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

Pulmonary sarcoid-like granulomatosis induced by nivolumab

The use of antibodies against programmed death (PD)1, such as nivolumab and pembrolizumab, has dramatically improved the prognosis of patients with advanced melanoma. Nivolumab is also approved in advanced squamous cell nonsmall-cell lung cancer. These immunotherapies are associated with a unique set of toxicities termed immune-related adverse events, which are different from toxicities observed with conventional cytotoxic chemotherapy. We report the case of a 56-year-old man who was diagnosed with metastatic melanoma and who received nivolumab. One week after the second infusion, he developed pulmonary symptoms, dry eye syndrome and a bilateral swelling of the parotid glands. Investigations were negative for infection. The bronchoalveolar lavage differential cell count showed 32% lymphocytes with an increased CD4 : CD8 ratio, and bronchial biopsies revealed noncaseating epithelioid granulomas, without malignant cells. The clinical and radiological courses were rapidly favourable with oral corticosteroid. This case illustrates that sarcoidosis can be induced by nivolumab treatment. With the increasing use of anti-PD1 inhibitors in patients with advanced melanoma and squamous cell nonsmall-cell lung cancer, clinicians should be aware of this potential associated immune-related adverse event.

MAPK Pathway Inhibitors Sensitize BRAF-Mutant Melanoma to an Antibody-Drug Conjugate Targeting GPNMB

PURPOSE

To determine if BRAF and/or MEK inhibitor-induced GPNMB expression renders melanomas sensitive to CDX-011, an antibody-drug conjugate targeting GPNMB.

EXPERIMENTAL DESIGN

The Cancer Genome Atlas melanoma dataset was interrogated for a panel of MITF-regulated melanosomal differentiation antigens, including GPNMB. BRAF-mutant melanoma cell lines treated with BRAF or MEK inhibitors were assessed for GPNMB expression by RT-qPCR, immunoblot, and FACS analyses. Transient siRNA-mediated knockdown approaches were used to determine if MITF is requirement for treatment-induced GPNMB upregulation. GPNMB expression was analyzed in serial biopsies and serum samples from patients with melanoma taken before, during, and after disease progression on MAPK inhibitor treatment. Subcutaneous injections were performed to test the efficacy of MAPK inhibitors alone, CDX-011 alone, or their combination in suppressing melanoma growth.

RESULTS

A MITF-dependent melanosomal differentiation signature is associated with poor prognosis in patients with this disease. MITF is increased following BRAF and MEK inhibitor treatment and induces the expression of melanosomal differentiation genes, including GPNMB. GPNMB is expressed at the cell surface in MAPK inhibitor-treated melanoma cells and is also elevated in on-treatment versus pretreatment biopsies from melanoma patients receiving MAPK pathway inhibitors. Combining BRAF and/or MEK inhibitors with CDX-011, an antibody-drug conjugate targeting GPNMB, is effective in causing melanoma regression in preclinical animal models and delays the recurrent melanoma growth observed with MEK or BRAF/MEK inhibitor treatment alone.

CONCLUSIONS

The combination of MAPK pathway inhibitors with an antibody-drug conjugate targeting GPNMB is an effective therapeutic option for patients with melanoma. Clin Cancer Res; 22(24); 6088-98. ©2016 AACR.

BRAF inhibitors and radiotherapy for melanoma brain metastases: potential advantages and disadvantages of combination therapy

Melanoma is an aggressive malignancy that frequently spreads to the brain, resulting in rapid deterioration in both quality and quantity of life. Historically, treatment options for melanoma brain metastases (MBM) have predominantly consisted of surgery and radiotherapy. While these options can help provide local control, the majority of patients still develop intracranial progression. Indeed, novel therapeutic options, including molecularly targeted agents and immunotherapy, have improved outcomes and are now changing the role of radiotherapy. Up to 50% of melanomas contain an activating BRAF mutation, resulting in hyperactive cellular proliferation and survival. Drugs that target BRAF have been introduced for the treatment of metastatic melanoma and offer hope in improving disease outcomes; however, many of these trials either excluded or had a limited amount of patients with MBM. Recent studies have revealed that melanoma cell lines become more radiosensitive following BRAF inhibition, thus providing a potential synergistic mechanism when combining BRAF inhibitor (BRAFi) and radiotherapy. However, neurotoxicity concerns also exist with this combination. This article reviews the efficacy and limitations of BRAFi therapy for MBM, describes current evidence for combining BRAFis with radiation, discusses the rationale and evidence for combination modalities, and highlights emerging clinical trials specifically investigating this combination in MBM.

Optimizing combination dabrafenib and trametinib therapy in BRAF mutation-positive advanced melanoma patients: Guidelines from Australian melanoma medical oncologists

BRAF mutations occur commonly in metastatic melanomas and inhibition of mutant BRAF and the downstream kinase MEK results in rapid tumor regression and prolonged survival in patients. Combined therapy with BRAF and MEK inhibition improves response rate, progression free survival and overall survival compared with single agent BRAF inhibition, and reduces the skin toxicity that is seen with BRAF inhibitor monotherapy. However, this combination is associated with an increase in other toxicities, particularly drug-related pyrexia, which affects approximately 50% of patients treated with dabrafenib and trametinib (CombiDT). We provide guidance on managing adverse events likely to arise during treatment with combination BRAF and MEK inhibition with CombiDT: pyrexia, skin conditions, fatigue; and discuss management of CombiDT during surgery and radiotherapy. By improving tolerability and in particular preventing unnecessary treatment cessations or reduction in drug exposure, best outcomes can be achieved for patients undergoing CombiDT therapy.

