Early switch from run-in treatment with vemurafenib plus cobimetinib to atezolizumab after 3 months leads to rapid loss of tumour control in patients with advanced BRAFV600-positive melanoma: The ImmunoCobiVem phase 2 randomised trial

AIM

ImmunoCobiVem investigated whether a planned switch to atezolizumab after achieving tumour control during run-in with vemurafenib + cobimetinib improves progression-free survival (PFS) and overall survival (OS) compared to continuous targeted therapy (TT) in patients with previously untreated advanced BRAF^V600-mutated melanoma.

METHODS

In this multicenter phase 2 study, patients received vemurafenib plus cobimetinib. After 3months, patients without progressive disease (PD) were randomly assigned (1:1) to continue vemurafenib + cobimetinib (Arm A) or switch to atezolizumab (Arm B) until first documented PD (PD1). Primary outcome was PFS1 (time from start of run-in until PD1 or death). OS and safety were also assessed.

RESULTS

Of 185 patients enroled between November 2016 and December 2019, 135 were randomly assigned after the run-in period (Arm A, n = 69; Arm B, n = 66). Median PFS1 was significantly longer in Arm A versus Arm B (13.9 versus 5.9months; hazard ratio [HR] 0.55; 95% confidence interval [CI], 0.37-0.84; P_Stratified=0.001). Median OS was not reached in either arm (HR 1.22; 95%CI, 0.69-2.16; P_Stratified=0.389); 2-year OS was higher in Arm B versus Arm A (67%; 95%CI, 53-78 versus 58%; 95%CI, 45-70). Grade 3/4 AEs occurred in 55% of patients in Arm A and 64% in Arm B; treatment-related AEs led to discontinuation of any drug in 7% and 9% of patients, respectively.

CONCLUSION

In patients with BRAF^V600-mutated advanced melanoma who achieve tumour control with TT, early switch at 3months to atezolizumab led to rapid loss of tumour control but provided a numerical OS benefit at 2years compared with continued TT.

Checkpoint immunotherapy of cutaneous squamous cell carcinoma in patients suffering from chronic lymphocytic leukaemia: divergent outcomes in two men treated with PD-1 inhibitors

Cutaneous squamous cell carcinoma (cSCC) numbers among the most common types of skin cancer and is known as one of the cancer entities with the highest mutational burden among all solid tumours. Due to the positive correlation between mutational burden and response rate to inhibitors of the programmed cell death 1 (PD-1), those inhibitors are considered promising candidates for the systemic therapy of cSCC. Recently, the PD-1 inhibitors pembrolizumab, nivolumab and cemiplimab demonstrated efficacy in the systemic treatment of locally advanced or metastatic cSCC leading to the approval of cemiplimab by the FDA (U.S. Food and Drug Administration) in 2018 and the EMA (European Medicines Agency) in 2019. Patients with haematological malignancies tend to develop skin cancers of high aggressiveness, enhanced cumulative recurrence rate and higher rates of metastases with subsequent death. Chronic lymphocytic leukaemia (CLL) is the most frequent type of leukaemia in the United States and Europe with the majority of patients older than 50 years of age. This neoplasm predominantly originates from B -cells leading to an impaired immune system of the patient. Although CLL is a B-cell malignancy, studies have also described the involvement of T cells in the pathogenesis and progression of the disease with contradictory findings on the effects of PD-1 inhibitors in CLL. Due to their underlying hematologic malignancy, these patients have commonly no access to PD-1 inhibitor trials for treatment of advanced cSCC. We report on two patients with locally advanced or metastatic cSCC. Both patients had been suffering from a CLL for many years without indication for treatment. Despite a potential immunosuppressive state of the patients due to their CLL, both were treated with the PD-1 inhibitor pembrolizumab resulting in different therapy outcomes.

Management of partial and non-responding cutaneous squamous cell carcinoma

Cutaneous squamous cell carcinoma (cSCC) and basal cell carcinoma are the most common types of skin cancer. For patients with locally advanced and metastatic cSCC, the programmed cell death 1 (PD-1) inhibitor cemiplimab is approved for systemic treatment. Despite this revolutionary immunomodulatory therapeutic approach, tumours may fail to respond either completely or partially. In addition to the previously established local treatment with radiotherapy or systemic treatment with chemotherapy and epidermal growth factor receptor inhibitors, ongoing trials are currently focussed on re-stimulating the antitumour immune response in patients with advanced cSCC refractory to PD-1 inhibitors. In this review, ongoing and recently finished trials with different therapeutic approaches will be discussed.

Response durability after cessation of immune checkpoint inhibitors in patients with metastatic Merkel cell carcinoma: a retrospective multicenter DeCOG study

BACKGROUND

Immune checkpoint inhibitors (ICI) have led to a prolongation of progression-free and overall survival in patients with metastatic Merkel cell carcinoma (MCC). However, immune-mediated adverse events due to ICI therapy are common and often lead to treatment discontinuation. The response duration after cessation of ICI treatment is unknown. Hence, this study aimed to investigate the time to relapse after discontinuation of ICI in MCC patients.

METHODS

We analyzed 20 patients with metastatic MCC who have been retrospectively enrolled at eleven skin cancer centers in Germany. These patients have received ICI therapy and showed as best overall response (BOR) at least a stable disease (SD) upon ICI therapy. All patients have discontinued ICI therapy for other reasons than disease progression. Data on treatment duration, tumor response, treatment cessation, response durability, and tumor relapse were recorded.

RESULTS

Overall, 12 of 20 patients (60%) with MCC relapsed after discontinuation of ICI. The median response durability was 10.0 months. Complete response (CR) as BOR to ICI-treatment was observed in six patients, partial response (PR) in eleven, and SD in three patients. Disease progression was less frequent in patients with CR (2/6 patients relapsed) as compared to patients with PR (7/11) and SD (3/3), albeit the effect of initial BOR on the response durability was below statistical significance. The median duration of ICI therapy was 10.0 months. Our results did not show a correlation between treatment duration and the risk of relapse after treatment withdrawal. Major reasons for discontinuation of ICI therapy were CR (20%), adverse events (35%), fatigue (20%), or patient decision (25%). Discontinuation of ICI due to adverse events resulted in progressive disease (PD) in 71% of patients regardless of the initial response. A re-induction of ICI was initiated in 8 patients upon tumor progression. We observed a renewed tumor response in 4 of these 8 patients. Notably, all 4 patients showed an initial BOR of at least PR.

