Efficacy and safety of avelumab treatment in patients with metastatic Merkel cell carcinoma: experience from a global expanded access program

Avelumab as second-line or later treatment in patients with metastatic Merkel cell carcinoma: Analysis of real-world outcomes in France using the CARADERM database linked to the French national healthcare database

AIM

Avelumab has been approved worldwide for treatment of metastatic Merkel cell carcinoma (mMCC), a rare and aggressive skin cancer. This study evaluated outcomes in patients with mMCC in France who received avelumab as second-line or later (2L+) treatment in routine clinical practice.

METHODS

This retrospective, noninterventional study evaluated all patients diagnosed with mMCC using two databases: CARADERM (French national database of rare dermatological cancers) and SNDS (national healthcare database), identified via probabilistic linkage. Eligible patients initiated avelumab as 2L+ treatment between August 2016 and December 2019 and were followed for 24 months. The primary endpoint was overall survival (OS) at 24 months.

RESULTS

Overall, 180 patients who received 2L+ avelumab were identified (112 from CARADERM, 68 after SNDS linkage). Median age at diagnosis was 74.0 years and 177 (98.3 %) had received chemotherapy alone as first-line treatment. Median follow-up was 13.1 months. Median OS from start of avelumab was 14.6 months (95 % CI, 9.9-21.3) in the overall population, 15.9 months (95 % CI, 8.6-28.3) in CARADERM patients, and 13.3 months (95 % CI, 6.7-19.1) in non-CARADERM patients. OS rates at 12 and 24 months were 53.8 % (95 % CI, 46.2 %-60.8 %) and 40.5 % (95 % CI, 33.2 %-47.6 %), respectively. In evaluable patients (CARADERM database), median progression-free survival was 3.6 months (95 % CI, 2.7-7.5) and the objective response rate was 55.3 % (95 % CI, 45.3-65.4), including complete response in 31.9 %.

CONCLUSIONS

Real-world outcomes with 2L+ avelumab treatment for mMCC are consistent with clinical trial findings, supporting the recommendation of avelumab as a standard of care.

Personalized treatment concepts in extraocular cancer

Background

The periocular skin is neoplasms-prone to various benign and malignant. Periocular malignancies are more aggressive and challenging to cure and repair than those in other skin areas. In recent decades, immunotherapy has significantly advanced oncology, allowing the autoimmune system to target and destroy malignant cells. Skin malignancies, especially periocular tumors, are particularly sensitive to immunotherapy. This technique has dramatically impacted the successful treatment of challenging tumors.

Main text

Extraocular cancers, including eyelid (basal cell carcinoma, squamous cell carcinoma, melanoma, merkel cell carcinoma), conjunctival tumors (conjunctival melanoma, ocular surface squamous neoplasia) and other rare tumors, are unique and challenging clinical situations. Several genetic alterations associated with the pathogenesis of these diseases have been identified, and molecular mechanism are essential for the development of the immunotherapy agents, such as Hedgehog pathway inhibitors (vismodegib and sonidegib) for basal cell carcinoma, BRAF/MEK inhibitors (vemurafenib, dabrafenib, and encorafenib) for melanoma, and immune checkpoint inhibitors (Avelumab, pembrolizumab) for Merkel cell carcinoma.

Conclusions

The optimal treatment for periocular skin cancer depends on the type and size of the tumor and whether it involves orbital and adnexal structures. Adjuvant and neoadjuvant therapy with chemotherapy-targeted therapies and immune checkpoint inhibitors should be considered based on tumor type, tumor molecular profile, expected response rate, and candidacy for systemic treatment.

Avelumab in the Treatment of Advanced Merkel Cell Carcinoma: A Systematic Review

BACKGROUND

Avelumab, a programmed death ligand-1 inhibitor, has shown success in providing durable responses for difficult-to-treat Merkel cell carcinomas (MCCs).

OBJECTIVE

Evaluate the efficacy and safety of avelumab in the treatment of advanced MCC.

METHODS

Studies reporting the use of avelumab as a monotherapy or in combination with other agents in the treatment of stage III or IV (advanced) MCC were included. The primary outcomes were overall response rate, overall survival (OS), and treatment-related adverse events.

RESULTS

A total of 48 studies were included, involving 1,565 patients with advanced MCC. Most patients were male (1,051, 67.3%) with stage IV MCC (517, 97.0%). The overall response rate was 46.1% (partial response-25.4% and complete response-20.7%) after a mean follow-up period of 9.5 months. Kaplan-Meier survival curves for the pooled stage III and IV group demonstrated OS rates of 58% at 1 year, 47% at 2 years, and 28% at 5 years after completion of treatment with avelumab (median OS: 23.1 months). The most common treatment-related adverse events consisted of constitutional (44%), gastrointestinal (19%), and dermatologic (12%) symptoms.

CONCLUSION

Avelumab monotherapy and combination therapy have shown success in the overall response rate and survival for patients with advanced MCC.

Avelumab to treat Merkel cell carcinoma: real-life experience in a dedicated oncology center

The arrival of immunotherapy has revolutioned the management of patients with metastatic Merkel cell carcinoma (MCC). We conducted an observational, retrospective study of 14 cases treated with avelumab. The response rate was 57%: complete response was reached in 29% of patients, and partial responses in 29%. The drug proved effective in 83% (5/6) of the patients with a single metastatic site. However, the disease progressed in 75% (3/4) of the patients with bone metastases. PD1-L expression, MCC polyomavirus (MCPyV) positivity, and an impaired neutrophil-to-lypmhocyte ratio (NLR) could not be associated with responses to the therapy. Avelumab is an effective and safe drug for the management of advanced MCC, and its effectiveness appears to be impacted by the number and location of metastases.

Moderne Diagnostik und Therapie des Merkelzellkarzinoms

Das Merkelzellkarzinom (MCC) ist ein seltener, aggressiver Hauttumor mit epithelialer und neuroendokriner Differenzierung, dessen Inzidenz in den letzten Jahrzehnten deutlich zugenommen hat. Risikofaktoren sind fortgeschrittenes Lebensalter, heller Hauttyp, UV‐Exposition und Immunsuppression. Pathogenetisch wird ein durch das Merkelzell‐Polyomavirus (MCPyV) hervorgerufener Typ von einem UV‐induzierten Typ mit hoher Tumormutationslast unterschieden.

Klinisch präsentiert sich das MCC als meist schmerzloser, schnell wachsender, rötlich‐violetter Tumor mit glänzender Oberfläche, der bevorzugt im Kopf‐Hals‐Bereich und an den distalen Extremitäten lokalisiert ist. Eine sichere Diagnose kann nur anhand histologischer und immunhistochemischer Merkmale gestellt werden. Bei Erstdiagnose weisen 20%–26% der Patienten lokoregionäre Metastasen und 8%–14% Fernmetastasen auf, weshalb eine Ausbreitungsdiagnostik unabdingbar ist. Bei fehlenden klinischen Hinweisen auf Metastasen wird eine Sentinel‐Lymphknotenbiopsie empfohlen.

Wesentliche Säulen der Therapie sind die Operation, die adjuvante oder palliative Strahlentherapie und in fortgeschrittenen inoperablen Stadien die medikamentöse Tumortherapie. Die Einführung von Immuncheckpoint‐Inhibitoren führte zu einem Paradigmenwechsel, da sich hiermit ein wesentlich langfristigeres Ansprechen und bessere Überlebensraten als mit Chemotherapie erreichen lassen. Zur Therapie des metastasierten MCC ist in Deutschland der PD‐L1‐Inhibitor Avelumab zugelassen, aber auch die PD‐1‐Antikörper Pembrolizumab und Nivolumab werden mit Erfolg eingesetzt. Adjuvante und neoadjuvante Therapiekonzepte, Immunkombinationstherapien und zielgerichtete Therapien als Monotherapie oder in Kombination mit Immuncheckpoint‐Inhibitoren befinden sich in klinischer Prüfung.