Stratified Treatment in Lung Cancer

Even though great efforts have been made to improve chemotherapy-based treatment approaches for lung cancer, the prognosis of patients with advanced and metastasized disease remains particularly poor. In recent years, a growing number of genetic aberrations driving lung cancer have been identified. Targeted inhibition of some of these aberrations, most prominently mutated EGFR and ALK, by tyrosine kinase inhibitors has dramatically increased efficacy and tolerability of systemic lung cancer treatment in subsets of patients. However, the duration of response is limited due to the acquisition of molecular mechanisms of resistance to targeted treatment. Modern next-generation inhibitors aim to break resistance. A deep understanding of the mechanisms of treatment failure is imperative to the development of new approaches. In this review, we focus on the current status of stratified therapy in lung cancer and highlight new, potentially promising treatment approaches.

Factors predictive of response, disease progression, and overall survival after dabrafenib and trametinib combination treatment: a pooled analysis of individual patient data from randomised trials

BACKGROUND

Dabrafenib plus trametinib treatment provides significant benefits over BRAF-inhibitor monotherapy in patients with BRAF^V600E-mutant or BRAF^V600K-mutant advanced melanoma; however, in many patients the disease progresses, leading to death. With many treatment options available, understanding clinical factors that predict long-term response and survival for treatments is important for optimisation of patient management. We aimed to identify clinical factors associated with long-term response and survival using pooled data from randomised trials of dabrafenib plus trametinib in patients with metastatic BRAF-mutant melanoma.

METHODS

We did a retrospective individual data analysis based on all published randomised trials that included treatment-naive patients with BRAF^V600E-mutant or BRAF^V600K-mutant metastatic melanoma who received the approved dose of dabrafenib 150 mg twice daily plus trametinib 2 mg once daily. Data were pooled from patients in the BRF113220 (part C; March 26, 2010, to Jan 15, 2015), COMBI-d (May 4, 2012, to Jan 12, 2015), and COMBI-v (June 4, 2012, to March 13, 2015) randomised trials. Patients with untreated brain metastases were not permitted to enrol in these trials. Baseline factors, identified a priori based on known melanoma clinical or prognostic characteristics, were analysed for association with progression-free survival and overall survival using univariate and multivariate analyses and assessed for hierarchical effect on outcomes using regression tree analyses. We also analysed factors identified after baseline, on treatment, and at progression, for associations with survival after progression. The trials included in this analysis are registered with ClinicalTrials.gov: BRF113220, number NCT01072175; COMBI-d, number NCT01584648; COMBI-v, number NCT01597908.

FINDINGS

617 patients were included in this analysis with a median follow-up of 20·0 months (range 0-48·0, IQR 10·1-24·8); 396 patients had progression events (ie, disease progression or death) and 290 patients had died. Median progression-free survival (11·1 months [95% CI 9·7-12·9]), median overall survival (25·6 months [23·1-34·3]), 1-year progression-free survival (48% [44-52]) and overall survival (74% [71-78]), and 2-year progression-free survival (30% [26-34]) and overall survival (53% [49-57]) were consistent with those in the individual trials. Patients with normal lactate dehydrogenase (LDH) concentration and fewer than three organ sites containing metastases (n=237) had the longest 1-year progression-free survival (68% [95% CI 62-74]) and overall survival (90% [87-94]) and 2-year progression-free survival (46% [40-54]) and overall survival (75% [70-81]), whereas patients with LDH concentration at least two times the upper limit of normal (n=70) had the shortest 1-year progression-free survival (8% [3-19]) and overall survival (40% [29-55]) and 2-year progression-free survival (2% [0-13]) and overall survival (7% [3-19]). Of patients with disease progression (n=379), survival after progression was longest in those with progression in baseline or new non-CNS lesions (n=205; median 10·0 months [95% CI 7·9-12·0]) and shortest in those with new CNS lesions or concurrent progression in baseline and new lesions (n=171; median 4·0 months [3·5-4·9]).

INTERPRETATION

Several patient and clinical characteristics at and after baseline are associated with outcomes with dabrafenib plus trametinib, and durable benefit is possible with targeted treatment in defined patient subsets.

FUNDING

Novartis.

Combinatorial immunotherapy for melanoma

Melanoma has been a long-standing focal point for immunotherapy development. In this review, we explore the evolution of melanoma treatments with particular attention to the history and recent advances in melanoma immunotherapy. We also discuss novel combinations of these modalities and their potential to offer novel therapeutic options for patients with advanced melanoma.

An Open-Label, Dose-Escalation Phase I Study of Anti-TYRP1 Monoclonal Antibody IMC-20D7S for Patients with Relapsed or Refractory Melanoma

PURPOSE

Tyrosinase-related protein-1 (TYRP1) is a transmembrane glycoprotein that is specifically expressed in melanocytes and melanoma cells. Preclinical data suggest that mAbs targeting TYRP1 confer antimelanoma activity. IMC-20D7S is a recombinant human IgG1 mAb targeting TYRP1. Here, we report the first-in-human phase I/Ib trial of IMC-20D7S.