CONCLUSION

Our results from this contemporary cohort of patients with metastatic MCC indicate that MCC patients are at higher risk of relapse after discontinuation of ICI as compared to melanoma patients. Notably, the risk of disease progression after discontinuation of ICI treatment is lower in patients with initial CR (33%) as compared to patients with initial PR (66%) or SD (100%). Upon tumor progression, re-induction of ICI is a feasible option. Our data suggest that the BOR to initial ICI therapy might be a potential predictive clinical marker for a successful re-induction.

High tumour mutational burden and EGFR/MAPK pathway activation are therapeutic targets in metastatic porocarcinoma

BACKGROUND

Eccrine porocarcinoma (EPC) is a rare skin cancer arising from the eccrine sweat glands. Due to the lack of effective therapies, metastasis is associated with a high mortality rate.

OBJECTIVES

To investigate the drivers of EPC progression.

METHODS

We carried out genomic and transcriptomic profiling of metastatic EPC (mEPC), validation of the observed alterations in an EPC patient-derived cell line, confirmation of relevant observations in a large patient cohort of 30 tumour tissues, and successful treatment of a patient with mEPC under the identified treatment regimens.

RESULTS

mEPC was characterized by a high tumour mutational burden (TMB) with an ultraviolet signature, widespread copy number alterations and gene expression changes that affected cancer-relevant cellular processes such as cell cycle regulation and proliferation, including a pathogenic TP53 (tumour protein 53) mutation, a copy number deletion in the CDKN2A (cyclin dependent kinase inhibitor 2A) region and a CTNND1/PAK1 [catenin delta 1/p21 (RAC1) activated kinase 1] gene fusion. The overexpression of EGFR (epidermal growth factor receptor), PAK1 and MAP2K1 (mitogen-activated protein kinase kinase 1; also known as MEK1) genes translated into strong protein expression and respective pathway activation in the tumour tissue. Furthermore, a patient-derived cell line was sensitive to EGFR and MEK inhibition, confirming the functional relevance of the pathway activation. Immunohistochemistry analyses in a large patient cohort showed the relevance of the observed changes to the pathogenesis of EPC. Our results indicate that mEPC should respond to immune or kinase inhibitor therapy. Indeed, the advanced disease of our index patient was controlled by EGFR-directed therapy and immune checkpoint inhibition for more than 2 years.

CONCLUSIONS

Molecular profiling demonstrated high TMB and EGFR/MAPK pathway activation to be novel therapeutic targets in mEPC.

[Cutaneous angiosarcoma clinically presenting as Quincke's edema]

Es wird über den Fall eines 75-jährigen Patienten mit einer Gesichtsschwellung v. a. periorbital berichtet, der unter der Verdachtsdiagnose eines Quincke-Ödems stationär aufgenommen wurde. Probebiopsien ergaben das Vorliegen eines kutanen Angiosarkoms. Bei nicht resezierbarem Befund und schwieriger Bestrahlungssituation wurde zunächst eine Chemotherapie eingeleitet. Im Verlauf erfolgte bei Befundprogress die Therapieumstellung auf Zweit- und Drittlinientherapie. Der geschilderte Fall verdeutlicht die Komplexität bei der Diagnostik und Therapie bei Patienten mit kutanem Angiosarkom.

Elevated baseline serum PD-1 or PD-L1 predicts poor outcome of PD-1 inhibition therapy in metastatic melanoma

BACKGROUND

Programmed cell death protein 1 (PD-1) checkpoint inhibition has recently advanced to one of the most effective treatment strategies in melanoma. Nevertheless, a considerable proportion of patients show upfront therapy resistance and baseline predictive biomarkers of treatment outcome are scarce. In this study we quantified PD-1 and programmed death-ligand 1 (PD-L1) in baseline sera from melanoma patients in relation to therapy response and survival.

PATIENTS AND METHODS

Sera taken at therapy baseline from a total of 222 metastatic melanoma patients (two retrospectively selected monocentric discovery cohorts, n = 130; one prospectively collected multicentric validation cohort, n = 92) and from 38 healthy controls were analyzed for PD-1 and PD-L1 concentration by sandwich enzyme-linked immunosorbent assay.

RESULTS

Melanoma patients showed higher serum concentrations of PD-1 (P = 0.0054) and PD-L1 (P < 0.0001) than healthy controls. Elevated serum PD-1 and PD-L1 levels at treatment baseline were associated with an impaired best overall response (BOR) to anti-PD-1 (P = 0.014, P = 0.041), but not to BRAF inhibition therapy. Baseline PD-1 and PD-L1 serum levels correlated with progression-free (PFS; P = 0.0081, P = 0.053) and overall survival (OS; P = 0.055, P = 0.0062) in patients who received anti-PD-1 therapy, but not in patients treated with BRAF inhibitors. By combining both markers, we obtained a strong discrimination between favorable and poor outcome of anti-PD-1 therapy, with elevated baseline serum levels of PD-1 and/or PD-L1 associated with an impaired BOR (P = 0.037), PFS (P = 0.048), and OS (P = 0.0098). This PD-1/PD-L1 combination serum biomarker was confirmed in an independent multicenter validation set of serum samples prospectively collected at baseline of PD-1 inhibition (BOR, P = 0.019; PFS, P = 0.038; OS, P = 0.022). Multivariable Cox regression demonstrated serum PD-1/PD-L1 as an independent predictor of PFS (P = 0.010) and OS (P = 0.003) in patients treated with PD-1 inhibitors.

CONCLUSION

Our findings indicate PD-1 and PD-L1 as useful serum biomarkers to predict the outcome of PD-1 inhibition therapy in melanoma patients and to select patients for PD-1-based versus BRAF-based therapy strategies.

Preclinical and clinical assessment of immune checkpoint inhibitor-associated left ventricular dysfunction

Background

Immune checkpoint inhibitor (ICI) therapy has improved treatment of advanced cancers but is associated with yet incompletely characterized cardiotoxic side effects. While inflammatory cardiac complications were initially described as a rare phenomenon, emerging evidence indicates frequent cardiotoxicity, particularly latent left ventricular (LV) dysfunction. Distinct clinical characteristics and potential pathomechanisms are so far unknown.

