respectively. Finally, the 6-month PFR was 23% (95% confidence interval [CI]: 10-39), with long-lasting stable disease in 5 patients (14%). Median PFS and OS were 12 weeks and 10 months, respectively. No unexpected toxicity occurred. Liver perfusion CT imaging was not useful in assessing tumor response, and VEGF-A gene polymorphisms were not correlated with toxicity or survival.

CONCLUSION

In patients with MUM, a combination of bevacizumab plus temozolomide achieved a 6-month PFR of 23%.

Uveal Melanoma Patient-Derived Xenografts

The prognosis of uveal melanoma (UM) remains poor due to a high risk of metastatic disease. No effective therapies have been described for metastatic UM, and new therapies are needed to improve the outcome for these patients. To achieve this goal, new preclinical animal models are needed. Existing animal models, including genetically engineered mice and orthotopic xenograft models in immunodeficient animals, are inadequate for modelling human disease. In this review, we present the development and characterization of a large panel of UM patient-derived xenografts (PDXs). Based on molecular features as identified in patient tumors, i.e. histopathological classification, specific gene mutations, as well as genomic and gene expression profiles, we show that PDXs closely resemble many important genetic and histological aspects of human UM with a remarkable stability over the course of their in vivo maintenance. Our techniques for establishing and maintaining primary UMs as xenograft tumors in immunodeficient mice provide a high degree of genetic conservation between the primary tumor and its xenograft over multiple in vivo passages. These models therefore represent a significant advance in the resources available for drug screening and studies of the pathogenesis of UM.

Development and external validation of a prognostic nomogram for metastatic uveal melanoma

Background

Approximately 50% of patients with uveal melanoma (UM) will develop metastatic disease, usually involving the liver. The outcome of metastatic UM (mUM) is generally poor and no standard therapy has been established. Additionally, clinicians lack a validated prognostic tool to evaluate these patients. The aim of this work was to develop a reliable prognostic nomogram for clinicians.

Patients and Methods

Two cohorts of mUM patients, from Veneto Oncology Institute (IOV) (N=152) and Mayo Clinic (MC) (N=102), were analyzed to develop and externally validate, a prognostic nomogram.

Results

The median survival of mUM was 17.2 months in the IOV cohort and 19.7 in the MC cohort. Percentage of liver involvement (HR 1.6), elevated levels of serum LDH (HR 1.6), and a WHO performance status=1 (HR 1.5) or 2–3 (HR 4.6) were associated with worse prognosis. Longer disease-free interval from diagnosis of UM to that of mUM conferred a survival advantage (HR 0.9). The nomogram had a concordance probability of 0.75 (SE .006) in the development dataset (IOV), and 0.80 (SE .009) in the external validation (MC). Nomogram predictions were well calibrated.

Conclusions

The nomogram, which includes percentage of liver involvement, LDH levels, WHO performance status and disease free-interval accurately predicts the prognosis of mUM and could be useful for decision-making and risk stratification for clinical trials.

Blinded by the light: why the treatment of metastatic melanoma has created a new paradigm for the management of cancer

Until recently, treatment for metastatic melanoma was characterised by a limited availability of treatment options that offer objective survival benefit. Cytotoxic agents fundamentally lack the ability to achieve disease control and cytokine therapy with interleukin-2 has an unacceptably high - for the use across all patient cohorts - rate of toxicities. The validation of braf as an oncogene driving melanoma tumorigenesis, as well as the discovery of the role of CTLA-4 receptor in the evasion of anticancer immune response by melanoma, has revolutionised our treatment options against a disease with dismal prognosis. Quick implementation of translational discoveries brought about BRAF/MEK inhibition in clinic, while at the same time, wider experience with CTLA-4 blockade enabled clinicians to manage previously fatal immune-related toxicities with greater confidence. The suitability for clinical use of other oncogenic drivers such as NRAS and c-kit is currently being tested whilst the PD-1/PD-L1/PD-L2 axis has emerged as a new immunotherapy target with exciting early phase results. The recent exponential progress in treatment of melanoma has set an example of translational medicine and the current review aims to explain why, as well as suggesting new goals for the future.

Hepatic intra-arterial versus intravenous fotemustine in patients with liver metastases from uveal melanoma (EORTC 18021): a multicentric randomized trial

BACKGROUND

In uveal melanoma (UM) with metastatic disease limited to the liver, the effect of an intrahepatic treatment on survival is unknown. We investigated prospectively the efficacy and toxicity of hepatic intra-arterial (HIA) versus systemic (IV) fotemustine in patients with liver metastases from UM.

PATIENTS AND METHODS

Patients were randomly assigned to receive either IV or HIA fotemustine at 100 mg/m(2) on days 1, 8, 15 (and 22 in HIA arm only) as induction, and after a 5-week rest period every 3 weeks as maintenance. Primary end point was overall survival (OS). Response rate (RR), progression-free survival (PFS) and safety were secondary end points.

RESULTS

Accrual was stopped after randomization of 171 patients based on the results of a futility OS analysis. A total of 155 patients died and 16 were still alive [median follow-up 1.6 years (range 0.25-6 years)]. HIA did not improve OS (median 14.6 months) when compared with the IV arm (median 13.8 months), hazard ratio (HR) 1.09; 95% confidence interval (CI) 0.79-1.50, log-rank P = 0.59. However, there was a significant benefit on PFS for HIA compared with IV with a median of 4.5 versus 3.5 months, respectively (HR 0.62; 95% CI 0.45-0.84, log-rank P = 0.002). The 1-year PFS rate was 24% in the HIA arm versus 8% in the IV arm. An improved RR was seen in the HIA (10.5%) compared with IV treatment (2.4%). In the IV arm, the most frequent grade ≥3 toxicity was thrombocytopenia (42.1%) and neutropenia (62.6%), compared with 21.2% and 28.7% in the HIA arm. The main grade ≥3 toxicity related to HIA was catheter complications (12%) and liver toxicity (4.5%) apart from two toxic deaths.