Modern diagnostics and treatment of Merkel cell carcinoma

Merkel cell carcinoma (MCC) is a rare, aggressive skin cancer with epithelial and neuroendocrine differentiation, the incidence of which has increased substantially during the last decades. Risk factors include advanced age, fair skin type, UV exposure, and immunosuppression. Pathogenetically, a type caused by the Merkel cell polyomavirus is distinguished from a UV-induced type with a high tumor mutational burden. Clinically, MCC presents as a mostly painless, rapidly growing, reddish-violet tumor with a shiny surface, which is preferentially localized in the head-neck region and at the distal extremities. A reliable diagnosis can only be made based on histological and immunohistochemical features. At initial diagnosis, 20-26% of patients show locoregional metastases and 8-14% distant metastases, making staging examinations indispensable. If there is no clinical evidence of metastases, a sentinel lymph node biopsy is recommended. Essential columns of therapy are surgery, adjuvant or palliative radiotherapy and, in advanced inoperable stages, medicamentous tumor therapy. The introduction of immune checkpoint inhibitors has led to a paradigm shift, as they provide a considerably longer duration of response and better survival rates than chemotherapy. The PD-L1 inhibitor avelumab is approved for treatment of metastatic MCC in Germany, but the PD-1 antibodies pembrolizumab and nivolumab are also used with success. Adjuvant and neoadjuvant treatment concepts, immune combination therapies and targeted therapies as monotherapy or in combination with immune checkpoint inhibitors are in the clinical trial phase.

Avelumab for Advanced Merkel Cell Carcinoma: Global Real-World Data on Patient Response and Survival

Introduction

Avelumab is a programmed cell death-ligand 1 (PD-L1) inhibitor approved by the Food and Drug Administration for advanced Merkel cell carcinoma (MCC). Studies conducted in real-world settings have shed light on its effectiveness and safety in clinical settings.

Areas Covered

Real-world studies on avelumab for MCC from North and South America, Europe, and Asia have been presented in this review. Most studies are on patients over age 70 and have a male-predominant sex ratio. Overall response rates range from 29.1% to 72.1%, (disease control rate: 60.0-72.7%; complete response rate: 15.8%-37.2%; partial rate: 18.2-42.1%; stable disease: 7.1-30.9%; progressive disease: 7.1-40.0%) and median progression free survival ranges from 8.1 to 24.1 months depending on the population studied. Immunosuppressed patients appear to benefit from avelumab as well, with response rates equivalent to the general population. Patients receiving avelumab as a first-line agent tend to have better outcomes than those using it as a second-line therapy. Fatigue, infusion-related reactions, and dyspnea were some of the most common adverse events identified in real-world studies. Autoimmune hepatitis and thyroiditis were also observed.

Conclusion

The use of avelumab as a safe and effective treatment option for advanced MCC is supported by real-world data, although additional study is required to assess long-term efficacy and safety outcomes.

Merkel cell carcinoma: an update

Merkel cell carcinoma (MCC) is an uncommon primary cutaneous neuroendocrine carcinoma associated with an adverse prognosis. In recent years, our understanding of MCC biology has markedly progressed. Since the discovery of the Merkel cell polyomavirus, it has become clear that MCC represents an ontogenetically dichotomous group of neoplasms with overlapping histopathology. Specifically, most MCCs arise secondary to viral oncogenesis, while a smaller subset is the direct result of UV-associated mutations. The distinction of these groups bears relevance in their immunohistochemical and molecular characterization, as well as in disease prognosis. Further recent developments relate to the landmark utilization of immunotherapeutics in MCC, providing optimistic options for the management of this aggressive disease. In this review, we discuss both fundamental and emerging concepts in MCC, with a particular focus on topics of practical relevance to the surgical or dermatopathologist.

Distinct Regulation of EZH2 and its Repressive H3K27me3 Mark in Polyomavirus-Positive and -Negative Merkel Cell Carcinoma

Merkel cell carcinoma (MCC) is an aggressive skin cancer for which Merkel cell polyomavirus integration and expression of viral oncogenes small T and Large T have been identified as major oncogenic determinants. Recently, a component of the PRC2 complex, the histone methyltransferase enhancer of zeste homolog 2 (EZH2) that induces H3K27 trimethylation as a repressive mark has been proposed as a potential therapeutic target in MCC. Because divergent results have been reported for the levels of EZH2 and trimethylation of lysine 27 on histone 3, we analyzed these factors in a large MCC cohort to identify the molecular determinants of EZH2 activity in MCC and to establish MCC cell lines' sensitivity to EZH2 inhibitors. Immunohistochemical expression of EZH2 was observed in 92% of MCC tumors (156 of 170), with higher expression levels in virus-positive than virus-negative tumors (P = 0.026). For the latter, we showed overexpression of EZHIP, a negative regulator of the PRC2 complex. In vitro, ectopic expression of the large T antigen in fibroblasts led to the induction of EZH2 expression, whereas the knockdown of T antigens in MCC cell lines resulted in decreased EZH2 expression. EZH2 inhibition led to selective cytotoxicity on virus-positive MCC cell lines. This study highlights the distinct mechanisms of EZH2 induction between virus-negative and -positive MCC.

LAMP1 targeting of the large T antigen of Merkel cell polyomavirus results in potent CD4 T cell responses and tumor inhibition

Introduction

Most cases of Merkel cell carcinoma (MCC), a rare and highly aggressive type of neuroendocrine skin cancer, are associated with Merkel cell polyomavirus (MCPyV) infection. MCPyV integrates into the host genome, resulting in expression of oncoproteins including a truncated form of the viral large T antigen (LT) in infected cells. These oncoproteins are an attractive target for a therapeutic cancer vaccine.

Methods

We designed a cancer vaccine that promotes potent, antigen-specific CD4 T cell responses to MCPyV-LT. To activate antigen-specific CD4 T cells in vivo, we utilized our nucleic acid platform, UNITE™ (UNiversal Intracellular Targeted Expression), which fuses a tumor-associated antigen with lysosomal-associated membrane protein 1 (LAMP1). This lysosomal targeting technology results in enhanced antigen presentation and potent antigen-specific T cell responses. LTS220A, encoding a mutated form of MCPyV-LT that diminishes its pro-oncogenic properties, was introduced into the UNITE™ platform.

Results

Vaccination with LTS220A-UNITE™ DNA vaccine (ITI-3000) induced antigen-specific CD4 T cell responses and a strong humoral response that were sufficient to delay tumor growth of a B16F10 melanoma line expressing LTS220A. This effect was dependent on the CD4 T cells' ability to produce IFNγ. Moreover, ITI-3000 induced a favorable tumor microenvironment (TME), including Th1-type cytokines and significantly enhanced numbers of CD4 and CD8 T cells as well as NK and NKT cells. Additionally, ITI-3000 synergized with an α-PD-1 immune checkpoint inhibitor to further slow tumor growth and enhance survival.

Conclusions

These findings strongly suggest that in pre-clinical studies, DNA vaccination with ITI-3000, using the UNITE™ platform, enhances CD4 T cell responses to MCPyV-LT that result in significant anti-tumor immune responses. These data support the initiation of a first-in-human (FIH) Phase 1 open-label study to evaluate the safety, tolerability, and immunogenicity of ITI-3000 in patients with polyomavirus-positive MCC (NCT05422781).

