Immune checkpoint inhibition and targeted therapy for melanoma: A patient‐oriented cross‐sectional comparative multicenter study

BACKGROUND

Choosing the adequate systemic treatment for melanoma is driven by clinical parameters and personal preferences.

OBJECTIVE

Evaluation of the impact of disease and treatment on the daily life of patients receiving systemic therapy for melanoma.

METHODS

A German-wide, cross-sectional comparative study was conducted at 13 specialized skin cancer centres from 08/2020 to 03/2021. A questionnaire was distributed to assess patients' perception of disease and symptoms, the impact of their current treatment on quality of life (QOL) and activities, adverse events (AEs), therapeutic visits, as well as believe in and satisfaction with their current systemic melanoma treatment. Patient-reported outcomes (PROs) were rated on a continuous numerical rating scale or selected from a given list.

RESULTS

Four hundred and fourteen patients with systemic melanoma therapy were included. 359 (87%) received immune checkpoint inhibition (ICI) and 55 (13%) targeted therapy (TT). About 1/3 of patients were adjuvantly treated, the remaining because of unresectable/metastatic melanoma. In subgroup analyses, only in the adjuvant setting, TT patients reported a significant decrease in their treatment associated QOL compared to patients with ICI (p = 0.02). Patients with TT were 1.9 times more likely to report AEs than patients with ICI, a difference being significant just for the adjuvant setting (p = 0.01). ICI treatment intervals differed significantly between adjuvant and unresectable/metastatic setting (p = 0.04), though all patients, regardless of their specific ICI drug, evaluated their treatment frequency as adequate. TT patients with dabrafenib/trametinib (n = 37) or encorafenib/binimetinib (n = 15) did not differ regarding the strain of daily pill intake. Patients older than 63 years rated various PROs better than younger patients.

CONCLUSIONS

Patients evaluated their treatment mainly positively. ICI might be preferred over TT regarding QOL and patient-reported AEs in the adjuvant setting. Older melanoma patients appeared to be less impacted by their disease and more satisfied with their treatment.

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.

Avelumab in patients with previously treated metastatic Merkel cell carcinoma (JAVELIN Merkel 200): updated overall survival data after >5 years of follow-up

BACKGROUND

Merkel cell carcinoma (MCC) is a rare, aggressive skin cancer that has a poor prognosis in patients with advanced disease. Avelumab [anti-programmed death-ligand 1 (PD-L1)] became the first approved treatment for patients with metastatic MCC (mMCC), based on efficacy and safety data observed in the JAVELIN Merkel 200 trial. We report long-term overall survival (OS) data after >5 years of follow-up from the cohort of patients with mMCC whose disease had progressed after one or more prior lines of chemotherapy.

PATIENTS AND METHODS

In Part A of the single-arm, open-label, phase II JAVELIN Merkel 200 trial, patients with mMCC that had progressed following one or more prior lines of chemotherapy received avelumab 10 mg/kg by intravenous infusion every 2 weeks until confirmed disease progression, unacceptable toxicity, or withdrawal. In this analysis, long-term OS was analyzed.

RESULTS

In total, 88 patients were treated with avelumab. At data cut-off (25 September 2020), median follow-up was 65.1 months (range 60.8-74.1 months). One patient (1.1%) remained on treatment, and an additional patient (1.1%) had reinitiated avelumab after previously discontinuing treatment. Median OS was 12.6 months [95% confidence interval (CI) 7.5-17.1 months], with a 5-year OS rate of 26% (95% CI 17% to 36%). In patients with PD-L1+ versus PD-L1- tumors, median OS was 12.9 months (95% CI 8.7-29.6 months) versus 7.3 months (95% CI 3.4-14.0 months), and the 5-year OS rate was 28% (95% CI 17% to 40%) versus 19% (95% CI 5% to 40%), respectively (HR 0.67; 95% CI 0.36-1.25).

CONCLUSION

Avelumab monotherapy resulted in meaningful long-term OS in patients with mMCC whose disease had progressed following chemotherapy. These results further support the role of avelumab as a standard of care for patients with mMCC.

