Faculty Bibliography

The incidence of melanoma has increased 3-7% per year, and is now approaching 30 per 100,000 individuals. This rate is faster than any other cancer, and is predicted to double every 10-20 years [1]. Surgery can be curative in Stage I, II, or III disease, but 75% of patients with deep primary lesions will develop extensive recurrence or distant metastases (Stage IV disease). To date, no curative treatment exists for Stage IV melanoma and these patients have a median overall survival of only 7 months [2]. A subset of patients can be salvaged with surgical resection of metastatic sites, but no adjuvant therapy has further improved the outcome [3]. The only FDA approved adjuvant therapy for Stage IV melanoma is alpha-interferon. Several trials have demonstrated an increase in relapse-free survival; however, toxicity is high and overall survival remains controversial. Several reports have demonstrated a role for aberrant Notch signaling in melanoma genesis or progression, prompting us to explore if targeting this pathway is a valid therapeutic approach against melanoma. To investigate the potential benefits of Notch inhibition in melanoma, we are using RO4929097, a novel inhibitor of gamma secretase, a key component of the enzymatic complex that cleaves and activates Notch. RO4929097 is completing Phase I dose escalation in cancer patients and a CTEP-sponsored Phase II clinical trial in melanoma is currently under review. We have generated DNA microarray data for a series of 22 melanoma cell lines at both the gene expression and DNA copy number level. Preliminary gene expression analysis has indicated that melanoma cells over express crucial components of NOTCH-pathway, such as Hey1 Hey2 and NOXA. Furthermore, integration of gene expression and copy number data for NOTCH2 suggests that the increased DNA copy number play a role in the increase in gene expression. We have also tested the efficacy of RO4929047 in human melanoma cell lines. We have observed that treatment with RO4929097 for 24h causes a!

PURPOSE: To identify a melanoma microRNA (miRNA) expression signature that is predictive of outcome and then evaluate its potential to improve risk stratification when added to the standard-of-care staging criteria. EXPERIMENTAL DESIGN: Total RNA was extracted from 59 formalin-fixed paraffin-embedded melanoma metastases and hybridized to miRNA arrays containing 911 probes. We then correlated miRNA expression with post-recurrence survival and other clinicopathologic criteria. RESULTS: We identified a signature of 18 miRNAs whose overexpression was significantly correlated with longer survival, defined as more than 18 months post-recurrence survival. Subsequent cross-validation showed that a small subset of these miRNAs can predict post-recurrence survival in metastatic melanoma with an estimated accuracy of 80.2% (95% confidence interval, 79.8-80.6%). In contrast to standard-of-care staging criteria, a six-miRNA signature significantly stratified stage III patients into 'better' and 'worse' prognostic categories, and a multivariate Cox regression analysis revealed the signature to be an independent predictor of survival. Furthermore, we showed that most miRNAs from the signature also showed differential expression between patients with better and worse prognoses in the corresponding paired primary melanoma. CONCLUSIONS: MiRNA signatures have potential as clinically relevant biomarkers of prognosis in metastatic melanoma. Our data suggest that molecularly based models of risk assessment can improve the standard staging criteria and support the incorporation of miRNAs into such models. Clin Cancer Res; 16(5); 1577-86

The V600E activating mutation of the BRAF gene occurs in approximately 50% of melanomas and is a potentially important molecular target for therapy in this disease. In a Phase I clinical trial, treatment with RG7204 (PLX4032), a low molecular weight, orally available selective inhibitor of oncogenic BRAF kinase, led to impressive tumor regression in patients whose tumors carried the V600E BRAF mutation. This is the first report of a pivotal open-label, multicenter, Phase II trial in previously treated patients with BRAF V600E mutation-positive metastatic melanoma. The primary endpoint is best overall response rate (BORR). Patients were selected with the cobas 4800 V600 Mutation Assay (Roche, Basel, Switzerland), a PCR-based companion diagnostic assay that is currently under development. Patients are treated with RG7204 (960 mg given twice daily) until they develop progressive disease, unacceptable toxicity, or death, whichever occurs first. A total of 132 patients were enrolled between September 2009 and March 2010. At the time of the presentation (based on the data cut-off date of September 27, 2010), we will report an interim analysis of the primary endpoint of BORR as assessed by independent review committee, as well as the secondary endpoints of BORR (as assessed by the investigator), response duration, median progression-free survival, time to response, and safety (adverse events, serious adverse events, dose reductions). We will also provide the median duration of treatment and the median safety follow up period. These results may provide additional clinical information in a larger sample of patients of the efficacy and safety profile of RG7204 in previously treated patients with BRAF V600Epositive metastatic melanoma