Purpose

This study aims to investigate incidence and frequency of LV dysfunction in patients receiving ICI therapy for malignant melanoma. Using a suitable melanoma mouse model, ICI-related cardiotoxicity will be reenacted to identify potential underlying pathomechanisms.

Methods

Patients receiving ICI therapy for stage IV melanoma that presented in our cardio-oncology unit were evaluated at baseline and four weeks after initiation of therapy including echocardiography, cardiac biomarkers, and dobutamine stress echocardiography in the absence of contraindications. Patients with decreased LV ejection fraction (LVEF) were further evaluated by 18-fludeoxyglucose PET-MRI to assess manifest myocarditis. To elucidate underlying pathomechanisms, we established a melanoma mouse model that showed profound response to anti-programmed death 1 (PD1) ICI therapy. Immune cell infiltration was assessed by flow cytometry and light sheet fluorescence microscopy. Myocardial biochemical function was analyzed using a multi-omics mass spectrometry-based approach.

Results

Seven patients were included to the analysis. Six patients received a combination ICI therapy with ipilimumab and nivolumab, and one patient received nivolumab monotherapy. Echocardiography revealed significantly decreased 3D-LVEF after 4 weeks of therapy in treated patients (p=0.021). A reduced global longitudinal strain was found in six of seven patients. Remarkably, dobutamine stress echocardiography revealed a more pronounced LVEF-decrease (p=0.009) as a sign for impaired myocardial contractility with a mean decrease of 5 percentage points. Using the melanoma mouse model, we were able to recapitulate the disease phenotype as indicated by decreased LVEF and impaired response to inotropic stress during mouse pressure/volume catheterization. Increased concentrations of intramyocardial CD4+ and CD8+ T cells were found in mice treated with anti-PD1 ICI therapy compared to controls (p=0.01). Mass spectrometry revealed disrupted energy metabolism and calcium homeostasis as a putative underlying pathomechanism for impaired myocardial function.

Conclusions

ICI-related left ventricular dysfunction may affect a large proportion of patients and potentially increase cardiac morbidity and mortality. Preclinical data proposes myocardial lymphocyte infiltration and disruption of cardiomyocyte metabolism as the underlying pathomechanism. Prospective studies are now needed for a further characterization of this novel form of ICI-related cardiotoxicity.

Funding Acknowledgement

Type of funding source: Public hospital(s). Main funding source(s): IFORES research grant, Medical Faculty, University Duisburg-Essen, Germany

[Immunotherapy for malignant melanoma]

Although cutaneous melanoma accounts for only about 4% of all skin cancers (including nonmelanocytic skin cancer), it is responsible for 80% of all deaths caused by skin cancer. The introduction of immune checkpoint inhibitors led to a significant improvement in long-term survival of patients in an advanced stage regardless of BRAF mutation status. In addition to targeted therapy for patients with BRAF-mutated melanoma, immunotherapies are the therapies of choice in advanced stages and, since 2018, also in the adjuvant setting. The effectiveness of combination therapies and sequences of targeted and immunotherapies are currently being tested.

GNAQ and GNA11 mutant nonuveal melanoma: a subtype distinct from both cutaneous and uveal melanoma

BACKGROUND

GNAQ and GNA11 mutant nonuveal melanoma represent a poorly characterized rare subgroup of melanoma with a gene mutation profile similar to uveal melanoma.

OBJECTIVES

To characterize these tumours in terms of clinical behaviour and genetic characteristics.

METHODS

Patients with nonuveal GNAQ/11 mutated melanoma were identified from the prospective multicentre tumour tissue registry ADOREG, Tissue Registry in Melanoma (TRIM) and additional cooperating skin cancer centres. Extensive data on patient, tumour and treatment characteristics were collected retrospectively. Targeted sequencing was used to determine tumour mutational burden. Immunohistochemistry staining was performed for programmed death-ligand 1 and BRCA1-associated protein (BAP)1. Existing whole-exome cutaneous and uveal melanoma data were analysed for mutation type and burden.

RESULTS

We identified 18 patients with metastatic GNAQ/11 mutant nonuveal melanoma. Tumours had a lower tumour mutational burden and fewer ultraviolet signature mutations than cutaneous melanomas. In addition to GNAQ and GNA11 mutations (nine each), six splicing factor 3b subunit 1 (SF3B1), three eukaryotic translation initiation factor 1A X-linked (EIF1AX) and four BAP1 mutations were detected. In contrast to uveal melanoma, GNAQ/11 mutant nonuveal melanomas frequently metastasized lymphatically and concurrent EIF1AX, SF3B1 and BAP1 mutations showed no apparent association with patient prognosis. Objective response to immunotherapy was poor with only one partial response observed in 10 treated patients (10%).

CONCLUSIONS

Our findings suggest that GNAQ/11 mutant nonuveal melanomas are a subtype of melanoma that is both clinically and genetically distinct from cutaneous and uveal melanoma. As they respond poorly to available treatment regimens, novel effective therapeutic approaches for affected patients are urgently needed. What is already known about this topic? The rare occurrence of GNAQ/11 mutations in nonuveal melanoma has been documented. GNAQ/11 mutant nonuveal melanomas also harbour genetic alterations in EIF1AX, SF3B1 and BAP1 that are of prognostic relevance in uveal melanoma. What does this study add? GNAQ/11 mutant nonuveal melanomas show metastatic spread reminiscent of cutaneous melanoma, but not uveal melanoma. GNAQ/11 mutant nonuveal melanomas have a low tumour mutational burden that is higher than uveal melanoma, but lower than cutaneous melanoma. What is the translational message? Primary GNAQ/11 mutant nonuveal melanomas are a subtype of melanoma that is clinically and genetically distinct from both cutaneous and uveal melanoma. As metastatic GNAQ/11 mutant nonuveal melanomas respond poorly to available systemic therapies, including immune checkpoint inhibition, novel therapeutic approaches for these tumours are urgently needed. Linked Comment: Rafei-Shamsabadi. Br J Dermatol 2020; 183:806-807.