EXPERIMENTAL DESIGN

The primary objective of this study was to establish the safety profile and the MTD of IMC-20D7S. Patients with advanced melanoma who progressed after or during at least one line of treatment or for whom standard therapy was not indicated enrolled in this standard 3 + 3 dose-escalation, open-label study. IMC-20D7S was administered intravenously every 2 or 3 weeks.

RESULTS

Twenty-seven patients were enrolled. The most common adverse events were fatigue and constipation experienced by nine (33%) and eight (30%) patients, respectively. There were no serious adverse events related to treatment, no discontinuations of treatment due to adverse events, and no treatment-related deaths. Given the absence of dose-limiting toxicities, an MTD was not defined, but a provisional MTD was established at the 20 mg/kg every 2-week dose based on serum concentration and safety data. One patient experienced a complete response. A disease control rate, defined as stable disease or better, of 41% was observed.

CONCLUSION

IMC-20D7S is well tolerated among patients with advanced melanoma with evidence of antitumor activity. Further investigation of this agent as monotherapy in selected patients or as part of combination regimens is warranted. Clin Cancer Res; 22(21); 5204-10. ©2016 AACR.

A phase I pharmacokinetic and pharmacodynamic study of the oral mitogen-activated protein kinase kinase (MEK) inhibitor, WX-554, in patients with advanced solid tumours

PURPOSE

We performed a multi-centre phase I study to assess the safety, pharmacokinetics (PK) and pharmacodynamics (PD) of the orally available small molecule mitogen-activated protein kinase kinase (MEK) 1/2 inhibitor, WX-554, and to determine the optimal biological dose for subsequent trials.

EXPERIMENTAL DESIGN

Patients with treatment-refractory, advanced solid tumours, with adequate performance status and organ function were recruited to a dose-escalation study in a standard 3 + 3 design. The starting dose was 25 mg orally once weekly with toxicity, PK and PD guided dose-escalation with potential to explore alternative schedules.

RESULTS

Forty-one patients with advanced solid tumours refractory to standard therapies and with adequate organ function were recruited in eight cohorts up to doses of 150 mg once weekly and 75 mg twice weekly. No dose-limiting toxicities were observed during the study, and a maximum tolerated dose (MTD) was not established. The highest dose cohorts demonstrated sustained inhibition of extracellular signal-regulated kinase (ERK) phosphorylation in peripheral blood mononuclear cells following ex-vivo phorbol 12-myristate 13-acetate stimulation. There was a decrease of 70 ± 26% in mean phosphorylated (p)ERK in C1 day 8 tumour biopsies when compared with pre-treatment tumour levels in the 75 mg twice a week cohort. Prolonged stable disease (>6 months) was seen in two patients, one with cervical cancer and one with ampullary carcinoma.

CONCLUSIONS

WX-554 was well tolerated, and an optimal biological dose was established for further investigation in either a once or twice weekly regimens. The recommended phase 2 dose is 75 mg twice weekly.

Dabrafenib in BRAFV600-mutated anaplastic pleomorphic xanthoastrocytoma

Pleomorphic xanthoastrocytoma (PXA) is a rare brain tumor. Anaplastic features are found in 20-30% of cases of PXA and are associated with poor outcomes. Typical treatment is with gross total resection, followed by radiation therapy and cytotoxic chemotherapy at relapse. BRAFV600 mutations have been identified in 38-60% of patients with PXA. Several case reports and small case series have identified clinical benefit with BRAF inhibition in patients with BRAFV600-mutated PXA. We report the second published case of successful treatment with the BRAF inhibitor dabrafenib in a female patient with relapsed anaplastic PXA with a BRAFV600 mutation, and the first published case of dabrafinib treatment following intolerance to vemurafenib.

Melanoma central nervous system metastases: current approaches, challenges, and opportunities

Melanoma central nervous system metastases are increasing, and the challenges presented by this patient population remain complex. In December 2015, the Melanoma Research Foundation and the Wistar Institute hosted the First Summit on Melanoma Central Nervous System (CNS) Metastases in Philadelphia, Pennsylvania. Here, we provide a review of the current status of the field of melanoma brain metastasis research; identify key challenges and opportunities for improving the outcomes in patients with melanoma brain metastases; and set a framework to optimize future research in this critical area.

New Therapeutic Opportunities Based on DNA Mismatch Repair and BRAF Status in Metastatic Colorectal Cancer

Recently, colorectal cancer (CRC) subtyping consortium identified four consensus molecular subtypes (CMS1-4). CMS1 is enriched for deficient mismatch repair (dMMR) and BRAF (V600E) tumors. Intriguingly, this subtype has better relapse-free survival but worse overall survival after relapse compared with the other subtypes. Growing evidence is accumulating on the benefit of specific therapeutic strategies such as immune checkpoint inhibition therapy in dMMR tumors and mitogen-activated protein kinase (MAPK) pathway targeted therapy in tumors harboring BRAF (V600E) mutation. After reviewing dMMR prognostic value, immune checkpoints as major targets for dMMR carcinomas will be highlighted. Following, BRAF (V600E) prognostic impact will be reviewed and therapeutic strategies with the combination of cytotoxic agents and especially the combinations of BRAF and MAPK inhibitors will be discussed.

