Chemotherapy For Melanoma Research Articles

Australian multi‐center experience outside of the Sydney Melanoma Unit of isolated limb infusion chemotherapy for melanoma

Isolated limb infusion (ILI) is a minimally invasive alternative to isolated limb perfusion (ILP) for delivering high-dose regional chemotherapy to treat locally advanced limb melanoma. The current study aimed to evaluate the applicability of ILI in four Australian tertiary referral centers outside of its originating institution, the Sydney Melanoma Unit (SMU; currently known as the Melanoma Institute Australia). Data of 131 patients, treated between 1992 and 2008 were collectively analyzed. The ILI procedures were based on the Sydney Melanoma Unit protocol using melphalan. Response was determined using the WHO criteria and toxicity was assessed using the Wieberdink scale. The median patient age was 74 years (range 28-100). Fifty-six percent were female. Overall response (OR) rate to ILI was 63% (CR 27%; PR 36%). Wieberdink toxicity grade III or higher was seen in 13%. No toxicity-related amputations occurred. Median follow-up was 24 months; median survival was 58 months. In patients with a complete response (CR), median survival was 101 months; in patients with a partial response (PR) this was 41 months (P = 0.026). On univariate analysis a younger age, lower-limb procedures and a lower Breslow thickness of the primary melanoma were associated with a favorable response. On multivariate analysis Breslow thickness and lower-limb ILI remained significant predictors for response. In this, to date, largest multi-center study of ILI for melanoma the results are comparable to other reports and demonstrate that ILI can be widely implemented and safely applied across tertiary referral centers.

ChemInform Abstract: Synthesis of Cytotoxic Palmerolides

AbstractReview: 60 refs.

Association of MITF and other melanosome-related proteins with chemoresistance in melanoma tumors and cell lines

Previous studies in cell lines have suggested a role for melanosomes and related protein trafficking pathways in melanoma drug response. We have investigated the expression of six proteins related to melanosomes and melanogenesis (MITF, GPR143, gp100/PMEL, MLANA, TYRP1, and RAB27A) in pretreatment metastases from melanoma patients (n = 52) with different response to dacarbazine/temozolomide. Microphthalmia-associated transcription factor (MITF) and G-protein coupled receptor 143 (GPR143) showed significantly higher expression in nonresponders compared with responders. The premelanosome protein (gp100/PMEL) has been indicated previously in resistance to cisplatin in melanoma cells, but the expression levels of gp100/PMEL showed no association with response to dacarbazine/temozolomide in our clinical material. We also investigated the effects on chemosensitivity of siRNA inhibition of gp100/PMEL in the MNT-1 melanoma cell line. As expected from the study of the tumor material, no effect was detected with respect to response to temozolomide. However, knockdown of gp100/PMEL sensitized the cells to both paclitaxel and cisplatin. Overall, our results suggest that MITF, and several MITF-regulated factors, are associated with resistance to chemotherapy in melanoma and that different MITF targets can be of importance for different drugs.

Preoperative chemotherapy for vulvar and vaginal melanoma

Preoperative chemotherapy for vulvar and vaginal melanoma

Hypoxia in Melanoma: Using Optical Spectroscopy and EF5 to Assess Tumor Oxygenation Before and During Regional Chemotherapy for Melanoma

There is increasing evidence that tumor hypoxia plays a significant role in the chemoresistance of melanoma, but to our knowledge, real-time tumor oxygenation during isolated limb infusion (ILI) has not been studied. We sought to demonstrate the feasibility of measuring real-time alterations in tissue oxygenation. Consecutive patients with histologically confirmed in-transit melanoma were enrolled onto a prospective single-arm pilot study and administered the hypoxia marker drug EF5. All patients were treated with ILI. Optical spectroscopy readings were obtained at three locations: two discrete target lesions and one normal skin control. Measurements were taken at 11 predefined time points during ILI. A total of six patients were enrolled onto this pilot study. Intratumor and normal skin optical spectroscopy readings were found to have discrete inflection points throughout the duration of therapy, corresponding with established time points. Baseline hypoxia as measured by both optical spectroscopy and EF5 immunofluorescence was variable, but on the basis of optical spectra, tumors appeared to become more hypoxic compared to normal skin after tourniquet application. The optical hypoxia signature was variable between patients while hemoglobin absorption increased. To our knowledge, this is the first use of real-time optical spectroscopy to evaluate oxygenation and perfusion within melanoma lesions during regional chemotherapy. We report our development of this new noninvasive means of assessing tumor vascular function, which has the potential to be a powerful tool for noninvasive examination of the melanoma tumor microenvironment.