Current and preclinical treatment options for Merkel cell carcinoma

INTRODUCTION

Merkel cell carcinoma (MCC) is a rare, highly aggressive form of skin cancer with neuroendocrine features. The origin of this cancer is still unclear, but research in the last 15 years has demonstrated that MCC arises via two distinct etiologic pathways, i.e. virus and UV-induced. Considering the high mortality rate and the limited therapeutic options available, this review aims to highlight the significance of MCC research and the need for advancement in MCC treatment.

AREAS COVERED

With the advent of the immune checkpoint inhibitor therapies, we now have treatment options providing a survival benefit for patients with advanced MCC. However, the issue of primary and acquired resistance to these therapies remains a significant concern. Therefore, ongoing efforts seeking additional therapeutic targets and approaches for MCC therapy are a necessity. Through a comprehensive literature search, we provide an overview on recent preclinical and clinical studies with respect to MCC therapy.

EXPERT OPINION

Currently, the only evidence-based therapy for MCC is immune checkpoint blockade with anti-PD-1/PD-L1 for advanced patients. Neoadjuvant, adjuvant and combined immune checkpoint blockade are promising treatment options.

An update on Merkel cell carcinoma

Merkel cell carcinoma (MCC) is a rare cancer of the skin characterized by a neuroendocrine phenotype and an aggressive clinical behavior. It frequently originates in sun-exposed body areas, and its incidence has steadily increased in the last three decades. Merkel cell polyomavirus (MCPyV) and ultraviolet (UV) radiation exposure are the main causative agents of MCC, and distinct molecular features have been documented in virus-positive and virus-negative malignancies. Surgery remains the cornerstone of treatment for localized tumors, but even when integrated with adjuvant radiotherapy is able to definitively cure only a fraction of MCC patients. While characterized by a high objective response rate, chemotherapy is associated with a short-lasting benefit of approximately 3 months. On the other hand, immune checkpoint inhibitors including avelumab and pembrolizumab have demonstrated durable antitumor activity in patients with stage IV MCC, and investigations on their use in the neoadjuvant or adjuvant setting are currently underway. Addressing the needs of those patients who do not persistently benefit from immunotherapy is currently one of the most compelling unmet needs in the field, and multiple clinical trials of new tyrosine kinase inhibitors (TKIs), peptide receptor radionuclide therapy (PRRT), therapeutic vaccines, immunocytokines as well as innovative forms of adoptive cellular immunotherapies are under clinical scrutiny at present.

The Role of Immune Checkpoint Inhibitors in Cancer Therapy

Over the years, immune checkpoint inhibitors (CPIs) have become a powerful treatment strategy in the field of cancer immunotherapy. In the last decade, the number of FDA-approved CPIs has been increasing prominently, opening new horizons for the treatment of a wide range of tumor types. Pointedly, three immune checkpoint molecules have been under extensive research, which include cytotoxic T-lymphocyte-associated protein 4 (CTLA-4) and programmed cell death protein-1 (PD-1) and its ligand-1 (PD-L1). Despite remarkable success, not all patients respond positively to therapy, which highlights the complexity of the tumor microenvironment (TME) and immune system. This has led to the identification of molecular biomarkers to predict response and toxicity. In addition, there has been an emerging focus on developing new delivery and targeting approaches for better drug efficacy and potency. In this review, we highlight the mechanism of action of major CPIs, their clinical impact, variation in effectiveness, response prediction, updated clinical indications, current challenges and limitations, promising novel approaches, and future directions.

Merkel Cell Carcinoma-Update on Diagnosis, Management and Future Perspectives

MCC is a rare but highly aggressive skin cancer. The identification of the driving role of Merkel cell polyomavirus (MCPyV) and ultraviolet-induced DNA damage in the oncogenesis of MCC allowed a better understanding of its biological behavior. The presence of MCPyV-specific T cells and lymphocytes exhibiting an 'exhausted' phenotype in the tumor microenvironment along with the high prevalence of immunosuppression among affected patients are strong indicators of the immunogenic properties of MCC. The use of immunotherapy has revolutionized the management of patients with advanced MCC with anti-PD-1/PD L1 blockade, providing objective responses in as much as 50-70% of cases when used in first-line treatment. However, acquired resistance or contraindication to immune checkpoint inhibitors can be an issue for a non-negligible number of patients and novel therapeutic strategies are warranted. This review will focus on current management guidelines for MCC and future therapeutic perspectives for advanced disease with an emphasis on molecular pathways, targeted therapies, and immune-based strategies. These new therapies alone or in combination with anti-PD-1/PD-L1 inhibitors could enhance immune responses against tumor cells and overcome acquired resistance to immunotherapy.

Potential new applications of immunotherapy for neuroendocrine neoplasms: immune landscape, current status and future perspectives

Neuroendocrine neoplasms (NENs) are a highly heterogeneous class of tumors arising from neuroendocrine cells and peptidergic neurons. After failure of first-line treatment, patients have poor prognosis and limited treatment options. Immune checkpoint inhibitors (ICIs) may be a powerful means of increasing therapeutic efficacy for such patients, but ICIs alone have low response rates and short disease control durations in most NENs and may be effective for only a portion of the population. ICIs combined with other immunotherapies, targeted therapies, or cytotoxic drugs have achieved some efficacy in patients with NENs and are worthy of further exploration to assess their benefits to the population. In addition, accumulating experimental and clinical evidence supports that the interaction between neuroendocrine and immune systems is essential to maintain homeostasis, and assessment of this broad neuroendocrine-immune correlation is essential for NEN treatment. In this review, we summarize the immune microenvironment characteristics, advances in immunotherapy, predictive biomarkers of ICI efficacy for NENs, and the effects of common endocrine hormones on the immune system, highlighting possible new application areas for this promising treatment in neglected NENs.

A Review of Cutaneous Diseases Observed in Solid Organ Transplant Recipients

Solid organ transplant recipients are at increased risk for numerous cutaneous conditions that fall within four categories: pre-neoplastic, neoplastic, infectious, or idiopathic. Many of these diseases can be attributed to immunosuppressive medications, including mycophenolate mofetil, cyclosporine, azathioprine, tacrolimus, or glucocorticoids. Iatrogenic lessening of the immune system places the patient at risk of malignancies, opportunistic infections, immune-mediated dermatoses, and adverse effects of medications. As the life expectancy of patients with solid organ transplants continues to increase, dermatologists and transplant physicians must stay abreast of this spectrum of dermatologic conditions, their respective prognoses, prevention, mitigation, and treatment.

Real-world clinical outcomes with avelumab in patients with Merkel cell carcinoma treated in the USA: a multicenter chart review study

Background

Merkel cell carcinoma (MCC) is a rare, aggressive, cutaneous neuroendocrine neoplasm with annual incidence rates of 0.13–1.6 cases/100,000/year worldwide as of 2018. Chemotherapy for metastatic MCC (mMCC) has high objective response rates (ORRs), but responses are not durable and overall survival (OS) is poor. Avelumab (anti-programmed death-ligand 1) has demonstrated meaningful survival benefit and durable responses in clinical trials for mMCC. This study investigated real-world clinical outcomes in avelumab-treated patients with advanced (stage IIIB/IV) MCC in US academic medical centers.

Methods

We conducted a retrospective chart review of patients with advanced MCC who initiated avelumab between March 1, 2017, and July 31, 2019, at six US academic centers. Data were requested for eligible patients from index date through December 31, 2020. Descriptive analyses were conducted to assess demographic and clinical characteristics, real-world ORR (rwORR), real-world duration of response, real-world progression-free survival (rwPFS), and OS.