Targeting mitosis-regulating genes in cisplatin-sensitive and -resistant melanoma cells: A live-cell RNAi screen displays differential nucleus-derived phenotypes

Chemoresistance in malignant melanoma remains an unresolved clinical issue. In the search for novel molecular targets, a live-cell high-content RNAi screen based on gene expression data was performed in cisplatin-sensitive and cisplatin-resistant MeWo melanoma cells, Mel-28 cells and a melanocyte cell line. Cells were exposed to 91 siRNAs and distinct nucleus-derived phenotypes such as cell division, cell death and migration phenotypes were detected by time-lapse microscopy over 60 h. Using this approach, cisplatin-sensitive and cisplatin-resistant melanoma cells were compared by automated image analysis and visual inspection. In cisplatin-sensitive MeWo melanoma cells, 14 genes were identified that showed distinct phenotype abnormalities after exposure to gene-specific siRNAs. In cisplatin-resistant MeWo cells, five genes were detected. Nine genes were detected whose knock-down led to differential nuclear phenotypes in cisplatin-sensitive and -resistant cells. In Mel-28 cells, nine genes were identified which induced nuclear phenotypes including all eight genes which were identified in cisplatin-resistant MeWo cells. An analogous RNAi screen on melanocytes revealed no detectable phenotype abnormalities after RNAi. Pathway analysis showed in cisplatin-sensitive MeWo cells and Mel-28 cells an enrichment of at least three genes in major mitotic pathways. We hereby show that siRNA screening may help to identify tumor-specific genes leading to phenotype abnormalities. These genes may serve as potential therapeutic targets in the treatment of melanoma.

[Cutaneous side effects of anti-tumor therapy with BRAF and MEK inhibitors]

BACKGROUND

BRAF and MEK inhibitors are new targeted therapies which are used in the treatment of malignancies, in particular of malignant melanoma.

SIDE EFFECTS

Cutaneous side effects are common during the treatment with both types of inhibitors. These side effects include inflammatory reactions such as maculopapular and papulopustular exanthema, hand-foot syndrome, panniculitis, paronychia, photo- and radio-sensitization. As a class effect, BRAF-inhibitors induce proliferative disorders of keratinocytes and melanocytes, such as palmoplantar hyperkeratosis (as part of the hand-foot syndrome), verruciform and acanthoma-like lesions, follicular and Grover disease-like hyperkeratoses, keratoacanthomas, squamous cell carcinomas and atypical melanocytic nevi with transition to secondary melanomas. Furthermore, hair alterations and xerosis are possible.

CONCLUSIONS

Treatment with BRAF and MEK inhibitors requires close dermatologic monitoring of the patient. This manuscript summarizes the most frequent cutaneous side effects and their management.

[Cutaneous sarcomas: update on selected fibrohistiocytic and myofibroblastic tumors]

BACKGROUND

Malignant fibrohistiocytic tumors are a heterogeneous group of mesenchymal neoplasms that may occur in the skin and subcutaneous tissues.

DIAGNOSIS

Diagnosis of these tumors may be difficult, as they are rare, and a wide morphological diversity of types and subtypes has been described. In this update, relevant aspects of selected entities like dermatofibrosarcoma protuberans, desmoid tumor, atypical fibroxanthoma, pleomorphic dermal sarcoma, and myxofibrosarcoma are discussed according to the WHO classification of 2013. The typical clinical feature of these tumors is their mostly asymptomatic appearance. For diagnosis, the histologic workup is therefore the key feature; herein immunohistochemistry as well as molecular diagnostics become increasingly important.

THERAPY

The primary treatment for locally resectable tumors is complete surgical removal; chemotherapy, radiation, and targeted therapies with kinase inhibitors are available for inoperable and metastatic disease.

Sorafenib and pegylated interferon-α2b in advanced metastatic melanoma: a multicenter phase II DeCOG trial

BACKGROUND

The combination of sorafenib, a multikinase inhibitor, and pegylated interferon-α2b (Peg-IFN-α2b) could potentially lead to an improved antitumoral response. Previously, combinations of interferon and sorafenib have been used in renal cell cancer.

PATIENTS AND METHODS

Patients with stage IV metastatic melanoma and no previous systemic therapies apart from adjuvant immunotherapy received Peg-IFN-α2b 3 μg/kg once per week, and sorafenib 400-mg b.i.d. for a minimum of 8 weeks. The primary study end point was disease control rate (DCR).

RESULTS

Between February 2008 and February 2009, 55 patients were enrolled with a median age of 64 years (20-85). At 8 weeks, 2 patients (3.6%) had a partial response (PR) and 14 patients a stable disease (25.5%), for a DCR of 29.1% in the intention-to-treat (ITT) population. The median progression-free survival in the ITT population was 2.47 months (95% confidence interval 1.22-3.72 months). The toxicity of sorafenib and Peg-IFN-α2b combination was characterized by mainly hematological side-effects, including one treatment-related bleeding complication with a fatal outcome. Other grade 3/4 toxic effects were fatigue and flu-like symptoms.

CONCLUSION

The combination of sorafenib and Peg-IFN-α2b showed modest clinical activity and some serious side-effects including fatal bleeding complications.

XPG D1104 single-nucleotide polymorphisms and the prognosis of melanoma

11096

Background: Sunlight is a major risk factor for melanoma. Since UV radiation causes DNA damage, it is not surprisingly, that genetic variants in DNA repair enzymes contribute to the susceptibility to cutaneous melanoma. Methods: Presence of common non-synonymous single-nucleotide polymorphism in different DNA repair enzymes were established and correlated with overall survival of melanoma patients. To this end, the SNPs of 6 different DNA repair enzymes were evaluated in a cohort of 742 melanoma patients. The impact of these polymorphisms on overall survival was subsequently calculated by the cox hazard model. Results: This analysis demonstrated that after adjustment to gender and primary tumor T classification XPG 1104 His/His as well as XPD 751 Lys/Lys genotypes were significantly associated with improved survival. Cox hazard coefficients were 0.744 for XPG 1104 His/His (p = 0.0059) and 0.651 for XPD 751 Lys/Lys (p = 0.017). Importantly, bootstrapping confirmed theses results for subpopulations. Furthermore, multivariate analysis demonstrated that XPG 1104 His/His is an independent factor affecting overall survival (cox coefficient 0.95788; p = 0.0011). Conclusions: XPG codon 1104 polymorphism may be predictive of survival outcome in patients with cutaneous melanoma.

No significant financial relationships to disclose.

