Dabrafenib and trametinib versus dabrafenib and placebo for Val600 BRAF-mutant melanoma: a multicentre, double-blind, phase 3 randomised controlled trial

Open-label, multicentre safety study of vemurafenib in 3219 patients with BRAFV600 mutation-positive metastatic melanoma: 2-year follow-up data and long-term responders' analysis

BACKGROUND

The orally available BRAF kinase inhibitor vemurafenib is an effective and tolerable treatment option for patients with metastatic melanoma harbouring BRAF^V600 mutations. We assessed the safety of vemurafenib in a large population of patients with few alternative treatment options; we report updated 2-year safety.

METHODS

This was an open-label, multicentre study of vemurafenib (960 mg bid) in patients with previously treated or untreated BRAF mutation-positive metastatic melanoma (cobas^® 4800 BRAF V600 Mutation Test). The primary end-point was safety; efficacy end-points were secondary. An exploratory analysis was performed to assess safety outcomes in patients with long duration of response (DOR) (≥12 or ≥24 months).

RESULTS

After a median follow-up of 32.2 months (95% CI, 31.1-33.2 months), 3079/3219 patients (96%) had discontinued treatment. Adverse events (AEs) were largely consistent with previous reports; the most common all-grade treatment-related AEs were arthralgia (37%), alopecia (25%) and hyperkeratosis (23%); the most common grade 3/4 treatment-related AEs were squamous cell carcinoma of the skin (8%) and keratoacanthoma (8%). In the exploratory analysis, patients with DOR ≥12 months (n = 287) or ≥24 months (n = 133) were more likely to experience grade 3/4 AEs than the overall population. No new specific safety signals were observed with longer vemurafenib exposure.

CONCLUSIONS

After 2 years' follow-up, safety was maintained in this large group of patients with BRAF^V600 mutation-positive metastatic melanoma who are more representative of routine clinical practice than typical clinical trial populations. These data suggest that long-term vemurafenib treatment is effective and tolerable without the development of new safety signals.

Successful retreatment with combined BRAF/MEK inhibition in metastatic BRAFV600-mutated melanoma

BACKGROUND

The combination treatment with BRAF and MEK inhibitors is amongst the current standard of care for stage IIIC/IV BRAF-mutated melanoma. However, therapeutic options are limited once patients have progressed upon both targeted and immunotherapy.

OBJECTIVE

To investigate whether retreatment with BRAF and MEK inhibitor combination is an option for patients with metastatic BRAF-mutated melanoma upon previous progression on kinase inhibitors.

METHODS

Two patients with metastatic BRAF-mutated melanoma were rechallenged with BRAF and MEK inhibitor combination after progression on targeted therapy and subsequent immunotherapy with anti-CTLA-4 and anti-PD-1 antibodies.

RESULTS

Both patients responded to retreatment. Responses were limited to a few months and associated with a considerable increase in quality of life.

CONCLUSION

Retreatment with BRAF and MEK inhibitors may present a feasible treatment option upon progression on both kinase inhibitors and immunotherapy, and should be considered when all other treatment options have been exhausted.

A systematic review and network meta-analysis of immunotherapy and targeted therapy for advanced melanoma

Immune and BRAF‐targeted therapies have changed the therapeutic scenario of advanced melanoma, turning the clinical decision‐making a challenging task. This Bayesian network meta‐analysis assesses the role of immunotherapies and targeted therapies for advanced melanoma. We retrieved randomized controlled trials testing immune, BRAF‐ or MEK‐targeted therapies for advanced melanoma from electronic databases. A Bayesian network model compared therapies using hazard ratio (HR) for overall survival (OS), progression‐free survival (PFS), and odds ratio (OR) for response rate (RR), along with 95% credible intervals (95% CrI), and probabilities of drugs outperforming others. We assessed the impact of PD‐L1 expression on immunotherapy efficacy. Sixteen studies evaluating eight therapies in 6849 patients were analyzed. For OS, BRAF‐MEK combination and PD‐1 single agent ranked similarly and outperformed all other treatments. For PFS, BRAF‐MEK combination surpassed all other options, including CTLA‐4‐PD‐1 dual blockade hazard ratio (HR: 0.56; 95% CrI: 0.33–0.97; probability better 96.2%), whereas BRAF single agent ranked close to CTLA‐4‐PD‐1 blockade. For RR, BRAF‐MEK combination was superior to all treatments including CTLA‐4‐PD‐1 (OR: 2.78; 1.18–6.30; probability better 97.1%). No OS data were available for CTLA‐4‐PD‐1 blockade at the time of systematic review, although PFS and RR results suggested that this combination could also bring meaningful benefit. PD‐L1 expression, as presently defined, failed to inform patient selection to PD‐1‐based immunotherapy. BRAF‐MEK combination seemed an optimal therapy for BRAF‐mutated patients, whereas PD‐1 inhibitors seemed optimal for BRAF wild‐type patients. Longer follow‐up is needed to ascertain the role of CTLA‐4‐PD‐1 blockade. Immunotherapy biomarkers remain as an unmet need.

The role for chemotherapy in the modern management of melanoma

The treatment of malignant melanoma has changed beyond recognition in the last 7 years. Where previously single agent dacarbazine was often the only treatment used for advanced disease, now there are potentially multiple lines of treatment, based on immunotherapy and targeted treatment options, either as monotherapy or in combination. In this brave new world the question arises, does chemotherapy still have any relevance in the modern management of melanoma? In this review, we summarize the various chemotherapeutic options that have been trialled in melanoma to date, and discuss the role chemotherapy may still play in treating melanoma, potentially in combination with more novel agents, or in certain subtypes of melanoma.

Cell cycle-tailored targeting of metastatic melanoma: Challenges and opportunities

The advent of targeted therapies of metastatic melanoma, such as MAPK pathway inhibitors and immune checkpoint antagonists, has turned dermato-oncology from the "bad guy" to the "poster child" in oncology. Current targeted therapies are effective, although here is a clear need to develop combination therapies to delay the onset of resistance. Many antimelanoma drugs impact on the cell cycle but are also dependent on certain cell cycle phases resulting in cell cycle phase-specific drug insensitivity. Here, we raise the question: Have combination trials been abandoned prematurely as ineffective possibly only because drug scheduling was not optimized? Firstly, if both drugs of a combination hit targets in the same melanoma cell, cell cycle-mediated drug insensitivity should be taken into account when planning combination therapies, timing of dosing schedules and choice of drug therapies in solid tumors. Secondly, if the combination is designed to target different tumor cell subpopulations of a heterogeneous tumor, one drug effective in a particular subpopulation should not negatively impact on the other drug targeting another subpopulation. In addition to the role of cell cycle stage and progression on standard chemotherapeutics and targeted drugs, we discuss the utilization of cell cycle checkpoint control defects to enhance chemotherapeutic responses or as targets themselves. We propose that cell cycle-tailored targeting of metastatic melanoma could further improve therapy outcomes and that our real-time cell cycle imaging 3D melanoma spheroid model could be utilized as a tool to measure and design drug scheduling approaches.

