Immune Checkpoint Inhibitors for Treatment of Metastatic Melanoma of the Orbit and Ocular Adnexa

New therapies for unresectable or metastatic cutaneous eyelid and orbital melanoma

PURPOSE

Newer treatment options offer the promise of improved outcomes for metastatic and unresectable melanoma. This investigation was performed to review these modalities for cutaneous eyelid and orbital disease.

METHODS

A search for articles that were related to this subject was performed in the PubMed database, and the bibliographies of these manuscripts were reviewed to ensure capture of the appropriate literature. Data was abstracted and analyzed.

RESULTS

Historically, patients who suffer from melanoma of the ocular adnexa have fared poorly. Approaches that employ BRAF and mitogen-associated protein kinase inhibitors, immunotherapy, and novel cellular therapies improve outcomes and survival rates, although the side effect profiles of these agents are problematic. Most of the existing strategies have not explored ocular adnexal disease specifically, and treatment plans are generally adapted from the general cutaneous oncology literature.

CONCLUSIONS

Thanks to advances in our comprehension of the cellular biology of the disease, the management of unresectable and metastatic melanoma has evolved considerably over the past several years. Newer modalities will likely continue to improve survival and reduce adverse events.

Targeted therapy in ophthalmic oncology: The current status

There have been rapid advancements in the field of ocular oncology for the diagnosis and management of intraocular, adnexal, and orbital tumors. Targeted therapy is in the forefront of medical research in all fields including ocular oncology. Targeted therapy include drugs that target specific genetic mutations, pathways or proteins involved in the development of cancer. In contrast to traditionally used chemotherapy, drugs used in targeted therapy are highly specific for tumor cells and preserve the function of normal cells. This review aims to familiarize ophthalmologists with the drugs that are currently approved or undergoing clinical trials for use in ocular oncology. Targeted therapy is particularly useful for locally advanced or metastatic tumors, including but not limited to eyelid and periocular basal cell carcinoma, periocular cutaneous and conjunctival squamous cell carcinoma, ocular adnexal lymphoma, conjunctival melanoma, and uveal melanoma. The results are promising with improved survival outcomes and better tolerability than chemotherapeutic drugs.

Treatment response and recurrence of conjunctival melanoma with orbital invasion treated with immune checkpoint inhibitors: case report and literature review

INTRODUCTION

Conjunctival melanoma (CM) has genetic characteristics that are similar to primary cutaneous melanoma (PCM). The management of advanced CM with orbital metastasis was limited until the adoption of novel immunotherapy agents that significantly improved the survival of metastatic PCM.

PURPOSE

To review and compare the immune checkpoint inhibitor (ICI) treatment response in cases reported in the English literature with orbital involvement secondary to CM versus PCM. In addition, we report a case of local recurrence of CM in a young female after successful treatment with ICI.

METHODS

In addition to reviewing the chart of one patient who presented to our clinic, we conducted a comprehensive literature review to identify CM cases and cases with orbital metastasis secondary to advanced CM and PCM. Outcomes included patient demographics, response to ICI, and associated adverse effects.

RESULTS

There were ten cases with orbital involvement, four were secondary to CM, and six were metastasis from PCM. Orbital metastasis from PCM regressed following treatment with ICI agents, whereas those secondary to CM resolved completely. There were 19 cases of CM without orbital invasion. Of the 29 cases identified, complete resolution of ocular melanoma was achieved in 15 patients, representing 52% of the cases collectively, and none of them reported recurrence except in our case.

CONCLUSION

CM with orbital invasion responds well to ICIs, with manageable toxic effects. Despite the complete resolution, close observation is needed as the recurrence risk remains.

Targeted Therapy and Immunotherapy for Advanced Malignant Conjunctival Tumors: Systematic Review

PURPOSE

To review the outcomes of targeted therapy and immunotherapy in advanced conjunctival tumors, including conjunctival squamous cell carcinoma, conjunctival melanoma, and conjunctival lymphoma.

METHODS

A Pubmed database systematic search was performed between January 1999 and December 2022. The literature search was limited to studies published in English.

