Combined PDE4+MEK inhibition shows antiproliferative effects in NRASQ61 mutated melanoma preclinical models.

Upregulation of phosphodiesterase type 4 (PDE4) has been associated with worse prognosis in several cancers. In melanomas harboring NRAS mutations, PDE4 upregulation has been shown to trigger a switch in signaling from BRAF to RAF1 which leads to mitogen-activated protein kinase pathway activation. Previous in vitro evidence showed that PDE4 inhibition induced death in NRASQ61mut melanoma cells and such a strategy may thus be a relevant therapeutic option in those cases with no molecular targeted therapies approved to date. In this study, we generated patient-derived xenografts (PDX) from two NRASQ61mut melanoma lesions. We performed ex vivo histoculture drug response assays and in vivo experiments. A significant ex vivo inhibition of proliferation with the combination of roflumilast+cobimetinib was observed compared to dimethyl sulfoxide control in both models (51 and 67%). This antiproliferative effect was confirmed in vivo for PDX-1 with a 56% inhibition of tumor growth. To decipher molecular mechanisms underlying this effect, we performed transcriptomic analyses and revealed a decrease in MKI67, RAF1 and CCND1 expression under bitherapy. Our findings strengthen the therapeutic interest of PDE4 inhibitors and support further experiments to evaluate this approach in metastatic melanoma.

Durability of response to immune checkpoint inhibitors in metastatic Merkel cell carcinoma after treatment cessation.

BACKGROUND: Metastatic Merkel cell carcinoma (mMCC) is highly responsive to immune checkpoint inhibitors (ICIs); however, durability of response after treatment cessation and response to retreatment in the setting of progression is unknown. METHODS: Patients (pts) having mMCC from 10 centres who discontinued ICI treatment for a reason other than progression were studied. RESULTS: Forty patients were included. Median time on treatment was 13.5 months (range 1-35). Thirty-one patients (77.5%) stopped treatment electively while 9 patients (22.5%) stopped due to treatment-related toxicity. After median of 12.3 months from discontinuation, 14 pts (35%) have progressed (PD). Disease progression rate following ICI discontinuation was 26% (8 of 31) in patients who discontinued in complete response (CR), 57% (4 of 7) in patients in partial response and 100% (2 of 2) in those with stable disease. Median progression-free survival (PFS) after treatment cessation was 21 months (95% confidence interval [CI], 18- not reached [NR]), with a third of patients progressing during their first year off treatment. PFS was longer for patients who discontinued ICI electively (median PFS 29 months; 95% CI, 21-NR) compared to those who stopped due to toxicity (median PFS 11 months; 95% CI, 10-NR). ICI was restarted in 8 of 14 pts (57%) with PD, with response rate of 75% (4 CR, 2 partial response, 1 stable disease, 1 PD). CONCLUSION: ICI responses in mMCC do not appear durable off treatment, including in patients who achieve a CR, though response to retreatment is promising. Extended duration of treatment needs to be investigated to optimise long-term outcomes.

Telomere-Associated Changes in Nuclear Architecture of Cancer-Associated Macrophage-like Cells in Liquid Biopsies from Melanoma Patients.

During phagocytosis, tumor-associated macrophages (TAMs) can incorporate genetic material from tumor cells. The incorporation of extra genetic material may be responsible for advanced malignant behavior observed in some TAMs, making TAMs potentially important players in cancer progression. More recently, similar cells were described in the blood as cancer-associated macrophage-like cells (CAMLs). CAMLs may be equivalent to TAMs cells in the blood, and they express macrophage markers. However, their origin is still unclear. In a previous study, we showed for the first time the distinct telomere 3D structure of circulating tumor cells (CTCs) in melanoma and other cancers. In the present pilot study, we investigated, comparatively, the 3D telomere structure of CAMLs, CTCs and leucocytes from nine melanoma patients with metastatic cutaneous melanoma stage IV. CTC capture was performed by size-based filtration followed by cytological and immunocytological evaluation. Three-dimensional Quantitative Fluorescent in situ Hybridization was performed to measure differences in five 3D telomere parameters. Telomere parameters, such as number, length, telomere aggregates, nuclear volume, and a/c ratio, were compared among different cellular types (CTCs, CAMLs, and normal leucocytes). Three telomere parameters were significantly different between CAMLs and leucocytes. The combination of two telomere parameters (telomere length against the number of telomeres) resulted in the identification of two CAMLs subpopulations with different levels of genomic instability. Those populations were classified as profile 1 and 2. Profile 2, characterized by a high number of short telomeres, was observed in four of the nine melanoma patients. To our knowledge, this is the first pilot study to investigate 3D telomere parameters as hallmarks of nuclear architecture in CAMLs' population in comparison to leucocytes from the same patient. Further studies involving a larger patient sample size are necessary to validate these findings and explore their potential prognostic value.