A phase I dose-escalation study of Selumetinib in combination with Erlotinib or Temsirolimus in patients with advanced solid tumors

Background Combinations of molecularly targeted agents may provide optimal anti-tumor activity and improve clinical outcomes for patients with advanced cancers. Selumetinib (AZD6244, ARRY-142886) is an oral, potent and highly selective, allosteric inhibitor of MEK1/2, a component of the RAS/RAF/MEK/ERK pathway which is constitutively activated in many cancers. We investigated the safety, tolerability, and pharmacokinetics (PK) of selumetinib in combination with molecularly targeted drugs erlotinib or temsirolimus in patients with advanced solid tumors. Methods Two-part study: dose escalation, to determine the maximum tolerated dose (MTD) of selumetinib in combination with erlotinib 100 mg once daily (QD) or temsirolimus 25 mg once weekly, followed by dose expansion at the respective combination MTDs to further investigate safety and anti-tumor effects. Results 48 patients received selumetinib plus erlotinib and 32 patients received selumetinib plus temsirolimus. The MTD with erlotinib 100 mg QD was selumetinib 100 mg QD, with diarrhea being dose limiting. The most common all grade adverse events (AEs): diarrhea, rash, nausea, and fatigue. Four (8.3%) patients had ≥12 weeks stable disease. The MTD with temsirolimus 25 mg once weekly was selumetinib 50 mg twice daily (BID), with mucositis and neutropenia being dose limiting. The most commonly reported AEs: nausea, fatigue, diarrhea, and mucositis. Ten (31.3%) patients had ≥12 weeks stable disease. The combination PK profiles were comparable to previously observed monotherapy profiles. Conclusions MTDs were established for selumetinib in combination with erlotinib or temsirolimus. Overlapping toxicities prevented the escalation of selumetinib to its recommended phase II monotherapy dose of 75 mg BID.

TRIAL REGISTRATION

ClinicalTrials.gov NCT00600496; registered 8 July 2009.

Baseline β-catenin, programmed death-ligand 1 expression and tumour-infiltrating lymphocytes predict response and poor prognosis in BRAF inhibitor-treated melanoma patients

BACKGROUND

The activation of oncogenic Wnt/β-catenin pathway in melanoma contributes to a lack of T-cell infiltration. Whether baseline β-catenin expression in the context of tumour-infiltrating lymphocytes (TILs) and programmed death ligand-1 (PD-L1) overexpression correlates with prognosis of metastatic melanoma patients (MMPs) treated with mitogen-activated protein kinase, MAPK inhibitor (MAPKi) monotherapy, however, has not been fully clarified.

PATIENTS AND METHODS

Sixty-four pre-treatment formalin-fixed and paraffin embedded melanoma samples from MMP treated with a BRAF inhibitor (n = 39) or BRAF and MEK inhibitors (n = 25) were assessed for presence of β-catenin, PD-L1, cluster of differentiation (CD)8, CD103 and forkhead box protein P3 (FOXP3) expression by immunohistochemistry, and results were correlated with clinical outcome. Quantitative assessment of mRNA transcripts associated with Wnt/β-catenin pathway and immune response was performed in 51 patients.

RESULTS

We found an inverse correlation between tumoural β-catenin expression and the level of CD8, CD103 or forkhead box protein P3 (FOXP3) positivity in the tumour microenvironment (TME). By multivariate analysis, PD-L1 <5% (odds ratio, OR 0.12, 95% confidence interval, CI 0.03-0.53, p = 0.005) and the presence of CD8+ T cells (OR 18.27, 95%CI 2.54-131.52, p = 0.004) were significantly associated with a higher probability of response to MAPKi monotherapy. Responding patients showed a significantly increased expression of mRNA transcripts associated with adaptive immunity and antigen presentation. By multivariate analysis, progression-free survival (PFS) (hazards ratio (HR) = 0.25 95%CI 0.10-0.61, p = 0.002) and overall survival (OS) (HR = 0.24 95%CI 0.09-0.67, p = 0.006) were longer in patients with high density of CD8+ T cells and β-catenin <10% than those without CD8+ T cells infiltration and β-catenin ≥10%.

CONCLUSION

Our findings provide evidence that in the context of MAPKi monotherapy, immune subsets in the (TME) and gene signature predict prognosis in MMPs.

Impact of BRAF kinase inhibitors on the miRNomes and transcriptomes of melanoma cells

BACKGROUND

Melanoma is an aggressive skin cancer with increasing incidence worldwide. The development of BRAF kinase inhibitors as targeted treatments for patients with BRAF-mutant tumours contributed profoundly to an improved overall survival of patients with metastatic melanoma. Despite these promising results, the emergence of rapid resistance to targeted therapy remains a serious clinical issue.

METHODS

To investigate the impact of BRAF inhibitors on miRNomes and transcriptomes, we used in vitro melanoma models consisting of BRAF inhibitor-sensitive and -resistant cell lines generated in our laboratory. Subsequently, microarray analyses were performed followed by RT-qPCR validations.

RESULTS

Regarding miRNome and transcriptome changes, the long-term effects of BRAF inhibition differed in a cell line-specific manner with the two different BRAF inhibitors inducing comparable responses in three melanoma cell lines. Despite this heterogeneity, several miRNAs (e.g. miR-92a-1-5p, miR-708-5p) and genes (e.g. DOK5, PCSK2) were distinctly differentially expressed in drug-resistant versus -sensitive cell lines. Analyses of coexpressed miRNAs, as well as inversely correlated miRNA-mRNA pairs, revealed a low MITF/AXL ratio in two drug-resistant cell lines that might be regulated by miRNAs.