Dose-intensified bi-weekly temozolomide in patients with asymptomatic brain metastases from malignant melanoma: a phase II DeCOG/ADO study

BACKGROUND

Temozolomide has shown some efficacy in metastatic melanoma and recently received extended approval to treat brain tumours. The purpose of this study was to test a dose-intensified regimen of temozolomide in melanoma patients with brain metastases in a prospective, open-label, multicentre phase II trial.

PATIENTS AND METHODS

Forty-five patients with asymptomatic brain metastases from melanoma were stratified into arm A (no prior chemotherapy; n = 21) and arm B (previous chemotherapy; n = 24). Patients received oral temozolomide either 150 mg/m(2)/day (arm A) or 125 mg/m(2)/day (arm B), days 1-7 and 15-21, every 28 days. The primary study end point was objective response, and secondary end points were overall survival and safety.

RESULTS

Two patients (4.4%) achieved a partial response (PR) in brain metastases (one in each arm), one of them (2.2%) also showing a PR in extracerebral disease. An additional five patients (11.1%; two in arm A, three in arm B) showed disease stabilisation (SD) in brain and other sites. However, 82% revealed progressive disease (PD) already evident 8 weeks after therapy initiation. Median survival time from therapy onset was 3.5 months (range 0.7-8.3; arm B) and 4.3 months (range 1.6-11.8; arm A), P = 0.43. Dose modifications and prolongations of therapy cycles due to toxicity were required in 20% of patients. Grade 3/4 toxicity was observed in one patient only (2.2%).

CONCLUSIONS

Oral administration of temozolomide given bi-weekly is well-tolerated in melanoma patients with cerebral involvement. However, the efficacy is limited, with lower than 5% objective responses observed in brain and extracerebral metastases.

CCR5 gene polymorphism in patients with cutaneous melanoma: Impact on survival following immunotherapy

21071

Background: Chemokines are supposed to influence both tumor progression and anti-tumoral immune responses. In this regard, a 32-bp-deletion polymorphism in the chemokine receptor 5 gene (CCR5Δ32) resulting in a non-functional receptor protein allows to study the potential impact of the CCR5 system on the clinical course and treatment outcome of malignant diseases. Methods: CCR5 genotyping was performed by PCR on DNA extracted from serum samples of 782 cutaneous melanoma patients with known disease history and long-term clinical follow-up. Genotypes were correlated with patient survival in consideration of different therapeutic modalities. Results: Out of 782 patients, 90 (11.5%) were heterozygous and 12 (1.5%) were homozygous for CCR5Δ32. Disease-specific survival starting from primary diagnosis was not influenced by CCR5 status. Equally, no impact of the CCR5 status could be detected on treatment outcomes of stage III patients. In 139 stage IV patients treated with immunotherapeutics, however, CCR5Δ32 was associated with a diminished survival compared to patients not carrying the Δ32 allele (p=0.029). Multivariate analysis revealed the CCR5 genotype as an independent factor impacting disease-specific survival in this patient group (p=0.0084), followed by gender (p=0.017), and type of primary (p=0.029). Vice versa, stage IV patients without immunotherapy revealed a trend towards a favorable survival when harboring CCR5?32 (p=0.12). Conclusions: The disadvantage of CCR5Δ32-bearing stage IV melanoma patients with respect to outcome of immunotherapy indicates a strong impact of the CCR5 mediator system on anti-tumoral immune responses, and should be taken into account when choosing therapeutic modalities for these patients.

No significant financial relationships to disclose.

Pegylated liposomal doxorubicin plus paclitaxel as an individualized chemosensitivity-directed treatment in advanced metastatic melanoma

8551

Background: Melanoma is a cutaneous neoplasm known for its high agressiveness and its poor prognosis once metastasized. Dacarbacine chemotherapy is actually considered standard first-line treatment of metastatic melanoma, with reported response rates of 6–7%. Due to this unsatisfactory situation, a number of non-standard anti-cancer drugs have been tested for improved efficacy. The present study was aimed to test doxorubicin plus paclitaxel in metastatic melanoma patients based on in-vitro chemosensitivity of this drug combination in fresh tumor samples. Methods: The primary study endpoint was objective response, secondary endpoints were safety and overall survival. Patients with histologically confirmed metastatic melanoma (AJCC stage IV), measurable tumor parameters, and an in-vitro chemosensitivity to doxorubicin plus paclitaxel which is superior to other test drugs determined by an ATP-based luminescence viability assay, were eligible. Patients received paclitaxel 175 mg/m2 i.v. followed by pegylated liposomal doxorubicin 30 mg/m2 i.v. at d1 every 28 days. Tumor assessment was performed every 8 weeks and evaluated according to RECIST. Treatment was continued at a tumor response of stable disease (SD) or better, and stopped in case of disease progression (PD) or intolerable side effects. Results: Out of 14 patients enrolled into this study, 12 received study treatment as first-line, and two as second-line therapy. Objective response was 14.3% (1 CR, 1 PR); progression arrest was 28.6% (1 CR, 1 PR, 2 SD). Median overall survival was 9.7 months. Common slight to moderate side effects were myelosuppression and neurotoxicity. Severe toxicities (CTC grade 3/4) were experienced by three patients (21.4%), with two of them presenting severe myelosuppression, and one experiencing myocardial infarction. Conclusions: Pegylated liposomal doxorubicin combined with paclitaxel shows significant efficacy in advanced metastatic melanoma if applied in an individualized, sensitivity- directed regimen. The observed side effects were comparable to other combination chemotherapies. This treatment regimen needs further evaluation in larger clinical trials containing standard therapy control groups.

No significant financial relationships to disclose.

