Avelumab for the treatment of locally advanced or metastatic Merkel cell carcinoma-A multicenter real-world experience in Israel

BACKGROUND

Merkel cell carcinoma (MCC) is a rare and aggressive malignancy of the skin, affecting predominantly the fair-skinned older population exposed to high levels of ultraviolet light. Immune suppression is considered a significant risk factor. With the recent advances in the field of immunotherapy, the treatment paradigm for advanced MCC, traditionally based on chemotherapy, has largely shifted to anti-PD-L1 and PD-1 agents such as avelumab and pembrolizumab, respectively. However, real-world data remain sparse. The aim of this study was to assess real-world evidence of the effectiveness of avelumab in a diverse group of patients with MCC in Israel.

METHODS

The electronic databases of five university hospitals in Israel were searched for all consecutive patients with MCC treated with at least one dose of avelumab in 2018-2022. Data on baseline, disease-related, treatment-related, and outcome parameters were collected and analyzed.

RESULTS

The cohort included 62 patients of whom 22% were immune-suppressed. The overall response rate to avelumab was 59%. The median progression-free survival was 8.1 months, and the median overall survival, 23.5 months, with no differences between immune-competent and immune-suppressed patients. Treatment was well tolerated; any-grade toxicity developed in 34% of patients, and grade 3-4 toxicity, in 14%.

CONCLUSIONS

Avelumab was found to be effective and safe for the treatment of advanced MCC in a diverse group of patients, including some with immune suppression. Further studies are warranted to evaluate the optimal sequence and duration of treatment and to assess the potential role of avelumab for earlier stages of MCC.

Merkel cell carcinoma: epidemiology, clinical features, diagnosis and treatment of a rare disease

Merkel cell carcinoma is a rare skin cancer with neuroendocrine differentiation. The risk factors include sun exposure, advanced age, immunosuppression (such as transplant recipients, patients with lymphoproliferative neoplasms, or patients with HIV), and Merkel cell polyomavirus infection. Clinically, Merkel cell carcinoma appears as a cutaneous or subcutaneous plaque or nodule, but this tumor diagnosis is rarely made clinically. Therefore, histopathology and immunohistochemistry are usually necessary. Primary tumors without evidence of metastases are treated with complete surgical excision and appropriate surgical margins. The presence of occult metastasis in a lymph node is frequent and a sentinel lymph node biopsy should be performed. Postoperative adjuvant radiotherapy increases local tumor control. Recently, agents that block the PD-1/PD-L1 pathway have shown objective and durable tumor regression in patients with advanced solid malignancies. The first anti-PD-L1 antibody used in patients with Merkel cell carcinoma was avelumab, but pembrolizumab and nivolumab have also shown efficacy. This article describes the current state of knowledge of the epidemiology, diagnosis, and staging of Merkel cell carcinoma, as well as new strategies for its systemic treatment.

Current treatments and emerging therapies of human polyomavirus-associated skin diseases: a comprehensive review

Since Merkel cell polyomavirus (MCPyV) was linked as the predominant etiology of Merkel cell carcinoma (MCC) in 2008, three additional human polyomaviruses (HPyV) have been definitively linked to cutaneous diseases-trichodysplasia spinulosa virus (TSPyV) and human polyomavirus 6 and 7 (HPyV6, HPyV7). TSPyV contributes to the development of trichodysplasia spinulosa (TS), and HPyV6/7 is associated closely with the eruption of pruritic and dyskeratotic dermatoses (PDD). Clinically, MCC is treated with surgical excision and radiation with adjuvant chemotherapy, although newer treatment options include immune checkpoint inhibition. These novel immunotherapies hold promise for the treatment of metastatic MCC, but resistance and side effects prevent a significant proportion of patients from realizing their benefits. Based on previous case reports, the standard of care for the less deadly but disfiguring cutaneous disease TS include immunosuppressant (IS) reduction, the use of antivirals such as cidofovir (CDV) or valganciclovir (VGCV), or a combination of these treatments. Similar treatments were attempted for PDD, but oral acitretin was found to be most effective. As MCC, TS, and PDD are rare diseases, further research is required for effective treatments. In this review, we summarize clinical trials, preclinical studies, and case reports that present outcomes and side effects of current and emerging treatments for HPyV-associated cutaneous diseases, offering a comprehensive resource for clinical application and prospective 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.