RESULTS

This review included 142 patients with advanced malignant conjunctival tumors from 42 articles. In the conjunctival squamous cell carcinoma group, 2 cases of advanced conjunctival squamous cell carcinoma treated with epidermal growth factor receptor inhibitors showed significant tumor size improvement after 7.5 months of follow-up. Among 7 cases treated with systemic immunotherapy, 5 cases (72%) had complete response (CR), 1 case (14%) showed partial response (PR), and 1 case (14%) had stable disease (SD) after 16 months. In the conjunctival melanoma group, among 18 cases treated with combined v-raf murine sarcoma viral oncogene homolog B1/mitogen-activated extracellular signal-regulated kinase inhibitors, 6 (33%) had CR, 5 (28%) had PR, 2 (11%) had SD, and 5 (28%) had progressive disease after 24.8 months of follow-up. Of 44 conjunctival melanoma cases treated with immunotherapy, 12 (28%) had CR, 9 (20%) had PR, 7(16%) had SD, and 16 (36%) had progressive disease after 14.2 months. Systemic Rituximab treatment for conjunctival lymphoma cases resulted in CR in 21 patients (63%), PR in 11 patients (33%), and SD in 1 patient (3%) after 20.5 months of follow-up. Intralesional Rituximab injections in 38 conjunctival lymphoma cases showed CR in 28 patients (75%), PR in 7 patients (19%), SD in 1 patient (2%), and progressive disease in 2 patients (4%) after 20.4 months of follow-up.

CONCLUSIONS

Despite limited clinical case reports and short-term follow-ups, targeted therapy and immunotherapy have shown promising results for advanced malignant conjunctival tumors.

Genetic Aspects of Conjunctival Melanoma: A Review

Conjunctival melanoma (CM) is a rare but aggressive cancer. Over the past decade, molecular studies using rapidly advancing technologies have increasingly improved our understanding of CM genetics. CMs are mainly characterized by dysregulated MAPK and PI3K/AKT/mTOR pathways, driven by commonly mutated (BRAF, NRAS, NF1) or less commonly mutated (KIT, PTEN) genes. Another group of genes frequently mutated in CMs include TERT and ATRX, with known roles in telomere maintenance and chromatin remodeling/epigenetic regulation. Uveal melanoma-related genes (BAP1, SF3B1, GNAQ/11) can also be mutated in CMs, albeit infrequently. Additional CM-related mutated genes have increasingly been identified using more comprehensive genetic analyses, awaiting further confirmation in additional/larger studies. As a tumor arising in a partly sun-exposed mucosal tissue, CM exhibits a distinct genomic profile, including the frequent presence of an ultraviolet (UV) signature (and high mutational load) and also the common occurrence of large structural variations (distributed across the genome) in addition to specific gene mutations. The knowledge gained from CM genetic studies to date has led to new therapeutic avenues, including the use of targeted and/or immuno-therapies with promising outcomes in several cases. Accordingly, the implementation of tumor genetic testing into the routine clinical care of CM patients holds promise to further improve and personalize their treatments. Likewise, a growing knowledge of poor prognosis-associated genetic changes in CMs (NRAS, TERT, and uveal melanoma signature mutations and chromosome 10q deletions) may ultimately guide future strategies for prognostic testing to further improve clinical outcomes (by tailoring surveillance and considering prophylactic treatments in patients with high-risk primary tumors).

Medical treatment for ocular surface squamous neoplasia

Ocular surface squamous neoplasia (OSSN) is the most common non-melanocytic tumour of the ocular surface. Surgical excision with wide margins using the "no-touch" method was originally the most popular treatment for OSSN. However, in the past two decades, the use of topical medications for OSSN treatment has gained a reputation amongst ophthalmologists for being an effective alternative to surgical excision. Furthermore, technological advancements, such as those seen in high-resolution optical coherence tomography (HR-OCT) for the anterior segment, have facilitated the diagnosis and monitoring of OSSN. When selecting a topical agent, interferon alpha-2b (IFNα-2b) and 5-fluorouracil (5-FU) are two of the gentlest medications used for OSSN and are often considered first line therapies due to their high-resolution rates and mild side effect profiles. Mitomycin C (MMC), on the other hand, has a highly toxic profile; therefore, while effective, in our hands it is considered as a second-line treatment for OSSN if the other modalities fail. In addition, newer and less studied agents, such as immune checkpoint inhibitors, retinoic acid, aloe vera, and anti-vascular endothelial growth factor have anti-neoplastic properties and have shown potential for the treatment of OSSN. We enclose an updated literature review of medical treatments for OSSN.