CONCLUSION

Several genes and miRNAs were differentially regulated in the drug-resistant and -sensitive cell lines and might be considered as prognostic and/or diagnostic resistance biomarkers in melanoma drug resistance.

GENERAL SIGNIFICANCE

Thus far, only little information is available on the significance and role of miRNAs with respect to kinase inhibitor treatments and emergence of drug resistance. In this study, promising miRNAs and genes were identified and associated to BRAF inhibitor-mediated resistance in melanoma. This article is part of a Special Issue entitled "Biochemistry of Synthetic Biology - Recent Developments" Guest Editor: Dr. Ilka Heinemann and Dr. Patrick O'Donoghue.

Targeted agents and immunotherapies: optimizing outcomes in melanoma

Treatment options for patients with metastatic melanoma, and especially BRAF-mutant melanoma, have changed dramatically in the past 5 years, with the FDA approval of eight new therapeutic agents. During this period, the treatment paradigm for BRAF-mutant disease has evolved rapidly: the standard-of-care BRAF-targeted approach has shifted from single-agent BRAF inhibition to combination therapy with a BRAF and a MEK inhibitor. Concurrently, immunotherapy has transitioned from cytokine-based treatment to antibody-mediated blockade of the cytotoxic T-lymphocyte-associated antigen-4 (CTLA-4) and, now, the programmed cell-death protein 1 (PD-1) immune checkpoints. These changes in the treatment landscape have dramatically improved patient outcomes, with the median overall survival of patients with advanced-stage melanoma increasing from approximately 9 months before 2011 to at least 2 years - and probably longer for those with BRAF-V600-mutant disease. Herein, we review the clinical trial data that established the standard-of-care treatment approaches for advanced-stage melanoma. Mechanisms of resistance and biomarkers of response to BRAF-targeted treatments and immunotherapies are discussed, and the contrasting clinical benefits and limitations of these therapies are explored. We summarize the state of the field and outline a rational approach to frontline-treatment selection for each individual patient with BRAF-mutant melanoma.

A murine preclinical syngeneic transplantation model for breast cancer precision medicine

We previously demonstrated that altered activity of lysophosphatidic acid in murine mammary glands promotes tumorigenesis. We have now established and characterized a heterogeneous collection of mouse-derived syngeneic transplants (MDSTs) as preclinical platforms for the assessment of personalized pharmacological therapies. Detailed molecular and phenotypic analyses revealed that MDSTs are the most heterogeneous group of genetically engineered mouse models (GEMMs) of breast cancer yet observed. Response of MDSTs to trametinib, a mitogen-activated protein kinase (MAPK) kinase inhibitor, correlated with RAS/MAPK signaling activity, as expected from studies in xenografts and clinical trials providing validation of the utility of the model. Sensitivity of MDSTs to talazoparib, a poly(adenosine 5'-diphosphate-ribose) polymerase (PARP) inhibitor, was predicted by PARP1 protein levels and by a new PARP sensitivity predictor (PSP) score developed from integrated analysis of drug sensitivity data of human cell lines. PSP score-based classification of The Cancer Genome Atlas breast cancer suggested that a subset of patients with limited therapeutic options would be expected to benefit from PARP-targeted drugs. These results indicate that MDSTs are useful models for studies of targeted therapies, and propose novel potential biomarkers for identification of breast cancer patients likely to benefit from personalized pharmacological treatments.

Cost-Effectiveness Analysis of a Skin Awareness Intervention for Early Detection of Skin Cancer Targeting Men Older Than 50 Years

OBJECTIVES

To assess the cost-effectiveness of an educational intervention encouraging self-skin examinations for early detection of skin cancers among men older than 50 years.

METHODS

A lifetime Markov model was constructed to combine data from the Skin Awareness Trial and other published sources. The model incorporated a health system perspective and the cost and health outcomes for melanoma, squamous and basal cell carcinomas, and benign skin lesions. Key model outcomes included Australian costs (2015), quality-adjusted life-years (QALYs), life-years, and counts of skin cancers. Univariate and probabilistic sensitivity analyses were undertaken to address parameter uncertainty.

RESULTS

The mean cost of the intervention was A$5,298 compared with A$4,684 for usual care, whereas mean QALYs were 7.58 for the intervention group and 7.77 for the usual care group. The intervention was thus inferior to usual care. When only survival gain is considered, the model predicted the intervention would cost A$1,059 per life-year saved. The likelihood that the intervention was cost-effective up to A$50,000 per QALY gained was 43.9%. The model was stable to most data estimates; nevertheless, it relies on the specificity of clinical diagnosis of skin cancers and is subject to limited health utility data for people with skin lesions.

CONCLUSIONS

Although the intervention improved skin checking behaviors and encouraged men to seek medical advice about suspicious lesions, the overall costs and effects from also detecting more squamous and basal cell carcinomas and benign lesions outweighed the positive health gains from detecting more thin melanomas.

The undifferentiated carcinoma that became a melanoma: Re-biopsy of a cancer of an unknown primary site: a case report

BACKGROUND

Cancer of unknown primary site is still a demanding condition as it is per definition metastatic, with heterogeneous biological behavior, and it is often resistant to therapy. Cancer of unknown primary site accounts for approximately 1 to 5 % of all cancers, but is currently among the top six causes of cancer deaths in Western countries. To correctly identify the biological origin of the tumor, a large spectrum of differential diagnoses must be considered and scrutinized. At progression, re-biopsy might be necessary to reveal the true origin of the tumor or actionable targets.

CASE PRESENTATION

A 62-year-old Norwegian woman, with a fast growing lump in her left groin, was primarily diagnosed as having undifferentiated carcinoma that was BRAF V600 positive. There was complete response with paclitaxel-carboplatin and she was recurrence-free for 18 months. She had recurrence in both lungs and subcutaneously in her left groin and thigh; a re-biopsy revealed transformation to a malignant melanoma. She was resistant to BRAF inhibitors, then treated with ipilimumab and is currently a long-term survivor of 4 years and 4 months since the first diagnosis, with no clinical or radiological evidence of recurrence.

CONCLUSIONS

A biopsy from patients with metastasis of unknown primary should be analyzed thoroughly to identify organ of origin, molecular make-up, and possible molecular targets. Re-biopsy of cancer of unknown primary site at progression can reveal the true cellular origin of the tumor as well as provide novel therapeutic opportunities, including immunotherapy.