Overcoming Resistance to Immunotherapy in Head and Neck Cancer Using Radiation: A Review

Radiation therapy remains at the center of head and neck cancer treatment. With improvements in treatment delivery, radiation therapy has become an affective ablative modality for head and neck cancers. Immune checkpoint inhibitors are now also playing a more active role both in the locally advanced and metastatic setting. With improved systemic options, local noninvasive modalities including radiation therapy are playing a critical role in overcoming resistance in head and neck cancer. The aim of this review is to describe the role of radiation therapy in modulating the tumor microenvironment and how radiation dose, fractionation and treatment field can impact the immune system and potentially effect outcomes when combined with immunotherapy. The review will encompass several common scenarios where radiation is used to improve outcomes and overcome potential resistance that may develop with immunotherapy in head and neck squamous cell carcinoma (HNSCC), including upfront locally advanced disease receiving definitive radiation and recurrent disease undergoing re-irradiation. Lastly, we will review the potential toxicities of combined therapy and future directions of their role in the management of HNSCC.

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.

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.

Anti-EGFR Antibody Plus Chemotherapy Treatment in a Patient with Synchronous Merkel Cell Carcinoma and Colorectal Cancer

Merkel cell carcinoma (MCC) is a rare neuroendocrine cutaneous malignancy. During early stages, surgery is the primary treatment followed by radiotherapy in patients at high risk of recurrence. Definitive radiation therapy is an alternative for patients who are not surgical candidates, reserving chemotherapy for metastatic disease. We present a case of a male patient diagnosed with MCC and stage IV colorectal cancer and we focus on the skin tumor shrinkage after specific colorectal cancer treatment.

The changing paradigm of managing Merkel cell carcinoma in Australia: An expert commentary

Merkel cell carcinoma (MCC) is a highly aggressive neuroendocrine tumor of the skin with an estimated disease-associated mortality of 15-33%. Australia has a higher incidence of MCC compared to the rest of the world, thought to be due to a higher ultraviolet index. The Australian MCC population is distinct from the MCC population of the Northern hemisphere, characterized by a predominantly viral negative etiology with high tumor mutational burden. The optimal management of MCC and the choice of treatment modality vary significantly across the world and even between institutions within Australia. Historically, the treatment for MCC has been resection followed by radiotherapy (RT), though definitive RT is an alternative treatment used commonly in Australia. The arrival of immune checkpoint inhibitors and the mounting evidence that MCC is a highly immunogenic disease is transforming the treatment landscape for MCC. Australia is playing a key role in the further development of treatment options for MCC with two upcoming Australian/New Zealand investigator-initiated clinical trials that will explore the interplay of RT and immunotherapy in the treatment of early and late stage MCC.

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.

An Unusual Presentation of Merkel Cell Carcinoma in a HIV Patient: A Case Report and Literature Review

Merkel cell carcinoma (MCC) is a rare, rapidly growing, aggressive neuroendocrine skin cancer that generally arises on sun-exposed areas of body such as head, neck, upper limbs, and shoulders of people with light complexity. Typically, MCC presents as shiny, flesh-colored or bluish-red, intracutaneous nodule, possibly with ulceration or crusting. In most of the cases, there is an association with Merkel cell polyomavirus. Even though these are very aggressive tumors, early detection and treatment has always given favorable outcome. There seems to be no consensus in definite prognostic markers, and advanced stages have the worst outcome even with treatment. There has been a recent trend in using PD-I/PD-L1 target therapy rather than chemotherapy in these cancers and have shown to improve survival by many months. In this article, we report a very unusual presentation of MCC first found on left frontoparietal skull as an 8-cm diameter fixed, subcutaneous mass without any typical features of MCC and was found to have metastatic spread to lung and liver. The patient was treated with palliative radiotherapy to brain and chemotherapy with cisplatin/etoposide with addition of immunotherapy later.