Multidisciplinary Management of Orbital Metastasis and Survival Outcomes

PURPOSE

To study the multidisciplinary management and survival outcomes of orbital metastasis (OM).

METHODS

All patients with a diagnosis of OM treated during 1999-2019 were included. Clinical data were retrospectively collected and analyzed.

RESULTS

The study included 118 patients, 71 females and 47 males, with a median age of 61 years. The most common primary tumor types were breast carcinoma (43 patients), melanoma (17), and lung (13), thyroid (7), renal cell (6), and neuroendocrine carcinoma (6). Ninety-six patients had a known history of cancer at OM diagnosis. The median time from diagnosis of primary cancer to OM was 31 months (range, 0-304). In 22 patients, OM was the first sign of cancer. In 47 patients, the orbit was the only site of metastasis. The most common presenting features were restricted by extraocular motility (77 patients) and proptosis (61). Eight patients had enophthalmos. OM was diagnosed based on clinical history and imaging studies in 81 patients and orbital biopsy in 37. One hundred nine patients were treated with chemotherapy and immunotherapy, 75 with radiation, and 21 with palliative surgical resection. Eighty-two patients died during follow up. The median overall survival (OS) time after diagnosis of OM was 17 months (95% CI: 12-28). OM from renal cell carcinoma was associated with the best and OM from thyroid cancer with the worst OS. Patients with breast cancer had longer median survival (28 months; 95% CI: 15-60) than patients with lung, melanoma, neuroendocrine, or thyroid cancer.

CONCLUSION

In this large series, breast cancer and melanoma were the most common causes of OM. Most patients had a known history of cancer at OM diagnosis and did not require orbital biopsy to confirm the diagnosis. Patients with renal cell carcinoma and breast carcinoma had the best prognosis after diagnosis of OM.

Conjunctival melanoma: New insights in tumour genetics and immunology, leading to new therapeutic options

Recent developments in oncology have led to a better molecular and cellular understanding of cancer, and the introduction of novel therapies. Conjunctival melanoma (CoM) is a rare but potentially devastating disease. A better understanding of CoM, leading to the development of novel therapies, is urgently needed. CoM is characterized by mutations that have also been identified in cutaneous melanoma, e.g. in BRAF, NRAS and TERT. These mutations are distinct from the mutations found in uveal melanoma (UM), affecting genes such as GNAQ, GNA11, and BAP1. Targeted therapies that are successful in cutaneous melanoma may therefore be useful in CoM. A recent breakthrough in the treatment of patients with metastatic cutaneous melanoma was the development of immunotherapy. While immunotherapy is currently sparsely effective in intraocular tumours such as UM, the similarities between CoM and cutaneous melanoma (including in their immunological tumour micro environment) provide hope for the application of immunotherapy in CoM, and preliminary clinical data are indeed emerging to support this use. This review aims to provide a comprehensive overview of the current knowledge regarding CoM, with a focus on the genetic and immunologic understanding. We elaborate on the distinct position of CoM in contrast to other types of melanoma, and explain how new insights in the pathophysiology of this disease guide the development of new, personalized, treatments.

Primary Orbital Melanoma: An Investigation of a Rare Malignancy Using the National Cancer Database

OBJECTIVES

Primary orbital melanoma (POM) is a rare disease with limited data on survival and best treatment practices. Here we utilize the National Cancer Database (NCDB) to determine the overall survival (OS) and covariates that influence mortality.

STUDY DESIGN

Retrospective cohort study.

METHODS

All patients diagnosed with POM from 2004 to 2016 were identified in the NCDB. Patient and oncologic data were analyzed using the Kaplan-Meier method and multivariate models for the primary outcome of OS.