Can binimetinib, encorafenib and masitinib be more efficacious than currently available mutation-based targeted therapies for melanoma treatment?

INTRODUCTION

Historically, there were few effective and durable treatments for metastatic melanoma. Recently, mutation based targeted therapies have revolutionized treatment and outcomes for patients with metastatic melanoma. Specifically, inhibitors aimed at BRAF, NRAS, and C-KIT mutations are now commonly used in treatment for patients harboring the specific mutations. Areas covered: A brief review of current BRAF, NRAS, and C-KIT inhibitors provides background for a thorough review of newly developed agents namely binimetinib, a MEK inhibitor, encorafenib a BRAF inhibitor, and masitinib which inhibits C-KIT. Expert opinion: While the 3 novel agents reviewed here have potential for use in melanoma, optimal utilization will occur once a more personalized approach incorporating genomic, proteomic, and immunologic data guides therapeutic decisions.

Panniculitis Associated with MEK Inhibitor Therapy: An Uncommon Adverse Effect

The combination of MEK inhibitor (cobimetinib, trametinib) and BRAF inhibitor (vemurafenib, dabrafenib) is now the first-line treatment in patients with BRAF V600-mutated metastatic melanoma. This association reduces cutaneous adverse events induced by BRAF inhibitors alone, including photosensitivity, hand-foot syndrome, hyperkeratosis, alopecia, skin papillomas, keratoacanthomas, and squamous-cell carcinomas. While panniculitis has exceptionally been reported with BRAF inhibitors, this rare side effect has never been described with the use of MEK inhibitors. We present here the first observation of panniculitis strictly induced by MEK inhibitors. Indeed, 10 days after the initiation of combined treatment with cobimetinib and vemurafenib for metastatic melanoma, our patient developed panniculitis predominantly on the upper and lower extremities. These cutaneous nodules disappeared during cobimetinib intermissions and recurred while the molecule was resumed. Recurrence of cutaneous nodules was observed after initiation of trametinib combined with dabrafenib, and resolved once again with trametinib discontinuation. We believe that clinicians should be aware of this cutaneous adverse event in patients treated with combined therapy, which can lead to unfounded BRAF inhibitor treatment discontinuation and compromise the antitumor response. Our case suggests a class effect linked with the MEK inhibition pharmacodynamic activity. Finally, laboratory investigation and histopathological examination are mandatory to exclude other panniculitis etiologies and subcutaneous metastasis of melanoma.

Combination of dabrafenib plus trametinib for BRAF and MEK inhibitor pretreated patients with advanced BRAFV600-mutant melanoma: an open-label, single arm, dual-centre, phase 2 clinical trial

BACKGROUND

Patients with BRAF^V600-mutant melanoma benefit from treatment with the combination of BRAF and MEK inhibitors, but resistance and disease progression develops in most patients. Preclinical studies and case studies have indicated that acquired resistance to BRAF inhibition can be reversible. We aimed to assess the anti-tumour activity of rechallenge with BRAF plus MEK inhibition in a prospective clinical trial.

METHODS

In this open-label, single arm, dual-centre, phase 2 academic study in Belgium, patients aged 18 years or older with BRAF^V600-mutant melanoma who had previously progressed on BRAF inhibitors (with or without MEK inhibitors) and were off-treatment for at least 12 weeks, were treated with dabrafenib 150 mg orally twice per day plus trametinib 2 mg orally once per day. The primary endpoint was the proportion of patients with investigator-assessed overall response at any time (defined as complete response or partial response according to Response Evaluation Criteria in Solid Tumors (RECIST) version 1.1 confirmed on two occasions, at least 28 days after the first response was recorded). Analyses were done in the intention-to-treat population. The study is ongoing but no longer recruiting patients. This trial is registered with ClinicalTrials.gov, number NCT02296996.

FINDINGS

Between April 5, 2014, and Feb 2, 2016, 25 patients were enrolled and initiated treatment in our study. A partial response was documented in eight (32%) of 25 patients (95% CI 15-54; six patients had progressed on previous treatment with dabrafenib plus trametinib and two patients had progressed on previous BRAF inhibitor monotherapy). Stable disease was noted in ten patients (40%; 95% CI 21-61). Rechallenge with dabrafenib plus trametinib was well tolerated. There were no unexpected or grade 4 or 5 treatment-related adverse events. Grade 3 adverse events occurred in two patients (8%; panniculitis [n=1] and pyrexia [n=1]). Serious adverse events which occurred on study were one patient with an Addison crisis triggered by grade 2 pyrexia symptoms that resolved after discontinuation of dabrafenib and trametinib. No patients died as a result of study treatment.

INTERPRETATION

Rechallenge with dabrafenib plus trametinib showed anti-tumour activity in patients who had previously progressed on BRAF inhibitors and as such, rechallenge represents a potential new treatment option for these patients.

FUNDING

Vlaamse Liga Tegen Kanker, Novartis.

Improvement of overall survival in stage IV melanoma patients during 2011-2014: analysis of real-world data in 441 patients of the German Central Malignant Melanoma Registry (CMMR)

BACKGROUND

During 2011 and 2014, new treatment modalities like tyrosine kinase inhibitors and checkpoint inhibitors were introduced into the therapy of metastatic melanoma. This study addresses the question whether overall survival (OS) of metastatic melanoma patients has already been improved in 441 patients diagnosed with metastatic melanoma between 2011 and 2014 in the real-world setting at the University Hospital Tuebingen.

METHODS

All patients were documented with their different therapies by the CMMR and followed up until March 2016. Survival probabilities were calculated by Kaplan-Meier estimators, and log-rank tests were used to evaluate significances. Hazard ratios were estimated by Cox regression analysis for survival probabilities and prognostic factors in stage IV melanoma.

RESULTS

Best OS was observed in patients (n = 93) treated by metastasectomy as primary treatment with the intention to completely excise all metastases (3-year OS 61%). OS for patients with first-line systemic treatment (n = 258) was unfavorable in general (3-year OS 23%). Of those, the most favorable outcome was observed in patients without brain metastasis and treated with immunotherapy (mostly ipilimumab), as first-line treatment (median OS 35 months, 3-year OS 43%). In case of brain metastases, patients with targeted therapy had a better OS (median 14 months) than patients with ipilimumab treatment (median 7 months). Among all patients with first-line systemic treatment, outcome of patients diagnosed in the years 2013/2014, compared to 2011 and 2012, showed an improved survival. Three-year OS for patients that entered stage IV in 2013/2014 was 37% compared to those that entered stage IV in 2011 (18%) and 2012 (20%).