Evaluation of survival extrapolation in immuno-oncology using multiple pre-planned data cuts: learnings to aid in model selection

BACKGROUND

Due to limited duration of follow up in clinical trials of cancer treatments, estimates of lifetime survival benefits are typically derived using statistical extrapolation methods. To justify the method used, a range of approaches have been proposed including statistical goodness-of-fit tests and comparing estimates against a previous data cut (i.e. interim data collected). In this study, we extend these approaches by presenting a range of extrapolations fitted to four pre-planned data cuts from the JAVELIN Merkel 200 (JM200) trial. By comparing different estimates of survival and goodness-of-fit as JM200 data mature, we undertook an iterative process of fitting and re-fitting survival models to retrospectively identify early indications of likely long-term survival.

METHODS

Standard and spline-based parametric models were fitted to overall survival data from each JM200 data cut. Goodness-of-fit was determined using an assessment of the estimated hazard function, information theory-based methods and objective comparisons of estimation accuracy. Best-fitting extrapolations were compared to establish which one provided the most accurate estimation, and how statistical goodness-of-fit differed.

RESULTS

Spline-based models provided the closest fit to the final JM200 data cut, though all extrapolation methods based on the earliest data cut underestimated the 'true' long-term survival (difference in restricted mean survival time [RMST] at 36 months: - 1.1 to - 0.5 months). Goodness-of-fit scores illustrated that an increasingly flexible model was favored as data matured. Given an early data cut, a more flexible model better aligned with clinical expectations could be reasonably justified using a range of metrics, including RMST and goodness-of-fit scores (which were typically within a 2-point range of the statistically 'best-fitting' model).

CONCLUSIONS

Survival estimates from the spline-based models are more aligned with clinical expectation and provided a better fit to the JM200 data, despite not exhibiting the definitively 'best' statistical goodness-of-fit. Longer-term data are required to further validate extrapolations, though this study illustrates the importance of clinical plausibility when selecting the most appropriate model. In addition, hazard-based plots and goodness-of-fit tests from multiple data cuts present useful approaches to identify when a more flexible model may be advantageous.

TRIAL REGISTRATION

JAVELIN Merkel 200 was registered with ClinicalTrials.gov as NCT02155647 on June 4, 2014.

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

BACKGROUND

Avelumab, a human anti-programmed death-ligand 1 immunoglobulin G1 monoclonal antibody, showed favorable efficacy and safety in patients with metastatic Merkel cell carcinoma (mMCC) in the phase II JAVELIN Merkel 200 trial, leading to approval in multiple countries. We describe real-world experience with avelumab in patients with mMCC from an expanded access program.

METHODS

Eligible patients had mMCC and progressive disease during or after chemotherapy or were ineligible for chemotherapy or clinical trial participation. Patients received an initial 3-month supply of avelumab (administered as 10 mg/kg intravenously every 2 weeks until progressive disease or unacceptable toxicity); resupply was allowed following complete response, partial response, stable disease, or clinical benefit per physician assessment.

RESULTS

Between December 15, 2015, and March 4, 2019, 558 of 620 requests from 38 countries were medically approved, and 494 patients received avelumab. Among 240 evaluable patients, the objective response rate was 46.7% (complete response in 22.9%, including 3 of 16 potentially immunocompromised patients), and the disease control rate was 71.2%. The median duration of treatment in evaluable patients with response was 7.9 months (range, 1.0-41.7) overall and 5.2 months (range, 3.0-13.9) in immunocompromised patients. No new safety signals were identified. The expanded access program closed for new requests on December 31, 2018, as required after regulatory approval; benefitting patients continued to receive avelumab.

CONCLUSIONS

The avelumab expanded access program for patients with mMCC demonstrated efficacy and safety in a real-world setting, consistent with the results from JAVELIN Merkel 200, and provided a treatment for patients with limited options.