18FDG PET Assessment of Therapeutic Response in Patients with Advanced or Metastatic Melanoma Treated with First-Line Immune Checkpoint Inhibitors.

BACKGROUND: Immune checkpoint inhibitors (ICI) are currently the first-line treatment for patients with metastatic melanoma. We investigated the value of positron emission tomography (PET) response criteria to assess the therapeutic response to first-line ICI in this clinical context and explore the potential contribution of total tumor metabolic volume (TMTV) analysis. METHODS: We conducted a retrospective study in patients treated with first-line ICI for advanced or metastatic melanoma, with 18F-FDG PET/CT performed at baseline and 3 months after starting treatment. Patients' metabolic response was classified according to PERCIST5 and imPERCIST 5 criteria. TMTV was recorded for each examination. RESULTS: Twenty-nine patients were included. The median overall survival (OS) was 51.2 months (IQR 13.6-not reached), and the OS rate at 2 years was 58.6%. Patients classified as responders (complete and partial response) had a 90.9% 2-year OS rate versus 38.9% for non-responders (stable disease and progressive disease) (p = 0.03), for PERCIST5 and imPERCIST 5 criteria. The median change in metabolic volume was 9.8% (IQR -59-+140%). No significant correlation between OS and changes in TMTV was found. CONCLUSION: The evaluation of response to immunotherapy using metabolic imaging with PERCIST5 and imPERCIST5 was significantly associated with OS in patients with advanced or metastatic melanoma.

PD-1 blockade with pembrolizumab in classic or endemic Kaposi's sarcoma: a multicentre, single-arm, phase 2 study.

BACKGROUND: Although the treatment of iatrogenic and HIV-related Kaposi sarcoma is well defined and mostly based on restoring immune function, the treatment of classic and endemic Kaposi sarcoma is less well established. Chemotherapy or interferon α is used for patients with extensive cutaneous or visceral Kaposi sarcoma, but tolerance might be poor and long-term remission is rare. We aimed to evaluate the activity of pembrolizumab in classic and endemic Kaposi sarcoma with cutaneous extension requiring systemic treatment. METHODS: We did a multicentre, single-arm, proof-of-concept, phase 2 trial in adults aged 18 years or older with histologically proven classic or endemic Kaposi's sarcoma with progressive cutaneous extension requiring systemic treatment and an Eastern Cooperative Oncology Group performance status of 0-1 in three hospitals in France. The patients were treated with 200 mg pembrolizumab intravenously every 3 weeks for 6 months (eight cycles) or until severe toxicity. The primary endpoint was the best overall response rate within the 6-month timeframe, defined by the occurrence of a complete response or partial response and assessed by an investigator using the modified AIDS Clinical Trial Group (ACTG) criteria. Three or more responses among a total 17 patients were needed for the primary endpoint to be met, using a Simon's two-stage optimal design assuming a 30% response rate as desirable. For this final study analysis, all patients were included following the intention-to-treat principle. This study is registered with ClinicalTrials.gov, NCT03469804, and is closed to new participants. FINDINGS: 30 patients were screened for eligibility and 17 patients (eight [47%] with classic and nine [53%] with endemic Kaposi's sarcoma) were enrolled between July 2, 2018, and Dec 16, 2019. The median follow-up was 20·4 months (IQR 18·1-24·1). Two (12%) patients had a complete response, ten (59%) had a partial response, and five (29%) had stable disease as the best response within the 6-month treatment timeframe, with a best overall response rate of 71% (95% CI 44-90), meeting the predefined primary outcome (ie, exceeding a response rate of 30%). Treatment-related adverse events occurred in 13 (76%) of 17 patients, including two grade 3 adverse events (one [6%] acute cardiac decompensation and one [6%] granulomatous reaction). Treatment was prematurely discontinued in two (12%) patients due to grade 3 acute reversible cardiac decompensation and grade 2 pancreatitis, and one other patient had a grade 3 granulomatous reaction in mediastinal lymph nodes requiring steroids and methotrexate treatment. There were no serious adverse events or treatment-related deaths. INTERPRETATION: In this prospective trial, which to our knowledge is the first to assess the role of PD-1 blockade in patients with classic and endemic Kaposi's sarcoma, pembrolizumab showed promising anti-tumour activity with an acceptable safety profile. If this result is supported by further studies, treatment with anti-PD-1 could be part of the therapeutic armamentarium for patients with classic and endemic Kaposi's sarcoma. FUNDING: MSD France.