Results

Ninety patients with advanced MCC (82%, stage IV; 18%, stage IIIB) received avelumab. Median follow-up was 20.8 months (95% CI: 19.1 to 24.2). Median age was 68 years (range, 48–83), and the majority of patients were men (58%) and white (93%). The primary tumor was most commonly located on the lower limb (38%), with metastases mostly located in lymph nodes (68%), lung (52%), and viscera (52%). Approximately 42% and 26% of patients had an Eastern Cooperative Oncology Group performance status of 2 and 3, respectively. Seventy-three patients (81%) received avelumab as first-line treatment of advanced MCC, while 17 (19%) received avelumab as second-line or later treatment. The median duration of avelumab treatment was 13.5 months (95% CI: 6.4 to 30.6), with 42% of patients still receiving avelumab by the end of follow-up. Patients with avelumab treatment had an rwORR of 73% (95% CI: 64 to 83), median rwPFS of 24.4 months (95% CI: 8.31 to not estimable (NE)), and median OS of 30.7 months (95% CI: 11.2 to NE).

Conclusions

This real-world study of patients with advanced MCC demonstrated that avelumab treatment resulted in a high response rate with durable responses and prolonged survival. The study findings validate the results demonstrated in prospective clinical trials and other observational studies.

Diagnosis and treatment of Merkel cell carcinoma: European consensus-based interdisciplinary guideline - Update 2022

Merkel cell carcinoma (MCC) is a rare skin cancer, accounting for less than 1% of all cutaneous malignancies. It is found predominantly in white populations and risk factors include advanced age, ultraviolet exposure, male sex, immunosuppression, such as AIDS/HIV infection, haematological malignancies or solid organ transplantation, and Merkel cell polyomavirus infection. MCC is an aggressive tumour with 26% of cases presenting lymph node involvement at diagnosis and 8% with distant metastases. Five-year overall survival rates range between 48% and 63%. Two subsets of MCC have been characterised with distinct molecular pathogenetic pathways: ultraviolet-induced MCC versus virus-positive MCC, which carries a better prognosis. In both subtypes, there are alterations in the retinoblastoma protein and p53 gene structure and function. MCC typically manifests as a red nodule or plaque with fast growth, most commonly on sun exposed areas. Histopathology (small-cell neuroendocrine appearance) and immunohistochemistry (CK20 positivity and TTF-1 negativity) confirm the diagnosis. The current staging systems are the American Joint Committee on Cancer/Union for international Cancer control 8th edition. Baseline whole body imaging is encouraged to rule out regional and distant metastasis. For localised MCC, first-line treatment is surgical excision with postoperative margin assessment followed by adjuvant radiation therapy (RT). Sentinel lymph node biopsy is recommended in all patients with MCC without clinically detectable lymph nodes or distant metastasis. Adjuvant RT alone, eventually combined with complete lymph nodes dissection is proposed in case of micrometastatic nodal involvement. In case of macroscopic nodal involvement, the standard of care is complete lymph nodes dissection potentially followed by post-operative RT. Immunotherapy with anti-PD-(L)1 antibodies should be offered as first-line systemic treatment in advanced MCC. Chemotherapy can be used when patients fail to respond or are intolerant for anti-PD-(L)1 immunotherapy or clinical trials.

Nationwide multidisciplinary consensus on the clinical management of Merkel cell carcinoma: a Delphi panel

Merkel cell carcinoma (MCC) is a rare and highly aggressive cutaneous neuroendocrine carcinoma. The MCC incidence rate has rapidly grown over the last years, with Italy showing the highest increase among European countries. This malignancy has been the focus of active scientific research over the last years, focusing mainly on pathogenesis, new therapeutic trials and diagnosis. A national expert board developed 28 consensus statements that delineated the evolution of disease management and highlighted the paradigm shift towards the use of immunological strategies, which were then presented to a national MCC specialists panel for review. Sixty-five panelists answered both rounds of the questionnaire. The statements were divided into five areas: a high level of agreement was reached in the area of guidelines and multidisciplinary management, even if in real life the multidisciplinary team was not always represented by all the specialists. In the diagnostic pathway area, imaging played a crucial role in diagnosis and initial staging, planning for surgery or radiation therapy, assessment of treatment response and surveillance of recurrence and metastases. Concerning diagnosis, the usefulness of Merkel cell polyomavirus is recognized, but the agreement and consensus regarding the need for cytokeratin evaluation appears greater. Regarding the areas of clinical management and follow-up, patients with MCC require customized treatment. There was a wide dispersion of results and the suggestion to increase awareness about the adjuvant radiation therapy. The panelists unanimously agreed that the information concerning avelumab provided by the JAVELIN Merkel 200 study is adequate and reliable and that the expanded access program data could have concrete clinical implications. An immunocompromised patient with advanced MCC can be treated with immunotherapy after multidisciplinary risk/benefit assessment, as evidenced by real-world analysis and highlighted in the guidelines. A very high consensus regarding the addition of radiotherapy to treat the ongoing focal progression of immunotherapy was observed. This paper emphasizes the importance of collaboration and communication among the interprofessional team members and encourages managing patients with MCC within dedicated multidisciplinary teams. New insights in the treatment of this challenging cancer needs the contribution of many and different experts.

Transcriptomic datasets of cancer patients treated with immune-checkpoint inhibitors: a systematic review

The availability of immune-checkpoint inhibitors (ICI) in the last decade has resulted in a paradigm shift in certain areas of oncology. Patients can be treated either by a monotherapy of anti-CTLA-4 (tremelimumab or ipilimumab), anti-PD-1 (nivolumab or pembrolizumab), or anti-PD-L1 (avelumab or atezolizumab or durvalumab) or as combination therapy of anti-CTLA-4 and anti-PD-1. To maximize the clinical treatment benefit of cancer immunotherapy, the prediction of the actual immune response by the identification and application of clinically useful biomarkers will be required. Whole transcriptomic datasets of patients with ICI treatment could provide the basis for large-scale discovery and ranking of such potential biomarker candidates. In this review, we summarize currently available transcriptomic data from different biological sources (whole blood, fresh-frozen tissue, FFPE) obtained by different methods (microarray, RNA-Seq, RT-qPCR). We directly include only results from clinical trials and other investigations where an ICI treatment was administered. The available datasets are grouped based on the administered treatment and we also summarize the most important results in the individual cohorts. We discuss the limitations and shortcomings of the available datasets. Finally, a subset of animal studies is reviewed to provide an overview of potential in vivo ICI investigations. Our review can provide a swift reference for researchers aiming to find the most suitable study for their investigation, thus saving a significant amount of time.

Clinical and molecular characteristics associated with response to therapeutic PD-1/PD-L1 inhibition in advanced Merkel cell carcinoma

Background

Based on its viral-associated or UV-associated carcinogenesis, Merkel cell carcinoma (MCC) is a highly immunogenic skin cancer. Thus, clinically evident MCC occurs either in immuno-compromised patients or based on tumor-intrinsic immune escape mechanisms. This notion may explain that although advanced MCC can be effectively restrained by treatment with PD-1/PD-L1 immune checkpoint inhibitors (ICIs), a considerable percentage of patients does not benefit from ICI therapy. Biomarkers predicting ICI treatment response are currently not available.

Methods

The present multicenter retrospective study investigated clinical and molecular characteristics in 114 patients with unresectable MCC at baseline before treatment with ICI for their association with therapy response (best overall response, BOR). In a subset of 21 patients, pretreatment tumor tissue was analyzed for activation, differentiation and spatial distribution of tumor infiltrating lymphocytes (TIL).

