Agents For Metastatic Melanoma Research Articles

A preclinical pipeline to evaluate migrastatics as therapeutic agents in metastatic melanoma

BackgroundMetastasis is a hallmark of cancer and responsible for most cancer deaths. Migrastatics were defined as drugs interfering with all modes of cancer cell invasion and thus cancers’ ability to metastasise. First anti-metastatic treatments have recently been approved.MethodsWe used bioinformatic analyses of publicly available melanoma databases. Experimentally, we performed in vitro target validation (including 2.5D cell morphology analysis and mass spectrometric analysis of RhoA binding partners), developed a new traceable spontaneously metastasising murine melanoma model for in vivo validation, and employed histology (haematoxylin/eosin and phospho-myosin II staining) to confirm drug action in harvested tumour tissues.ResultsUnbiased and targeted bioinformatic analyses identified the Rho kinase (ROCK)-myosin II pathway and its various components as potentially relevant targets in melanoma. In vitro validation demonstrated redundancy of several RhoGEFs upstream of RhoA and confirmed ROCK as a druggable target downstream of RhoA. The anti-metastatic effects of two ROCK inhibitors were demonstrated through in vivo melanoma metastasis tracking and inhibitor effects also confirmed ex vivo by digital pathology.ConclusionsWe proposed a migrastatic drug development pipeline. As part of the pipeline, we provide a new traceable spontaneous melanoma metastasis model for in vivo quantification of metastasis and anti-metastatic effects by non-invasive imaging.

TLR4-mediated immunomodulatory properties of the bacterial metalloprotease arazyme in preclinical tumor models

ABSTRACTDespite the recent approval of new agents for metastatic melanoma, its treatment remains challenging. Moreover, few available immunotherapies induce a strong cellular immune response, and selection of the correct immunoadjuvant is crucial for overcoming this obstacle. Here, we studied the immunomodulatory properties of arazyme, a bacterial metalloprotease, which was previously shown to control metastasis in a murine melanoma B16F10-Nex2 model. The antitumor activity of arazyme was independent of its proteolytic activity, since heat-inactivated protease showed comparable properties to the active enzyme; however, the effect was dependent on an intact immune system, as antitumor properties were lost in immunodeficient mice. The protective response was IFNγ-dependent, and CD8+ T lymphocytes were the main effector antitumor population, although B and CD4+ T lymphocytes were also induced. Macrophages and dendritic cells were involved in the induction of the antitumor response, as arazyme activation of these cells increased both the expression of surface activation markers and proinflammatory cytokine secretion through TLR4-MyD88-TRIF-dependent, but also MAPK-dependent pathways. Arazyme was also effective in the murine breast adenocarcinoma 4T1 model, reducing primary and metastatic tumor development, and prolonging survival. To our knowledge, this is the first report of a bacterial metalloprotease interaction with TLR4 and subsequent receptor activation that promotes a proinflammatory and tumor protective response. Our results show that arazyme has immunomodulatory properties, and could be a promising novel alternative for metastatic melanoma treatment.

Metastatic melanoma can be cured: advances in immunotherapy and targeted approaches

The therapeutic options for patients with metastatic melanoma have improved substantially in the last few years. The approvals of the checkpoint inhibitor, ipilimumab, and the BRAF inhibitor, vemurafenib, transformed melanoma treatment and have relegated chemotherapy to where it belongs – ‘the dustbin of history’ (attributed to Leon Trotsky, Petrograd Second Congress of Soviets, October 25, 1917). A recent article in Clinical Investigation described this ‘Therapeutic Renaissance’ with a focus on the ‘emergence of novel targeted agents for metastatic melanoma’ [1]. There is no denying the importance of the identification of specific genetic alterations involved in the pathogenesis of melanoma and the therapeutic opportunities that have arisen therefrom. The discovery of mutations in BRAF, c-KIT, NRAS and GNAQ have led to an improved understanding of melanoma cell biology, a molecular classification that now supersedes histologic classification, and the identification of the abnormally activated MAP kinase pathway as a target for effective therapy. The review described the specific inhibitors that have been developed for melanomas with BRAF mutations (the BRAF inhibitors vemurafenib and dabrafenib and the MEK inhibitor trametinib) and c-KIT alterations (imatinib). By targeting specific mutations these agents inhibit the altered cellular pathways, and vemurafenib and dabrafenib led to tumor regression in more than 50% of patients and improved survival in patients whose tumors had the V600 BRAF mutation [2]; trametinib also improved survival compared with chemotherapy [3]. However, responses were rarely complete and because tumors can reactivate pathways by alternate means or deploy alternate pathways to maintain their growth advantage, they universally recur and patients eventually die from progressive tumor growth. This is not just true for melanoma, but is the pattern that has emerged for targeted therapy of most solid tumors. Long-term results may improve as we better understand the pathways involved, develop agents that can target multiple steps in one pathway (i.e., BRAFi and MEKi) or use combination therapy to inhibit multiple pathways. These strategies are being tested and may ultimately lead to long-term disease control (cure); however, currently, complete remissions are rare, development of drug resistance is the rule and nobody is cured with targeted therapy. Thus, despite the excitement generated by the randomized Phase III studies showing enhanced survival in patients with metastatic melanoma who received targeted therapy [2,3], we believe results with targeted agents are inferior to the results obtained with a variety of immunotherapies because of the latter’s ability to induce long-term disease control and cure of a small but significant fraction of patients [4–6].