Immune checkpoint inhibitors increase T cell immunity during SARS-CoV-2 infection.

The COVID-19 pandemic has spread worldwide, yet the role of antiviral T cell immunity during infection and the contribution of immune checkpoints remain unclear. By prospectively following a cohort of 292 patients with melanoma, half of which treated with immune checkpoint inhibitors (ICIs), we identified 15 patients with acute or convalescent COVID-19 and investigated their transcriptomic, proteomic, and cellular profiles. We found that ICI treatment was not associated with severe COVID-19 and did not alter the induction of inflammatory and type I interferon responses. In-depth phenotyping demonstrated expansion of CD8 effector memory T cells, enhanced T cell activation, and impaired plasmablast induction in ICI-treated COVID-19 patients. The evaluation of specific adaptive immunity in convalescent patients showed higher spike (S), nucleoprotein (N), and membrane (M) antigen-specific T cell responses and similar induction of spike-specific antibody responses. Our findings provide evidence that ICI during COVID-19 enhanced T cell immunity without exacerbating inflammation.

Long-Term Outcome of Neoadjuvant Tyrosine Kinase Inhibitors Followed by Complete Surgery in Locally Advanced Dermatofibrosarcoma Protuberans.

In locally advanced dermatofibrosarcoma protuberans (DFSP), imatinib mesylate has been described as an efficient neoadjuvant therapy. This retrospective study included patients with locally advanced DFSP who received neoadjuvant TKI (imatinib or pazopanib) from 2007 to 2017 at Saint Louis Hospital, Paris. The primary endpoint was the evaluation of the long-term status. A total of 27 patients were included, of whom nine had fibrosarcomatous transformation. The median duration of treatment was 7 months. The best response to TKI treatment before surgery, evaluated according to RECIST1.1 on MRI, consisted of complete/partial response (38.5%) or stability (46.2%). DFSP was surgically removed in 24 (89%) patients. A total of 23 patients (85%) were disease-free after 64.8 months of median follow-up (95% confidence interval 47.8; 109.3). One patient developed distant metastases 37 months after surgical tumor resection and finally died. Two patients (7%) did not get surgery because of metastatic progression during TKI treatment, and one patient refused surgery even though the tumor decreased by 30%. Treatment-related adverse events (AE) occurred in 23 patients (85%). Only four patients (imatinib: n = 3, pazopanib: n = 1) had grade ≥3 AE requiring temporary treatment disruption. Neoadjuvant TKI followed by complete surgery with micrographic analysis is an effective strategy for locally advanced and unresectable DFSP, with durable local recurrence disease-free survival.

Phase I-II Open-Label Multicenter Study of Palbociclib + Vemurafenib in BRAF V600MUT Metastatic Melanoma Patients: Uncovering CHEK2 as a Major Response Mechanism.