Lymphatic endothelium-specific hyaluronan receptor LYVE-1 is expressed by stabilin-1+, F4/80+, CD11b+ macrophages in malignant tumours and wound healing tissue in vivo and in bone marrow cultures in vitro: implications for the assessment of lymphangiogenesis

Lymphangiogenesis is a novel prognostic parameter for several cancers that is preferentially quantified by immunohistochemistry of the lymphatic endothelium-specific hyaluronan receptor LYVE-1. Recently, the specificity of LYVE-1 was challenged by serendipitous observations of LYVE-1 expression in rare tissue macrophages. As expression of the hyaluronan receptor-like molecule stabilin-1 is shared by sinusoidal endothelium and macrophages, a thorough analysis of LYVE-1 expression was performed using macrophage-specific markers in vivo and in vitro. In murine tumour models and excisional wound healing, LYVE-1 expression occurred in a subset of CD11b(+), F4/80(+) tissue macrophages that preferentially co-expressed stabilin-1. Upon comparison of single- and double-labelling immunofluorescence, it became apparent that LYVE-1(+) macrophages mimic sprouting and collapsed lymphatic vessels. In vitro, LYVE-1 expression was induced in 25-40% of murine bone marrow-derived macrophages upon exposure to B16F1 melanoma-conditioned medium and IL-4/dexamethasone. By FACS analysis, 11.5% of bone marrow-derived macrophages were LYVE-1(+), stabilin-1(+) double-positive, while 9.9% were LYVE-1(+), stabilin-1(-) and 33.5% were LYVE-1(-), stabilin-1(+). Northern and western analyses confirmed expression of LYVE-1 mRNA and protein in bone marrow-derived macrophages. In the light of the current debate about true endothelial trans-differentiation versus endothelial mimicry of monocytes/macrophages, LYVE-1(+), stabilin-1(+) non-continuous endothelial-like macrophages will require further developmental and functional analyses. In conclusion, the findings imply that LYVE-1 staining must be supplemented by double labelling with macrophage markers in order to differentiate clearly between LYVE-1(+) lymphatics and LYVE-1(+) tumour-infiltrating macrophages. This improved approach will help to clarify the prognostic significance of lymphangiogenesis in malignant tumours.

Imatinib in locally advanced dermatofibrosarcoma protuberans (DFSP): A phase II trial of the Dermatologic Cooperative Oncology Group (DeCOG)

9561

Background: DFSP is known for its low metastatic potential but locally infiltrative growth, hereby enforcing extensive and often multiple surgical procedures. DFSP cells were recently shown to display chromosomal translocations of the regions 17q22 and 22q13, resulting in an autocrine growth stimulation loop via the platelet-derived growth factor (PDGF) pathway. The tyrosine kinase inhibitor imatinib blocks PDGF signal transduction, thus offering a new therapeutic option for DFSP patients. This multicenter phase II trial was aimed to investigate the efficacy of imatinib in locally advanced DFSP. Methods: The primary study endpoint was objective response, secondary endpoints were safety and relapse-free survival. Patients with histological proof of locally advanced primary or relapsed DFSP, measurable tumor parameters according to RECIST, and no evidence of distant metastases were eligible. Patients received imatinib 600 mg/d PO. Tumor measurements were performed at week 6 and 12, and every 8 weeks thereafter. At the end of imatinib treatment, at the earliest after week 12, residual tumors were surgically excised with histological proof of tumor-free margins. Results: By January 2006, nine out of 13 recruited patients were evaluable for response (per protocol, PP), three are still on treatment and one stopped treatment after 12 days due to side effects. Among the nine PP patients, seven partial responses, one stabilization, and one progression were observed. Five responders showed an ongoing tumor shrinkage until complete surgical excision, whereas two patients revealed an initial response at 6 weeks, followed by a disease progression at 12 weeks. None of the patients developed distant metastases under treatment or thereafter. Side effects were mostly mild to moderate (CTC grade 1–2). Severe side effects (CTC grade 3–4), reversible angina pectoris and septicemia, respectively, were observed in two patients. Conclusions: The study results indicate imatinib as a potent systemic treatment option in locally advanced DFSP. However, a subset of DFSP patients appeared resistant to imatinib, either primarily after treatment onset, or secondarily after showing an initial response.

No significant financial relationships to disclose.

Impact of a functional polymorphism in the IL12B promoter region on survival in patients with malignant melanoma

8001

Background: Interleukin-12 (IL-12), a heterodimeric cytokine, is important in the generation of a Th1-biased immune response. Several polymorphisms have been described in IL12B, the gene encoding the p40 subunit of IL-12. A bi-allelic polymorphism within the IL12B promoter region has been reported to show association with diseases as diverse as severe childhood asthma and fatal cerebral malaria. Methods: In order to define the molecular basis for these disease associations we investigated the secretion of IL-12 by human monocyte-derived dendritic cells. The amount of IL-12p40 and p70 produced by DCs from normal blood donors was determined following CD40L activation. Subsequently, we therefore sought to investigate the frequency of IL12B genotypes and their impact on the outcome of patients with malignant melanoma. Genomic DNA was isolated from 75 normal blood donors and 80 melanoma cell lines and used for genotyping the IL12B polymorphism. Corresponding clinical data were retrieved from the in-house melanoma database. Results: Allele frequency for IL12Bpro-1 is 0.45 and for IL12Bpro-2 0.55. Homozygotes for the IL12B promoter polymorphism showed a 10-fold difference in median p70 secretion in response to CD40 ligation. Remarkably, this difference resulted from the inability of most allele 1 homozygotes to secrete heterodimeric IL-12. In contrast, most of the donors homozygous for allele 2 had detectable secretion. Distribution of genotypes in melanoma patients was not significantly different from normal blood donors. Kaplan-Meier survival analysis showed significantly decreased survival of patients homozygous for the longer allele, previously defined as being associated with decreased IL-12 secretion (log-rank p=0.015). Subgroup analysis indicated that this survival advantage was seen exclusively in female patients. Conclusions: The recently described IL12B promoter polymorphism is highly correlated with secretion of bioactive IL-12 and has a significant impact on the clinical course of disease in patients with melanoma and may therefore be useful for prognostic stratification.

No significant financial relationships to disclose.

A phase II multicenter study on the histone deacetylase (HDAC) inhibitor MS-275, comparing two dosage schedules in metastatic melanoma