Enrollment in Clinical Trials Correlates with Improved Survival in Metastatic Melanoma

Background: Although the current median survival time of stage-IV melanoma patients is less than 12 months, there is a subset of patients who experience long-term survival. Due to poor response rates to standard cytotoxic agents in metastatic melanoma, patients are encouraged to participate in clinical trials, the overall impact of which has not been studied, however. The aim of our study was to identify the factors associated with long-term survival and to determine the impact of clinical trial enrollment on patient outcome. Methods: We studied stage-IV melanoma patients prospectively enrolled at New York University Medical Center from 2002–2008. Associations between clinicopathologic variables and overall post-stage-IV survival were examined. Kaplan-Meier survival analysis was used to identify univariate predictors of post-stage-IV survival and the independent effect of these variables was assessed in a multivariate Cox proportional hazards regression model. The associations between clinicopathologic variables and long-term survival status (≧2 vs. <2 years) were examined by χ² analysis and the independent effect of these variables on the latter was assessed in a multivariate logistic regression model. Results: Site of metastasis, treatment (systemic vs. localized) and pretreatment lactate dehydrogenase (LDH) level independently correlated with post-stage-IV survival. Participation in clinical trials and normal LDH levels were associated with a long-term survival of ≧2 years. Conclusion: Our data suggest that enrollment in clinical trials independently correlates with prolonged survival after a diagnosis of stage IV melanoma.

Targeted inhibition of BRAF kinase: opportunities and challenges for therapeutics in melanoma

Malignant melanoma is the most aggressive form of skin cancer and its incidence has increased dramatically in the last two decades. Even with a high rate of success in the treatment of early stages of this malignancy, currently there are no effective strategies for the treatment of advanced metastatic melanoma. Much effort has been put into the use of different target-specific drugs, among which BRAF kinase-specific small-molecule inhibitors have rendered promising results as therapeutic agents in metastatic melanoma. Nonetheless, some side effects, such as development of SCC (squamous cell carcinoma), as well as tumour resistance and recurrence, are common limitations of this therapeutic strategy. The use of combination treatments in which different regulatory pathways or the immunological response are targeted seems to be a promising tool for the future success of melanoma therapeutics.

Retrospective study of the efficacy and safety of fotemustine in 170 patients with metastatic melanoma.

e19011 Background: Fotemustine is a third-generation nitrosourea authorized in Europe for the treatment of metastatic melanoma. Fotemustine crosses the brain-blood barrier with a relevant activity on brain metastases (BM) and it is authorized in some European countries for primary brain tumors. Methods: We assessed the pattern of use, efficacy (tumor response, median progression-free survival [PFS], and median overall survival [OS]) and toxicity of fotemustine in Spain through a retrospective study on medical record data of 170 patients (pts) (56% male, 44% female). Median age: 61 years (range 20–87). ECOG PS: 0 in 28% of pts, 1 in 55%, ≥ 2 in 17%. High LDH values: 42 pts. Results: The most used scheme was induction at a 100 mg/m2 i.v. dose (days 1, 8, 15), 4-5 weeks of therapeutic rest and maintenance (100 mg/m2 i.v. every 3 weeks). 41% of pts were treated in first line, 38% in second, and 21% in third or higher. The median number of cycles was 3 (range 1-10). 160 pts were evaluable for efficacy. Tumor response: 3% complete response (CR), 14% partial response (PR), 31% stable disease (SD), 52% progression disease (PD). The clinical benefit in first line was 61% (CR=5%, PR=14%, SD=42%) and 39% (CR=3%, PR=14%, SD=22%) in second line. PFS was 84 days (95% CI 71-109), 100 days (95% CI 72-127) in first line and 77 days (95% CI 63-110) in second line. OS was 200 days (6.5 months) (95% CI 172–284). In 17 pts (10.3%) with BM the tumor response was CR=6% (1 pt), PR=18% (3 pts), SD=35% (6 pts), PD=41% (7 pts). 165 pts were evaluable for toxicity. The most common grade 3/4 toxicities were hematological and included neutropenia (40 pts, 24.2%), thrombocytopenia (39 pts, 23.6%), and anemia (14 pts, 8.5%). Conclusions: Fotemustine is an active and well-tolerated agent in metastatic melanoma, including brain metastases. Tumor response n % CR 5 3 PR 23 14 SD 49 31 Clinical benefit (CR+PR+SD) 77 48 PD 83 52 Total 160 100 Author Disclosure Employment or Leadership Position Consultant or Advisory Role Stock Ownership Honoraria Research Funding Expert Testimony Other Remuneration Italfarmaco, S.A.