CONCLUSION

The analysis of real-world data of treatment of metastatic melanoma showed an improvement of OS with both immunotherapy and targeted therapy. In case of cerebral metastasis, patients treated with targeted therapy showed a longer median OS than patients treated with ipilimumab.

The proportion of circulating CD45RO+CD8+ memory T cells is correlated with clinical response in melanoma patients treated with ipilimumab

BACKGROUND

Immune checkpoint blockade (ICB) has been a breakthrough in the treatment of metastatic melanoma. But with only about 20-40% long-term responders and severe side-effects in about 12-17%, finding predictive markers for treatment response is of great interest.

METHODS

We prospectively assessed clinical data, haematologic parameters and freshly isolated peripheral blood mononuclear cells of 30 patients treated with ipilimumab (n = 21) and pembrolizumab (n = 9) prior to the first 4 cycles with ICB and before the first tumour assessment.

RESULTS

We discovered that the baseline levels of CD45RO⁺CD8⁺ T cells significantly differed among the patients. Thirteen (43%) of our patients had normal baseline levels of CD45RO⁺CD8⁺ T cells, whereas 17 (57%) patients were low on CD45RO⁺CD8⁺ T cells. The baseline levels of CD45RO⁺CD8⁺ T cells correlated significantly with the response to ipilimumab but not pembrolizumab. Patients with baseline levels of lower/equal 25% of CD45RO⁺CD8⁺ T cells did not respond to treatment with ipilimumab. Phenotyping the CD8⁺ T cells in patients treated with ipilimumab revealed an activated HLA-DR⁺CD25^- phenotype, implying antigen non-specific stimulation. The levels of the HLA-DR⁺CD25^-CD8⁺ T cells were significantly higher in patients with a normal baseline of CD45RO⁺CD8⁺ T cells and even increased significantly during treatment. Furthermore, proliferation of melanoma antigen recognized by T cells 1 (MART-1)-specific CD8⁺ T cells was not observed. Patients with normal baseline levels of CD45RO⁺CD8⁺ T cells showed a significant longer overall survival when treated with ipilimumab but not pembrolizumab.

CONCLUSION

Patients with normal baseline levels of CD45RO⁺CD8⁺ T cells respond significantly more frequently to treatment with ipilimumab and the CD8⁺ T cells appear to be antigen non-specifically activated. The baseline level of CD45RO⁺CD8⁺ T cells represents a promising factor as biomarker for the prediction of the response to ipilimumab.

BRAF Signaling Pathway Inhibition, Podocyte Injury, and Nephrotic Syndrome

Dabrafenib and trametinib, BRAF and MEK inhibitors, respectively, are effective targeted metastatic melanoma therapies, but little is known about their nephrotoxicity. Although tubulointerstitial injury has been the most widely reported renal side effect of targeted melanoma therapy, nephrotic syndrome has not been reported before. We report on a patient with metastatic melanoma who developed nephrotic syndrome during dabrafenib and trametinib treatment. Kidney biopsy showed diffuse loss of podocyte cytoarchitecture, extensive foot-process effacement, and glomerular endothelial injury. Kidney function and glomerular ultrastructural changes recovered fully after drug withdrawal. In vitro, BRAF inhibition decreased PLCε1 expression in podocytes, accompanied by a reduction in nephrin expression and an increase in permeability to albumin. Additionally, these drugs inhibited the podocyte-vascular endothelial growth factor (VEGF) system. In addition to implications for nephrotic syndrome pathophysiology, we suggest that patients given dabrafenib and trametinib be monitored closely for potential glomerular damage.

Towards therapeutic advances in melanoma management: An overview

Melanoma is one of the most aggressive types of skin cancer with rapidly increasing incidence rate. The disease is largely considered incurable and the patients diagnosed with metastatic melanoma have a survival of not more than five years. Despite of the recent advances in anti-melanoma chemo- and immunotherapies, the available drugs are relatively toxic and responsive to only a limited subset of lesions. Currently, topical pharmacotherapy is demonstrated as an effective approach for the treatment of various skin cancers. Also, in vitro testing of melanoma cell lines and murine melanoma models has identified a number of relatively safe and effective phytochemicals. In this review, we described the use of topical pharmacotherapy for the treatment of skin cancers. Melanoma treatment by drugs targeting MAPK-pathway has also been discussed. Long non-coding RNAs and therapeutics targeting ER-associated pathways looks quite promising for the treatment of melanoma. Moreover, some natural anticancer compounds that have been reported to have anti-melanoma effects have also been described. At present a better understanding of genetics and epigenetics of initiation and progression of melanoma is needed for the identification of novel biomarkers and development of targeted therapeutics against melanoma.

Survival of patients with melanoma brain metastasis treated with stereotactic radiosurgery and active systemic drug therapies

INTRODUCTION

With new systemic therapies demonstrating activity in melanoma brain metastasis, most of the previously reported stereotactic radiosurgery (SRS) data are superseded. In this study, we report the outcomes (overall survival [OS] and brain control [BC]) and identify factors that associate with such outcomes in the era of modern systemic therapy.

METHOD

A total of 108 patients treated with SRS from 2010 to 2015 were included. Systemic treatment use within 6 weeks of SRS was noted. OS was defined as time from SRS to death or last follow-up, and BC was defined as absence of any active intracranial disease during follow-up. Univariate and multivariate Cox proportional hazard analyses were performed on clinico-pathological prognostic features associated with OS and BC.

RESULTS

The median age was 64.3 years, and the median follow-up was 8.6 months. Seventy-nine (73.1%) patients received systemic treatment. The median OS were as follows: anti-CTLA4 - 7.5 months (95% CI: 4.4-15.6), anti-PD1 - 20.4 months (95% CI: 8.8 - N/A) and BRAF inhibitor (BRAFi) ± MEK inhibitor (MEKi) - 17.8 months (95% CI: 11.8 - N/A). Median BC was as follows: anti-CTLA4 - 7.5 months (95% CI: 4.0-15.6), anti-PD1 - 12.7 months (95% CI: 5.5 - N/A) and BRAFi ± MEKi - 12.7 months (95% CI: 8.3-18.5). In multivariate analysis, age and type of systemic therapy were strongly associated with OS. Age, Eastern Cooperative Oncology Group performance status, Graded Prognostic Assessment (GPA) score, and presence of symptoms were associated with BC.