8044

Background: The acetylation of histones is a key component of gene regulation, which plays an important role in tumor initiation and progression. MS-275, an inhibitor of the benzamide series, is a synthetic orally available inhibitor of HDACs which showed anti-tumor activity in 3 phase 1 trials. Methods: A phase II, multicenter, randomized, parallel-group study of oral MS-275 evaluated the efficacy and toxicity in patients with non-resectable metastatic melanoma. Patients should have received at least one, but not more than two previous systemic therapies (chemo- and/or immunotherapy) for stage IV melanoma. Patients were stratified to receive either 3 mg MS-275 biweekly (days 1+15 of a 4-week cycle) or 7 mg MS-275 weekly (days 1+8+15 of a 4-week cycle) until disease progression or unacceptable toxicity. Study endpoints were the assessment of tumor response and toxicity. Results: A total of 28 patients have been randomized equally to the two dosing groups. Patients were classified as belonging to AJCC stage IVa (n=0), IVb (n=9; 32%), and IVc (n=19; 68%). In general, MS-275 was very well tolerated. No treatment-related SAEs have been observed. Most frequently reported side effects were nausea (CTC Grade 1+2, 32%) hypophosphatemia (CTC Grade 1–3, 29%), and diarrhea (CTC Grade 1+2, 18%). Stable diseases lasting from 8 wks to more than 48 wks have been observed in 4 pts (29%) in the 3 mg and 3 pts (21%) in the 7 mg dose group. Stabilizations occurred in these metastatic localizations: skin, peripheral and visceral lymph nodes, lung and bone, respectively. However, objective tumor responses were not observed. Conclusions: The results suggest that MS-275 is well tolerated and shows long-lasting tumor stabilizations in patients with pre-treated metastatic melanoma. The failure of objective tumor responses in the single-agent treatment with MS-275 warrants further evaluation also in combinational settings.

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Dacarbazine (DTIC) versus vaccination with autologous peptide-pulsed dendritic cells (DC) in first-line treatment of patients with metastatic melanoma: a randomized phase III trial of the DC study group of the DeCOG

BACKGROUND

This randomized phase III trial was designed to demonstrate the superiority of autologous peptide-loaded dendritic cell (DC) vaccination over standard dacarbazine (DTIC) chemotherapy in stage IV melanoma patients.

PATIENTS AND METHODS

DTIC 850 mg/m2 intravenously was applied in 4-week intervals. DC vaccines loaded with MHC class I and II-restricted peptides were applied subcutaneously at 2-week intervals for the first five vaccinations and every 4 weeks thereafter. The primary study end point was objective response (OR); secondary end points were toxicity, overall (OS) and progression-free survival (PFS).

RESULTS

At the time of the first interim analysis 55 patients had been enrolled into the DTIC and 53 into the DC-arm (ITT). OR was low (DTIC: 5.5%, DC: 3.8%), but not significantly different in the two arms. The Data Safety & Monitoring Board recommended closure of the study. Unscheduled subset analyses revealed that patients with normal serum LDH and/or stage M1a/b survived longer in both arms than those with elevated serum LDH and/or stage M1c. Only in the DC-arm did those patients with (i) an initial unimpaired general health status (Karnofsky = 100) or (ii) an HLA-A2+/HLA-B44- haplotype survive significantly longer than patients with a Karnofsky index <100 (P = 0.007 versus P = 0.057 in the DTIC-arm) or other HLA haplotypes (P = 0.04 versus P = 0.57 in DTIC-treated patients).

CONCLUSIONS

DC vaccination could not be demonstrated to be more effective than DTIC chemotherapy in stage IV melanoma patients. The observed association of overall performance status and HLA haplotype with overall survival for patients treated by DC vaccination should be tested in future trials employing DC vaccines.

Lack of clinical efficacy of imatinib in metastatic melanoma

This two-centre phase-II trial aimed at investigating the efficacy of imatinib in metastasised melanoma patients in correlation to the tumour expression profile of the imatinib targets c-kit and platelet-derived growth factor receptor (PDGF-R). The primary study end point was objective response according to RECIST, secondary end points were safety, overall and progression-free survival. In all, 18 patients with treatment-refractory advanced melanoma received imatinib 800 mg day(-1). In 16 evaluable patients no objective responses could be observed. The median overall survival was 3.9 months, the median time to progression was 1.9 months. Tumour biopsy specimens were obtained from 12 patients prior to imatinib therapy and analysed for c-kit, PDGF-Ralpha and -Rbeta expression by immunohistochemistry. In four cases, cell lines established from these tumour specimens were tested for the antiproliferative effects of imatinib and for functional mutations of genes encoding the imatinib target molecules. The tumour specimens stained positive for CD117/c-kit in nine out of 12 cases (75%), for PDGF-Ralpha in seven out of 12 cases (58%) and for PDGF-Rbeta in eight out of 12 cases (67%). The melanoma cell lines showed a heterogenous expression of the imatinib target molecules without functional mutations in the corresponding amino-acid sequences. In vitro imatinib treatment of the cell lines showed no antiproliferative effect. In conclusion, this study did not reveal an efficacy of imatinib in advanced metastatic melanoma, regardless of the expression pattern of the imatinib target molecules c-kit and PDGF-R.

Clinical phase II study of pegylated liposomal doxorubicin as second-line treatment in disseminated melanoma

BACKGROUND

Stage IV melanoma has a poor prognosis with a median survival of 3-11 months from diagnosis of distant metastases. Response rates in first-line regimens range around 15-20%. Non-responders have a median survival around 6 months. Currently, no second-line treatment in advanced melanoma has been established.

PATIENTS AND METHODS

In a clinical phase II study we evaluated the efficacy of liposomal doxorubicin (Caelyx) in 30 patients (17 m, 13 f) with progressing metastatic melanoma who had failed a previous chemotherapy. Liposomal doxorubicin was given in an outpatient setting at a dose of 50 mg/m2 i.v. on d1, d22, d43 and d64, subsequently at 40 mg/m2 at d85 before first staging and in 4-week intervals thereafter. Treatment was very well tolerated with 100 cycles given in total. Response rate, survival time, time-to-progression and toxicity were assessed.

RESULTS

Erythrodysesthesia was the most severe toxicity in 6% at CTC grade 3. Liposomal doxorubicin was of limited clinical efficacy with 21 patients progressing within the first 12 weeks. However, 7 patients were treated 3-9 months and were stable for >90 days, achieving 5 SD, 1 PR and 1 CR. Median survival after initiation of second-line treatment was 214 days (95% CI: 151-304 days) with 7 patients surviving >300 and 5 patients >400 days.

CONCLUSIONS

Liposomal doxorubin as monotherapy is well tolerated but of limited clinical efficacy. Whether the survival benefit of a significant proportion of patients (20%) holds true in larger cohorts and whether the efficacy of liposomal doxorubicin can be improved by combinations without compromising the low toxicity profile needs further studies.