Landscape of current and future therapies of Merkel cell carcinoma

Merkel cell carcinoma is rare and aggressive skin cancer, which occurrence is linked to exposure to ultraviolet light and the Merkel-cell polyomavirus. In recent years, significant progress in understanding the mechanism of Merkel cell carcinoma pathogenesis has been observed. This neoplasm often expresses PD-L1, and MCPyV-specific T cells can express PD-1 thus PD-1/PD-L1 checkpoint therapies seem to be remarkably interesting treatment options. Many clinical trials are currently being conducted to confirm their effectiveness and safety for this group of patients. However, only about half of advanced Merkel cell carcinoma patients could achieve remission or disease stabilization through PD-1/PD-L1 checkpoint therapies thus innovative treatments are still needed. In this article, we have presented current and future directions in the development of Merkel cell carcinoma therapy.

Phase III, randomised trial of avelumab versus physician's choice of chemotherapy as third-line treatment of patients with advanced gastric or gastro-oesophageal junction cancer: primary analysis of JAVELIN Gastric 300

Background

There currently are no internationally recognised treatment guidelines for patients with advanced gastric cancer/gastro-oesophageal junction cancer (GC/GEJC) in whom two prior lines of therapy have failed. The randomised, phase III JAVELIN Gastric 300 trial compared avelumab versus physician’s choice of chemotherapy as third-line therapy in patients with advanced GC/GEJC.

Patients and methods

Patients with unresectable, recurrent, locally advanced, or metastatic GC/GEJC were recruited at 147 sites globally. All patients were randomised to receive either avelumab 10 mg/kg by intravenous infusion every 2 weeks or physician’s choice of chemotherapy (paclitaxel 80 mg/m² on days 1, 8, and 15 or irinotecan 150 mg/m² on days 1 and 15, each of a 4-week treatment cycle); patients ineligible for chemotherapy received best supportive care. The primary end point was overall survival (OS). Secondary end points included progression-free survival (PFS), objective response rate (ORR), and safety.

Results

A total of 371 patients were randomised. The trial did not meet its primary end point of improving OS {median, 4.6 versus 5.0 months; hazard ratio (HR)=1.1 [95% confidence interval (CI) 0.9–1.4]; P = 0.81} or the secondary end points of PFS [median, 1.4 versus 2.7 months; HR=1.73 (95% CI 1.4–2.2); P > 0.99] or ORR (2.2% versus 4.3%) in the avelumab versus chemotherapy arms, respectively. Treatment-related adverse events (TRAEs) of any grade occurred in 90 patients (48.9%) and 131 patients (74.0%) in the avelumab and chemotherapy arms, respectively. Grade ≥3 TRAEs occurred in 17 patients (9.2%) in the avelumab arm and in 56 patients (31.6%) in the chemotherapy arm.

Conclusions

Treatment of patients with GC/GEJC with single-agent avelumab in the third-line setting did not result in an improvement in OS or PFS compared with chemotherapy. Avelumab showed a more manageable safety profile than chemotherapy.

Trial registration

ClinicalTrials.gov: NCT02625623.

Heart Block Caused by Cardiac Metastasis From Merkel Cell Carcinoma: A Case Report

Merkel cell carcinoma (MCC) is a rare, rapidly proliferating skin cancer that commonly metastasizes to regional lymph nodes. We present the case of a 73-year-old woman with a history of MCC and non-Hodgkin B-cell lymphoma who presented with second-degree heart block (Mobitz type II) caused by an interatrial mass. Temporary pacing was required before biopsy, which revealed metastatic MCC. Treatment included permanent pacing, anti–programmed cell death ligand 1 immunotherapy, and radiation to the heart resulting in notable decrease in tumor size and normalized cardiac rhythm.