Targets, Structures, and Recent Approaches in Malignant Melanoma Chemotherapy

Malignant metastatic melanoma is one of the oncologic diseases with the worst clinical prognosis, due primarily to resistance phenomena against chemotherapeutic agents in current use. However, over the last few years, characterization of the molecular mechanisms involved in the development and progression of the disease has contributed to elucidation of the main pathways by which tissue invasion and metastasis can occur. More importantly, the identification of abnormalities in signaling cascades in melanoma cells has facilitated new therapeutic approaches against malignant melanoma through the design of highly potent and selective drugs with low associated toxicity. Ultimately, recognition of the restricted applicability of new chemotherapies in certain genetic contexts has led to significant improvements in the results of clinical trials, anticipating the existing need for investment in personalized therapies, and taking into account the molecular alterations observed in tumors. Although significant advances have been made in terms of extending the median overall survival rate and improving the quality of life for patients, the mechanisms that compromise in vivo drug efficacy remain poorly understood, particularly those concerning therapeutic resistance phenomena. This review summarizes recently validated targets from the perspective of the medicinal chemistry carried out in the design of the most promising structures.

Isolated limb infusion chemotherapy for melanoma: an overview of early experience at the Adelaide Melanoma Unit

BackgroundIsolated limb infusion (ILI) using cytotoxic agents has been demonstrated to be an effective and less invasive alternative modality than isolated limb perfusion for the treatment of melanoma localized to a limb. Percutaneous catheters were inserted into the axial artery and vein of the affected limb while using a pneumatic cuff to restrict limb vascular flow proximally to “isolate” the limb from the body and enable delivery of high-dose intra-arterial chemotherapy selectively to the limb. The ILI technique was developed at the Sydney Melanoma Unit (now renamed the Melanoma Institute Australia), and only a few other centers have reported separate results. We report our early results using the ILI technique for management of locally recurrent surgically nonresectable melanoma.Methods and resultsTwenty-eight ILI procedures were performed in 20 patients treated with one or more procedures between 1997 and 2007. Patient parameters and clinical responses were evaluated. The median follow-up duration was 15.9 months after the first ILI, with an overall response rate after one or more infusions of 70%, of which 35% were complete responders and 35% were partial responders, with a further 20% showing stable disease, giving a “clinically significant” response rate of 90%. After one ILI (n = 20), the overall response rate was 70%, with 20% complete responders and 50% partial responders, and 20% with stable disease. Low limb toxicities were generally observed, and no amputations were required.ConclusionILI chemotherapy is a useful technique, which can be readily repeated for control of melanoma in the limb. It is generally well tolerated, and is capable of achieving a cure, delayed progression, or effective palliation in selected cases. The longest survivors in this series were 8 and 10 years from the last ILI.

Predicting Disease Progression After Regional Therapy for In-Transit Melanoma

Although approximately 30% to 50% of patients experience a complete response after regional chemotherapy for in-transit melanoma, a subset of patients will develop rapidly progressive disease. In the current era of an expanding armamentarium, including both regional and systemic options for treating advanced melanoma, identifying perioperative factors that predict disease progression may obviate unnecessary morbidity associated with regional therapy and avoid delays in systemic therapy. To identify patient-related clinical and pathological variables, as well as procedural factors, that correlate with disease progression. Using a prospectively maintained database, we identified patients who either underwent first-time melphalan-based isolated limb infusion (ILI) or first-time hyperthermic isolated limb perfusion (HILP) for in-transit melanoma. Response was defined using modified Response Evaluation Criteria in Solid Tumors for cutaneous disease at 3 months after treatment. Survival analyses were performed using the Kaplan-Meier method, with the differences in survival curves compared using a log-rank test. Potential preoperative and procedural predictors of in-field progressive disease were analyzed using logistic regression. Of the 258 patients included in the database, 215 were identified as having undergone first-time regional therapy. Of these 215 patients, 134 underwent ILI, and 81 underwent HILP. Regional therapy (ILI or HILP). Complete response or progressive disease. Of 134 patients who underwent ILI, 43 (32.1%) experienced in-field progressive disease. Of 81 patients who underwent HILP, 9 (11.1%) experienced in-field progressive disease. The median survival for patients with in-field progressive disease was 20.3 months for the ILI cohort and 15.0 months for the HILP cohort. In general, patients with progressive disease were younger, with advanced-stage melanoma and increased tumor burden. Compared with patients who experienced a complete response, patients with in-field progressive disease after ILI were younger (odds ratio, 1.06 [95% CI, 0.90-0.98]; P = .002). For patients who underwent HILP, no clinically relevant preoperative predictors of in-field progressive disease were identified. Procedural variables, including chemotherapeutic dosing, degree of acidosis or base deficit achieved, and peak temperature attained, were not predictors of in-field progressive disease after ILI or HILP. Patient, clinical, and procedural factors are unreliable predictors of in-field progressive disease after regional therapy in patients with in-transit melanoma. Defining the potential utility of molecular markers in predicting response or failure of regional therapy should be the focus of future research efforts.