Klinik für Dermatologie, Allergologie und Venerologie der Universität zu Lübeck: Interaktion von Forschung und klinischer Versorgung

Die Ursprünge der Lübecker Universitäts-Hautklinik reichen in die 30er-Jahre des letzten Jahrhunderts zurück. Die Klinik hat in den letzten Jahrzehnten eine konsequente bauliche und inhaltliche Weiterentwicklung erfahren und verfügt heute über 85 Betten auf 2 Stationen und in einer Tagesklinik. Ein modernes Weiterbildungsprogramm, das auf einem Rotationsprinzip durch 5 verschiedene stationäre und ambulante Teams beruht, vermittelt alle wesentlichen Lerninhalte der Dermatologie. Die Erweiterung der Klinik in den letzten Jahren beruhte auf einer engen Interaktion von Grundlagenforschung und klinischer Tätigkeit, insbesondere auf dem Gebiet kutaner Autoimmunerkrankungen und entzündlicher Dermatosen. Die wissenschaftliche Entwicklung der Hautklinik profitierte seit 2007 insbesondere von der Förderung durch die Exzellenzinitiative des Bundes (Exzellenzcluster Inflammation at Interfaces). Daneben wurde durch die Deutsche Forschungsgemeinschaft (DFG) seit 2011 unter Federführung der Hautklinik ein Graduiertenkolleg Modulation of Autoimmunity gefördert, das zur Entwicklung des wissenschaftlichen Nachwuchses und zur Ausbildung zahlreicher naturwissenschaftlicher und medizinischer Doktoranden/Doktorandinnen1 beitrug. Seit 2015 besteht an der Klinik auch eine Klinische Forschungsgruppe der DFG zum Thema Pemphigoid Diseases – Molecular Pathways and their Therapeutic Potential. Im Jahr 2018 haben Mitarbeiter der Klinik wesentlich zur Einwerbung eines Clinician Scientist-Programms der DFG beigetragen, das die wissenschaftliche Ausbildung forschender Kliniker verbessern soll. In den letzten Jahren haben sich aus der Lübecker Hautklinik heraus 2 eigenständige Institute neu etabliert. Hierzu zählen das Institut für Entzündungsmedizin unter der Leitung von Prof. Diamant Thaçi, in dem klinische Studien zu entzündlichen Hauterkrankungen initiiert und koordiniert werden und die Versorgung von Patienten mit entzündlichen Dermatosen stattfindet. Daneben ist aus der Hautklinik heraus das Lübecker Institut für Experimentelle Dermatologie (LIED) entstanden, in dem derzeit 5 Professoren mit ihren jeweiligen Arbeitsgruppen zu unterschiedlichen Themen der Entzündung an der Haut forschen. Die interdisziplinären wissenschaftlichen Aktivitäten zur Entzündung an der Haut am Lübecker Campus werden seit 2015 in einem Center for Research on Inflammation of the Skin (CRIS) gebündelt. CRIS erhielt kürzlich die Zusage für ein eigenständiges Forschungsgebäude, das nach § 91 Grundgesetz durch Bund und Land finanziert wird und derzeit im Zentrum des Lübecker Campus entsteht. Der Ausbau der Forschungsstrukturen der Klinik ging mit der Einrichtung von Spezialambulanzen für verschiedene entzündliche Hauterkrankungen, aber auch für die Versorgung von Hautkrebs und chronischen Wunden einher. Die Klinik verfügt über ein zertifiziertes Hautkrebszentrum und ist Teil der Lübecker universitären Gefäß- und Krebszentren. Weitere wichtige Pfeiler der klinischen Versorgung sind zertifizierte diagnostische Einsendelabore für Dermato-Histopathologie und kutane Autoimmunerkrankungen.

Sequentielle Immuncheckpoint-Inhibition beim Merkelzellkarzinom

Das Merkelzellkarzinom (MCC) ist der Hauttumor mit der höchsten Mortalität. Auf eine Therapie mit Immuncheckpoint-Inhibitoren spricht zwar mehr als die Hälfte der metastasierten Patienten an, es ist aber nicht bekannt, wie bei Patienten, die nur unzureichend oder nicht mehr von einer PD-1- oder PD-L1-Blockade profitieren, vorzugehen ist.