PURPOSE: In BRAF V600MUT metastatic melanoma, cyclin D-CDK4/6-INK4-Rb pathway alterations are involved in resistance to MAPK inhibitors, suggesting a clinical benefit of cyclin-dependent kinase 4 (CDK4) inhibitors. In this phase I-II study, we aimed to establish the MTD of palbociclib when added to vemurafenib. PATIENTS AND METHODS: Patients with BRAF V600E/KMUT metastatic melanoma harboring CDKN2A loss and RB1 expression were included and stratified into two groups according to previous BRAF inhibitor treatment (no:strata 1; yes:strata 2). Treatment comprised palbociclib once daily for 14 days followed by a 7-day break + continuous dosing of vemurafenib. The primary endpoint was the occurrence of dose-limiting toxicity (DLT), and the secondary endpoints included the best response, survival, pharmacokinetics, and tumor molecular profiling. RESULTS: Eighteen patients were enrolled, with 15 in strata 2. Characteristics at inclusion were American Joint Committee on Cancer stage IVM1c (N = 16; 88.9%), high lactate dehydrogenase (N = 9; 50.0%), and median number of previous treatments of 2. One and 5 patients experienced DLT in strata 1 and 2, respectively, defining the MTD at palbociclib 25 mg and vemurafenib 960 mg in strata 2. No significant evidence for drug-drug interactions was highlighted. The median progression-free survival was 2.8 months, and 5 (27.8%) patients showed a clinical response. The baseline differential mRNA expression analysis and in vitro data revealed the role of CHEK2 in the response to palbociclib. CONCLUSIONS: Although the combination of palbociclib + fixed-dose vemurafenib did not allow an increased palbociclib dosage above 25 mg, a significant clinical benefit was achieved in pretreated patients with melanoma. An association between the transcriptomic data and clinical response was highlighted.

A Multicenter Phase II Study of Pazopanib in Patients with Unresectable Dermatofibrosarcoma Protuberans.

Dermatofibrosarcoma protuberans (DFSP) is a soft-tissue sarcoma characterized by a high risk of local infiltration. The identification of the COL1A1-PDGFB t(17;22) translocation activating the PDGF pathway led to the use of imatinib in unresectable DFSP, with a response rate of 36-80%. Pazopanib is a multitarget tyrosine kinase inhibitor approved for soft-tissue sarcomas. We conducted a phase II study of patients with unresectable DFSP to evaluate the efficacy and safety of pazopanib. Patients received 800 mg of pazopanib daily. The primary endpoint was the objective response rate defined as the reduction of the largest diameter of the tumor by ≥30% at 6 months or at surgery. A total of 23 patients, including one pretreated with imatinib, were enrolled. With a median follow-up of 6.2 months (interquartile range = 5.6-7.8 months), five patients (22%, 95% confidence interval = 7-22%) had a partial response to pazopanib. The best objective response rate was 30% (95% confidence interval = 13-53%) using Response Evaluation Criteria in Solid Tumors. One patient with metastatic DFSP previously treated with imatinib died after 2.4 months. Nine patients (39%) discontinued the treatment owing to adverse events. Pharmacodynamics analyses of tumor samples were conducted: the enrichment of EGF and the EGFR-associated gene panel was associated with resistance, suggesting that EGFR-targeted therapies could be a therapeutic option to explore in DFSP. TRIAL REGISTRATION: ClinicalTrials.gov identifier: NCT01059656.

A Melanoma-Tailored Next-Generation Sequencing Panel Coupled with a Comprehensive Analysis to Improve Routine Melanoma Genotyping.

BACKGROUND: Tumor molecular deciphering is crucial in clinical management. Pan-cancer next-generation sequencing panels have moved towards exhaustive molecular characterization. However, because of treatment resistance and the growing emergence of pharmacological targets, tumor-specific customized panels are needed to guide therapeutic strategies. OBJECTIVE: The objective of this study was to present such a customized next-generation sequencing panel in melanoma. METHODS: Melanoma patients with somatic molecular profiling performed as part of routine care were included. High-throughput sequencing was performed with a melanoma tailored next-generation sequencing panel of 64 genes involved in molecular classification, prognosis, theranostic, and therapeutic resistance. Single nucleotide variants and copy number variations were screened, and a comprehensive molecular analysis identified clinically relevant alterations. RESULTS: Four hundred and twenty-one melanoma cases were analyzed (before any treatment initiation for 94.8% of patients). After bioinformatic prioritization, we uncovered 561 single nucleotide variants, 164 copy number variations, and four splice-site mutations. At least one alteration was detected in 368 (87.4%) lesions, with BRAF, NRAS, CDKN2A, CCND1, and MET as the most frequently altered genes. Among patients with BRAFV600 mutated melanoma, 44.5% (77 of 173) harbored at least one concurrent alteration driving potential resistance to mitogen-activated protein kinase inhibitors. In patients with RAS hotspot mutated lesions and in patients with neither BRAFV600 nor RAS hotspot mutations, alterations constituting potential pharmacological targets were found in 56.9% (66 of 116) and 47.7% (63 of 132) of cases, respectively. CONCLUSIONS: Our tailored next-generation sequencing assay coupled with a comprehensive analysis may improve therapeutic management in a significant number of patients with melanoma. Updating such a panel and implementing multi-omic approaches will further enhance patients' clinical management.