BACKGROUND: Ixabepilone (BMS-247550), an epothilone B analog, is a microtubule stabilizing agent which has shown activity in several different tumor types and preclinical models in melanoma. In an open label, one-arm, multi-center phase II trial the efficacy and toxicity of this epothilone was investigated in two different cohorts: chemotherapy-naive (previously untreated) and previously treated patients with metastatic melanoma. METHODOLOGY/PRINCIPAL FINDINGS: Eligible patients had histologically-confirmed stage IV melanoma, with an ECOG performance status of 0 to 2. Ixabepilone was administered at a dose of 20 mg/m(2) on days 1, 8, and 15 during each 28-day cycle. The primary endpoint was response rate (RR); secondary endpoints were time to progression (TTP) and toxicity. Twenty-four patients were enrolled and 23 were evaluable for response. Initial serum lactate dehydrogenase (LDH) levels were elevated in 6/11 (55%) of the previously treated and in 5/13 (38%) of the previously untreated patients. No complete or partial responses were seen in either cohort. One patient in the previously treated group developed neutropenia and fatal septic shock. Seventeen patients (8 in the previously untreated group and 9 in the previously treated group) progressed after 2 cycles, whereas six patients (3 in each group) had stable disease after 2-6 cycles. Median TTP was 1.74 months in the previously untreated group (95% CI = 1.51 months, upper limit not estimated) and 1.54 months in the previously treated group (95% CI = 1.15 months, 2.72 months). Grade 3 and/or 4 toxicities occurred in 5/11 (45%) of previously untreated and in 5/13 (38%) of previously treated patients and included neutropenia, peripheral neuropathy, fatigue, diarrhea, and dyspnea. CONCLUSIONS/SIGNIFICANCE: Ixabepilone has no meaningful activity in either chemotherapy-naive (previously untreated) or previously treated patients with metastatic melanoma. Further investigation with ixabepilone as single agent in the treatment of melanoma is not warranted. TRIAL REGISTRATION: Clinical Trials.gov NCT00036764

The V600E activating mutation of the BRAF gene occurs in approximately 50% of melanomas and is a potentially important molecular target for therapy in this disease. In a Phase I clinical trial, treatment with RG7204 (PLX4032), a low molecular weight, orally available selective inhibitor of oncogenic BRAF kinase, led to impressive tumor regression in patients whose tumors carried the V600E BRAF mutation. This is the first report of a pivotal open-label, multicenter, Phase II trial in previously treated patients with BRAF V600E mutation-positive metastatic melanoma. The primary endpoint is best overall response rate (BORR). Patients were selected with the cobas-4800 V600 Mutation Assay, a PCR-based companion diagnostic assay that is currently under development. Patients are treated with RG7204 (960 mg given twice daily) until they develop progressive disease, unacceptable toxicity, or death, whichever occurs first. A total of 132 patients were enrolled between September 2009 and March 2010. At the time of the presentation (based on the data cut-off date of September 27, 2010), we will report an interim analysis of the primary endpoint of BORR as assessed by independent review committee, as well as the secondary endpoints of BORR (as assessed by the investigator), response duration, median progression-free survival, time to response, and safety (adverse events, serious adverse events, dose reductions). We will also provide the median duration of treatment and the median safety follow up period. These results may provide additional clinical information in a larger sample of patients of the efficacy and safety profile of RG7204 in previously treated patients with BRAF V600E-positive metastatic melanoma

Mucosal melanoma is a rare cancer that is clearly distinct from its cutaneous counterpart in biology, clinical course, and prognosis. Recent studies have shown important differences in the frequencies of various genetic alterations in different subtypes of melanoma. Activating mutations in the c-KIT gene are detected in a significant number of patients with mucosal melanoma. This observation has resulted in the initiation of several clinical trials aimed at exploring the role of receptor tyrosine kinases that inhibit c-KIT in this patient population. We herein present a comprehensive literature review of mucosal melanoma along with case vignettes of a number of pertinent cases. We further discuss melanomas of the head and neck, the female genital tract, and the anorectum, which are the three most common sites of mucosal melanoma, with a particular focus on the diagnostic, prognostic, and therapeutic data available in the literature