Chemotherapy in the management of advanced cutaneous malignant melanoma

The recent past has witnessed unprecedented clinical progress in the treatment of advanced malignant melanoma through targeting of mutant BRAF in approximately 50% of patients and immune check point blockade in all patients. As has been well documented, responses to targeted therapy are of limited duration, and rates of clinical benefit to immunotherapy are modest. Given these factors, palliation of patients with chemotherapy remains an essential aspect of melanoma oncology. Many chemotherapeutics (and combinations with other agents, such as immunotherapy) have been evaluated in melanoma, although no chemotherapy regimen has been documented to provide an overall survival benefit in a prospective, randomized, well-controlled phase III study. We provide an overview of the development of the most common chemotherapy regimens for melanoma, discuss the clinical trial evidence supporting and contrasting them, and highlight appropriate clinical situations in which they might be used. We also discuss the future of chemotherapy for melanoma, noting the potential for combinations of chemotherapy with either targeted or immunotherapeutic agents.

Targeted chemotherapy of metastatic melanoma: the impact of tumor cell heterogeneity

Evaluation of: Flaherty KT, Infante JR, Daud A et al. Combined BRAF and MEK inhibition in melanoma with BRAF V600 mutations. N. Engl. J. Med. 367(18), 1694–1703 (2012).The treatment of metastatic melanoma with BRAF inhibitors initially gave dramatic results compared with standard chemotherapy with significant progression-free survival times. Unfortunately, within a matter of months, the melanomas become refractory to anti-BRAF-targeted therapy and some patients experience toxicity in the form of primary cutaneous squamous cell carcinomas. While recent reports of dual therapy targeting the MAPK pathway (e.g., dabrafenib and trametinib) show increased response rates and less toxicity, it is not apparent that overall survival has been significantly impacted. While targeted therapy has significantly altered the management of melanoma, novel approaches and strategies will likely have to be employed to counter melanoma cell heterogeneity and the selection of resistant clones.

Safety and efficacy of decitabine in combination with temozolomide in metastatic melanoma: a phase I/II study and pharmacokinetic analysis

BackgroundTemozolomide (TMZ) is widely used for chemotherapy of metastatic melanoma. We hypothesized that epigenetic modulators will reverse chemotherapy resistance, and in this article, we report studies that sought to determine the recommended phase 2 dose (RP2D), safety, and efficacy of decitabine (DAC) combined with TMZ. Patients and methodsIn phase I, DAC was given at two dose levels: 0.075 and 0.15 mg/kg intravenously daily × 5 days/week for 2 weeks, TMZ orally 75 mg/m2 qd for weeks 2–5 of a 6-week cycle. The phase II portion used a two-stage Simon design with a primary end point of objective response rate (ORR). ResultsThe RP2D is DAC 0.15 mg/kg and TMZ 75 mg/m2. The phase II portion enrolled 35 patients, 88% had M1c disease; 42% had history of brain metastases. The best responses were 2 complete response (CR), 4 partial response (PR), 14 stable disease (SD), and 13 progressive disease (PD); 18% ORR and 61% clinical benefit rate (CR + PR + SD). The median overall survival (OS) was 12.4 months; the 1-year OS rate was 56%. Grade 3/4 neutropenia was common but lasted >7 days in six patients. ConclusionsThe combination of DAC and TMZ is safe, leads to 18% ORR and 12.4-month median OS, suggesting possible superiority over the historical 1-year OS rate, and warrants further evaluation in a randomized setting.