Wir stellen einen 67-jährigen Patienten mit multiplen Lebermetastasen eines MCC vor. Die Erstdiagnose wurde 5 Jahre vor Auftreten der Fernmetastasierung gestellt. Nachdem es unter einer Chemotherapie mit Paclitaxel und Carboplatin als Erstlinientherapie zu einem Progress der Lebermetastasen gekommen war, wurde eine Therapie mit dem Immuncheckpoint-Inhibitor Avelumab (anti-PD-L1-Antikörper) eingeleitet. Unter dieser Therapie zeigte sich trotz initialen guten Ansprechens im 1. Staging nach 6 Gaben ein Progress einer Lebermetastase bei stabilem Befund weiterer Lebermetastasen. Der Patient wurde wegen der progredienten Lebermetastase hemihepatektomiert. In der Folge bildeten sich weitere Lebermetastasen, sodass eine Therapie mit dem PD-1-Inhibitor Pembrolizumab eingeleitet wurde. Unter dieser Therapie zeigte sich nun eine über mehr als 2 Jahre anhaltende und fortbestehende komplette Remission.

Dieser Fall könnte darauf hinweisen, dass beide Moleküle unterschiedliche Wirkmechanismen haben und ein sequentielles Vorgehen eine sinnvolle Strategie sein kann. Wir empfehlen, zu dieser Frage eine gezielte klinische Studie durchzuführen.

[Cutaneous angiosarcoma : Radiochemotherapy with liposomal pegylated doxorubicin]

BACKGROUND

Whilst cutaneous angiosarcoma is rare tumour which primarily affects elderly patients, its management presents a significant therapeutic challenge. Indeed, complete surgical excision is often not possible due to the location and the diffuse and extensive nature of the tumour. Therefore, current treatment strategies often include chemo- and/or radiotherapy.

METHODS

We report our experience of combined chemo- and radiotherapy in the clinical course of 6 patients with cutaneous angiosarcoma who were treated between 2007 and 2018.

RESULTS

All patients presented non-resectable tumours and were treated with radiotherapy in combination with the administration of liposomal, pegylated doxrubicin (25 mg/m² every 2 weeks). The mean duration of progression-free survival was 8 months (5-14 months), corresponding to an overall survival of 13 months (13-34 months). A partial response was seen in 4 patients and 1 patient developed progressive disease. One patient abandoned therapy after one administration. Two patients developed severe adverse events which led to termination of therapy after 1.5 months and 7 months, i.e. after 4 and 15 cycles respectively.

DISCUSSION

Combined radio- and chemotherapy with liposomal, pegylated doxorubicin is a useful therapeutic option in the management of cutaneous angiosarcoma. Given the short-lived response rate, new treatment options are urgently required.

[Immune checkpoint inhibition in Merkel cell carcinoma]

BACKGROUND

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

AIM

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

METHODS

A review of the scientific literature listed in PubMed.

RESULTS

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

DISCUSSION

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

Sequence-dependent cross-resistance of combined radiotherapy plus BRAFV600E inhibition in melanoma

INTRODUCTION

Treatment of patients with metastatic melanoma is hampered by drug-resistance and often requires combination with radiotherapy as last-resort option. However, also after radiotherapy, clinical relapses are common.

METHODS & RESULTS

Our preclinical models indicated a higher rate of tumour relapse when melanoma cells were first treated with BRAF^V600E inhibition (BRAFi) followed by radiotherapy as compared to the reverse sequence. Accordingly, retrospective follow-up data from 65 stage-IV melanoma patients with irradiated melanoma brain metastases confirmed a shortened duration of local response of mitogen-activated protein kinase (MAPK)-inhibitor-pretreated compared with MAPK-inhibitor-naïve intracranial metastases. On the molecular level, we identified JARID1B/KDM5B as a cellular marker for cross-resistance between BRAFi and radiotherapy. JARID1B^high cells appeared more frequently under upfront BRAFi as compared with upfront radiation. JARID1B favours cell survival by transcriptional regulation of genes controlling cell cycle, DNA repair and cell death.