Results

Of the 114 patients, n=74 (65%) achieved disease control (BOR=complete response/partial response/stable disease) on ICI. A Bayesian cumulative ordinal regression model revealed absence of immunosuppression and a limited number of tumor-involved organ systems was highly associated with a favorable therapy response. Unimpaired overall performance status, high age, normal serum lactate dehydrogenase and normal serum C reactive protein were moderately associated with disease control. While neither tumor Merkel cell polyomavirus nor tumor PD-L1 status showed a correlation with therapy response, treatment with anti-PD-1 antibodies was associated with a higher probability of disease control than treatment with anti-PD-L1 antibodies. Multiplexed immunohistochemistry demonstrated the predominance of CD8⁺ effector and central memory T cells (T_CM) in close proximity to tumor cells in patients with a favorable therapy response.

Conclusions

Our findings indicate the absence of immunosuppression, a limited number of tumor-affected organs, and a predominance of CD8⁺ T_CM among TIL, as baseline parameters associated with a favorable response to PD-1/PD-L1 ICI therapy of advanced MCC. These factors should be considered when making treatment decisions in MCC patients.

Targeting CD56 with an antibody-drug conjugate in Merkel cell carcinoma

Linked Article: Esnault et al. Br J Dermatol 2022; 186:295–306.

Merkel Cell Carcinoma: An Immunotherapy Fairy-Tale?

Merkel cell carcinoma (MCC) is a rare, highly aggressive, neuroendocrine cutaneous tumor. The incidence of MCC is growing worldwide, and the disease-related mortality is about three-fold higher than melanoma. Since a few years ago, very little has been known about this disease, and chemotherapy has been the standard of care. Nowadays, new discoveries about the pathophysiology of this neoplasm and the introduction of immunotherapy allowed to completely rewrite the history of these patients. In this review, we provide a summary of the most important changes in the management of Merkel cell carcinoma, with a focus on immunotherapy and a landscape of future treatment strategies.

The treatment of Merkel cell carcinoma with immune checkpoint inhibitors: implications for patients with rheumatoid arthritis

Objectives

Merkel cell carcinoma (MCC) is a rare, highly aggressive neuroendocrine skin cancer, which typically affects elderly and immunocompromised and/or immunosuppressed patients. The checkpoint inhibitor avelumab, a mAb targeting the anti-programmed cell death ligand 1 (anti-PD-L1), has revolutionized the treatment of metastatic MCC, achieving dramatic improvements in disease control and overall survival. However, checkpoint inhibitors are associated with the development of immune-related adverse events, such as exacerbation of pre-existing RA. Although most immune-related adverse events can be managed successfully with CSs, their frequent and/or long-term use runs the risk of undermining the efficacy of immune checkpoint inhibition.

Methods

We report two cases of MCC, in which immunosuppressive therapy for the management of RA was administered.

Results

Immunosuppression for (i) pre-existing and (ii) immune checkpoint inhibitor-exacerbated RA was associated with progression of metastatic MCC.

Conclusion

Any decision to initiate immunosuppressive treatment for RA in patients receiving immune checkpoint inhibitor therapy should include careful consideration of the risk of potentially fatal cancer progression and be taken after consultation with the patient’s oncologist and rheumatologist. When the immunosuppressive treatment is required, it should be administered for as short a time as possible and under strict clinical and radiological surveillance.

"Present and future of immunotherapy in Neuroendocrine Tumors"

Immunotherapy, so promising in many neoplasms, still does not have a precise role in the treatment of neuroendocrine neoplasms (NENs). In this article, we provide an overview on the current knowledge about immunotherapy with immune checkpoint inhibitors (ICIs) applied to NENs, evaluating future perspectives in this setting of tumors.Evidence so far available for ICIs in gastroenteropancreatic (GEP)-NENs is definitively not as robust as for other tumors such as Small Cell Lung Cancer or Merkel Cell Carcinoma. In fact, with regard to the well-differentiated forms of NENs (NETs), the results obtained nowadays have been disappointing. However, the near future, might reserve interesting results for ICIs in GEP-NEN from a total of nine different ICI drugs, used throughout 19 randomised controlled trials. Such numbers highlight the growing attention gathering around NENs and ICIs, in response to the need of stronger evidences supporting such therapy.For the future, the most important aspect will be to study strategies that can make NETs more susceptible to response to ICI and, thus, enhance the effectiveness of these treatments. Therefore, the combination of conventional therapy, target therapy and immunotherapy deserve attention and warrant to be explored. A sequential chemotherapy, possibly inducing an increase in tumor mutational burden and tested before immunotherapy, could be a hypothesis deserving more consideration. A radiation treatment that increases tumor-infiltrating lymphocytes, could be another approach to explore before ICIs in NENs. Equally essential will be the identification of biomarkers useful for selecting patients potentially responsive to this type of treatment.

Avelumab expanded access program in metastatic Merkel cell carcinoma: Efficacy and safety findings from patients in Europe and the Middle East

Incidence rates of Merkel cell carcinoma (MCC), an uncommon skin cancer with an aggressive disease course, have increased in recent decades. Limited treatment options are available for patients with metastatic MCC (mMCC). Avelumab, an anti‐programmed cell death‐ligand 1 monoclonal antibody, became the first approved treatment for mMCC after the results of the phase 2 JAVELIN Merkel 200 study. Prior to its regulatory approval, an expanded access program (EAP) enabled compassionate use of avelumab in patients with mMCC. Here we report findings from patients enrolled in the EAP in Europe and the Middle East. Efficacy and safety data were provided at the discretion of treating physicians. Between March 2, 2016, and December 22, 2018, 403 requests for avelumab were received from 21 countries, and avelumab was supplied to 335 patients. Most patients (96.7%) received avelumab as second‐line or later treatment. In 150 patients for whom response data were available, the objective response rate was 48.0%, and in responding patients, median duration of treatment was 7.4 months (range, 1.0‐41.7 months). The most common treatment‐related adverse events were infusion‐related reaction (2.4%) and pyrexia (2.1%), and no new safety signals were observed. Overall, results from European and Middle Eastern patients enrolled in this EAP confirm the efficacy and safety of avelumab treatment observed in previous studies in patients with mMCC.

What's new?

Patients with the aggressive skin cancer Merkel cell carcinoma (MCC) have few treatment options. The first approved treatment for metastatic MCC, the anti‐PD‐L1 monoclonal antibody avelumab, was made available through an expanded access program (EAP) prior to regulatory approval. Here, the authors analyze data from 150 patients in Europe and the Middle East enrolled in that EAP. Avelumab's efficacy and safety in this real‐world population of patients, they found, confirm the findings reported from the JAVELIN Merkel 200 trial.

Real-World Clinical Outcomes in Patients with Locally Advanced or Metastatic Merkel Cell Carcinoma Treated in U.S. Oncology Clinical Practices: Results from SPEAR-Merkel

BACKGROUND

Immunotherapy (IO) has been associated with improved outcomes in patients with locally advanced Merkel cell carcinoma (laMCC) and metastatic Merkel cell carcinoma (mMCC). The primary objective of SPEAR-Merkel was to explore treatment patterns, clinical outcomes, and health care resource utilization (HCRU) in patients with laMCC or mMCC initiating first-line (1L) treatment with avelumab, non-avelumab IO, or chemotherapy in a U.S. community oncology setting.

METHODS

Adult patients with laMCC or mMCC initiating 1L avelumab, non-avelumab IO, or chemotherapy from January 1, 2015, to March 31, 2019, were identified from the U.S. Oncology Network electronic health care record database and followed up through September 30, 2019. Baseline characteristics and HCRU were analyzed descriptively, including physician-stated overall response rate in the real-world clinical setting. Kaplan-Meier methods were used to measure duration of response, real-world progression-free survival (rwPFS), and overall survival (OS).

RESULTS

Among the overall population (n = 94), 28 received 1L avelumab (9 laMCC, 19 mMCC), 26 received 1L non-avelumab IO (8 laMCC, 18 mMCC), and 40 received 1L chemotherapy (10 laMCC, 30 mMCC). The real-world overall response rate was 64.3%, 61.5%, and 42.5%, respectively. From 1L treatment initiation, median rwPFS was 11.4, 8.1, and 6.1 months, and median OS was 20.2 months, not reached, and 14.7 months for the respective cohorts.

