Merkel Cell Carcinoma: An Immunotherapy Fairy-Tale?

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.

Chemoreactive 2,5-Diketopiperazines from a Penicillium sp., Structure Revision of Reported Analogues and Proposed Facile Transformation Pathways

Merkel cell carcinoma (MCC) is a rare and aggressive cutaneous cancer. Two new prenylated indole 2,5-diketopiperazine alkaloids, brevianamides E1 (1) and E2 (2), were isolated from a Penicillium fungus. Both compounds showed moderate cytotoxic activity against select MCC cell lines (i.e., MCC13, MKL-1, UISO, and WaGa) in the low micromolar range. The relative and absolute configurations of 1 and 2 were determined by combined approaches, including NOESY spectroscopy, DFT ECD and DP4 plus calculations, and Marfey's reaction. Literature research and the comparison of NMR and ECD data led to the structure revision of three previously reported natural analogues, notoamides K and P and asperversiamide L. The structurally unstable 1 and 2 underwent steady interconversion under neutral aqueous conditions. Investigation of the degradation of 2 in acidic methanol solutions led to the identification of a new methoxylated derivative (6) and two new ring-opened products (7 and 8) with the rearranged, elongated, 4-methylpent-3-ene side chain. The facile transformation of 2 to 7 and 8 was promoted by the intrinsic impurity (i.e., formaldehyde) of HPLC-grade methanol through the aza-Cope rearrangement.

Systematic evaluation of Merkel cell carcinoma clinical practice guidelines using the AGREE II instrument

Merkel cell carcinoma (MCC) is a rare type of skin cancer that requires a multidisciplinary approach with a variety of specialists for management and treatment. Clinical practice guidelines (CPGs) have recently been established to standardize management algorithms. The objective of this study was to appraise such CPGs via the Appraisal of Guidelines for Research and Evaluation (AGREE II) instrument. Eight CPGs were identified via systematic literature search following Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) criteria. Four appraisers trained in AGREE II protocols evaluated each CPG and deemed two CPGs as high quality, five as moderate quality, and one as low quality. Intraclass correlation coefficients (ICCs) were calculated to verify reviewer consistency as excellent, good, and moderate across four, one, and one domain, respectively. The majority of MCC CPGs are lacking in specifying stakeholder involvement, applicability, and rigor of development. The two high quality CPGs are from the Alberta Health Services (AHS) and the collaboration between the European Dermatology Forum, the European Association of Dermato-Oncology, and the European Organization of Research and Treatment of Cancer (EDF/EADO/EORTC). The EDF/EADO/EORTC CPG had the highest overall score with no significant deficiencies across any domain. An important limitation is that the AGREE II instrument is not designed to evaluate the validity of each CPG's recommendations; conclusions therefore can only be drawn about each CPG's developmental quality. Future MCC CPGs may benefit from garnering public perspectives, inviting external expert review, and considering available resources and implementation barriers during their developmental stages.

Safety and effectiveness of avelumab in patients with Merkel cell carcinoma in general clinical practice in Japan: Post-marketing surveillance

Avelumab, a programmed cell death ligand 1 blocking antibody, was approved for its first indication in Japan in September 2017 to treat unresectable Merkel cell carcinoma (MCC). Given that the pivotal JAVELIN Merkel 200 study only included a few Japanese patients, this post-marketing surveillance (PMS) evaluated the safety and effectiveness outcomes of patients with MCC who received avelumab in general clinical practice in Japan. This prospective, non-comparative, multicenter PMS included data from all patients with unresectable MCC who received avelumab between November 22, 2017 (avelumab launch date) and October 31, 2019. The primary objective was to evaluate avelumab safety (i.e., adverse events [AEs], adverse drug reactions [ADRs], and ADRs of safety specifications). The secondary objective was to evaluate avelumab effectiveness (i.e., objective response rate and overall survival [OS] rate). Seventy-five evaluable patients were included, of whom 81.3% experienced AEs of any grade (57.3% experienced AEs of grade ≥ 3; 41.3% experienced AEs of grade 5) and 61.3% experienced ADRs (14.7% experienced ADRs of grade ≥ 3; no grade 5 ADRs were observed). The most common ADRs were pyrexia (18.7%), infusion related reaction (10.7%), and chills (6.7%). The most common ADRs of safety specifications were infusion reactions (any grade: n = 21 [28.0%]; grade 3 or 4: n = 3 [4.0%]), thyroid dysfunction (n = 7 [9.3%]), and hepatic function disorders (n = 4 [5.3%]). The median observation period was 51 weeks. An objective response was achieved by 34/75 patients (45.3%; complete response, 24.0%; partial response, 21.3%) and 6- and 12-month OS rates were 77.7% and 59.6%, respectively. This PMS confirmed the clinical tolerability and effectiveness of avelumab in patients with MCC, with no new safety concerns. The risk-benefit profile of avelumab was comparable with that observed in clinical trials and remains favorable for use in general clinical practice in Japan.