Similar efficacy for phase I trials in comparison with DTIC for advanced malignant melanoma

After ipilimumab, vemurafenib, and interleukin-2, standard of care chemotherapy for melanoma remains dacarbazine (response rate ∼9%). Despite this, many physicians hesitate to refer patients to phase I protocols given a perceived lack of clinical benefit and potential for harm. To better understand the validity of these perceptions, the experience of all patients with melanoma treated on phase I trials sponsored by the National Cancer Institute-Cancer Therapy Evaluation Program (NCI-CTEP) from 1995 to 2011 were analyzed and compared with the pooled results of six contemporary phase III trials of dacarbazine. A total of 937 patients with melanoma were treated in 148 CTEP phase I trials. The majority were men with a median of two prior therapies (46% receiving prior dacarbazine). Response and clinical benefit rates in these trials were not clinically different from those of dacarbazine (phase I: 6.3 and 26.8% vs. dacarbazine: 8.8 and 27.9%) although grades 3 and 4 toxicity was significantly higher (54 vs. 28%). Efficacy and toxicity were generally consistent within phase I subgroups (targeted agents, immunotherapies, or chemotherapeutics) though targeted therapy was associated with a lower response rate, immunotherapy with lower clinical benefit rate, and chemotherapy with higher incidence of grade 4 toxicity. Thus, the perception of limited efficacy of phase I trials for patients with melanoma was disproven, whereas the perception of toxicity was observed. However, this difference in toxicity may have been largely because of the nature of phase I vs. phase III trials (i.e. more heavily pretreated) and because of the phase I trials often being multiagent as opposed to dacarbazine alone.

Immunohistochemical analysis of O6-methylguanine-DNA methyltransferase in human melanoma in comparison with skin squamous cell carcinoma

Alkylating agents, often used for chemotherapy in patients with melanoma, can produce O(6)-alkylguanine (O(6)AG) which is related to tumor cell killing after treatment with alkylating agents. O(6)AG is effectively eliminated by O(6)-methylguanine-DNA methyltransferase (O(6)MGMT) and its level is correlative to the resistance to alkylating agents. However, little is known about the relationship of O(6)MGMT to the characteristics of melanoma. This study investigated the expression of O(6)MGMT in 12 melanomas and compared it with that in 11 skin squamous cell cancers (SCCs) immunohistochemically to evaluate the O(6)MGMT activity in melanoma and its clinical significance. All of the SCC samples had high O(6)MGMT expression, while the expression of O(6)MGMT in melanoma was diverse and 4 out of 12 samples had no or extremely low O(6)MGMT activity. Out of 6 lesions obtained from metastasis, 4 had a high O(6)MGMT activity. Two out of 3 cases with a low O(6)MGMT activity in each primary lesion did not show any evidence of metastasis or local recurrence. The evaluation of O(6)MGMT activity in melanoma may, therefore, be useful to determine the characteristics of tumor in each melanoma case. In addition, the present study implies the possibility of selective cancer chemotherapy for melanoma in the near future.

Tremelimumab: A Review of Development to Date in Solid Tumors

Tremelimumab is an investigational, fully human IgG monoclonal antibody directed against CTLA-4, a coinhibitory receptor that represses effector T-cell activity in cancer. Tremelimumab has produced promising anticancer responses in early clinical trials. However, a phase III trial of tremelimumab monotherapy versus chemotherapy in advanced melanoma was stopped early when no statistically significant difference in overall survival was observed between the two interventions. This article describes tremelimumab's putative mechanism of action, its preclinical pharmacology and clinical results to date across a range of cancer settings as monotherapy, as well as in combination with other therapies. The failure of the Phase III trial in melanoma is examined and factors affecting the possible future clinical development of tremelimumab are also explored.

Targeting Brain Metastases in Patients with Melanoma

Patients with brain metastases from malignant melanoma historically have a very poor outcome. Surgery and radiotherapy can be used, but for the majority of patients the disease will progress quickly. In the recent past, patients with brain metastases derived only minimal benefit from cytotoxic chemotherapy. Novel therapies that have been shown to be superior to chemotherapy in metastatic melanoma have made their way in clinic and data regarding their use in patients with treated or untreated brain metastases are encouraging. In this paper we describe the use of vemurafenib, dabrafenib, and ipilimumab in patients with melanoma disseminated to the brain in addition to other treatments currently in development.