CONCLUSIONS

Favourable outcomes are seen in patients treated with SRS and with the best survival seen in patients treated with anti-PD1. Known independent prognostic factors for survival such as age and performance status and GPA score remain relevant in this setting.

First-line treatment of metastatic melanoma: role of nivolumab

Historically, the median overall survival of metastatic melanoma patients was less than 1 year and long-term survivors were rare. Recent advances in therapies have dramatically shifted this landscape with increased survival rates and the real possibility that long-term disease control is achievable. Advances in immune modulators, including cytotoxic T-lymphocyte antigen-4 and programmed death-1 based treatments, have been an integral part of this success. In this article, we review previous and recent therapeutic developments for metastatic melanoma patients. We discuss advances in immunotherapy while focusing on the use of nivolumab alone and in combination with other agents, including ipilimumab in advanced melanoma. One major goal in melanoma research is to optimize combination strategies allowing for more patients to experience benefit while minimizing toxicity. A better understanding of the optimal sequencing, combinations, and mechanisms underlying the development of resistance may provide evidence for rational clinical trial designs of novel immunotherapy strategies in melanoma and other cancer subtypes.

Immunomodulating property of MAPK inhibitors: from translational knowledge to clinical implementation

Treatment of metastatic melanoma was radically changed by the introduction of inhibitors of BRAF, an oncogene mutated in 40-50% of patients. Another area of advancement was the use of immunotherapy, and specifically, immune checkpoint inhibitors. There is compelling evidence that oncogenic BRAF, in addition to driving melanoma proliferation, differentiation and survival, induces T-cell suppression directly through the secretion of inhibitory cytokines or through membrane expression of co-inhibitory molecules such as the PD-1 ligands PD-L1 or PD-L2. Furthermore, the presence of oncogenic BRAF leads to an immune suppressive phenotype characterized by the presence of inhibitory immune cells such as regulatory T cells, myeloid-derived suppressor cells, or tumor-associated macrophages, which can in turn inhibit the function of tumor-infiltrating T cells. Growing evidence suggests that, in addition to their established molecular mechanism of action, the therapeutic efficacy of BRAF inhibitors and MEK inhibitors relies on additional factors that affect the tumor-host interactions, including the enhancement of melanoma antigen expression and the increase in immune response against tumor cells. Focus of the present review is to summarize the off target mechanisms of response to BRAF inhibitors and MEK inhibitors and the synergy between targeted therapy and immunotherapy as the biological source to open a window of strategic opportunities for the design of new exciting clinical trials.

Combination Treatment of Patients with BRAF-Mutant Melanoma: A New Standard of Care

Raf-mitogen-activated protein kinase (Raf-MAPK) pathway inhibition with the BRAF inhibitors vemurafenib and dabrafenib, alone or in combination with a MEK inhibitor, has become a standard therapeutic approach in patients with BRAF-mutated metastatic melanoma. Both vemurafenib and dabrafenib have shown good safety and efficacy as monotherapy compared with chemotherapy. However, the duration of response is limited in the majority of patients treated with BRAF inhibitor monotherapy because of the development of acquired resistance. The addition of a MEK inhibitor can improve blockade of the MAPK pathway and may help to overcome resistance and thereby prolong efficacy, as well as reduce cutaneous toxicity. Combinations of BRAF inhibitors and MEK inhibitors (dabrafenib plus trametinib and vemurafenib plus cobimetinib) have been approved for the treatment of BRAF-mutant metastatic melanoma and may become a new standard of care. However, acquired resistance is still a significant concern with BRAF and MEK inhibitor combination therapy, and other strategies are being investigated, including the use of sequential and intermittent schedules. The combination of BRAF or MEK inhibitors with immunotherapy has been shown to hold considerable promise, with several combinations being evaluated in clinical trials. Preliminary results from clinical trials involving triple combination therapy with BRAF-MEK inhibitors and anti-PD-L1 antibodies appear promising and may indicate a new strategy to treat patients with BRAF-mutated metastatic melanoma. Biomarkers are needed to help identify patients with BRAFV600 mutations most likely to benefit from first-line BRAF/MEK inhibitor therapy rather than immunotherapy and vice versa.

Extranodal Spread is Associated with Recurrence and Poor Survival in Stage III Cutaneous Melanoma Patients

BACKGROUND

Inconsistent data suggests extranodal spread (ENS) is an adverse prognostic factor in Stage III melanoma patients but it remains contentious. By rigorously matching cohorts, this study sought to clarify associations with recurrence and survival.

METHODS

Melanoma patients with lymph node metastases (AJCC Stage III), with or without ENS, sub-classified on the basis of known (MKP) or unknown primary (MUP), were identified from a single institution prospective database. Of 725 ENS patients identified, 567 were able to be precisely matched 1:1 with a non-ENS cohort. Clinicopathologic factors were analyzed for associations with outcome.

RESULTS

There were 481 MKP and 86 MUP patients in each cohort. ENS, compared to non-ENS, was an independent predictor of worse melanoma specific survival (MSS) (HR = 1.71, 95% CI = 1.39-2.11, P < 0.0001) with median MSS 56.4 versus 175.2 months, P < 0.001; worse disease free survival (DFS) (HR = 1.16, 95%CI = 1.00-1.34, P = 0.044) with median DFS 15.6 versus 21.5 months, P = 0.009; and worse post-recurrence survival (PRS) (HR = 1.66, 95%CI = 1.37-2.02, P < 0.0001) with median PRS 20.1 versus 51.1 months, P < 0.001. ENS was also associated with reduced time to distant recurrence (Distant Disease Free Survival [DDFS]) (HR = 2.00, 95% CI = 1.24-3.24, P = 0.0047), however median time to distant recurrence not reached within the study time period.

CONCLUSIONS

ENS represents a significant independent predictor of worse MSS, DFS, PRS and DDFS in Stage III melanoma patients. ENS should be considered in the stratification of patients in adjuvant therapy trials.