RESULTS

A total of 129 patients were identified. Median OS was 36.9 months (95% confidence interval [CI] 24.1-78.7 months) with mean 5-year survival of 42.0% (CI 33.2%-53.2%). Treatments received included surgery alone (43.4%), radiation alone (23.3%), and surgery followed by radiation (20.2%). The multivariate model demonstrated an increased risk of death associated with age over 80 years (hazard ratio [HR] 3.41, CI 1.31-8.86, P = .012), a Charlson-Deyo comorbidity score of 2 or greater (HR 5.30, CI 1.87-15.03, P = .002), and no treatment (HR 2.28, CI 1.03-5.06, P = .042). For every 1 cm increase in tumor size, there was an increased risk of death (HR 1.06, CI 1.00-1.13, P = .039). When compared to surgery alone, no other treatment modality had an effect on OS.

CONCLUSIONS

This study leveraged multiyear data from the NCDB to provide prognostic and demographic information on the largest known cohort of POM cases. Increased age, increased comorbidities, not receiving treatment, and larger tumor size were associated with increased mortality. There was no clear survival advantage for specific treatments.

LEVEL OF EVIDENCE

4 Laryngoscope, 131:1790-1797, 2021.

Immune Checkpoint Inhibitor Therapy as an Eye-Preserving Treatment for Locally Advanced Conjunctival Melanoma

The authors present 2 patients with locally advanced conjunctival melanoma for whom definitive surgery would mean an orbital exenteration with its associated inherent total visual loss and major facial disfigurement. Instead both patients were treated with immune checkpoint inhibitor therapy. In 1 patient neoadjuvant pembrolizumab was used for approximately 12 months and the patient experienced near-total clinical resolution of the conjunctival melanoma. Multiple surgical biopsies of very small residual pigmentation showed pigmented macrophages and a complete pathologic response. In the second patient who presented with a locally advanced and metastatic conjunctival melanoma, significant shrinkage of conjunctival mass was observed after treatment with a combination of ipilimumab and nivolumab for 5 months, and this allowed preservation of the eye and ocular function.

PD-L1 Expression in 65 Conjunctival Melanomas and Its Association with Clinical Outcome

Conjunctival melanoma (CM) iss a rare and aggressive tumour that is increasing in frequency. The prognostic value of PD-L1 expression, alone or in combination with CD8 and PD-1 expression and the BRAF and NRAS status, has not been determined in CM to date. We evaluated the expression of PD-L1, CD8, PD-1 in CM and investigated whether there was an association between the expression of these markers and the BRAF and NRAS molecular profile as well as some clinico-pathological criteria. A total of sixty-five CM were assessed for PD-L1, PD-1, and CD8 expression by immunohistochemistry (IHC) and for BRAF and NRAS genomic alterations using molecular biology techniques and anti-BRAF and anti-NRAS antibodies. PD-L1 expression in tumour cells (TC) was very low or absent but detected in tumour-infiltrating immune cells (IC). A correlation was observed between the expression of PD-L1, CD8, and PD-1 in IC. No correlation between PD-L1 expression (in tumour and/or immune cells) and BRAF or NRAS mutations was observed. PD-L1 expression in IC correlated with a higher pTNM stage and PD-L1 expression in TC with worse disease-specific survival. PD-L1 expression is a potential prognostic biomarker that correlates with poor prognosis in CM patients.

Conjunctival Melanoma: Update on Genetics, Epigenetics and Targeted Molecular and Immune-Based Therapies

Purpose

To present the molecular mechanisms involved in the pathogenesis of conjunctival melanoma (CM) and review the existing literature on targeted molecular inhibitors as well as immune checkpoint inhibitors for the management of locally advanced and metastatic disease.

Methods

A comprehensive review of the literature was performed using the keywords "conjunctival melanoma", "immune checkpoint inhibitors", "BRAF inhibitors", "MEK inhibitors", "CTLA4 inhibitors", "PD1 inhibitors", "c-KIT mutations", "BRAF mutations", "NRAS mutations", "dabrafenib", "trametinib", "vemurafenib", "ipilimumab", "pembrolizumab", and "nivolumab". A total of 250 articles were reviewed and 120 were included in this report.