Skin Investigation Network of Canada (SkIN Canada) Priority Setting Initiative ranks the top 10 evidence uncertainties for Merkel cell carcinoma

The Skin Investigation Network of Canada (SkIN Canada) completed a national Priority Setting Initiative to identify the top 10 knowledge uncertainties for Merkel cell carcinoma based on the James Lind Alliance principles. Overall, 48 patients, clinicians and researchers provided input in two survey rounds and one workshop. The top 10 list of research priorities will help the skin research community, funders and policymakers to address key knowledge uncertainties for the benefit of patients with Merkel cell carcinoma.

The emerging role of miRNAs in Merkel cell carcinoma pathogenesis: Signaling pathway crosstalk

Merkel cell carcinoma (MCC) is an uncommon invasive form of skin cancer that typically manifests as a nodule on the face, head, or neck that is flesh-colored or bluish-red in appearance. Rapid growth and metastasis are hallmarks of MCC. MCC has the second-greatest mortality rate among skin cancers after melanoma. Despite the recent cascade of molecular investigations, no universal molecular signature has been identified as responsible for MCC's pathogenesis. The microRNAs (miRNAs) play a critical role in the post-transcriptional regulation of gene expression. Variations in the expression of these short, non-coding RNAs have been associated with various malignancies, including MCC. Although the incidence of MCC is very low, a significant amount of study has focused on the interaction of miRNAs in MCC. As such, the current survey is a speedy intensive route revealing the potential involvement of miRNAs in the pathogenesis of MCC beyond their association with survival in MCC.

Real-world treatment outcomes of medicines used in special situations (off-label and compassionate use) in oncology and hematology: A retrospective study from a comprehensive cancer institution

PURPOSE

Medicines in special situations (MSS) refer to off-label or to unlicensed drugs under investigation (compassionate use). Our objectives were to evaluate characteristics and to estimate overall survival (OS), event-free survival (EFS), and the duration of treatment (DT) of MSS used for cancer treatment at a multicentre comprehensive cancer institution.

METHODS

Retrospective cohort study on adult cancer patients for whom an MSS treatment was requested (January 2011-December 2020). A descriptive analysis was performed and median OS and EFS and 95% confidence intervals (CIs) were estimated. Survival curves were stratified by type of tumor, ECOG (Eastern Cooperative Oncology Group) performance status (PS), age, sex, treatment stage and type of drug (mechanism of action and target).

RESULTS

Treatment was initiated in 2092 episodes (1930 patients) out of 2377 MSS episodes (2189 patients) requested, 33% for hematological treatment and 87% for advanced stage cancer. Median OS (months) was 21.1 (95% CI 19.4-22.7), median EFS was 5.6 (95% CI 5.1-6.0) months, and median DT was 4.5 [0.0; 115.3] months. OS and EFS statistically significantly favored female patients, ECOG PS ≥2 episodes showed worse OS and EFS outcomes (p < 0.0001). Statistically significant differences in survival were found within solid and hematological cancer, disease stage, drug mechanism of action, and type of cancer (p < 0.001) but not for age. Survival outcomes by tumor subtype and drug are presented both globally and separately based on disease stage.

CONCLUSION

MSS uses are practiced across almost all cancer types, mostly for advanced disease. ECOG PS ≥2, along with advanced disease, was related to worse survival. Information about real-world outcomes is valuable and contributes to better decision-making regarding MSS and our experience in this field could be of interest for other colleagues.