Correlation between previous treatment with BRAF inhibitors and clinical response to pembrolizumab in patients with advanced melanoma

The optimal sequencing of targeted treatment and immunotherapy in the treatment of advanced melanoma is a key question and prospective studies to address this are ongoing. Previous observations suggest that treating first with targeted therapy may select for more aggressive disease, meaning that patients may not gain full benefit from subsequent immunotherapy. In a single-center retrospective analysis, we investigated whether response to pembrolizumab was affected by previous BRAF inhibitor therapy. A total of 42 patients with metastatic cutaneous or mucosal melanoma who had received previous treatment with ipilimumab were treated with pembrolizumab as part of the Italian expanded access program. Sixteen of these patients had BRAF-mutated melanoma and had also been previously treated with a BRAF inhibitor (vemurafenib or dabrafenib), while 26 had BRAF wild-type melanoma (no previous BRAF inhibitor). Patients with BRAF-mutant melanoma who were previously treated with BRAF inhibitors had a significantly lower median progression-free survival (3 [2.3-3.7] versus not reached [2-8+] mo; p = 0.001) and disease control rate (18.6% versus 65.4%; p = 0.005) than patients with BRAF wild-type, while there was also a trend toward a lower response rate (assessed using immune-related response criteria) although this was not significantly different between groups (12.5% versus 36.4%; p = 0.16). These data are consistent with previous reports that BRAF inhibitor therapy may affect subsequent response to immunotherapy.

Melanoma therapy: Check the checkpoints

Recent mutational and translational studies have revealed that the Ras/Raf/mitogen-activated protein kinase kinase (MEK)/extracellular signal-regulated kinase (ERK) pathway plays a key role in melanomagenesis. Mutations in NRAS and BRAF are found in the majority of melanomas resulting in the formation of constitutively active NRAS and BRAF molecules, which leads to the proliferation and survival of melanoma cells through the activation of MEK/ERK signals. Inhibitors of BRAF or MEK significantly extend the progression-free survival and overall survival of melanoma patients compared with conventional chemotherapies. Combining BRAF and MEK inhibitors further enhances the clinical effectiveness. Cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) is an immune checkpoint molecule that downregulates T-cell activation by binding to B7 (CD80/CD86) molecules on antigen-presenting cells. Programmed death receptor ligand 1 on melanoma cells negatively regulates T-cell function by binding to the programmed death-1 (PD-1) receptor on T cells. Antibodies against CTLA-4 and PD-1 also enhance the survival of melanoma patients. In this review, we summarize the clinical effectiveness and adverse events of the BRAF inhibitors, MEK inhibitors and anti-immune checkpoint antibodies in melanoma treatment.

Is there still a role for cytotoxic chemotherapy after targeted therapy and immunotherapy in metastatic melanoma? A case report and literature review

Metastatic melanoma has long been considered to have a very poor prognosis and to be chemo-resistant. However, a subgroup of patients with metastatic melanoma presents remarkable responses to chemotherapeutic agents, even in the absence of a response to modern targeted therapies and immunotherapies; accordingly, determining predictive biomarkers of the response to chemotherapies for metastatic melanoma remains a priority to guide treatment in these patients. We report a case study of a patient with B-Raf proto-oncogene serine/threonine kinase-mutated metastatic melanoma harbouring many genetic mutations. The patient did not respond to prior targeted therapies or immunotherapies but experienced a dramatic objective radiological and clinical response to subsequent dacarbazine-based chemotherapy. In the era of targeted therapies and immunotherapies for metastatic melanoma, cytotoxic chemotherapies may still represent an interesting therapeutic weapon in a well-defined subgroup of patients presenting with specific genetic and molecular features.

Tumor Heterogeneity and Therapeutic Resistance

The rapidly changing landscape of oncology has brought new light, and with it, new challenges to optimizing therapeutic strategies for patients. Although the concept of patient heterogeneity is well known to any practicing clinician, a more detailed understanding of the biologic changes that underscore the clinical picture is beginning to emerge. Thus, tumor heterogeneity has come to encompass more than just the clinical picture and can represent both intratumor and intertumor differences. Within the fields of thoracic oncology and melanoma, the discovery of key molecular drivers has resulted in landmark breakthroughs in therapy. However, the complexities of tumor genetics and the interaction within the environment continue to drive the search for better therapies. Ongoing challenges include the accurate and timely assessment of genetic changes as well as the development of resistance and the resultant compensatory mechanisms. Novel technologies, including commercially available next-generation sequencing, have allowed for a greater breadth and depth of information to be gained from a single pathologic specimen, and it is now being incorporated into routine clinical practice. Translational advances have subsequently provided valuable insight into mechanisms of resistance, with the development of novel treatment strategies. Future work will focus on novel diagnostic techniques and adaptive mechanisms that can ultimately drive the development of the next generation of cancer therapy.

Patient and oncologist preferences for attributes of treatments in advanced melanoma: a discrete choice experiment

PURPOSE

To examine and compare patient and oncologist preferences for advanced melanoma treatment attributes and to document their trade-offs for benefits with risks.

MATERIALS AND METHODS

A discrete choice experiment (DCE) was conducted among advanced melanoma patients and oncologists. Qualitative pilot testing was used to inform the DCE design. A series of scenarios asked stakeholders to choose between two hypothetical medications, each with seven attributes: mode of administration (MoA), dosing schedule (DS), median duration of therapy (MDT), objective response rate (ORR), progression-free survival (PFS), overall survival (OS), and grade 3-4 adverse events (AEs). Hierarchical Bayesian logistic regression models were used to determine patients' and oncologists' choice-based preferences, analysis of variance models were used to estimate the relative importance of attributes, and independent t-tests were used to compare relative importance estimates between stakeholders.

RESULTS

In total, 200 patients and 226 oncologists completed the study. OS was most important to patients (33%), followed by AEs (29%) and ORR (25%). For oncologists, AEs were most important (49%), followed by OS (34%) and ORR (12%). An improvement from 55% to 75% in 1-year OS was valued similar in magnitude to a 23% decrease (from 55% to 32%) in likelihood of AEs for oncologists.

CONCLUSION

Patients valued OS, AEs, and ORR sequentially as the most important attributes in making a treatment decision, whereas oncologists valued AEs most, followed by OS and ORR. In comparison, patients differed significantly from oncologists on the importance of ORR, AEs, and PFS, but were consistent in OS and the rest of attributes.