CONCLUSION

The level of cross-resistance between combined MAPK inhibition and radiotherapy is dependent on the treatment sequence. JARID1B may represent a novel therapy-overarching resistance marker.

[Spectroscopic imaging of the human liver using 3D CSI: optimization and application in patients with metastatic uvea melanoma]

PURPOSE

(31)P MR spectroscopy (MRS) allows the noninvasive assessment of metabolic alterations in tumors. Due to physical as well as technical limitations, mostly large and single voxels are used. We used a spatially resolved (31)P MRS technique to characterize metabolic abnormalities inside and adjacent to liver metastases of patients with uvea melanoma.

MATERIALS AND METHODS

Optimization of 3D chemical shift imaging (3D CSI) was performed in healthy volunteers (n = 19; voxel size 25 ml). Patients (n = 8) with liver metastases were then examined. Cross sectional imaging was available for all patients.

RESULTS

Compared to healthy volunteers, the PME/PDE ratios of patients with liver metastasis were significantly higher (0.56 +/- 0.30 vs. 0.39 +/- 0.21; p < 0.05). A trend towards increased PME/beta ATP ratios (2.07 +/- 1.83 vs. 1.02 +/- 0.45; p = 0.12) and decreased Pi/PME ratios (0.57 +/- 0.29 vs. 1.06 +/- 0.58; p = 0.06) was also observed. Patients with metastases > or = 5 cm showed significantly higher PME/PDE ratios (0.68 +/- 0.17 vs. 0.45 +/- 0.03; p < 0.05). Liver parenchyma adjacent to metastases did not show any significant changes compared to non-diseased tissue.

CONCLUSION

3D CSI allows the simultaneous analysis of metabolic alterations in diseased as well as in healthy human liver. Metastases show significant metabolic alterations. Thus, (31)P MRS opens new possibilities for therapeutic monitoring.

Chemoimmunotherapy for cutaneous melanoma with dacarbazine and epifocal contact sensitizers: results of a nationwide survey of the German Dermatologic Co-operative Oncology Group

PURPOSE

To scrutinize published data from small mono-centric studies and case reports which implicated high response rates and promising survival times for a combination therapy consisting of epifocal dinitrochlorobenzene (DNCB) and dacarbazine (DTIC) for metastasized melanoma. This therapy merges the effects of an allergic contact dermatitis elicited at the site of a cutaneous metastasis, and systemic chemotherapy.

METHODS

We performed a retrospective survey with nine German centers and evaluated 72 patients treated from 1993 to 2005.

RESULTS

The objective response rate in stage III melanoma (n = 39) was 62%. In contrast, only 9% objective responses were observed in 33 stage IV patients. Interestingly, more than half of patients with objective remissions remained progression-free for more than 1 year irrespective of the stage of disease.

CONCLUSIONS

Epifocal DNCB combined with DTIC is effective in patients with regionally metastasized melanoma not amenable to surgery or isolated limb perfusion, whereas in stage IV disease in spite of few durable remissions the addition of DNCB does not improve the therapeutic efficacy of DTIC.

Clinical evaluation of in vitro chemosensitivity testing: the example of uveal melanoma

PURPOSE

Results from in vitro chemosensitivity testing recommend treosulfan/gemcitabine chemotherapy for the treatment of stage IV uveal melanoma.

METHODS

Twenty patients received treosulfan 3,500 mg/m2 followed by gemcitabine 1,000 mg/m2 on day 1 and day 8 repeated on day 29. In cases of prior chemotherapy only 75% of these dosages were used.

RESULTS

Without any patient achieving an objective response, 25% of patients (95% confidence interval, 8.6-49.1%) had stabilisation of disease. This stabilisation was associated with a prolonged median overall survival of 17 months compared with 7 months for the patients with progressive disease. First-line treatment was not associated with better response or survival although prognostic parameters did not significantly differ from that of other patients.