Multidisciplinary Treatment of Merkel Cell Carcinoma of the Extremities: Outcomes and Factors Associated with Poor Survival in Nodal Disease

Merkel cell carcinoma (MCC) has a tendency for lymphatic spread and locoregional recurrence, although there is little data examining the risk factors for patients with lymph node-positive extremity lesions. The purpose of the current study was to examine the outcomes and risk factors associated with nodal metastasis in extremity MCC. We retrospectively reviewed the medical record of 120 patients with extremity MCC evaluated at our institution between 1994 and 2021. The mean age of this cohort was 71 years; 33% of patients were female; and 98% were Caucasian. Seventy-eight (65%) patients presented with localized disease. Thirty-seven (31%) patients had stage III disease, and five (4%) patients had stage IV disease. Treatment of primary lesions consisted primarily of margin-negative excision and adjuvant radiotherapy. Nodal metastases were most treated with adjuvant radiation or completion lymph node dissection. Five-year disease-specific survival in our series was 88% for patients with localized disease, 89% for stage IIIa disease, 40% for stage IIIb disease and 42% for stage IV. Factors associated with worse survival included immunosuppression and macroscopic nodal disease. In conclusion, extremity MCC has a low rate of local recurrence when treated with margin-negative excision and adjuvant radiation. However, treatment of nodal metastases remains a challenge with high rates of recurrence and mortality, particularly for patients who are immunosuppressed or who have macroscopic nodal disease.

Association of Merkel Cell Polyomavirus Status With p53, RB1, and PD-L1 Expression and Patient Prognosis in Merkel Cell Carcinomas: Clinical, Morphologic, and Immunohistochemical Evaluation of 17 Cases

BACKGROUND

Merkel cell carcinoma (MCC) is a rare, aggressive, primary neuroendocrine carcinoma of the skin whose main risk factors are immunosuppression, UV radiation exposure, and Merkel cell polyomavirus. Programmed death-1/programmed death ligand-1 (PD-L1)-based immunotherapy is currently the first choice for treating patients with metastatic MCC.

METHODS

MCC biopsies (17) were evaluated for their nucleus and cytoplasm characteristics and growth patterns, as well as for intratumor lymphocytes, mitotic number, and lymphovascular invasion. Paraffin-embedded tissue samples of the biopsies were stained with MCPyV large T-antigen (LTag), RB1, p53, and PD-L1.

RESULTS

We observed MCPyV LTag expression in 9 out of the 17 tumors, and all 9 cases were positive for RB1 (P<0.000). p53 staining was not significantly correlated with MCPyV LTag. We observed no relationship between p53 expression and any other parameters, and PD-L1 expression was low in the MCC samples. We evaluated PD-L1 using both the combined positive score and tumor proportion score (TPS), and found that TPS was correlated with MCPyV LTag expression (P=0.016). Tumors with tumor-infiltrating lymphocytes showed a better prognosis than those without these lymphocytes (P=0.006).

DISCUSSION

Our data demonstrated that RB1 was effective for immunohistochemically investigating the MCPyV status of tumors. TPS was superior to the combined positive score in evaluating PD-L1 in MCC. Tumor-infiltrating lymphocytes were the only parameters that were associated with survival. Further studies with larger series are required to confirm these results.

Intestinal obstruction due to small intestinal metastasis from primary Merkel cell carcinoma of the gluteal region

Merkel cell carcinoma (MCC) is a rare neoplasm of unknown multifactorial origin first described in 1972. It occurs most often in older Caucasian males and is typically associated with sun-exposed areas of skin. However, cases have also been reported in other areas, such as the trunk and the gluteal region. Metastatic disease will occur in up to one-third of cases at onset or during the course of the disease, including metastases to the abdominal organs. We present the case of a 53-year-old male with a history of primary MCC of the right buttock and local resection surgery. Eighteen months later, he presented with a small bowel obstruction and had an emergency segmental bowel resection. Pathology examination with immunohistochemistry concluded that findings were consistent with metastatic MCC.