Value assessment of immuno-oncology in the treatment of rare tumors in the era of accelerated conditional approvals

Aim: To conduct a value assessment of an immuno-oncology (IO) therapy for a rare cancer and evaluate whether existing frameworks consider challenges associated with valuing IOs for rare cancers. Materials & methods: Value frameworks developed by American Society of Clinical Oncologists, Memorial Sloan Kettering Cancer Center and National Comprehensive Cancer Network were used to estimate the value of an IO therapy in a rare cancer based on single-arm trial data and retrospective studies. Results: Paucity of direct evidence comparing rare cancer treatments and lack of acceptance of indirect comparisons hinder appropriate value assessment. Measurement of value based on short-term outcomes may not capture the value of IOs, where survival is often characterized by a plateau. Conclusion: Further work is required to factor in nuances associated with rare cancers and guide end users of the frameworks. To capture true value, multiple or more holistic value assessments are required.

Treatment of Advanced Merkel Cell Carcinoma: Current Therapeutic Options and Novel Immunotherapy Approaches

Advanced Merkel cell carcinoma (MCC) is a very aggressive, rare neuroendocrine tumor of the skin with a high frequency of locoregional recurrence and metastasis, and a high mortality rate. Surgical resection, sentinel lymph node biopsy, and radiotherapy represent the gold standard of treatment in patients with localized disease, while chemotherapy has a significant role in the treatment of advanced disease. However, no definitive evidence on the survival impact of radiotherapy in the advanced stages has been provided to date, and response to chemotherapy remains brief in the majority of cases, indicating an urgent need for alternative approaches. Biological and genome sequencing studies have implicated multiple molecular pathways in MCC, thus leading to the development of new agents that target angiogenic factors, anti-apoptosis molecules, poly-ADP ribose polymerase, intracellular signal proteins such as the PI3K/AKT/mTOR pathway, and peptide receptors such as somatostatin receptors. More recently, immunotherapy agents such as avelumab, pembrolizumab, and nivolumab, which act by blocking the programmed cell-death (PD)-1/PD-L1 immune checkpoint, have shown promising results, especially in the advanced setting, and should now be considered standard of care for metastatic MCC. Current research is focusing on developing new immunotherapeutic strategies, identifying predictive biomarker to aid in the selection of patients responsive to immunotherapy, and defining combination approaches to increase efficacy in refractory patients.

Caring for Patients Treated With Checkpoint Inhibitors for the Treatment of Metastatic Merkel Cell Carcinoma

OBJECTIVE

To provide an overview for oncology nurses about Merkel cell carcinoma and its management with immunotherapy.

DATA SOURCES

A literature search was conducted from 2013 to the present using search terms including "Merkel cell carcinoma," "avelumab," "pembrolizumab," "immune-mediated adverse events," and "infusion-related reactions." Clinical experience of the authors was also considered.

CONCLUSION

Oncology nurses can expect to manage an increasing number of patients with Merkel cell carcinoma because of increased incidence of the disease, as well as evolving immunotherapy treatment paradigms. Both avelumab and pembrolizumab possess favorable safety profiles but are associated with immune-mediated and infusion-related reactions.

IMPLICATIONS FOR NURSING PRACTICE

Oncology nurses need to understand Merkel cell carcinoma and be able to recognize the signs and symptoms of immune-mediated adverse events and infusion-related reactions associated with treatment to provide early intervention.

Survival Analysis in Patients with Metastatic Merkel Cell Carcinoma Treated with Avelumab

Introduction

Complex underlying risk functions associated with immuno-oncology treatments have led to exploration of different methods (parametric survival, spline, landmark, and cure-fraction models) to estimate long-term survival outcomes. The objective of this study was to examine differences in estimated short- and long-term survival in previously treated metastatic Merkel cell carcinoma (mMCC) patients receiving avelumab, when using alternative extrapolation approaches.

Methods

Efficacy data from the phase 2 JAVELIN Merkel 200 trial (part A) with at least 12 months of follow-up were analyzed. Standard parametric survival analyses and analyses of overall survival (OS) as a function of surrogate outcomes comprised of response (landmark analyses) and progression-free survival plus post-progression survival (PFS + PPS) were used to project OS. Overall survival throughout lifetime was projected and compared with the observed OS data with at least 24 months of follow-up.