Combined treatment with pegylated interferon–α‐2a and dacarbazine in patients with advanced metastatic melanoma

AbstractBACKGROUND.Dacarbazine (DTIC) and pegylated interferon (IFN)–α‐2a have both demonstrated some efficacy as single agents in metastatic melanoma. To the authors' knowledge, the current study is the first to test a combination of these 2 agents in a phase 2 trial.METHODS.Twenty–eight patients with stage IV melanoma without brain metastases were treated with DTIC (at a dose of 850 mg/m2 every 3 weeks) combined with weekly pegylated IFN–α‐2a at a dose of 180 μg. The study was initiated to evaluate the efficacy and tolerability of the combination. The primary study endpoint was objective response.RESULTS.Twenty–five patients were evaluable for response. Two patients (8.0%) achieved a complete response that continued for &gt;480 days and 746 days, respectively. Four patients (16.0%) demonstrated a partial response, and another patient experienced stable disease. Six of 7 nonprogressive patients had either not received treatment or had not developed disease progression during adjuvant IFN treatment for stage II/III disease. The median duration of response was 236 days, the median progression‐free survival was 56 days, and the overall survival time was 403 days. Few grade 3 toxicities and only 1 grade 4 toxicity were observed (according to National Cancer Institute Common Toxicity Criteria).CONCLUSIONS.The combination of DTIC and pegylated IFN–α‐2a was found to be well tolerated in patients with metastatic melanoma. The response rate of 24%, including 2 long‐lasting complete responses, is encouraging, but must be confirmed in larger trials. Cancer 2008. © 2008 American Cancer Society.

A phase II study of thalidomide in patients with brain metastases from malignant melanoma

Introduction. Brain metastases develop in nearly half of the patients with advanced melanoma and in 15 to 20% of these patients CNS is the first site of relapse. Overall median survival is short, ranging from 2 to 4 months. Thalidomide has antiangiogenic and immunomodulatory effects. Results obtained in prior trials indicate that Thalidomide acts as a cytostatic agent in metastatic melanoma. We evaluated single agent antitumour activity and toxicity of Thalidomide in a phase II setting in patients with brain metastases associated with metastatic melanoma. Material and methods. Patients with measurable metastatic melanoma in progression and with PS≤2 were enrolled in the study. Thalidomide was given orally. Dose was escalated over 4 weeks from 100 mg/day to 400 mg/day. Primary objective of the study was to determine response rate, according to RECIST. Secondary objectives were to estimate time to progression, overall survival and to evaluate tolerability of the regimen. Results. Twenty five men and 11 women were enrolled in the study, median age 48 years. Among 36 eligible patients 35 were evaluable for response. None of the patients obtained a response in brain metastases. Three patients obtained a partial response in extracranial lesions. Toxicity was acceptable and manageably. Median time to progression and overall survival time was 1.7 and 3.1 months, respectively. Conclusion. There were no objective responses in the brain but single agent Thalidomide has some activity in melanoma patients with brain metastases. It has encouraged us to investigate Thalidomide in combination with Temozolomide, a very lipophilic agent, in this group of patients.