Isolated limb hyperthermic perfusion chemotherapy for melanoma of the extremities

To investigate the effect of isolated limb hyperthermic perfusion chemotherapy for melanoma of the extremities. Limb isolated hyperthermic perfusion chemotherapy was performed in 41 patients with malignant melanoma of the extremities, and then the primary lesions in 24 patients were removed at 14 - 21 days after chemotherapy. Tumor necrosis was examined by pathology. Among the 41 patients, 40 cases were followed up for 6-113 months, and one was lost. There was no local recurrence in those patients. 29 cases were followed up for more than 3 years, and 26 of them were surviving. Forteen cases were followed up for more than five years, among them 9 cases were surviving. The 3-year and 5-year survival rates of the whole group were 95.0% and 70.0%, respectively. The average reduction of the tumor volume was 55.6% after perfusion. The pathological examination showed that tumor necrosis was 90% - 100% (complete response) in 21 cases (87.5%) and 60% - 89% (partial response) in 3 cases (12.5%). The isolated limb hyperthermic perfusion chemotherapy is an effective treatment of limb malignant melanoma. It can significantly reduce the local recurrence rate, and improve the 5-year survival rate, prognosis and the quality of life of the patients.

Oncology in 2012: from personalized medicine to precision medicine

Although oncologists seem unable to name the new paradigm of cancer treatment, a certain trend seems to take shape in favor of the precision medicine. To paraphrase Mickael P. Link, President of the American Society of Clinical Oncology, precision medicine identifies and makes the most of the weaknesses of cancer genetics so that the tumoral growth can be stopped. Doubtless, major advances in this oncologic medicine of precision have been observed throughout 2012. These advances have first of all affected the theranostics. This is how two new oncogenic drivers were discovered in lung adenocarcinoma. The first one ROS1 is situated in 6q. 22 chromosome. ROS1 is observed in 1 % of the cases and would seem to be sensitive to the anaplastic lymphoma kinase (ALK) and C-MET inhibitors [1]. Kinase inhibitor fusion 5B—rearranged during transfection [1], the second, is observed in 1.3 % of non-small cell lung cancer (NSCLC). Two aspects of these discoveries are important to underline because there are agents targeting these molecular modifications (crizotinib and a tyrosine kinase inhibitor anti-RET) and also because these molecular targets exist in other tumoral types: glioblastoma or cholangiocarcinoma for ROS1. In addition to this progress in theranostics, numerous advances have concerned new, soon-to-be-available agents in oncology practice. This is the way crizonitinb, a powerful inhibitor of ALK tyrosine kinase receptor [2], demonstrates its efficacy in the ALK-positive NSCLC previously treated with first-line platinum-based chemotherapy. This treatment is superior to standard second-line chemotherapy with a striking hazard ratio (HR) of 0.49 [3]. Regorafenib [4] offers a new therapeutic option in metastatic colorectal cancers in second-line treatment and in GIST. Cabozantinib, a new potent inhibitor of VEGFR and MET and VEGFr2 [5], shows promise in several tumor types, such as prostate, breast, and hepatocarcinoma. Dabrafenib, a new anti-RAF agent can achieve an HR of 0.35 for progression-free survival in patients with metastatic melanoma [6]. MEK blockade is one of the last novelties in signaling. Take the example of trametinib, which compares favorably to chemotherapy in metastatic melanoma (HR0 0.54 (0.32–0.92)) [7]. Signaling pathways are not the only process that is “targetable.” Immunotherapeutics is currently regaining its former glory. The stimulation of the immune system against tumors through targeting regulatory T cells is taking shape. It is now evident that monoclonal antibodies directed against cytotoxic T lymphocyte antigen 4 or programmed cell death 1 represent dramatic progress in the management of melanoma [8]. Thanks to new agents, there is even more hope for our patients:

1392P - Increased Incidence of Renal Cell Carcinoma (RCC) Among Melanoma Patients