Treatment of brain metastases in the modern genomic era

Development of brain metastasis (BM) portends a dismal prognosis for patients with cancer. Melanomas and carcinomas of the lung, breast, and kidney are the most common malignancies to metastasize to the brain. Recent advances in molecular genetics have enabled the identification of actionable, clinically relevant genetic alterations within primary tumors and their corresponding metastases. Adoption of genotype-guided treatment strategies for the management of systemic malignancy has resulted in dramatic and durable responses. Unfortunately, despite these therapeutic advances, central nervous system (CNS) relapses are not uncommon. Although these relapses have historically been attributed to limited blood brain barrier penetration of anti-neoplastic agents, recent work has demonstrated genetic heterogeneity such that metastatic sites, including BM, harbor relevant genetic alterations that are not present in primary tumor biopsies. This improved insight into molecular mechanisms underlying site specific recurrences can inform strategies for targeting these oncogenic drivers. Thus, development of rational, genomically guided CNS-penetrant therapies is crucial for ongoing therapeutic success.

Cobimetinib

OBJECTIVE

To review and summarize data on cobimetinib, which was approved by the US Food and Drug Administration (FDA) in November 2015 for use in combination with vemurafenib for unresectable or metastatic melanoma with a BRAFV600E or V600K mutation.

DATA SOURCES

A literature search using PubMed was conducted using the terms cobimetinib, MEK inhibitor, and melanoma from January 2000 to June 2016.

STUDY SELECTION AND DATA EXTRACTION

The literature search was confined to human studies published in English. Trials of cobimetinib for melanoma were prioritized.

DATA SYNTHESIS

Cobimetinib is a reversible inhibitor of MEK1 and MEK2. Its FDA approval was based on a phase III, randomized trial of vemurafenib monotherapy (n = 248) or vemurafenib and cobimetinib (n = 247) in unresectable stage IIIC or IV melanoma with a BRAFV600 mutation. Cobimetinib was administered as 60 mg orally daily for 21 days/7 days off, whereas vemurafenib was administered as 960 mg twice daily. Vemurafenib and cobimetinib were associated with an objective response rate of 68%, and median progression-free survival of 9.9 months. The overall survival was not reached at the time of first interim analysis. Clinically relevant grade ≥3 adverse events were diarrhea (6%), rash (6%), photosensitivity (2%), elevated liver function tests (LFTs) (8%-12%), increased creatine kinase (11%), and retinal detachment (3%).

CONCLUSION

Cobimetinib combined with vemurafenib is an alternative BRAF/MEK inhibitor therapy for unresectable or metastatic melanoma with BRAFV600 mutation. The role of cobimetinib in melanoma and other solid tumors is likely to expand as the results from ongoing studies become available.

Therapeutic approach to treating patients with BRAF-mutant lung cancer: latest evidence and clinical implications

Lung adenocarcinoma is known for its high rate of somatic mutations and genomic rearrangements. The identification of epidermal growth factor receptor (EGFR) mutations and anaplastic lymphoma kinase (ALK) rearrangements that sensitize tumors to specific drugs has changed the therapeutic approach and prognosis in these molecularly-defined subgroups. Several other key genetic alterations have been identified, of which BRAF mutations are found in 4% of non-small cell lung cancer (NSCLC) cases. Targeted drugs against BRAF and downstream MEK were recently approved for the treatment of BRAF-positive melanoma and have entered clinical evaluation in NSCLC. In this review we discuss the latest evidence on the treatment of BRAF-mutated NSCLC, including tumor biology, targeted treatment with BRAF and MEK inhibitors, therapeutic resistance and strategies to overcome resistance.

Network Meta-analysis of Progression-Free Survival and Overall Survival in First-Line Treatment of BRAF Mutation-Positive Metastatic Melanoma

INTRODUCTION

The present study aimed to inform an economic evaluation of dabrafenib and trametinib combination as first-line treatment of metastatic melanoma in a Canadian setting. A network meta-analysis was conducted to estimate hazard ratios (HRs) for progression-free survival (PFS)and overall survival (OS) of dabrafenib plus trametinib versus other first-line treatments of BRAF mutation-positive metastatic melanoma including dabrafenib, trametinib, vemurafenib, ipilimumab, and dacarbazine (DTIC).

METHODS

HRs for PFS and OS were from randomized controlled trials identified from systematic literature reviews. HRs for PFS and OS (adjusted for crossover as appropriate) were analyzed using multivariate and univariate Bayesian network meta-analysis.

RESULTS

In multivariate network-meta analyses (HRs for PFS and OS estimated simultaneously to account for the correlation of treatment effects on PFS and OS), HRs (95% credible interval) for PFS and OS favored dabrafenib plus trametinib [PFS: 0.23 (0.18-0.29) versus DTIC, 0.32 (0.24-0.42) versus ipilimumab plus DTIC, 0.52 (0.32-0.83) versus trametinib, 0.57 (0.48-0.69) versus vemurafenib, and 0.59 (0.50-0.71) versus dabrafenib]; OS [0.41 (0.29-0.56) versus DTIC, 0.52 (0.38-0.71) versus ipilimumab plus DTIC, 0.68 (0.47-0.95) versus trametinib, 0.69 (0.57-0.84) versus vemurafenib, and 0.72 (0.60-0.85) versus dabrafenib]. The beneficial effects on OS of dabrafenib plus trametinib versus ipilimumab plus DTIC and versus trametinib were attenuated when HRs were estimated using univariate network meta-analysis (HRs for PFS and OS estimated separately).