Multicenter Phase II trial of high‐dose imatinib mesylate in metastatic melanoma

Systemic treatment of metastatic melanoma is largely ineffective and alternative approaches are needed. Imatinib mesylate is an oral tyrosine kinase inhibitor that targets bcr-Abl, c-kit, platelet-derived growth factor receptor (PDGFR)-alpha, and PDGFR-beta, leading to remarkable clinical responses in several cancers. Signal transduction via c-kit, PDGFR-alpha, and PDGFR-beta has been demonstrated in malignant melanoma. The primary objective of this Phase II study was to determine the response rate, response duration, and the frequency of 6-month progression-free survival in patients who could receive up to 2 prior therapeutic regimens. Initially, patients received imatinib at at dose of 400 mg twice orally each day. Based on Simon's optimal design, the study allowed entry of 21 patients; if there were > or = 2 objective responses, accrual would then continue to a total of 41 patients. Twenty-six patients were enrolled. Patients experienced 29 episodes of Grade 3 and 2 episodes of Grade 4 toxicity (according to National Cancer Institute common toxicity criteria). No objective clinical responses were noted among the 25 evaluable patients. The median time to progression was 54 days and the median overall survival was 200 days. No patient was free of disease progression at 6 months. Paraffin-embedded tumor specimens from 15 patients were tested for expression of imatinib responsive kinases by immunohistochemistry. Three tumors had moderate and 5 tumors had weak staining for c-kit. Five tumor samples had weak staining for PDGFR-alpha and -beta. Imatinib is an inactive single agent in metastatic melanoma in a population of predominantely pretreated patients. The levels of c-kit and/or PDGFR-alpha, -beta expression in the current study were lower than previously reported. Alternative treatment strategies remain a priority for patients with advanced melanoma.

Second-line chemotherapy of disseminated malignant melanoma with cystemustine at 60 mg/m2: a phase II trial

Nitrosoureas possess some anti-tumor activity as a single agent in metastatic melanoma (MM). In a phase II trial, we evaluated the anti-tumor effects of cystemustine chemotherapy, a new nitrosourea, as a second-line treatment. Patients were required to have histologic evidence of disseminated MM and had failed in first-line chemotherapy. Treatment comprised cystemustine given at a dose of 60 mg/m every 2 weeks by a 15-min infusion. From February 1997 to September 1999, 22 patients (median age 66 years) were enrolled and were assessable. Two complete responses, one partial response, three stable diseases and 16 progressions were observed, giving an overall response rate of 13.6%. Median duration of response was 10 months (range 4-63). Median survival of responders and non-responders was 11 and 4 months, respectively. However, hematological toxicity, particularly thrombopenia, was a limiting factor for one-third of patients. We conclude that cystemustine at 60 mg/m is active in patients who progressed after one line of chemotherapy in advanced disease, and offers the possibility of complete responses and long durations of these responses.

A phase II study of weekly Edatrexate (10-EDAM) in metastatic melanoma: A National Cancer Institute of Canada Clinical Trials Group Study

Phase I and II clinical trials have demonstrated acceptable toxicity and promising activity of Edatrexate (10-EDAM). The objective of this multicentre phase II study was to determine the efficacy and toxicity of this agent in patients with metastatic melanoma. Sixteen previously untreated patients with metastatic melanoma received 10-EDAM, 80 mg/m2/week intravenously. Patients were evaluated for response and toxicity. There were no objective responses. The median dose intensity of 10-EDAM actually delivered was 56.25 mg/m2/week (70% of projected). Mucositis of any degree was encountered in 93.8% of patients. Grade 3 or 4 mucositis, skin rash, nausea, abdominal pain, neutropenia, thrombocytopenia, anemia and hyperbilirubinemia each were encountered in 1-2 patients. There was 1 toxic death due to 10-EDAM. 10-EDAM is an inactive agent in metastatic melanoma.

Melatonin therapy of advanced human malignant melanoma

We undertook a study to investigate the therapeutic potential of orally administered melatonin in patients with advanced melanoma. Forty-two patients received melatonin in doses ranging from 5 mg/m2/day to 700 mg/m2/day in four divided doses. Two were excluded from analysis. After a median follow-up of 5 weeks, six patients had partial responses, six additional patients had stable disease. Sites of response included the central nervous system, subcutaneous tissue and lung. The median response duration was 33 weeks for the partial responders. There was a suggestion of a dose-response relationship. The toxicity encountered was minimal and consisted primarily of fatigue in 17 of 40 patients. Melatonin also appeared to reduce basal levels of follicle-stimulating hormone (FSH). No significant changes were encountered in serum levels of luteinizing hormone (LH) or thyroid stimulating hormone (TSH). We conclude that further study of melatonin as a potentially useful agent in metastatic melanoma is warranted.