Serummarker des malignen Melanoms

Tumor markers in the serum of cancer patients have an important role in clinical diagnosis and in prognosis, and also in the monitoring of the patients' disease and response to therapy over time. The serum markers currently available for melanoma have only limited clinical use. Those most widely used in clinical applications are S100-beta, melanoma inhibitory activity, and lactate dehydrogenase; there are close correlations between the serum concentrations of these and tumor load. Regular determination of S100-beta and MIA levels during follow-up can therefore be used for early detection of a tumor relapse in melanoma patients, increased serum concentrations of these marker proteins being indicative of tumor growth. Patients with distant metastases from melanoma who present with elevated serum levels of S100-beta, MIA, or LDH have poorer overall survival than do patients whose serum concentrations are within normal ranges. These three markers can also be used to monitor the course of disease and therapy outcome in patients with distant metastases. Since there are no marker proteins for melanoma that are not dependent on tumor load, it is not currently possible to forecast the survival of patients who are tumor free after surgery. Serum markers are also not suitable for screening or for the diagnosis of primary melanomas.

Komplette Remission kutaner Satelliten- und In-transit-Filiae nach intral�sionaler Interleukin-2-Applikation bei 2�Patienten mit malignem Melanom

Multiple cutaneous satellite and in-transit metastases of melanoma without involvement of lymph nodes or other organs are a challenge especially when they occur in elderly inoperable patients with multiple internal diseases. In this particular situation, intralesional application of interleukin-2 may represent an effective alternative to systemic chemo- or immunotherapy as it can be performed on an out-patient basis and has few side effects. We treated two elderly female patients with multiple cutaneous metastases of malignant melanoma with intra- and perilesional application of interleukin-2 (3 x 6-12 Mio IE) over 12 weeks and achieved a complete remission of these metastases. In follow-up biopsies, no viable tumor cells were found. Despite a slight burning at the injection side and a transient local inflammatory reaction, the therapy was well tolerated in both cases after premedication with paracetamol 500 mg orally and pretreatment of the injection site with a cream containing lidocaine and prilocaine. No systemic side effects were observed.

Melanoma-associated retinopathy: high frequency of subclinical findings in patients with melanoma

BACKGROUND

Melanoma-associated retinopathy (MAR) is a paraneoplastic syndrome with symptoms of night blindness, light sensations, visual loss, defect in visual fields, and reduced b-waves in the electroretinogram. Patients with MAR often suffer from a sudden onset of ocular symptoms that are believed to result from antibody production against melanoma-associated antigens that cross-react with corresponding epitopes on retinal depolarizing bipolar cells.

OBJECTIVES

To correlate the frequency of subclinical symptoms suggestive of MAR in melanoma patients to different stages of disease, patient age, type and thickness of the primary tumour, form of therapy, S-100 level and tumour burden.

METHODS

We analysed 28 patients with melanoma in stages I-IV (according to the American Joint Committee on Cancer tumour classification) for the presence of subclinical MAR symptoms using scotopic electroretinography, static and kinetic perimetry and nyctometry.

RESULTS

Seven patients had clinical signs and symptoms consistent with MAR, 18 had some indications, while the remaining three had none. We found no correlation between clinical symptoms and stage of disease, tumour burden or S-100 level, but findings suggestive of MAR were observed more frequently in advanced stages of disease.

CONCLUSIONS

Subclinical retinal involvement characteristic of MAR appears to be more common than previously suspected in patients with cutaneous malignant melanoma. Our findings in this small cohort seem to indicate that the percentage of patients with symptoms suggestive of MAR is higher in advanced stages of disease. Further clinical studies are required to evaluate if the presence of subclinical symptoms suggestive of MAR is correlated with a worse prognosis and a shortened progression-free and overall survival.

Mucosal metastases in malignant melanoma

BACKGROUND

We present the case of a patient with malignant melanoma stage IV according to the American Joint Committee on Cancer (AJCC) classification and an unusual pattern of metastasis to the mucosa of the esophagus, the stomach, the bladder and the palatine tonsil.

CASE REPORT

A 38-year-old male patient with metastatic malignant melanoma of stage III (AJCC) was admitted for initiation of adjuvant therapy. 4 months earlier a primary melanoma of the left upper leg had been excised and 2 months later the patient had undergone a left inguinal lymph node dissection revealing 2 metastatic lymph nodes. On admission the patient complained of a sore throat and right cervical lymphadenopathy. He underwent a tonsillectomy and a lymphadenectomy which both revealed melanoma metastases. A PET scan using F-18-fluorodeoxyglucose (FDG) showed focal metabolic activity in the middle mediastinum. Two cycles of dacarbazine (DTIC) chemotherapy were performed during which the patient developed cutaneous metastases, dyspepsia, and mild hematemesis. Gastroscopy revealed bleeding from mucosal metastases of the esophagus and stomach. A few weeks later the patient developed macroscopic hematuria. A cystoscopy was performed and showed metastases to the mucosa of the bladder. Nutrient vessels of these bladder metastases were embolized in order to control bleeding. The patient is currently alive with progressive disease.

RESULTS

This case presents common and uncommon sites of metastatic melanoma to the mucosa with the typical clinical manifestations in a single patient.

Systemic treatment in advanced melanoma: innovative perspectives

Malignant melanoma is a tumor of increasing incidence. Patients with early diagnosed and surgically excised primary tumors have a high probability to be completely cured. In contrast, the prognosis of patients with distant organ metastases is still extremely poor despite a variety of therapeutical efforts that have been evaluated in numerous clinical trials. Cytotoxic treatment using single agents as well as polychemotherapy revealed only temporary clinical responses but no improvement of patients' overall survival. Likewise, therapy regimens combining cytostatics with cytokines showed no substantial benefit compared to cytostatics alone. Due to these disappointing results, recent research strategies focused on the elucidation of the mechanisms responsible for the complex therapy resistance of melanoma. New treatment concepts have been developed to overcome some of these mechanisms. Another promising approach is the development of advanced vaccination strategies. This paper reviews a selection of innovative therapeutic strategies that are currently tested in clinical trials; in particular pretherapeutic chemosensitivity testing, chemosensitization by downregulation of bcl-2, vaccination with autologous peptide-pulsed dendritic cells and immunomodulation by histamine.

Dose-dependent severe cutaneous reactions to imatinib

The protein kinase inhibitor imatinib has been approved as an efficient anticancer drug with common but mild cutaneous toxicities. We here report on two out of four melanoma patients treated with high-dose imatinib presenting with severe and strongly dose-dependent skin eruptions, suggesting a cutaneous reactivity pattern different from allergic hypersensitivity.