Results

Mutations of mediators in the MAP kinase pathway, such as RAS, BRAF, MEK and ERK, and mutations of the PI3K/AKT/mTOR pathway play a major role in the pathogenesis of conjunctival melanoma. In addition, alterations of c-KIT, NF1, TERT, chemokine receptors as well as chromosomal copy number alterations and micro RNAs are thought to have a causative association with CM development. Targeted molecular inhibitors, such as BRAF and MEK inhibitors, are currently being implemented in the therapy of BRAF-mutated CM. Furthermore, immune checkpoint PD-1 and CTLA4 inhibitors with favorable clinical outcomes in the treatment of cutaneous melanoma have increased recurrence-free survival and reduced metastatic spread in CM cases.

Conclusion

The complex molecular mechanisms that contribute to the development of CM can be targeted both by molecular inhibitors of oncogenic pathways as well as immune checkpoint inhibitors in order to halt progression of the disease and increase survival.

Immune Checkpoint Inhibitor-associated Uveitis: Review of Treatments and Outcomes

Purpose: Immune checkpoint inhibitors (ICPIs), novel immunotherapy agents employed in the treatment of metastatic melanoma and other solid tumors, are associated with immune-related adverse events, including ocular inflammation. We review the current literature on immune checkpoint inhibitor-associated uveitis (ICIPU).Methods: A comprehensive literature review utilizing MEDLINE/PubMed, Cochrane, and Web of Science databases was conducted. One hundred and twenty-six cases of ICPIU reported in the literature prior to January 31, 2020 were identified and reviewed.Results: ICPIs were associated with 126 cases of anterior uveitis, intermediate uveitis, posterior uveitis, and panuveitis from 67 reports in the literature. Patients typically developed intraocular inflammation a median of 9 weeks after initiation of ICPI and 83.6% of the patients developed uveitis within 6 months. The vast majority of patients recovered to within one line of baseline vision in response to topical, local, and/or systemic steroid treatment as well as the cessation of medication.Conclusions: Prompt recognition and steroid treatment of ICPIU are critical to the care of patients receiving ICPIs.

Efficacy of immune checkpoint inhibitors in different types of melanoma

Immunotherapy can be used for cutaneous, mucosal, uveal and conjunctival melanoma. Nevertheless, we cannot expect the same benefit from checkpoint inhibitors for all the types of melanoma. The different biological features can explain the variable efficacy. The main results obtained with immune checkpoint inhibitors in the various types of melanoma were reviewed.

Immunotherapy With Programmed Cell Death 1 Inhibitors for 5 Patients With Conjunctival Melanoma

Importance

Conjunctival melanoma has the potential for regional lymphatic and distant metastasis. There is an urgent need for effective treatment for patients with metastatic or locally advanced conjunctival melanoma.

Objective

To describe the use of immune checkpoint inhibitors for the treatment of conjunctival melanoma in 5 adult patients.

Design, Setting, and Participants

A retrospective review was conducted of the medical records of 5 patients with conjunctival melanoma who were treated with immune checkpoint inhibitors from March 6, 2013, to July 7, 2017.

Main Outcomes and Measures

Response to treatment and disease-free survival.

Results

Of the 5 patients (4 women and 1 man) with metastatic conjunctival melanoma, 4 were treated with a programmed cell death 1 (PD-1) inhibitor, nivolumab, and had a complete response to treatment with no evidence of disease at 1, 7, 9, and 36 months after completing treatment. One patient with metastatic conjunctival melanoma was treated with another PD-1 inhibitor, pembrolizumab, and had stable metastases during the first 6 months of treatment. Later disease progression resulted in treatment cessation after 11 months and switching to another therapy. Two patients treated with nivolumab developed autoimmune colitis that necessitated stopping the immunotherapy; these patients subsequently were managed with systemic corticosteroids or infliximab.

Conclusions and Relevance

This case series report suggests that anti-PD-1 therapy can be used to treat metastatic conjunctival melanoma. Longer follow-up is needed to determine the long-term disease-free survival. Future studies might assess the potential for immune checkpoint inhibitors to obviate the need for orbital exenteration in selected patients with locally advanced disease.

Advances in Immunotherapy and Periocular Malignancy

Immunotherapy has significantly advanced the field of oncology in recent decades. Understanding normal immunosurveillance, as well as the ways in which tumor cells have evolved to evade it, has provided the knowledge for development of drugs that allow one's own immune system to target and destroy malignant cells (immunotherapy). Cutaneous malignancies are particularly sensitive to this class of drugs. In a very sensitive anatomic region such as the periocular tissue, where surgical excision may come with significant morbidity, this technology has had a strong impact in the successful treatment of historically challenging tumors.