CONCLUSIONS

The results are disappointing and question the value of individualized chemotherapy based on in vitro assays.

Longitudinal analysis of MART-1/HLA-A2-reactive T cells over the course of melanoma progression

An HLA-A2-positive patient with advanced stage IV melanoma was vaccinated with dendritic cells (DCs) pulsed with melanoma antigens, whereby the rapid progression of disease stalled for a period of 10 months. Monitoring of the cellular immune response against one of the vaccinated HLA-A2-restricted epitopes demonstrated both induction and subsequent decline in the number of interferon-gamma (IFN-gamma)-producing MART-1-reactive cells present in the blood. Enumeration of reactive T cells by MART-126-35/HLA-A2 tetramer staining revealed an induction of such cells after three vaccinations and a subsequent decline that most prominent at times of rapid disease progression. However, a substantial number of reactive cells were present even when no MART-1 reactivity was detectable by functional assays. Isolation of such MART-126-35-reactive T cells by means of peptide/HLA-A2-coated magnetic beads demonstrated the persistence of a TCRVbeta14+ T-cell clone in this population over the whole observation period. Intracellular fluorescence-activated cell sorter staining of such TCRVbeta14+ T cells for IFN-gamma and interleukin-2 after maximal stimulation with phorbol 12-myristate 13-acetate/ionomycin revealed an impairment in their capacity to produce cytokines at the end of the observation period. Thus, functional changes of individual T-cell clones, e.g. clonal exhaustion, seem to be responsible for the known discrepancy between functional and phenotype assays for immune monitoring of tumour patients.

Treatment of disseminated ocular melanoma with sequential fotemustine, interferon alpha, and interleukin 2

Malignant melanoma of the uvea is remarkable for purely haematogenous dissemination and its tendency to metastasise to the liver. Although the liver is involved in up to 95% of patients, 50% of these also develop extrahepatic metastases, most often in the lungs, bone, skin, and brain. The only effective treatments reported to date relied on hepatic arterial chemoembolisation or -perfusion. The objective of this study was to establish a therapy protocol addressing patients with both sole liver involvement and systemic disease. Forty-eight patients with metastatic ocular melanoma received fotemustine 100 mg m(-2) either as 60-min infusion into the hepatic artery or as 15-min infusion via a peripheral vein, depending on the metastatic sites involved, i.e., restriction to the liver or hepatic together with extrahepatic disease. For the first treatment cycle this infusion was repeated after one week. For all cycles, subsequent to a three week resting period, patients received an immunotherapy consisting of subcutaneous interleukin 2 and interferon alpha(2). Although objective responses were more frequent within the cohort receiving intraarterial fotemustine (21.7 vs 8%), this difference did not translate into a significant benefit in overall survival, i.e., 369 and 349 days, respectively. Of note, this overall survival is much longer than that repeatedly reported for stage IV uveal melanoma not treated with fotemustine, suggesting a therapeutic activity of this cytostatic drug even after systemic administration.

[Nevus of Ota and choroid melanoma]

A 59-year-old patient presented with metastatic uveal melanoma that developed in a nevus of Ota. The nevus of Ota or oculodermal melanocytosis contains an increased number of dermal melanocytes in the distribution of the ophthalmic and maxillary divisions of the trigeminal nerve. Malignant transformation arising in a nevus of Ota may occur in all anatomical sites influenced by the nevus. Most often the choroid is involved. Although the nevus of Ota is rare in Caucasians, associated melanoma is more common than in Asians or black people. The dermatologist should be aware of this problem and aim at an interdisciplinary management of these patients.