Immunotolerance as a Mechanism of Resistance to Targeted Therapies in Melanoma

The therapy of metastatic melanoma (MM) was radically changed by the introduction of inhibitors of BRAF, an oncogene mutated in ≈40-50% of patients. Oncogenic BRAF promotes an immune-compromised tumour microenvironment (TME). Inhibition of MAPK pathway signaling with BRAF (BRAFi) and MEK inhibitors (MEKi) attenuates immune escape and increases the melanoma immunogenicity through multiple mechanisms, including elevation of melanoma antigen expression and improved T cell infiltration and function. These changes sustain the TME for response to immunotherapy. In this chapter we discuss preclinical and clinical data supporting the immunomodulating activities of targeted therapies, the immunotolerance as a mechanisms of resistance and highlight the rationale for novel combinations of targeted therapies and immunotherapies with the potential to significantly improve the future treatment of MM patients.

Efficacy and toxicity of rechallenge with combination immune checkpoint blockade in metastatic melanoma: a case series

BACKGROUND

The efficacy and potential toxicity of rechallenge with combination ipilimumab and nivolumab has not been described. Retreatment of patients with immune checkpoint inhibitors in the setting of prior significant toxicity lacks evidence-based guidance.

METHODS

We present the first three, consecutive patients who received re-treatment with combination ipilimumab and nivolumab for metastatic melanoma managed at our institution.

RESULTS

Rechallenge with combination ipilimumab and nivolumab in the setting of prior grade 3 toxicity with initial combination therapy is feasible, and responses are seen. We highlight the fact that grade 3 toxicity is likely to recur, but if so, can be manageable.

CONCLUSIONS

Retreatment with ipi + nivo may be considered an option in carefully selected, well-informed patients. More research is required to delineate the benefits and risks with this approach.

Systemic Therapy Options for Patients With Unresectable Melanoma

There has been a therapeutic revolution in the treatment of metastatic melanoma over the past decade. Patients presenting with inoperable disease have several therapeutic options, which can include both targeted and immune therapy. Immune checkpoint inhibitors have demonstrated an improvement in overall survival and led to some durable responses. However, toxicity, especially in combination regimens, can be severe. Adverse events should be anticipated, diagnosed as early as possible, monitored, and managed. Combination BRAF and MEK inhibition has also been shown to improve overall survival in patients with V600E-mutated melanoma. Responses to therapy are often rapid, and treatment is not associated with immune-related adverse events. Current trials are under way to determine which option is optimal as frontline therapy for patients with V600E melanoma. In patients with progressive disease despite standard therapies, clinical trials are recommended. There are several promising agents in development.

Combine and conquer: challenges for targeted therapy combinations in early phase trials

Our increasing understanding of cancer biology has led to the development of molecularly targeted anticancer drugs. The full potential of these agents has not, however, been realised, owing to the presence of de novo (intrinsic) resistance, often resulting from compensatory signalling pathways, or the development of acquired resistance in cancer cells via clonal evolution under the selective pressures of treatment. Combinations of targeted treatments can circumvent some mechanisms of resistance to yield a clinical benefit. We explore the challenges in identifying the best drug combinations and the best combination strategies, as well as the complexities of delivering these treatments to patients. Recognizing treatment-induced toxicity and the inability to use continuous pharmacodynamically effective doses of many targeted treatments necessitates creative intermittent scheduling. Serial tumour profiling and the use of parallel co-clinical trials can contribute to understanding mechanisms of resistance, and will guide the development of adaptive clinical trial designs that can accommodate hypothesis testing, in order to realize the full potential of combination therapies.

Burden of illness for metastatic melanoma in Canada, 2011-2013

BACKGROUND

Detailed epidemiology for patients with advanced metastatic melanoma in Canada is not well characterized. We conducted an analysis of patients with this disease in the province of Ontario, with the aim being to study the presentation, disease characteristics and course, and treatment patterns for malignant melanoma.

METHODS

In this Canadian observational prospective and retrospective study of patients with malignant melanoma, we used data collected in the Canadian Melanoma Research Network (cmrn) Patient Registry. We identified patients who were seen at 1 of 3 cancer treatment centres between April 2011 and 30 April 2013. Patient data from 2011 and 2012 were collected retrospectively using chart records and existing registry data. Starting January 2013, data were collected prospectively. Variables investigated included age, sex, initial stage, histology, mutation type, time to recurrence, sites of metastases, resectability, and previous therapies.

RESULTS

A cohort of 810 patients with melanoma was identified from the cmrn registry. Mean age was 58.7 years, and most patients were men (60% vs. 40%). Factors affecting survival included unresectable or metastatic melanoma, initial stage at diagnosis, presence of brain metastasis, and BRAF mutation status. The proportion of surviving patients decreased with higher initial disease stages.

CONCLUSIONS

Using registry data, we were able to determine the detailed epidemiology of patients with melanoma in the Canadian province of Ontario, validating the comprehensive and detailed information that can be obtained from registry data.

A phase IB study of ipilimumab with peginterferon alfa-2b in patients with unresectable melanoma

Background

Ipilimumab and peginterferon alfa-2b are established systemic treatment options for melanoma that have distinct mechanisms of action. Given the need for improved therapies for advanced melanoma, we conducted an open-label, single institution, phase Ib study to assess the safety and tolerability of using these two agents in combination.

Methods

Study treatment consisted of ipilimumab given every 3 weeks, for a total of four infusions, concurrent with peginterferon alfa-2b administered subcutaneous weekly for a total of 12 weeks. This was followed by maintenance therapy with peginterferon alfa-2b administered subcutaneously weekly for up to 144 additional weeks. The study was designed as a two-stage dose escalation scheme with continuous dose-limiting toxicity monitoring during the induction phase.

Results

Thirty one patients received at least 1 dose of study treatment and 30 were assessable for efficacy endpoints. We found that ipilimumab at 3 mg/kg dosing with peginterfeon alfa-2b at 2 μg/kg/week was the maximum tolerated dose of this combination. The incidence of grade 3 drug-related adverse events (AEs) was 45.2%. There were no grade 4/5 AEs. The overall response rate was 40% by immune-related response criteria. Median progression-free survival was 5.9 months. The median overall survival was not reached with at a median follow-up of 35.8 months.

Conclusions

We report that the combination of ipilimumab at 3 mg/kg dosing combined with peginterfeon alfa-2b at 2 μg/kg/week demonstrated an acceptable toxicity profile and a promising efficacy signal. Further study of this combination is warranted.

Trial registration

ClinicalTrials.gov identifier: NCT01496807, Registered December 19th, 2011.