CONCLUSION

This analysis demonstrates improved PFS and OS with dabrafenib + trametinib versus dabrafenib, trametinib, vemurafenib, ipilimumab plus DTIC, and DTIC as first-line treatment for patients with BRAF mutation-positive metastatic melanoma.

FUNDING

Novartis Pharmaceuticals.

Systemic therapy of metastatic melanoma

For patients with metastatic melanoma, there are currently several effective therapeutic options. The BRAF inhibitors vemurafenib and dabrafenib are characterized by rapid tumor control and high response rates. In combination with one of the two MEK inhibitors trametinib and cobimetinib, they achieve response rates (CR + PR, complete plus partial remissions) of 70%, while delaying the development of treatment resistance, as well as a median overall survival of > 2 years with tolerable side effects. Showing long-term survival rates of approximately 20%, the anti-CTLA-4 antibody ipilimumab is the first substance that has led to a significant prolongation of overall survival in patients with metastatic melanoma. However, delayed treatment response and severe immune-mediated side effects may pose limitations to its therapeutic benefit. Usually well tolerated, anti-PD-1 antibody monotherapy using nivolumab and pembrolizumab has yielded response rates (CR + PR) of up to 45% and one-year survival rates of > 70%. The combination of ipilimumab and nivolumab has shown response rates of up to 58% and a median progression-free survival of > 11 months. While this combination is expected to result in a rapid and long-lasting response, this potential benefit comes at the expense of a high level of toxicity. Strategies for treatment sequencing and treatment combinations are currently being investigated in clinical studies. Overall, the prognosis for patients with metastatic melanoma has significantly improved. With long-term survival a possibility, not only acute but also long-term therapeutic side effects must be taken into account.

BRAF Alterations as Therapeutic Targets in Non-Small-Cell Lung Cancer

BACKGROUND

Several subsets of non-small-cell lung cancer (NSCLC) are defined by molecular alterations acting as tumor drivers, some of them being currently therapeutically actionable. The rat sarcoma (RAS)-rapidly accelerated fibrosarcoma (RAF)-mitogen-activated protein/extracellular signal-regulated kinase kinase (MEK)-extracellular signal-regulated kinase (ERK) pathway constitutes an attractive potential target, as v-Raf murine sarcoma viral oncogene homolog B (BRAF) mutations occur in 2-4% of NSCLC adenocarcinoma.

METHODS

Here, we review the latest clinical data on BRAF serine/threonine kinase inhibitors in NSCLC.

RESULTS

Treatment of V600E BRAF-mutated NSCLC with BRAF inhibitor monotherapy demonstrated encouraging antitumor activity. Combination of BRAF and MEK inhibitors using dabrafenib and trametinib is under evaluation. Preliminary data suggest superior efficacy compared with BRAF inhibitor monotherapy.

CONCLUSION

Targeting BRAF alterations represents a promising new therapeutic approach for a restricted subset of oncogene-addicted NSCLC. Prospect ive trials refining this strategy are ongoing. A next step will probably aim at combining BRAF inhibitors and immunotherapy or alternatively improve a multilevel mitogen-activated protein kinase (MAPK) pathway blockade by combining with ERK inhibitors.

Clinical outcomes of melanoma brain metastases treated with stereotactic radiosurgery and anti-PD-1 therapy, anti-CTLA-4 therapy, BRAF/MEK inhibitors, BRAF inhibitor, or conventional chemotherapy

BACKGROUND

The effect of immunologic and targeted agents on intracranial response rates in patients with melanoma brain metastases (MBMs) is not yet clearly understood. This report analyzes outcomes of intact MBMs treated with single-session stereotactic radiosurgery (SRS) and anti-PD-1 therapy, anti-CTLA-4 therapy, BRAF/MEK inhibitors(i), BRAFi, or conventional chemotherapy.

PATIENTS AND METHODS

Patients were included if MBMs were treated with single-session SRS within 3 months of receiving systemic therapy. The primary end point of this study was distant MBM control. Secondary end points were local MBM control defined as a >20% volume increase on follow-up MRI, systemic progression-free survival, overall survival (OS) from both SRS and cranial metastases diagnosis, and neurotoxicity. Images were reviewed alongside two neuro-radiologists at our institution.

RESULTS

Ninety-six patients were treated to 314 MBMs over 119 SRS treatment sessions between January 2007 and August 2015. No significant differences were noted in age (P = 0.27), gender (P = 0.85), treated gross tumor volume (P = 0.26), or the diagnosis-specific graded prognostic assessment (P = 0.51) between the treatment cohorts. Twelve-month Kaplan-Meier (KM) distant MBM control rates were 38%, 21%, 20%, 8%, and 5% (P = 0.008) for SRS with anti-PD-1 therapies, anti-CTLA-4 therapy, BRAF/MEKi, BRAFi, and conventional chemotherapy, respectively. No significant differences were noted in the KM local MBM control rates among treatment groups (P = 0.25). Treatment with anti-PD-1 therapy, anti-CTLA-4 therapy, or BRAF/MEKi significantly improved OS on both univariate and multivariate analyses when compared with conventional chemotherapy.

CONCLUSION

In our institutional analysis of patients treated with SRS and various systemic immunologic and targeted melanoma agents, significant differences in distant MBM control and OS are noted. Prospective evaluation of the potential synergistic effect between these agents and SRS is warranted.