CONCLUSION

SPEAR-Merkel showed that patients with laMCC or mMCC treated with IO had improved outcomes compared with chemotherapy in clinical practice. The study provides insight on utilization and clinical outcomes associated with newer, more innovative therapies in clinical practice, which may help clinicians understand the variety of newer treatment options for both laMCC and mMCC.

IMPLICATIONS FOR PRACTICE

To the authors' knowledge, SPEAR-Merkel is the first study to evaluate real-world clinical outcomes in patients with locally advanced Merkel cell carcinoma (laMCC) and metastatic Merkel cell carcinoma (mMCC) receiving first-line (1L) avelumab, non-avelumab immuno-oncology therapies, or chemotherapy in a real-world setting. SPEAR-Merkel showed clinical benefit for immuno-oncology therapies compared with chemotherapy. The study provides insight on uses and clinical outcomes associated with innovative therapies in clinical practice, which may help clinicians understand the variety of newer treatment options for both laMCC and mMCC. The study is of particular importance as it shows that chemotherapy is still being used as 1L treatment despite its inferior clinical and safety profile.

Merkel Cell Carcinoma from Molecular Pathology to Novel Therapies

Merkel cell carcinoma (MCC) is an uncommon and highly aggressive skin cancer. It develops mostly within chronically sun-exposed areas of the skin. MCPyV is detected in 60-80% of MCC cases as integrated within the genome and is considered a major risk factor for MCC. Viral negative MCCs have a high mutation burden with a UV damage signature. Aberrations occur in RB1, TP53, and NOTCH genes as well as in the PI3K-AKT-mTOR pathway. MCC is highly immunogenic, but MCC cells are known to evade the host's immune response. Despite the characteristic immunohistological profile of MCC, the diagnosis is challenging, and it should be confirmed by an experienced pathologist. Sentinel lymph node biopsy is considered the most reliable staging tool to identify subclinical nodal disease. Subclinical node metastases are present in about 30-50% of patients with primary MCC. The basis of MCC treatment is surgical excision. MCC is highly radiosensitive. It becomes chemoresistant within a few months. MCC is prone to recurrence. The outcomes in patients with metastatic disease are poor, with a historical 5-year survival of 13.5%. The median progression-free survival is 3-5 months, and the median overall survival is ten months. Currently, immunotherapy has become a standard of care first-line therapy for advanced MCC.

Systemic Treatment of Gastroenteropancreatic Neuroendocrine Carcinoma

OPINION STATEMENT

Treatment recommendations for advanced gastroenteropancreatic neuroendocrine carcinomas (GEP-NEC) are based on uncontrolled, mainly retrospective data. Chemotherapy can offer palliative relief, but long-lasting complete responses or cures are rare. The European Neuroendocrine Tumour Society (ENETS) and European Society for Medical Oncology (ESMO) recommend platinum-based chemotherapy as first-line treatment. This has been the golden standard since the late 1980s and has been evaluated in mostly retrospective clinical studies. However, progression is inevitable for most patients. Unfortunately, data on effective second-line treatment options are scant, and ENETS and ESMO recommendations propose fluorouracil- or temozolomide-based chemotherapy schedules. As such, there is a huge unmet need for improved care. Improved knowledge on GEP-NEC biology may provide a pathway towards more effective interventions including chemotherapy, targeted gene therapy, peptide receptor radionuclide therapy, as well as immune checkpoint inhibitors. The review summarises this current state of the art as well as the most promising developments for systemic therapy in GEP-NEC patients.

Perspectives in immunotherapy: meeting report from the immunotherapy bridge (December 2nd-3rd, 2020, Italy)

Improved understanding of tumor immunology has enabled the development of therapies that harness the immune system and prevent immune escape. Numerous clinical trials and real-world experience has provided evidence of the potential for long-term survival with immunotherapy in various types of malignancy. Recurring observations with immuno-oncology agents include their potential for clinical application across a broad patient population with different tumor types, conventional and unconventional response patterns, durable responses, and immune-related adverse events. Despite the substantial achievements to date, a significant proportion of patients still fail to benefit from current immunotherapy options, and ongoing research is focused on transforming non-responders to responders through the development of novel treatments, new strategies to combination therapy, adjuvant and neoadjuvant approaches, and the identification of biomarkers of response. These topics were the focus of the virtual Immunotherapy Bridge (December 2nd-3rd, 2020), organized by the Fondazione Melanoma Onlus, Naples, Italy, in collaboration with the Society for Immunotherapy of Cancer and are summarised in this report.

Case Report: Clinical Experience With Avelumab in Patients With Metastatic Merkel Cell Carcinoma and Brain Metastases Treated in Europe

Merkel cell carcinoma (MCC) is a rare and aggressive skin cancer that can metastasize rapidly. In patients with metastatic MCC (mMCC), brain metastases are uncommon but are associated with poor prognosis; furthermore, there is limited published literature regarding treatment of these patients, and no specific regimens are currently recommended by guidelines. Avelumab, an anti-programmed death ligand 1 monoclonal antibody, was the first approved treatment for patients with mMCC. Here, we present 4 cases of patients with mMCC and brain metastases treated with avelumab. Patient age ranged from 48 to 70 years, and all patients received avelumab as second-line therapy following disease progression with platinum-based chemotherapy. Patient cases 1 and 2 received avelumab alone and experienced rapid disease progression according to Response Evaluation Criteria in Solid Tumors version 1.1 (RECIST 1.1). In patient case 3, avelumab alone resulted in a prolonged complete response by RECIST 1.1 of 1 brain metastasis and partial response by RECIST 1.1 of a second brain metastasis. After 11 months of avelumab treatment, the patient received concurrent stereotactic radiosurgery that resulted in complete response of the second metastasis. Patient case 4 achieved a partial response by RECIST 1.1 with avelumab plus stereotactic radiosurgery. These results suggest that avelumab followed by radiotherapy or with concurrent radiotherapy may be an effective treatment option for patients with mMCC and brain metastases.

Merkel Cell Carcinoma: New Trends

Simple Summary

In this review, we discuss a rare skin cancer that occurs mostly in elderly people called “Merkel cell carcinoma” (MCC). The incidence is increasing due to ageing of the population, increased sun exposure, and the use of medication that inhibits the immune system. Unlike most other skin cancers, MCC grows rapidly and forms metastases easily. We discuss the biology and treatment of MCC. Management should be by an experienced and multidisciplinary team, and treatment must start quickly. The standard practice of MCC treatment is surgery followed by radiotherapy. However, because it concerns an elderly and often frail population, (extensive) surgery may not always be feasible due to the associated morbidity. In those situations, radiotherapy alone is a good alternative. An important new development is immunotherapy that can cause long-lasting responses in a significant proportion of the patients with recurrent or metastatic MCC.

Abstract

Merkel cell carcinoma (MCC) is a rare neuroendocrine tumor of the skin mainly seen in the elderly. Its incidence is rising due to ageing of the population, increased sun exposure, and the use of immunosuppressive medication. Additionally, with the availability of specific immunohistochemical markers, MCC is easier to recognize. Typically, these tumors are rapidly progressive and behave aggressively, emphasizing the need for early detection and prompt diagnostic work-up and start of treatment. In this review, the tumor biology and immunology, current diagnostic and treatment modalities, as well as new and combined therapies for MCC, are discussed. MCC is a very immunogenic tumor which offers good prospects for immunotherapy. Given its rarity, the aggressiveness, and the frail patient population it concerns, MCC should be managed in close collaboration with an experienced multidisciplinary team.