Management and Prognosis of Cardiac Metastatic Merkel Cell Carcinoma: A Case-Control Study and Literature Review

Merkel cell carcinoma (MCC), an aggressive neuroendocrine skin cancer, has a high rate (20%) of distant metastasis. Within a prospective registry of 582 patients with metastatic MCC (mMCC) diagnosed between 2003-2021, we identified 9 (1.5%) patients who developed cardiac metastatic MCC (mMCC). We compared overall survival (OS) between patients with cardiac and non-cardiac metastases in a matched case-control study. Cardiac metastasis was a late event (median 925 days from initial MCC diagnosis). The right heart was predominantly involved (8 of 9; 89%). Among 7 patients treated with immunotherapy, 6 achieved a complete or partial response of the cardiac lesion. Among these 6 responders, 5 received concurrent cardiac radiotherapy (median 20 Gray) with immunotherapy; 4 of 5 did not have local disease progression or recurrence in the treated cardiac lesion. One-year OS was 44%, which was not significantly different from non-cardiac mMCC patients (45%, p = 0.96). Though it occurs relatively late in the disease course, cardiac mMCC responded to immunotherapy and/or radiotherapy and was not associated with worse prognosis compared to mMCC at other anatomic sites. These results are timely as cardiac mMCC may be increasingly encountered in the era of immunotherapy as patients with metastatic MCC live longer.

Seroprevalence of Four Polyomaviruses Linked to Dermatological Diseases: New Findings and a Comprehensive Analysis

Our aim was to study the seroprevalence of human polyomaviruses (HPyV) linked to skin diseases. A total of 552 serum samples were analysed by the enzyme-linked immunosorbent assay to detect IgG antibodies against Merkel cell polyomavirus (MCPyV), HPyV6, HPyV7 and Trichodysplasia spinulosa-associated polyomavirus (TSPyV) using recombinant major capsid proteins of these viruses. The individuals (age 0.8−85 years, median 33) were sorted into seven age groups: <6, 6−10, 10−14, 14−21, 21−40, 40−60 and >60 years. The adulthood seroprevalence was 69.3%, 87.7%, 83.8% and 85% for MCPyV, HPyV6, HPyV7 and TSPyV, respectively. For all four polyomaviruses, there was increasing seropositivity with age until reaching the adulthood level. There was a significant increase in seroreactivity for those age groups in which the rate of already-infected individuals also showed significant differences. The adulthood seropositvity was relatively stable with ageing, except for TSPyV, for which elevated seropositivity was observed for the elderly (>60 years) age group. Since seroepidemiological data have been published with wide ranges for all the viruses studied, we performed a comprehensive analysis comparing the published age-specific seropositivities to our data. Although the cohorts, methods and even the antigens were variable among the studies, there were similar results for all studied polyomaviruses. For MCPyV, geographically distinct genotypes might exist, which might also result in the differences in the seroprevalence data. Additional studies with comparable study groups and methods are required to clarify whether there are geographical differences.

Prognostic Value of Radiotherapy and Chemotherapy in Stage I–III Merkel Cell Carcinoma

Purpose

Merkel cell carcinoma (MCC) is a highly malignant cancer associated with dismal survival outcomes. Surgery is the cornerstone for the management of MCC, but the benefit of radiotherapy (RT) and chemotherapy (CT) is still controversial. We aimed to investigate the prognostic value of RT and CT in the management of stage I-III MCC patients using the Surveillance, Epidemiology, and End Results (SEER) database.

Methods

Patients with a histopathological diagnosis of MCC between 2010 and 2016 were included. The primary endpoint of this study was overall survival (OS). The prognostic significance for OS was analyzed by Cox proportional hazard regression model.

Results

A total of 1,691 patients were identified in the SEER database. Over half of the patients had received RT (56.7%), and 9.8% of the patients were documented to have received CT. The median OS for the entire cohort was 66.0 months, and the 5-year OS rate was 53.8%. In the multivariate analysis, receiving RT was associated with significantly improved OS (P < 0.001), while receiving CT significantly negatively impacted OS (P = 0.010). In stage III patients who underwent treatment based on surgical resection, RT was still demonstrated to be a positive factor (P = 0.002), while CT had no significant association with OS in the univariate analysis (P = 0.295).

Conclusions

The current data in the SEER database are consistent with earlier studies supporting the benefit of adjuvant RT for stage I-III MCC patients, but caution should be taken regarding the routine use of CT. For stage III MCC patients, the value of adjuvant CT needs to be confirmed in future studies.