Combination therapeutics in complex diseases

The biological redundancies in molecular networks of complex diseases limit the efficacy of many single drug therapies. Combination therapeutics, as a common therapeutic method, involve pharmacological intervention using several drugs that interact with multiple targets in the molecular networks of diseases and may achieve better efficacy and/or less toxicity than monotherapy in practice. The development of combination therapeutics is complicated by several critical issues, including identifying multiple targets, targeting strategies and the drug combination. This review summarizes the current achievements in combination therapeutics, with a particular emphasis on the efforts to develop combination therapeutics for complex diseases.

Immunotherapy in melanoma: Recent advances and future directions

Malignant melanoma contributes the majority of skin cancer related deaths and shows an increasing incidence in the past years. Despite all efforts of early diagnosis, metastatic melanoma still has a poor prognosis and remains a challenge for treating physicians. In recent years, improved knowledge of the pathophysiology and a better understanding of the role of the immune system in tumour control have led to the development and approval of several immunotherapies. Monoclonal antibodies against different immune checkpoints have been revolutionizing the treatment of metastatic and unresectable melanoma. Ipilimumab, a monoclonal antibody against the cytotoxic T-lymphocyte antigen 4 (CTLA-4) as well as nivolumab and pembrolizumab which target the programmed cell death protein 1 (PD-1) have been shown to prolong overall survival in patients with advanced melanoma. The latter substances seem to have an increased response rate and more tolerable safety profile compared to ipilimumab. The combination of a CTLA-4 and a PD-1 inhibitor seems to be superior to the monotherapies, especially in patients with PD-L1 negative tumours. Checkpoint inhibitors are currently being tested in the adjuvant setting with initial data for ipilimumab suggesting efficacy in this context. Talimogene laherparepvec (TVEC) is the first oncolytic virus approved in the therapy of metastatic melanoma offering a treatment option especially for patients with limited disease. In this review, data on these recently developed and approved immunotherapies are presented. However, further studies are necessary to determine the optimal duration, sequencing and combinations of immunotherapies to further improve the outcome of patients with advanced melanoma.

Copper suppression as cancer therapy: the rationale for copper chelating agents in BRAFV600 mutated melanoma

The successful targeting of oncogenic BRAF^V600 represents one of the landmark breakthroughs in therapy for advanced melanoma. While the initial clinical benefit can be dramatic, resistance is common due to a number of mechanisms, including MAPK pathway reactivation. Recent data have revealed a novel role for copper (Cu) in BRAF signaling with potential clinical implications. The history, preclinical data and efficacy of Cu chelating agents in cancer, specifically tetrathiomolybdate, will be reviewed with a focus on the rationale for targeting the MAPK cascade in melanoma through novel combination strategies.

Cost and economic burden of adverse events associated with metastatic melanoma treatments in five countries

OBJECTIVE

To estimate per-event cost and economic burden associated with managing the most common and/or severe metastatic melanoma (MM) treatment-related adverse events (AEs) in Australia, France, Germany, Italy, and the UK.

METHODS

AEs associated with chemotherapy (dacarbazine, paclitaxel, fotemustine), immunotherapy (ipilimumab), and targeted therapy (vemurafenib) were identified by literature review. Medical resource use data associated with managing AEs were collected through two blinded Delphi panel cycles in each of the five countries. Published costs were used to estimate per-event costs and combined with AEs incidence, treatment usage, and MM prevalence to estimate the economic burden for each country.

RESULTS

The costliest AEs were grade 3/4 events due to immunotherapy (Australia/France: colitis; UK: diarrhea) and chemotherapy (Germany/Italy: neutropenia/leukopenia). Treatment of AEs specific to chemotherapy (Australia/Germany/Italy/France: neutropenia/leukopenia) and targeted therapy (UK: squamous cell carcinoma) contributed heavily to country-specific economic burden.

LIMITATIONS

Economic burden was estimated assuming that each patient experienced an AE only once. In addition, the context of settings was heterogeneous and the number of Delphi panel experts was limited.

CONCLUSIONS

Management costs for MM treatment-associated AEs can be substantial. Results could be incorporated in economic models that support reimbursement dossiers. With the availability of newer treatments, establishment of a baseline measure of the economic burden of AEs will be crucial for assessing their impact on patients and regional healthcare systems.

The cutting edge of metastatic melanoma therapy

The past decade has witnessed impressive new developments for the treatment of melanoma. The discovery of key oncogenic driver mutations, upon which tumor establishment and progression are dependent, changed the prognosis of patients with stage IV disease. Extensive preclinical and clinical studies have shown high response rates and survival benefits over conventional chemotherapies provided by target-specific inhibitors of BRAF- or NRAS-activating mutations. Recent genomic analyses of melanoma have also given new potentially targetable driver mutations. In addition, the quickened pace of development of immune checkpoint inhibitors for the treatment of melanoma offers the unique opportunity to provide a long-term clinical benefit. In this emerging era, predictive biomarkers for the selection of patients are required to help us develop an optimal therapeutic strategy.