Oligoclonal T-cell receptor usage of melanocyte differentiation antigen-reactive T cells in stage IV melanoma patients

Ex vivo ELISPOT analysis of peripheral blood lymphocytes obtained from stage IV melanoma patients demonstrated reactivity against peptides derived from MART-1 and gp100. However, the number of reactive T cells was < 1% that of total lymphocytes as detected by flow cytometry using tetrameric MHC/peptide complexes. Despite this low frequency, we were able to directly isolate these populations ex vivo by means of magnetic beads coated with MHC/peptide complexes and to subject these cells to T-cell receptor clonotype mapping. This analysis revealed that the MART-1/A*0201- and gp100/A*0201-reactive T-cell populations are composed of oligoclonal T cells that engage several T-cell receptor beta chain families. Longitudinal studies using this approach may result in a better correlation between T-cell reactivity and the course of neoplastic disease.

Sequential interferon-alpha2b, interleukin-2 and fotemustine for patients with metastatic melanoma

The aim of this study was the evaluation of both the antitumour activity and toxicity of an immunochemotherapeutic regimen consisting of interferon-alpha2b and interleukin-2 in combination with fotemustine for patients with metastatic melanoma. To improve the penetration of fotemustine into the brain, it was given immediately after immunotherapy, when the blood-brain barrier is still disturbed. Of the 19 patients treated, three complete remissions (CRs) and one partial remission (PR) were induced, giving an objective response rate of 21% (95% confidence interval 6-46%). The durations of the CRs were 9, 19 and 44 months; the PR lasted for 59+ months. The overall survival times for the patients with CR were 21, 25 and 70+ months, and 59+ months for the PR. For nine patients (47%, 95% confidence interval 24-71%) disease was stabilized for a median period of 8 months (range 2-18 months), resulting in a median survival of 18 months (range 10-41+ months). No haematological toxicity of World Health Organization grade 3 or more was observed and in general toxicity was low. In summary, this immunochemotherapy regimen led to long-term survival in occasional patients, and about half of the patients achieved stable disease, with prolonged treatment- and progression-free survival compared with nonresponding patients. The occurrence of brain metastases, however, was not prevented, and in fact was the site of recurrence in those patients achieving a CR. Due to its low toxicity, this protocol can be applied at a community hospital level.

CD40-ligated dendritic cells effectively expand melanoma-specific CD8+ CTLs and CD4+ IFN-gamma-producing T cells from tumor-infiltrating lymphocytes

Professional APC, notably dendritic cells (DC), are necessary for stimulation and expansion of naive T cells. By means of murine models, the interaction between CD40 on DC and its ligand CD154 has been recognized as an important element for conditioning of DC to prime and expand CTL. We translated these findings into the human system, scrutinizing the ability of DC to initiate clonal expansion of single T cells. DC generated under completely autologous conditions from peripheral blood monocytes were cocultured at a rate of 0.3 cell/well with melanoma-infiltrating T cells; this procedure guaranteed that either a CD4+ or a CD8+ cell interacted with the DC, thus avoiding the contact of more than one T cell to the DC. In the absence of further stimulation, this cloning protocol yielded almost exclusively CD4+ T cell clones that predominantly exhibited a Th2 phenotype. However, cross-linking of CD40 on DC resulted in the induction of IFN-gamma-producing Th1 CD4+ T cell clones. In addition, CD40-activated DC were capable of expanding CD8+ CTL clones. The ratio of CD4 to CD8 T cell clones corresponded to the ratio present in the initial tumor-infiltrating lymphocyte preparation. The CTL clones efficiently lysed autologous tumor cells whereas autologous fibroblasts or MHC-mismatched melanoma cells were not killed. Our findings support the critical role of CD40/CD154 interactions for the induction of cellular immune responses.

Expression of CD94/NKG2 subtypes on tumor-infiltrating lymphocytes in primary and metastatic melanoma