BACKGROUND: Sorafenib monotherapy in patients with metastatic melanoma was explored in this multi-institutional phase II study. In correlative studies the impact of sorafenib on cyclin D1 and Ki67 was assessed. METHODOLOGY/PRINCIPAL FINDINGS: Thirty-six patients treatment-naive advanced melanoma patients received sorafenib 400 mg p.o. twice daily continuously. Tumor BRAF(V600E) mutational status was determined by routine DNA sequencing and mutation-specific PCR (MSPCR). Immunohistochemistry (IHC) staining for cyclin D1 and Ki67 was performed on available pre- and post treatment tumor samples. The main toxicities included diarrhea, alopecia, rash, mucositis, nausea, hand-foot syndrome, and intestinal perforation. One patient had a RECIST partial response (PR) lasting 175 days. Three patients experienced stable disease (SD) with a mean duration of 37 weeks. Routine BRAF(V600E) sequencing yielded 27 wild-type (wt) and 6 mutant tumors, whereas MSPCR identified 12 wt and 18 mutant tumors. No correlation was seen between BRAF(V600E) mutational status and clinical activity. No significant changes in expression of cyclin D1 or Ki67 with sorafenib treatment were demonstrable in the 15 patients with pre-and post-treatment tumor samples. CONCLUSIONS/SIGNIFICANCE: Sorafenib monotherapy has limited activity in advanced melanoma patients. BRAF(V600E) mutational status of the tumor was not associated with clinical activity and no significant effect of sorafenib on cyclin D1 or Ki67 was seen, suggesting that sorafenib is not an effective BRAF inhibitor or that additional signaling pathways are equally important in the patients who benefit from sorafenib. TRIAL REGISTRATION: Clinical Trials.gov NCT00119249

Activating mutations in BRAF kinase are common in melanomas. Clinical trials with PLX4032, the mutant-BRAF inhibitor, show promising preliminary results in patients selected for the presence of V600E mutation. However, activating V600K mutation is the other most common mutation, yet patients with this variant are currently excluded from the PLX4032 trials. Here we present evidence that a patient bearing the BRAF V600K mutation responded remarkably to PLX4032, suggesting that clinical trials should include all patients with activating BRAF V600E/K mutations

The incidence of melanoma is on the rise and the elderly population disproportionately accounts for the majority of melanoma cases and melanoma-related deaths. Advanced age is an independent adverse prognostic factor. Surgical resection remains the mainstay of treatment; however, elderly patients receive care that is nonconformant with well-established guidelines. Medical therapy options for high-risk and metastatic melanomas remain limited. New treatment approaches targeting the MAPK pathway, c-kit gene aberrations and novel immune-based therapies will pave the road to individualized and more effective treatment for invasive melanoma. 2010 Future Medicine Ltd

Background: Skp2, a known oncogene, is overexpressed in several types of tumors and is associated with worse recurrence rate and overall survival in primary melanoma patients. Moreover, the anti-proliferative effects of Skp2 siRNA on various tumor cell lines have prompted the preclinical testing of Skp2 small molecule inhibitors. In this study, we assessed the clinical relevance and molecular mechanism(s) underlying Skp2 overexpression in metastatic melanoma patients. Methods: Skp2 protein levels were measured in 122 metastatic melanoma specimens using immunohistochemistry (IHC), and the association between Skp2 overexpression and post-recurrence survival was examined. Moreover, 22 cell lines (2 normal primary melanocytes, 2 primary immortal melanocytes, 4 primary melanoma cell lines, and 18 metastatic melanoma cell lines) were evaluated for Skp2 genomic amplification using Single Nucleotide Polymorphism (SNP) arrays (Affymetrix 6.0) and Skp2 gene expression using mRNA arrays (Affymetrix U133A 2.0) and quantitative RT-PCR. We also screened 18 cell lines for Skp2 mutation by sequencing. Results: Skp2 overexpression, defined as >25% tumor cells, was associated with shorter 3-yr post-recurrence survival (37%) compared to Skp2 expression <= 25% (55%) (HR=1.89, 95%, CI= 1.04, 3.42, p=0.04). Skp2 overexpression was significantly associated with the site of melanoma metastasis: visceral (n= 12; 89%), lymph node (n=49; 36%), brain (n=15; 14%), and soft-tissue (n=36; 6%) (p<0.001). SNP array revealed genomic amplification at the Skp2 locus in 6 (33%) metastatic cell lines and one primary melanoma cell line. Skp2 genomic amplification was associated with increased transcript expression. No Skp2 mutations were identified. Conclusions: Skp2 protein overexpression is associated with worse prognosis in metastasis in melanoma. Our results also support that gene amplification, rather than a Skp2 gene mutation, may be the major mechanism responsible for Skp2 aberrant expression in metastatic melanoma