The pharmacogenomics of drug resistance to protein kinase inhibitors

Dysregulation of growth factor cell signaling is a major driver of most human cancers. This has led to development of numerous drugs targeting protein kinases, with demonstrated efficacy in the treatment of a wide spectrum of cancers. Despite their high initial response rates and survival benefits, the majority of patients eventually develop resistance to these targeted therapies. This review article discusses examples of established mechanisms of drug resistance to anticancer therapies, including drug target mutations or gene amplifications, emergence of alternate signaling pathways, and pharmacokinetic variation. This reveals a role for pharmacogenomic analysis to identify and monitor for resistance, with possible therapeutic strategies to combat chemoresistance.

Non-V600 BRAF mutations recurrently found in lung cancer predict sensitivity to the combination of Trametinib and Dabrafenib

Approximately half of BRAF-mutated Non-small cell lung cancers (NSCLCs) harbor a non-V600 BRAF mutation, accounting for ∼40,000 annual deaths worldwide. Recent studies have revealed the benefits of combined targeted therapy with a RAF-inhibitor (Dabrafenib) and a MEK-inhibitor (Trametinib) in treating V600 BRAF mutant cancers, including NSCLC. In contrast, sensitivity of non-V600 BRAF mutations to these inhibitors is not documented. Non-V600 mutations can either increase or impair BRAF kinase activity. However, impaired BRAF kinases can still activate the ERK pathway in a CRAF-dependent manner. Herein, beyond describing a cohort of BRAF mutant NSCLC patients and functionally analyzing 13 tumor-derived BRAF mutations, we demonstrate that both types of non-V600 BRAF mutations can be sensitive to clinically relevant doses of Dabrafenib and Trametinib in HEK293T cells, in lung epithelial cellular model (BEAS-2B) and in human cancer cell lines harboring non-V600 BRAF mutations. ERK activity induced by both types of these mutations is further reduced by combinatorial drug treatment. Moreover, the combination leads to more prolonged ERK inhibition and has anti-proliferative and pro-apoptotic effects in cells harboring both types of non-V600 BRAF mutations. This study provides a basis for the clinical exploration of non-V600 BRAF mutant lung cancers upon treatment with Trametinib and Dabrafenib.

Current treatments for advanced melanoma and introduction of a promising novel gene therapy for melanoma (Review)

Metastatic melanoma is a fatal form of skin cancer that has a tendency to proliferate more rapidly than any other solid tumor. Since 2010, treatment options for metastatic melanoma have been developed including chemotherapies, checkpoint inhibition immunotherapies, e.g., anti‑cytotoxic T‑lymphocyte antigen‑4 (CTLA‑4) and anti‑programmed death‑1 (PD‑1), and molecular-targeted therapies, e.g., BRAF and MEK inhibitors. These treatments have shown not only high response rates yet also side‑effects and limitations. Notwithstanding its limitations, stem cell therapy has emerged as a new auspicious therapy for various tumor types. Since stem cells possess the ability to serve as a novel vehicle for delivering therapeutic or suicide genes to primary or metastatic cancer sites, these cells can function as part of gene‑directed enzyme prodrug therapy (GDEPT). This review focuses on introducing engineered neural stem cells (NSCs), which have tumor‑tropic behavior that allows NSCs to selectively approach primary and invasive tumor foci, as a potential gene therapy for melanoma. Therapy using engineered NSCs with cytotoxic agents resulted in markedly reduced tumor volumes and significantly prolonged survival rates in preclinical models of various tumor types. This review elucidates current treatment options for metastatic melanoma and introduces a promising NSC therapy.

Phase II study of vemurafenib followed by ipilimumab in patients with previously untreated BRAF-mutated metastatic melanoma

BACKGROUND

Ipilimumab (IPI), an anti-CTLA-4 antibody, and vemurafenib (VEM), a BRAF inhibitor, have distinct mechanisms of action and shared toxicities (e.g., skin, gastrointestinal [GI] and hepatobiliary disorders) that may preclude concomitant administration. Concurrent administration of IPI and VEM previously showed significant dose-limiting hepatotoxicity in advanced melanoma. This single-arm, open-label, phase II study evaluated a sequencing strategy with these two agents in previously untreated patients with BRAF-mutated advanced melanoma.

METHODS

This study was divided into two parts. During Part 1 (VEM1-IPI), patients received VEM 960 mg twice daily for 6 weeks followed by IPI 10 mg/kg every 3 weeks for 4 doses (induction), then every 12 weeks (maintenance) beginning at week 24 until disease progression or unacceptable toxicity. During Part 2 (VEM2), patients who progressed after IPI received VEM at their previously tolerated dose. The primary objective was to estimate the incidence of grade 3/4 drug-related skin adverse events (AEs) during VEM1-IPI.

RESULTS

All patients who were initially treated with VEM (n = 46) received IPI induction therapy; 8 received IPI maintenance and 19 were treated during VEM2. During VEM1-IPI, the incidence of grade 3/4 drug-related AEs associated with the skin, GI tract, and hepatobiliary system was 32.6 %, 21.7 %, and 4.3 %, respectively. There were no drug-related deaths. At a median follow-up of 15.3 months, median overall survival was 18.5 months. Median progression-free survival was 4.5 months.

CONCLUSIONS

VEM (960 mg twice daily for 6 weeks) followed by IPI 10 mg/kg has a manageable safety profile. The benefits/risks of BRAF inhibitors followed by immunotherapy should be evaluated further in light of continuing developments in treatment options for metastatic melanoma.