Conjunctival melanoma copy number alterations and correlation with mutation status, tumor features, and clinical outcome

Relatively little is known about the genetic aberrations of conjunctival melanomas (CoM) and their correlation with clinical and histomorphological features as well as prognosis. The aim of this large collaborative multicenter study was to determine potential key biomarkers for metastatic risk and any druggable targets for high metastatic risk CoM. Using Affymetrix single nucleotide polymorphism genotyping arrays on 59 CoM, we detected frequent amplifications on chromosome (chr) 6p and deletions on 7q, and characterized mutation‐specific copy number alterations. Deletions on chr 10q11.21‐26.2, a region harboring the tumor suppressor genes, PDCD4, SUFU, NEURL1, PTEN, RASSF4, DMBT1, and C10orf90 and C10orf99, significantly correlated with metastasis (Fisher's exact, p ≤ 0.04), lymphatic invasion (Fisher's exact, p ≤ 0.02), increasing tumor thickness (Mann–Whitney, p ≤ 0.02), and BRAF mutation (Fisher's exact, p ≤ 0.05). This enhanced insight into CoM biology is a step toward identifying patients at risk of metastasis and potential therapeutic targets for systemic disease.

Desmoplastic Melanoma of the Periorbital Region

Desmoplastic melanoma (DM) is a rare subtype of melanoma and an even smaller proportion of periocular melanomas. Here, the authors report 2 cases of DM in the periocular region. Staged according to the American Joint Committee on Cancer (AJCC) eighth edition classification, patient 1 presented with a stage IIIC (pT4apN1cM0) DM in the left lateral canthus with upper and lower eyelid and patient 2 presented with a stage IIIB (T4aN1bM0) DM in the left brow and supraorbital region with a parotid lymph node metastasis. In both patients, the lesions were amelanotic, with inflammatory appearance, and had been noted for several years before the correct diagnosis was made. In both patients, wide excision led to large surgical defects, and perineural invasion prompted adjuvant radiation therapy postoperatively. Patient 2 was treated with an immune checkpoint inhibitor for his parotid metastasis. Ophthalmologists should be aware of DM, its neurotrophic nature, and potential to metastasize with locally advanced lesions.

CHECKPOINT INHIBITOR IMMUNE THERAPY: Systemic Indications and Ophthalmic Side Effects

PURPOSE

To review immune checkpoint inhibitor indications and ophthalmic side effects.

METHODS

A literature review was performed using a PubMed search for publications between 1990 and 2017.

RESULTS

Immune checkpoint inhibitors are designed to treat system malignancies by targeting one of three ligands, leading to T-cell activation for attack against malignant cells. These ligands (and targeted drug) include cytotoxic T-lymphocyte antigen-4 (CTLA-4, ipilimumab), programmed death protein 1 (PD-1, pembrolizumab, nivolumab), and programmed death ligand-1 (PD-L1, atezolizumab, avelumab, durvalumab). These medications upregulate the immune system and cause autoimmune-like side effects. Ophthalmic side effects most frequently manifest as uveitis (1%) and dry eye (1-24%). Other side effects include myasthenia gravis (n = 19 reports), inflammatory orbitopathy (n = 11), keratitis (n = 3), cranial nerve palsy (n = 3), optic neuropathy (n = 2), serous retinal detachment (n = 2), extraocular muscle myopathy (n = 1), atypical chorioretinal lesions (n = 1), immune retinopathy (n = 1), and neuroretinitis (n = 1). Most inflammatory side effects are managed with topical or periocular corticosteroids, but advanced cases require systemic corticosteroids and cessation of checkpoint inhibitor therapy.

CONCLUSION

Checkpoint inhibitors enhance the immune system by releasing inhibition on T cells, with risk of autoimmune-like side effects. Ophthalmologists should include immune-related adverse events in their differential when examining cancer patients with new ocular symptoms.