Results

Estimated OS from all three approaches provided a good fit to the observed OS curve from at least 12 months of follow-up. However, performance compared with OS data from at least 24 months showed that the landmark approach followed by PFS + PPS provided a better fit to the data as compared to standard parametric analysis. Mean life expectancy estimated with avelumab was 2.48 years with best-fitting parametric function (a log-normal distribution), 3.15 years with the landmark approach, and 3.54 years with PFS + PPS.

Conclusion

Although standard parametric survival analysis may provide a good fit to short-term survival, it appears to underestimate the long-term survival benefits associated with avelumab in mMCC. Extrapolations based on surrogate outcomes of response or progression predict OS outcomes from longer follow-up better and appear to provide more clinically plausible projections.

Funding

EMD Serono Inc, Rockland, MA, a business of Merck KGaA, Darmstadt, Germany.

Electronic Supplementary Material

The online version of this article (10.1007/s12325-019-01034-0) contains supplementary material, which is available to authorized users.

Cost Effectiveness of Avelumab for Metastatic Merkel Cell Carcinoma

BACKGROUND

Metastatic Merkel cell carcinoma (mMCC) is a rare and aggressive skin cancer. Until recently, there were no licensed treatment options for patients with mMCC, and prognosis was poor. A cost-effectiveness analysis was conducted for avelumab, a newly available treatment option for mMCC, versus standard care (SC), from a UK National Health Service perspective.

METHODS

A partitioned survival model was developed to assess the lifetime costs and effects of avelumab versus SC. Data from the JAVELIN Merkel 200 trial (NCT02155647) were used to inform estimates of quality-adjusted life-years (QALYs). Unit costs and associated frequencies of use were informed by published literature and clinical expert opinion. Results were presented as incremental cost-effectiveness ratios (ICERs, i.e. the cost per QALY gained) for treatment-experienced (TE) and treatment-naïve (TN) patients. Uncertainty was explored through a range of sensitivity analyses.

RESULTS

Discounting costs and QALYs at 3.5% per annum, avelumab was associated with ICERs of £35,274 (TE)/£39,178 (TN) per QALY gained. Probabilistic sensitivity analysis results demonstrated that avelumab was associated with an 88.3% (TE)/69.3% (TN) probability of being cost effective at a willingness-to-pay threshold for end-of-life treatments of £50,000 per QALY gained. Results were most sensitive to alternative survival extrapolations and dosing assumptions.

CONCLUSIONS

The analysis results suggest that avelumab is likely to be a cost-effective treatment option for UK mMCC patients. The results for TN patients are subject to some uncertainty, and a confirmatory analysis will be conducted with more mature data.

[Immune checkpoint inhibition in Merkel cell carcinoma]

BACKGROUND

Merkel cell carcinoma (MCC) is a rare but aggressive form of skin cancer in which Merkel cell polyomavirus infection and chronic exposure to ultraviolet radiation are key risk factors. Immune checkpoint inhibition has revolutionized the treatment of locally advanced, inoperable and metastatic MCC.

AIM

To outline the modern management of MCC based on advances in our understanding of MCC tumour biology and the development of immune checkpoint inhibitors, namely inhibitors of programmed cell death protein (PD)-1- and PD‑1 ligand 1 (PD-L1).

METHODS

A review of the scientific literature listed in PubMed.

RESULTS

First line therapy with the PD-L1 blocking antibody avelumab is associated with a response rate of 62%. In the second line setting, for example after chemotherapy, the response rate only reaches 33%. However, in patients who responded in the second line setting, 69% remained relapse free after 2 years. Treatment responses occurred on average after 6.1 weeks of therapy. First line treatment with pembrolizumab (anti-PD‑1 antibody) is associated with a 2-year survival rate of 69% and the median survival rate has not been reached. Whilst the various chemotherapy regimens are associated with similar response rates, these are typically short lived.