Real-world clinical outcomes with first-line avelumab in locally advanced/metastatic Merkel cell carcinoma in the USA: SPEAR-Merkel

Aim: To assess clinical outcomes in patients with locally advanced (la) or metastatic (m) Merkel cell carcinoma (MCC) initiating first-line (1L) avelumab in a USA community oncology setting. Materials & methods: Adults with laMCC or mMCC initiating 1L avelumab were identified from The US Oncology Network electronic health record database and chart review. Results: Median overall survival and progression-free survival were not reached in laMCC (n = 9) vs 20.2 and 10.0 months in mMCC (n = 19); response rates were similar (66.7% vs 63.2%). Conclusion: This is the first study to show clinical benefit in patients with laMCC receiving 1L avelumab in a US real-world setting. Response rates in patients with mMCC were consistent with pivotal trials.

Cancer Immunotherapy Update: FDA-Approved Checkpoint Inhibitors and Companion Diagnostics

Immune checkpoint inhibitors (ICIs) are considered a new standard-of-care across many cancer indications. This review provides an update on ICIs approved by the Food and Drug Administration (FDA), with focus on monoclonal antibodies that target the programmed cell death 1 (PD-1) or its ligand, PD-1 ligand 1 (PD-L1), including information on their clinical indications and associated companion diagnostics. The information is further discussed with strategies for identifying predictive biomarkers to guide the clinical use of PD-1/PD-L1-targeted therapies.

γδ T Cells in Merkel Cell Carcinomas Have a Proinflammatory Profile Prognostic of Patient Survival

Merkel cell carcinomas (MCC) are immunogenic skin cancers associated with viral infection or UV mutagenesis. To study T-cell infiltrates in MCC, we analyzed 58 MCC lesions from 39 patients using multiplex-IHC/immunofluorescence (m-IHC/IF). CD4⁺ or CD8⁺ T cells comprised the majority of infiltrating T lymphocytes in most tumors. However, almost half of the tumors harbored prominent CD4/CD8 double-negative (DN) T-cell infiltrates (>20% DN T cells), and in 12% of cases, DN T cells represented the majority of T cells. Flow cytometric analysis of single-cell suspensions from fresh tumors identified DN T cells as predominantly Vδ2^- γδ T cells. In the context of γδ T-cell inflammation, these cells expressed PD-1 and LAG3, which is consistent with a suppressed or exhausted phenotype, and CD103, which indicates tissue residency. Furthermore, single-cell RNA sequencing (scRNA-seq) identified a transcriptional profile of γδ T cells suggestive of proinflammatory potential. T-cell receptor (TCR) analysis confirmed clonal expansion of Vδ1 and Vδ3 clonotypes, and functional studies using cloned γδ TCRs demonstrated restriction of these for CD1c and MR1 antigen-presenting molecules. On the basis of a 13-gene γδ T-cell signature derived from scRNA-seq analysis, gene-set enrichment on bulk RNA-seq data showed a positive correlation between enrichment scores and DN T-cell infiltrates. An improved disease-specific survival was evident for patients with high enrichment scores, and complete responses to anti-PD-1/PD-L1 treatment were observed in three of four cases with high enrichment scores. Thus, γδ T-cell infiltration may serve as a prognostic biomarker and should be explored for therapeutic interventions.See related Spotlight on p. 600.

Immunotherapy for Merkel cell carcinoma

Merkel cell carcinoma (MCC) is an aggressive form of skin cancer which, while chemosensitive, has high rates of relapse and chemoresistance, limiting the impact of chemotherapy. An immunogenic tumor, the management of advanced MCC has changed dramatically with the introduction of checkpoint inhibitors. This review will focus on the impact of immunotherapy in unresectable and metastatic MCC, ongoing research in the adjuvant and neoadjuvant settings, and future directions of immune-based strategies for this challenging cancer.

Radiolabelling and preclinical characterization of 89Zr-Df-radiolabelled bispecific anti-PD-L1/TGF-βRII fusion protein bintrafusp alfa

PURPOSE

Τhis study aimed to optimize the ⁸⁹Zr-radiolabelling of bintrafusp alfa investigational drug product and controls, and perform the in vitro and in vivo characterization of ⁸⁹Zr-Df-bintrafusp alfa and ⁸⁹Zr-Df-control radioconjugates.

METHODS

Bintrafusp alfa (anti-PD-L1 human IgG1 antibody fused to TGF-β receptor II (TGF-βRII), avelumab (anti-PD-L1 human IgG1 control antibody), isotype control (mutated inactive anti-PD-L1 IgG1 control antibody), and trap control (mutated inactive anti-PD-L1 human IgG1 fused to active TGF-βRII) were chelated with p-isothiocyanatobenzyl-desferrioxamine (Df). After radiolabelling with zirconium-89 (⁸⁹Zr), radioconjugates were assessed for radiochemical purity, immunoreactivity, antigen binding affinity, and serum stability in vitro. In vivo biodistribution and imaging studies were performed with PET/CT to identify and quantitate ⁸⁹Zr-Df-bintrafusp alfa tumour uptake in a PD-L1/TGF-β-positive murine breast cancer model (EMT-6). Specificity of ⁸⁹Zr-Df-bintrafusp alfa was assessed via a combined biodistribution and imaging experiment in the presence of competing cold bintrafusp alfa (1 mg/kg).

RESULTS

Nanomolar affinities for PD-L1 were achieved with ⁸⁹Zr-Df-bintrafusp alfa and ⁸⁹Zr-avelumab. Biodistribution and imaging studies in PD-L1- and TGF-β-positive EMT-6 tumour-bearing BALB/c mice demonstrated the biologic similarity of ⁸⁹Zr-Df-bintrafusp alfa and ⁸⁹Zr-avelumab indicating the in vivo distribution pattern of bintrafusp alfa is driven by its PD-L1 binding arm. Competition study with 1 mg of unlabelled bintrafusp alfa or avelumab co-administered with trace dose of ⁸⁹Zr-labelled bintrafusp alfa demonstrated the impact of dose and specificity of PD-L1 targeting in vivo.

CONCLUSION

Molecular imaging of ⁸⁹Zr-Df-bintrafusp alfa biodistribution was achievable and allows non-invasive quantitation of tumour uptake of ⁸⁹Zr-Df-bintrafusp alfa, suitable for use in bioimaging clinical trials in cancer patients.

Avelumab treatment in Italian patients with metastatic Merkel cell carcinoma: experience from an expanded access program

Background

The incidence of Merkel cell carcinoma (MCC), a rare form of skin cancer with a poor prognosis, has increased in Italy in recent decades. Avelumab, an anti-programmed death ligand 1 monoclonal antibody, is approved for the treatment of metastatic MCC (mMCC) based on the results of the phase 2 JAVELIN Merkel 200 trial. The global avelumab expanded access program (EAP) was designed to provide compassionate use of avelumab prior to approval for patients with mMCC who had limited treatment options. We report findings from a subgroup of Italian patients enrolled in the avelumab EAP.

Methods

Eligible patients had mMCC and progressive disease following ≥ 1 prior line of chemotherapy or were ineligible for chemotherapy or clinical trial participation. Patients received avelumab 10 mg/kg intravenously every 2 weeks. Treating physicians were provided with an initial 3-month supply of avelumab; resupply was permitted if the patient achieved a complete response, partial response, stable disease, or other clinical benefit per physician assessment. Safety and efficacy data for the EAP were reported at the treating physician’s discretion.