CONCLUSION

HIA treatment with fotemustine did not translate into an improved OS compared with IV treatment, despite better RR and PFS. Intrahepatic treatment should still be considered as experimental.

EUDRACT NUMBER AND CLINICALTRIALSGOV IDENTIFIER

2004-002245-12 and NCT00110123.

Genome-wide profiling is a clinically relevant and affordable prognostic test in posterior uveal melanoma

Objective

This study investigated the capacity of genetic analysis of uveal melanoma samples to identify high-risk patients and discusses its clinical implications.

Methods

Patients with posterior uveal melanoma were prospectively enrolled. Tumour samples were derived from enucleated globe, fine-needle aspirates or endoresection. Chromosome 3 and 8 status was determined by array comparative genomic hybridisation (array-CGH). Patients were followed after treatment to detect metastasis.

Results

Four groups were classified by array-CGH. Patients were divided into disomy 3 and normal chromosome 8 (D3/8nl), disomy 3 and 8q gain (D3/8g), monosomy 3 and normal chromosome 8 (M3/8nl) and monosomy 3 and 8 or 8q gain (M3/8g). Median follow-up was 28 months (range: 1–147 months). At the end of the study, 128 patients (33.7%) had developed metastasis and 96 patients had died. Univariate Cox proportional hazard analysis showed that factors associated with metastasis included basal tumour diameter p=0.0007, tumour thickness p=0.01, mixed/epithelioid cell type p=0.0009 and genomic data p<0.0001. High-risk profile was more strongly associated with metastasis than the other prognostic factors p<0.001. Multivariate Cox modelling analysis showed that the status of chromosomes 3 and 8 were the only two variables that independently contributed to prognosis: monosomy 3 alone p=0.001 and monosomy 3 and 8q gain p<0.0001.

Conclusions

Array-CGH allowed identification of three prognostic groups with low, intermediate and high risk of developing metastasis. Array-CGH is a reliable and inexpensive method for uveal melanoma prognosis. This method is now currently used in France.

Current and emerging treatment options for uveal melanoma

Uveal melanoma (UM) is the most common primary malignant intraocular tumor in adults, with a 10-year cumulative metastatic rate of 34%. The most common site of metastasis is the liver (95%). Unfortunately, the current treatment of metastatic UM is limited by the lack of effective systemic therapy. Options for the management of the primary intraocular tumor include radical surgery as well as conservative treatments in order to preserve visual acuity. For metastatic disease, several approaches have been described with no standard method. Nevertheless, median survival after liver metastasis is poor, being around 4–6 months, with a 1-year survival of 10%–15%. In this review, the authors summarize current and promising new treatments for UM.

Role of IL-8 induced angiogenesis in uveal melanoma

Introduction Uveal melanoma (UM) is a highly vascularised tumour generally treated with radiotherapy (RT). A recent preclinical study from our group [1] demonstrated that RT-associated anti-angiogenic therapy has more than additive effects on cell growth, by modulating vascular endothelial growth factor (VEGF) levels. The pro-angiogenic interleukin-8 (IL-8) is highly expressed in both tumour and endothelial cells and is associated with resistance to VEGF-targeted therapies in various tumour types. The aim of this study is to investigate IL-8 release in response to the anti-angiogenic drug bevacizumab (AV) and RT given alone and in combination. Material and methods The human ocular melanoma cells (OCM-1) and human umbilical vein endothelial cells (HUVEC) were grown in transwell plates. AV was administered at a 2,500 μg/ml dose and cells were irradiated with a 6 Gy dose. IL-8 concentrations were determined by ELISA assay. Protein expression was detected by western blot. Results AV alone or in combination with RT reduces VEGF levels in both cell lines when co-cultured; unexpectedly, RT alone did not increase VEGF levels. In transwell plate AV alone lowered IL-8 secretion in both cell lines. This inhibitory effect was reduced when co-cultured cells are treated with AV + RT, suggesting that RT-induced VEGF may reactivate IL-8 secretion, enhancing an alternative pathway to sustain tumour angiogenesis. Conclusions These data indicate that the UM microenvironment, beside VEGF, can activate IL-8 signalling as an alternative pro-angiogenic pathway.

[Translational research and diagnostics of melanoma]

Although early stage malignant melanoma (MM) has a favorable prognosis five year survival rate is poor (<10%) in patients suffering from distant metastases. Due to molecular typing of MM recently high response rates were achieved in metastatic MM by using specific inhibitors directed against the mutated form of BRAF kinase, e.g. Vemurafinib and Dabrafinib. Therefore BRAF mutation analysis has become standard of care in advanced MM and pathologists are urged to provide a quality guaranteed molecular diagnostics. However, squamous neoplasias (e. g., keratoacanthomas) and recurrences of MM mostly within 6 months during targeted therapy point to the need of further translational research. Thus new drugs, such as MEK inhibitors, based on the MAP-kinase pathway downstream of BRAF have already effectively been used. Finally, the impact of molecular characteristics in different subtypes of MM (acral, mucosal, uveal) will be discussed with respect to their specific mutational spectrum (e.g. cKIT , NRAS , GNAQ).