DISCUSSION

Checkpoint inhibition offers an effective treatment option for patients with MCC. Avelumab is currently licensed as a treatment for metastatic disease. Chemotherapy remains an option to reduce tumor load, or in the context of resistance and/or contraindications to immune checkpoint therapy. Adjuvant and neoadjuvant use of checkpoint inhibition in MCC may represent a future treatment strategy pending the results of on-going clinical trials.

Complete response with neoadjuvant avelumab in Merkel cell carcinoma - A case report

Merkel cell carcinoma (MCC) is a rare but aggressive neuroendocrine skin malignancy. We report here a case of localized MCC achieving pathologic complete response upon treatment with avelumab in the neoadjuvant setting. Preclinical and clinical studies have revealed a close relationship between MCC and the immune system, thus supporting a role for PD-1/PD-L1 inhibitors in MCC. This neoadjuvant use of PD-1/PD-L1 inhibitors can avoid potentially disfiguring surgery in MCC. As the incidence of MCC is rising, clinical trials are needed to evaluate the efficacy and safety of immunotherapy in resectable disease.

Immune Checkpoint Inhibitors and Beyond: An Overview of Immune-Based Therapies in Merkel Cell Carcinoma

Merkel cell carcinoma (MCC) is an aggressive skin cancer. Until 2017, patients with advanced disease were typically treated with conventional chemotherapies, with a median response duration of 3 months. Increased evidence of the role of the immune system in controlling this cancer has paved the way for immune-based therapies, with programmed cell death protein 1 (PD-1)/programmed cell death protein ligand 1 (PD-L1) inhibitors at the frontline. Avelumab, an anti-PD-L1 antibody, was the first-ever drug approved in advanced MCC after showing meaningful efficacy in a second-line setting. Objective responses were observed in one-third of patients and, most importantly, were durable with half of patients and one-third of patients still alive at 1 and 2 years, respectively. When used in a first-line setting, PD-1/PD-L1 inhibitors (avelumab, pembrolizumab, nivolumab) are even more promising as objective responses are observed in approximately 50-70% of patients within the first 4-8 weeks of treatment. Safety profiles are acceptable with 10-20% of patients experiencing adverse events grade ≥ 3. PD-1/PD-L1 inhibitors are considered the standard of care in advanced MCC and are currently being investigated in the adjuvant and neoadjuvant settings. However, innovative treatments are still needed in the metastatic setting, as approximately 50% of these patients will not persistently respond to currently available immunotherapies, and no predictors of response are available yet. Therefore, other immunotherapeutic strategies are now being investigated-ideally in combinations-to enhance the various aspects of the immune response against tumoral cells.

Time-Varying Clearance and Impact of Disease State on the Pharmacokinetics of Avelumab in Merkel Cell Carcinoma and Urothelial Carcinoma

Avelumab, a human anti-programmed death ligand 1 immunoglobulin G1 antibody, has shown efficacy and manageable safety in multiple tumors. A two-compartment population pharmacokinetic model for avelumab incorporating intrinsic and extrinsic covariates and time-varying clearance (CL) was identified based on data from 1,827 patients across three clinical studies. Of 14 tumor types, a decrease in CL over time was more notable in metastatic Merkel cell carcinoma and squamous cell carcinoma of the head and neck, which had maximum decreases of 32.1% and 24.7%, respectively. The magnitude of reduction in CL was higher in responders than in nonresponders. Significant covariate effects of baseline weight, baseline albumin, and sex were identified on both CL and central distribution volume. Significant covariate effects of black/African American race, C-reactive protein, and immunogenicity were found on CL. None of the covariate or time-dependent effects were clinically important or warranted dose adjustment.