[Focus on clinical and pathological management of conjunctival melanocytic tumors]

Conjunctival-pigmented tumors are rare, but they are one of the most commonly encountered by the pathologist working with the department of ophthalmology. Nevus and melanoma can be encountered and have some histological difference compared to their cutaneous counterpart. Primary acquired melanosis (PAM) is a conjunctival specific entity. This clinical term includes several histological lesions ranging from benignity to melanoma precursor lesion. Histologic examination determines the therapy and the risk of progression to melanoma. We present here a histopathological, clinical and therapeutic synthesis of conjunctival-pigmented lesions, emphasizing the importance of a good understanding between clinicians and pathologists.

Effect of Gamma Knife Radiosurgery and Programmed Cell Death 1 Receptor Antagonists on Metastatic Melanoma

Learning objectives

To evaluate radiation-induced changes in patients with brain metastasis secondary to malignant melanoma who received treatment with Gamma Knife radiosurgery (GKRS) and programmed cell death 1 (PD-1) receptor antagonists.

Introduction 

Stereotactic radiosurgery and chemotherapeutics are used together for treatment of metastatic melanoma and have been linked to delayed radiation-induced vasculitic leukoencephalopathy (DRIVL). There have been reports of more intense interactions with new immunotherapeutics targeting PD-1 receptors, but their interactions have not been well described and may result in an accelerated response to GKRS. Here we present data on subjects treated with this combination from a single institution.

Methods

Records from patients who underwent treatment for metastatic melanoma to the brain with GKRS from 2011 to 2016 were reviewed. Demographics, date of brain metastasis diagnosis, cause of death when applicable, immunotherapeutics, and imaging findings were recorded. The timing of radiation therapy and medications were also documented. 

Results

A total of 79 subjects were treated with GKRS, and 66 underwent treatment with both GKRS and immunotherapy. Regarding the 30 patients treated with anti-PD-1 immunotherapy, 21 patients received pembrolizumab, seven patients received nivolumab, and two patients received pembrolizumab and nivolumab. Serial imaging was available for interpretation in 25 patients, with 13 subjects who received GKRS and anti-PD-1 immunotherapy less than six weeks of each other. While four subjects had indeterminate/mixed findings on subsequent magnetic resonance imaging (MRI), nine subjects were noted to have progression. Two of these patients showed progression but subsequent imaging revealed a decrease in progression or improvement on MRI to previously targeted lesions by GKRS. None of the 13 subjects had surgery following their combined therapies.

Conclusions

This data suggests that there is need for further investigation of the role for concurrent treatment with PD-1 inhibitors and GKRS to enhance the treatment of metastatic melanoma. We present data on 13 patients who appear to have some radiologic benefit to this treatment combination, two of whom had radiographic pseudoprogression.

PD-L1/PD-1 expression and tumor-infiltrating lymphocytes in conjunctival melanoma

Conjunctival melanoma (CM) is an infrequent but potentially lethal malignancy, with limited therapeutic options for metastases. Recent inhibitors of the interaction of programmed cell death protein 1 (PD-1) and its ligand PD-L1 are associated with good clinical responses in many malignancies. To investigate the therapeutic potential of targeting the PD-1/PD-L1 axis in CM, we analyzed the expression of PD-1 and PD-L1 and the density of various types of tumor-infiltrating lymphocytes (TILs) in primary CM (n = 27), using immunofluorescence staining. Results were compared with clinical parameters and outcome. Flow cytometry was exploited to determine the PD-L1 and PD-1 protein expression in conjunctival and cutaneous melanoma cell lines. PD-L1 expression was identified on tumor cells in five (19%) primary CM and on stromal cells (mainly CD68⁺CD163⁺ M2 macrophages) in 16 (59%) cases. PD-L1 expression on tumor cells was associated with the presence of distant metastases and a worse melanoma-related survival. PD-1 expression was seen in 17 (63%) cases, all of which were T2 stage tumors. Small tumors had a higher density of TILs than large tumors. The density of TILs was not correlated with survival, tumoral/stromal PD-L1 or PD-1 expression. In vitro results showed that most CM and cutaneous melanoma cell lines do not constitutively express PD-L1. However, expression could be upregulated after interferon gamma stimulation. Our findings suggest that blocking the PD-1/PD-L1 axis should be evaluated as a treatment for CM.