Results

Between April 1, 2016, and September 14, 2018, 109 requests for avelumab were received from Italy, and 102 were approved. All but 1 of the approved patients had received ≥ 1 prior line of therapy. At data cutoff (March 22, 2019), 95 patients had been supplied with avelumab and response data were available for 55 patients. The objective response rate in response-evaluable patients was 29.1%, including 6 patients (10.9%) who achieved a complete response and 10 patients (18.2%) who achieved a partial response; in the total population supplied with avelumab (n = 95), the proportion who had an objective response was 16.8%. The median duration of treatment in responding patients was 9.7 months (range, 3.5–41.7 months). The most frequently reported treatment-related adverse events were infusion-related reaction (single preferred term; n = 3 [3.2%]) and pyrexia (n = 2 [2.1%]).

Conclusions

Results from Italian patients enrolled in the avelumab EAP are consistent with the findings of the JAVELIN Merkel 200 trial and confirm the efficacy and safety of avelumab treatment in this population.

Merkel cell carcinoma

Merkel cell carcinoma (MCC) of the skin is a rare, aggressive form of skin cancer that metastasizes to other parts of the body. This cutaneous neuroendocrine tumour mainly affects older people, with most cases generally occurring over the age of 50 years. Merkel cell polyomavirus has been shown to induce gene mutations resulting in this skin cancer, with immunosuppression and ultraviolet radiation being other key risk factors in its pathogenesis. MCC is clinically seen as a rapidly enlarging, isolated, irregular erythematous nodule typically found on sun-exposed sites. Diagnosis is through clinical examination followed by tissue biopsy, which demonstrates characteristic histopathological neuroendocrine features. Immunohistochemistry plays a crucial role in diagnosis with the characteristic perinuclear staining with cytokeratin-20 helping to differentiate it from other morphologically similar tumours. Sentinel lymph node biopsy and imaging is essential for staging and determining prognosis. Surgical excision is the mainstay of treatment for localized disease although adjuvant radiotherapy is often required. Metastatic disease involves a very poor prognosis, and immune checkpoint inhibitors have recently shown promise in the treatment of metastatic disease. Avelumab, a monoclonal antibody that binds to the programmed death-1 receptor, has been approved by the National Institute for Health and Care Excellence and shown encouraging survival outcomes. It provides an option for treating metastatic carcinoma in adults after they have failed ≥ 1 line of chemotherapy for metastatic disease.

Pembrolizumab and other immune checkpoint inhibitors in locally advanced or metastatic Merkel Cell Carcinoma: safety and efficacy

INTRODUCTION

Merkel Cell Carcinoma (MCC) is a rare aggressive skin cancer, mostly affecting elderly patients. Until recently, patients with advanced disease were treated with cytotoxic chemotherapies despite rapid chemoresistance and high toxicity. As with other cancers, immune checkpoint inhibitors (CPI), including pembrolizumab, allow durable responses with a manageable safety profile in these patients.

AREAS COVERED

This review describes the rationale for using PD-1/PD-L1 inhibitors in MCC, as well as efficacy and safety results from the three open-label trials investigating pembrolizumab or other PD-1/PD-L1 inhibitors in patients with advanced MCC. Real-life experience and predictive pre-treatment biomarkers are discussed to assess which patients are likely to be candidates for such strategies. Ongoing fields of research include the use of CPI in the adjuvant or neoadjuvant setting and combined strategies in refractory patients. Expert Opinion: CPI have become the standard of care for frontline treatment in patients with advanced MCC. Earlier introduction of CPI in the disease course, including neo-adjuvant and adjuvant settings, is likely to improve the outcomes further. Given the rarity of this cancer, we still need to harmonize efforts in order to conduct large-scale trials and efficiently identify best optimal care.

Merkel cell carcinoma in Latin America: a contribution from an expanded access program for avelumab to address issues from experts' recommendations

BACKGROUND

Merkel cell carcinoma (MCC) is an aggressive malignancy, associated with poor outcomes in patients with metastatic disease (mMCC). Management has been dramatically altered as a result of incorporating immune checkpoint blockade agents. MCC data from Latin America (LATAM) come from case-series or individual records. Regional registries are lacking. A need for better registries to improve current knowledge about MCC is highlighted. Our objectives were to describe a real-world experience with avelumab as a second-line (or first-line in unfit patients) treatment in a subset of LATAM participants enrolled in a global Expanded Access Program (EAP) for patients with mMCC, and to evaluate its contribution to the resolution of the concerns described in a recent regional experts review.

MATERIALS AND METHODS

We reviewed data of LATAM participants in an avelumab EAP for mMCC treatment (NCT03089658). EAP patient had unresectable or mMCC with progressive disease after one line of chemotherapy, and were ineligible for clinical trials or unfit for chemotherapy.

RESULTS

46 patients (median age: 71.6 years; 60.9% males; median treatment duration: 7.9 months) were included in the LATAM EAP. Physician-assessed objective responses were available for 19 patients. Complete response rate was 15.8% and partial response rate reached 42.1%, summarizing an objective response rate of 57.9%. Stable disease rate was 10.5%, with a disease control response of 68.4%.

CONCLUSION

Avelumab showed robust efficacy and a safety profile consistent with global EAP data. Results are aimed to improve current knowledge about mMCC treatment and access to immunooncologic strategies for treating LATAM patients.

Avelumab for advanced Merkel cell carcinoma in the Netherlands: a real-world cohort

BACKGROUND

Merkel cell carcinoma (MCC) is associated with high recurrence rates and poor survival when metastatic disease is present. The immune checkpoint inhibitor avelumab has shown high response rates (RRs) and durable responses in patients with advanced MCC (aMCC) in clinical trials. To date, only results from clinical trials, patients treated in an expanded access program and very small numbers of patients have been reported. In this study, detailed real-world efficacy and toxicity data of avelumab in patients with aMCC are reported.

METHODS

Patients with aMCC treated in four dedicated referral centers in the Netherlands were analyzed from February 2017 until December 2019. Patients were included if they had received at least one administration of avelumab, regardless of previous lines of therapy. Patient data were collected retrospectively from patient records. Primary endpoints were response rate (RR) and duration of response (DOR). Secondary endpoints were progression-free survival (PFS), overall survival (OS), and toxicity.

RESULTS

Fifty-four patients received avelumab. Eight (15%) patients had locally advanced disease (laMCC). In 40 (74%) patients, avelumab was first-line treatment, these included all patients with laMCC. The median follow-up was 8.9 (range 0.5-35.9) months. RR was 57% (n=31) with 24% (n=13) of patients achieving a complete response. The median DOR was 8.4 (range 1.3-22.1) months and 23 (43%) patients had an ongoing response at the end of the study. The median PFS was 8.6 (95% CI 1.6-15.5) months, and the median OS was 25.8 (95% CI 9.1-42.4) months. Six (11%) patients experienced grade 3 toxicity. No grade 4-5 toxicity was seen.

CONCLUSIONS

In this real-world cohort, clinical efficacy and toxicity outcomes in clinical practice were in line with results from clinical trials and showed relatively high RRs and durable responses in patients with aMCC.

Non-Melanoma Skin Cancers: Biological and Clinical Features

Non-melanoma skin cancers (NMSCs) include basal cell carcinoma (BCC), squamous cell carcinoma (SCC) and Merkel cell carcinoma (MCC). These neoplasms are highly diverse in their clinical presentation, as well as in their biological evolution. While the deregulation of the Hedgehog pathway is commonly observed in BCC, SCC and MCC are characterized by a strikingly elevated mutational and neoantigen burden. As result of our improved understanding of the biology of non-melanoma skin cancers, innovative treatment options including inhibitors of the Hedgehog pathway and immunotherapeutic agents have been recently investigated against these malignancies, leading to their approval by regulatory authorities. Herein, we review the most relevant biological and clinical features of NMSC, focusing on innovative treatment approaches.