Recent Therapeutic Advances and Change in Treatment Paradigm of Patients with Merkel Cell Carcinoma

Merkel cell carcinoma (MCC) is a rare, aggressive, primary cutaneous neuroendocrine tumor that typically presents as an indurated nodule on sun-exposed areas of the head and neck in the white population. Major risk factors include immunosuppression, UV light exposure, and advanced age. Up to 80% of MCC are associated with Merkel cell polyomavirus. About 50% of patients present with localized disease, and surgical resection with or without adjuvant radiotherapy is generally indicated in this context. However, recurrence rates are high and overall prognosis rather poor, with mortality rates of 33%-46%. MCC is a chemosensitive disease, but responses in the advanced setting are seldom durable and not clearly associated with improved survival. Several recent trials with checkpoint inhibitors (pembrolizumab, avelumab, nivolumab) have shown very promising results with a favorable safety profile, in both chemonaïve and pretreated patients. In 2017, avelumab was approved by several regulatory agencies for the treatment of metastatic MCC, the first drug to be approved for this orphan disease. More recently, pembrolizumab has also been approved by the U.S. Food and Drug Administration in this setting. Immunotherapy has therefore become the new standard of care in advanced MCC. This article reviews current evidence and recommendations for the diagnosis and treatment of MCC and discusses recent therapeutic advances and their implications for care in patients with advanced disease. This consensus statement is the result of a collaboration between the Spanish Cooperative Group for Neuroendocrine Tumors, the Spanish Group of Treatment on Head and Neck Tumors, and the Spanish Melanoma Group. IMPLICATIONS FOR PRACTICE: Merkel cell carcinoma (MCC) is an uncommon aggressive skin cancer associated with advanced age, UV light exposure, and immunosuppression. Up to 80% are associated with Merkel cell polyomavirus. MCC is a chemosensitive disease, but tumor responses in the advanced setting are short-lived with no long-term survivors. Recent clinical trials with immune checkpoint inhibitors (i.e., pembrolizumab, avelumab, nivolumab) have shown promising results, with avelumab becoming the first drug to receive regulatory approval for this orphan indication. Further follow-up is needed, however, to define more adequately the long-term benefits of these drugs, and continued research is warranted to optimize immunotherapeutic strategies in this setting.

Unknown primary Merkel cell carcinoma with cutaneous spread

The authors present the case of a woman in the seventh decade of life with medical history of: left nephrectomy for renal tuberculosis and non-Hodgkin's lymphoma treated with chemotherapy (QT) and radiotherapy. She presented with a 2-month history of non-tender, left inguinal lymph node enlargement. Positron Emission Tomography (PET)-CT -scanshowed hypermetabolic inguinal and retroperitoneal lymphadenopathies, no primary tumour. On the second dermatological examination a pink, 2 cm plaque on the anterior left knee was noted. The histopathological analysis revealed Merkel cell carcinoma. The patient underwent two lines of systemic QT, with life-threatening toxicities limiting treatment. Followed overwhelming disease progression with lymphoedema and numerous skin metastases in the left lower limb. The patient received palliative care until death. The rare incidence of such neoplasia and its uncommon clinical presentation justifies reporting this case and highlights the importance of multidisciplinary teams in the management of cancer patients.

Prognostic Factors in Merkel Cell Carcinoma: A Retrospective Single-Center Study in 90 Patients

Merkel Cell Carcinoma (MCC) is a rare but highly aggressive neuroendocrine neoplasm of the skin. This study aimed at describing characteristics, treatment, and prognosis of a series of consecutive cases of MCC patients, in order to contribute to the investigation of this rare malignancy and provide better patient care. This is a retrospective cohort study including all 90 patients diagnosed and/or treated for MCC between 1991 and 2018 at the Veneto Institute of Oncology in Padua (Italy). Patient and tumor characteristics, treatment, and immunohistochemical data were extracted from a prospectively collected local database. There were 68 primary (76%) and 22 non-primary (15 occult primary, three metastatic, four recurrence) tumors (24%). CK20 expression was associated with reduced overall (HR 2.92, 95% CI 1.04–8.16) and disease-specific (HR 4.62, 95% CI 1.31–16.28) survival. Immunomodulatory regimens for treatment of other comorbidities were associated with reduced disease-specific ((HR 2.15, 95% CI 1.06–4.36) and recurrence-free (HR 3.08, 95% CI 1.44–6.57) survival. Iatrogenic immunomodulation resulted as the main factor associated with impaired prognosis. Lack of CK20 expression was associated with better survival.