Baseline Genomic Features in BRAFV600-Mutated Metastatic Melanoma Patients Treated with BRAF Inhibitor + MEK Inhibitor in Routine Care.

In BRAFV600mut metastatic melanoma, the combination of BRAF and MEK inhibitors (BRAFi, MEKi) has undergone multiple resistance mechanisms, limiting its clinical benefit and resulting in the need for response predicting biomarkers. Based on phase III clinical trial data, several studies have previously explored baseline genomic features associated with response to BRAFi + MEKi. Using a targeted approach that combines the examination of mRNA expression and DNA alterations in a subset of genes, we performed an analysis of baseline genomic alterations involved in MAPK inhibitors' resistance in a real-life cohort of BRAFV600mut metastatic melanoma patients. Twenty-seven patients were included in this retrospective study, and tumor samples were analyzed when the BRAFi + MEKi therapy was initiated. The clinical characteristics of our cohort were consistent with previously published studies. The BRAFi + MEKi treatment was initiated in seven patients as a following-line treatment, and had a specific transcriptomic profile exhibiting 14 genes with lower mRNA expression. However, DNA alterations in CCND1, RB1, and MET were only observed in patients who received BRAFi + MEKi as the first-line treatment. Furthermore, KIT mRNA expression was significantly higher in patients showing clinical benefit from the combined therapy, emphasizing the tumor-suppressor role of KIT already described within the context of BRAF-mutant melanoma.

Occurrence of type 1 and type 2 diabetes in patients treated with immunotherapy (anti-PD-1 and/or anti-CTLA-4) for metastatic melanoma: a retrospective study.

Anti-PD-1 and anti-CTLA-4 antibodies cause immune-related side effects such as autoimmune type 1 diabetes (T1D). It has also been suggested that by increasing TNF-α, IL-2 and IFN-γ production, anti-PD-1 and/or anti-CTLA-4 treatment could affect pancreatic beta cell function and insulin sensitivity. This study was based on a retrospective observational analysis from 2 July 2014 to 27 June 2016, which evaluated the occurrence of T1D and changes in glycemia and C-reactive protein (CRP) plasma concentrations in patients undergoing anti-PD-1 and/or anti-CTLA-4 treatment for melanoma at the Saint Louis Hospital. All cases of T1D that developed during immunotherapy registered in the French Pharmacovigilance Database (FPVD) were also considered. Among the 132 patients included, 3 cases of T1D occurred. For the remaining subjects, blood glucose was not significantly affected by anti-PD-1 treatment, but CRP levels (mg/l) significantly increased during anti-PD-1 treatment (p = 0.017). However, 1 case of type 2 diabetes (T2D) occurred (associated with a longer therapy duration). Moreover, glycemia of patients pretreated (n = 44) or concomitantly treated (n = 8) with anti-CTLA-4 tended to increase during anti-PD-1 therapy (p = 0.068). From the FPVD, we obtained 14 cases of T1D that occurred during immunotherapy and were primarily characterized by the rapidity and severity of onset. In conclusion, in addition to inducing this rare immune-related diabetes condition, anti-PD-1 treatment appears to increase CRP levels, a potential inflammatory trigger of insulin resistance, but without any short-term impact on blood glucose level.

Focal necrotizing myopathy with 'dropped-head syndrome' induced by cobimetinib in metastatic melanoma.