ABSTRACT Purpose There is scant evidence for an increased risk for developing RCC among melanoma patients (pts), and evidence for possible risk factors for the association between melanoma and RCC is lacking. We examined the risk of developing both melanoma and RCC, and also the possible risk factors. Methods We searched our institutional tumor registry for pts with a diagnosis of melanoma and RCC. We used summary statistics to describe the population of pts and calculate total person-years at risk for RCC. We computed standardized incidence ratios (SIRs), which is the ratio of the observed to the expected number of pts with RCC among pts with melanoma using the Cohort Analysis for Genetic Epidemiology program. The expected number of pts with RCC was determined from SEER data. The 95% confidence intervals (CI) for the SIRs were determined by assuming a Poisson distribution for the observed number of RCC. SIRs were also calculated for subsets of the data according to race and gender. Results Between 1980 and 2005, we identified 15,482 pts with a diagnosis of melanoma: 59% were male and 94% were white. Among these pts, 114 (0.7%) pts had a diagnosis of RCC either before or after the diagnosis of melanoma. The mean age of RCC presentation was 59.4 years. The total person-years at risk for RCC were 886,506. We observed a significant excess of RCC (SIR = 1.64, 95% CI = 1.37-1.95) among our cohort of melanoma pts. This excess of RCC was also significant among white pts (SIR = 1.64, 95% CI = 1.36-1.92) and among both genders. None of the 114 pts with a diagnosis of both melanoma and RCC had a concomitant diagnosis of immunocompromised disease nor received chronic immunosuppressive drugs. Only 17% of the pts received radiation or chemotherapy for melanoma. Conclusions There is an increase risk of RCC among melanoma pts. Neither preexisting immunocompromised condition nor the chronic use of immunosuppressants were risk factors for developing both malignancies. Group Observed Expected SIR (95% CI) for development of RCC All (n = 15482) 114 69.53 1.64 (1.37-1.95) Gender M (n = 9072) F (n = 6410) 81 33 54.85 14.67 1.48 (1.19-1.82) 2.25 (1.61-3.08) Ethnicity White (n = 14580) Non-White (n = 902) 109 5 66.37 3.15 1.64 (1.36-1.96) 1.59 (0.70-3.25) Disclosure All authors have declared no conflicts of interest.

Bevacizumab-Induced Alterations in Vascular Permeability and Drug Delivery: A Novel Approach to Augment Regional Chemotherapy for In-Transit Melanoma

To investigate whether the systemically administered anti-VEGF monoclonal antibody bevacizumab could improve regional chemotherapy treatment of advanced extremity melanoma by enhancing delivery and tumor uptake of regionally infused melphalan (LPAM). After treatment with systemic bevacizumab or saline, changes in vascular permeability were determined by spectrophotometric analysis of tumors infused with Evan's blue dye. Changes in vascular structure and tumor hemoglobin-oxygen saturation HbO(2) were determined by intravital microscopy and diffuse reflectance spectroscopy, respectively. Rats bearing the low-VEGF secreting DM738 and the high-VEGF secreting DM443 melanoma xenografts underwent isolated limb infusion (ILI) with melphalan (LPAM) or saline via the femoral vessels. The effect of bevacizumab on terminal drug delivery was determined by immunohistochemical analysis of LPAM-DNA adducts in tumor tissues. Single-dose bevacizumab given three days before ILI with LPAM significantly decreased vascular permeability (50.3% in DM443, P < 0.01 and 35% in DM738, P < 0.01) and interstitial fluid pressure (57% in DM443, P < 0.01 and 50% in DM738, P = 0.01). HbO(2) decreased from baseline in mice following treatment with bevacizumab. Systemic bevacizumab significantly enhanced tumor response to ILI with LPAM in two melanoma xenografts, DM443 and DM738, increasing quadrupling time 37% and 113%, respectively (P = 0.03). Immunohistochemical analyses of tumor specimens showed that pretreatment with systemic bevacizumab markedly increased LPAM-DNA adduct formation. Systemic treatment with bevacizumab before regional chemotherapy increases delivery of LPAM to tumor cells and represents a novel way to augment response to regional therapy for advanced extremity melanoma.

P2.17 Proteomics and Gene Expression Profiling of Melanoma Chemotherapy Response in Tumors

ABSTRACT Efficient means to overcome chemotherapy resistance in melanoma and clinically useful tools to predict the response are lacking. We have performed proteomics and microarray gene expression profiling of pre-treatment metastases from melanoma patients with different response to DNA alkylating agents dacarbazine (DTIC) or temozolomide (TMZ). Functional categories identified by both gene expression and proteomics profiling include regulation of the cell cycle, cell death, developmental processes, transcription, transport functions, immune system processes and several cell signaling pathways. Twelve candidates were identified in both analyses. In a second independent study, gene expression was analyzed in pre- and post-treatment biopsies from the same patients, and genes that were upregulated after DTIC/TMZ treatment in metastases from non-responders were identified. Five of these genes had also been identified as resistance candidates in the first studies. Many of the same biological pathways were also identified, including “actin cytoskeleton signaling”which is among the top significantly overrepresented functional categories in all studies. Several candidates have been validated in an extended set of tumor biopsies from melanoma patients with different response to DTIC/TMZ. We have also performed in vitro studies using different melanoma cell lines and tested if siRNA inhibition of selected candidates can affect chemosensitivity.