Natural killer receptors are expressed both on natural killer populations and subpopulations of T cells, mainly alpha/beta TCR+CD8+ T cells. We have characterized the expression of the C-type lectin natural killer receptor CD94/NKG2 on tumor-infiltrating lymphocytes in primary and metastatic melanoma lesions. By immunohistochemistry, 5-10% of the tumor-infiltrating lymphocytes, both in primary and metastatic lesions, expressed CD94. More than 95% of these CD94+ cells coexpressed CD8 and the percentage of CD94 expression within the CD8+ cell population ranged from 5 to 20% with a higher expression in metastatic lesions. CD94/NKG2 exists both in an inhibitory and an activating form; thus, it was necessary to determine whether the inhibitory CD94/NKG2-A/B, the activating CD94/NKG2-C/E, or both were expressed on tumor-infiltrating lymphocytes. Reverse transcription-polymerase chain reaction using specific primers for NKG2-A/B and C/E mRNA revealed the presence of NKG2-C/E in all primary and metastatic lesions. In contrast, the inhibitory NKG2-A/B was only present in 50% of primary tumors whereas 80% of tumor-infiltrating lymphocytes in metastatic lesions expressed these transcripts. In healthy humans, the mean number of inhibitory natural killer receptors is higher than that of activating receptors, but the opposite was true for tumor-infiltrating lymphocytes in melanoma. The reversal of the ratio of inhibitory to activating natural killer receptors among tumor-infiltrating lymphocytes suggests a regulated event due to either specific factors within the tumor microenvironment, preferential homing of T cell subsets, or certain stages of T cell activation.

Predominant expression of Fas (CD95) ligand in metastatic melanoma revealed by longitudinal analysis

The expression of Fas ligand has recently been proposed as a novel tumor escape mechanism for melanoma. To establish the characteristics of Fas ligand expression during the course of melanoma progression we performed a longitudinal study analyzing primary tumors as well as subsequently evolving metastases. In primary melanoma Fas ligand was expressed in two of 20 lesions; this expression was weak and restricted to few parts of the tumors. The Fas ligand positive primary melanomas were rather thick, i.e., 8.5 and 3.8 mm, versus a median of 2.4 mm of the remaining tumors. In contrast, for metastatic melanoma Fas ligand expression was present in six of 11 cases investigated. The metastases of primary tumors displaying Fas ligand maintained its expression. As Fas ligand positive melanoma cells are capable of inducing apoptosis in susceptible cells, e.g., Fas positive tumor infiltrating lymphocytes, we tested for the presence of apoptotic cells in situ by terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling. This analysis revealed that apoptotic cells were present within the Fas ligand positive tumors. The number of apoptotic cells, however, never exceeded 5% of the total cells. Thus, Fas ligand mediated apoptosis does not seem to be a major immune escape mechanism for melanoma but its expression correlates with the stage of melanoma.

[Immunochemotherapy of metastatic uveal melanoma with interferon alfa-2b, interleukin-2 and fotemustine. Case reports and review of the literature]

In spite of their tumor's origin in the uveal tract, many patients suffering from advanced uveal melanoma are admitted to dermatological oncology units. Most patients with metastases from uveal melanoma receive treatments that were established for stage IV cutaneous melanoma. However, both the biology as well as the metastastic behaviour of this tumor is different from cutaneous melanoma. Lymphatic metastases do not occur, and hematogeneous metastases usually occur later and predominantly involve the liver. The prognosis is very bad ranging from 2 to 5 months. We describe three patients with advanced uveal melanoma who received immunochemotherapy containing interferon-alpha 2b, interleukin-2, and fotemustine. This therapy induced a partial response of more than 49 months duration in one patient, whereas for the remaining patients the disease progression could be stabilized for eight and 16 months, respectively. This therapeutic success is reflected by a prolonged survival of 14,43+, and 59+ months.

Molecular basis of T-cell dysfunction in melanoma

Human melanoma is an immunogenic tumour which is characterized by a number of defined tumour-associated antigens and a specific T-cell-mediated immune response. Nevertheless, there is only limited evidence for an effective antitumour immune response able to eradicate established melanoma. Thus, the existence of an immunologically suppressed state in the tumour-bearing host has become an axiom in tumour immunology. There is increasing evidence that abnormalities in signal transduction events involved in cell activation are the molecular basis for the observed T-cell dysfunction. These abnormalities include altered patterns of protein tyrosin phosphorylation, decreased protein levels of the Src-family kinases p56(lck) and p59(lyn), and of the CD3zeta chain. Furthermore, differences in the expression of transcription factors of the nuclear factor NF-kappaB/Rel family have been described.