Therapeutic advances derived from targeted therapy and immune checkpoint inhibitors can improve melanoma prognosis. Since 2015, cobimetinib has been approved in combination with vemurafenib in the first-line treatment for BRAF-mutated melanoma. For NRAS-mutated melanomas, MEK inhibition seems to be a therapeutic target, and association with checkpoint inhibitor provides a further therapeutic perspective. Infraclinical creatine phosphokinase (CPK) elevation is an MEK inhibitor side effect. We describe a case of focal necrotizing myopathy with 'dropped-head syndrome' induced by cobimetinib, 1 month after its introduction. The clinical presentation comprised interscapular pain, axial fatigue with cervical hypotonia, CPK elevation, intense fluorine-18-fluorodeoxyglucose uptake in cervical muscles, and necrotizing myopathy was confirmed by muscle biopsy. Cobimetinib was temporarily discontinued, resulting in CPK normalization. Re-evaluation showed partial response, motivating continuation of combination therapy with a reduced dose of cobimetinib (40 mg/day). Because prescription of targeted therapies is likely to increase, this adverse event should be known.

Autoimmune diabetes induced by PD-1 inhibitor-retrospective analysis and pathogenesis: a case report and literature review.

Anti-PD-1 antibody treatment is approved in advanced melanoma and provides median overall survival over 24 months. The main treatment-related side effects are immune-related adverse events, which include rash, pruritus, vitiligo, thyroiditis, diarrhoea, hepatitis and pneumonitis. We report a case of autoimmune diabetes related to nivolumab treatment. A 73-year-old man was treated in second line with nivolumab at 3 mg/kg every two weeks for metastatic melanoma. At 6 weeks of treatment, he displayed diabetic ketoacidosis. Nivolumab was withheld 3.5 weeks and insulin therapy was initiated, enabling a normalization of glycaemia and the disappearance of symptoms. Laboratory investigations demonstrated the presence of islet cell autoantibodies, while C-peptide was undetectable. Retrospective explorations on serum banked at week 0 and 3 months before the start of nivolumab, already showed the presence of autoantibodies, but normal insulin, C-peptide secretion and glycaemia. Partial response was obtained at month 3, and nivolumab was then resumed at the same dose. The clinical context and biological investigations before, at and after nivolumab initiation suggest the autoimmune origin of this diabetes, most likely induced by anti-PD-1 antibody in a predisposed patient. The role of PD-1/PD-L1 binding is well known in the pathogenesis of type 1 diabetes. Therefore, this rare side effect can be expected in a context of anti-PD-1 treatment. Glycaemia should be monitored during PD-1/PD-L1 blockade. The presence of autoantibodies before treatment could identify individuals at risk of developing diabetes, but systematic titration may not be relevant considering the rarity of this side effect.

Remitting seronegative symmetrical synovitis with pitting edema (RS3PE) syndrome induced by nivolumab.

INTRODUCTION: A new articular syndrome described as immunrelated side effect of immunotherapy: PD-1 inhibitors have revolutionized the treatment of advanced melanoma but are responsible for immune-related toxicity. We report a case of remitting seronegative symetrical synovitis with pitting edema (RS3PE) syndrome induced by nivolumab. CASE REPORT: A 80 year-old man with stage IV BRAF-wild type and NRAS exon 2-mutated melanoma was treated first line by nivolumab 3mg/kg every 2 weeks. At week 4, before the 3rd infusion, he presented with inflammatory arthralgia, synovitis of proximal interphalangeal, wrist and ankle joints, and edema of both hands and forearms. Laboratory tests showed inflammatory syndrome (CRP = 8.4mg/dL), negative rheumatoid factor, and anti-CCP antibodies. Radiographs did not show any joint erosion but joint ultrasound displayed intra-articular effusion and tenosynovitis. PET/CT performed 6 and 3 months before treatment for melanoma work-up showed an isolated hypermetabolism of the shoulder girdle. The diagnosis of RS3PE was retained. A systemic corticosteroid treatment (0.5mg/kg/d) was initiated; nivolumab was hold during 4 weeks leading to remission of clinical symptoms within 10 days, CRP level normalization and without relapse when nivolumab was resumed. Corticosteroids were progressively tapered and stopped after 9 months. After 5 months, anti-PD1 was definitively stopped because of disease progression. CONCLUSION: With this atypical case, clinicians should remain alert on a whole range of autoimmune diseases susceptible to be induced.