TRIAL REGISTRATION

ClinicalTrials.gov identifier: NCT01673854 (CA184-240) Registered 24 August 2012.

[Not Available]

ANTI-PD1 ROLE IN TREATMENT OF CUTANEOUS MELANOMA: The treatment of metastatic melanoma dramatically changed over the last years. Two therapeutic revolutions emerged in parallel, targeted anti-BRAF and anti-MEK therapies, for patients BRAFV600 mutated and immunotherapy with immune checkpoint blockers using anti-CTLA-4 then anti-PD1 monoclonal antibodies. Indeed, melanoma immunotherapy was a golden objective for many years but in spite of important efforts using cytokines (interferon, interleukin) and different vaccine approaches no objective improvement of patients 'prognosis was obtained. Ipilimumab, authorized in 2011, was the first drug which showed a benefit of overall survival in patients with metastatic melanoma in spite a low response rate (10-15) and the occurrence of about 25% of serious toxicity. Anti-PD1 appear as a new generation of immune checkpoint blockade with response rates between 30 to 40% of the patients, a proven overall survival benefit as compared with chemotherapy or ipilimumab and less toxicity than ipilimumab. Two molecules, pembrolizumab and nivolumab were recently approved in monotherapy, for metastatic melanoma. Several questions remain unresolved: the respective indications of anti-PD1 and targeted therapies in first line therapy in patients with BRAF mutant melanoma, the benefit of combining immunotherapy with radiotherapy or with targeted therapies, the optimal treatment duration, and the benefit of the anti-PD1 in the adjuvant setting. The combination of ipilimumab and nivolumab, recently approved by the FDA but not yet in Europ, shows an improvement of the objective response rates (50-57%) and progression free survival compared with nivolumab but is associated with an higer incidence of serious adverse events (more than 50%).

Novel melanoma therapy

With the rapid succession of new effective agents for melanoma in the recent years, the paradigm for treatment of metastatic melanoma is changing. The success of combining multiple effective agents compared with outcomes of monotherapy also brings increasing complexity in the treatment algorithm for various subsets of metastatic melanoma patients. We reviewed the recent reports on novel melanoma therapy to shed light on rational decision-making in treating these patients.

MEK inhibitor-associated retinopathy (MEKAR) in metastatic melanoma: Long-term ophthalmic effects

BACKGROUND

Mitogen-activated protein kinase kinase (MEK) inhibitors have aroused considerable interest in oncology. Activity has been demonstrated in various types of cancer, especially melanoma. MEK inhibitors induce a transient retinopathy, considered to be a class effect. At present, only sparse data are available on retinal effects with long-term MEK inhibition.

PATIENTS AND METHODS

In this prospective, observational study, patients with advanced melanoma participating in different phase 1/2 or phase 3 clinical trials were treated with the MEK inhibitor binimetinib, with a v-Raf murine sarcoma viral oncogene homolog B (BRAF) inhibitor, or with combination therapy. They underwent regular ophthalmological examinations including determination of visual function, biomicroscopy, dilated fundoscopy and optical coherence tomography (OCT) for a period of up to 2 years. Retinopathy was diagnosed on defined OCT criteria.

RESULTS

Sixty-two patients were investigated between 1st October 2011 and 31st July 2015: 13 were treated with the MEK inhibitor binimetinib alone, 10 with a selective BRAF inhibitor, and 39 with combination therapy. In 92% of patients on monotherapy and 100% of those on combination treatment, binimetinib caused dose-related lesions with serous neuroretinal detachments and oedema, strongly dependent on the time after medication. With continued treatment, retinal volume and thickness decreased to levels below baseline, without any apparent functional deficits or changes in structural integrity.

CONCLUSIONS

Binimetinib induces a specific retinopathy with daily fluctuations depending on the time interval after medication. The retinopathy partially recovers, but can still be detected many months later. Retinal thinning, possible first signs of retinal atrophy have been observed after long-term treatment, but, so far, without functional relevance.

Prognostic factors and disease-specific survival among immigrants diagnosed with cutaneous malignant melanoma in Sweden

Little is known about cutaneous malignant melanoma (CMM) among immigrants in Europe. We aimed to investigate clinical characteristics and disease-specific survival among first- and second-generation immigrants in Sweden. This nationwide population-based study included 27,235 patients from the Swedish Melanoma Register diagnosed with primary invasive CMM, 1990-2007. Data were linked to nationwide, population-based registers followed up through 2013. Logistic regression and Cox regression models were used to determine the association between immigrant status, stage and CMM prognosis, respectively. After adjustments for confounders, first generation immigrants from Southern Europe were associated with significantly more advanced stages of disease compared to Swedish-born patients [Stage II vs. I: Odds ratio (OR) = 2.37, 95% CI = 1.61-3.50. Stage III-IV vs I: OR = 2.40, 95% CI = 1.08-5.37]. The ORs of stage II-IV versus stage I disease were increased among men (OR = 1.9; 95% CI = 1.1-3.3; p = 0.020), and women (OR = 4.8; 95% CI = 2.6-9.1; p < 0.001) in a subgroup of immigrants from former Yugoslavia compared to Swedish-born patients. The CMM-specific survival was significantly decreased among women from former Yugoslavia versus Swedish-born women [hazard ratio (HR)=2.2; 95% CI = 1.1-4.2; p = 0.043]. After additional adjustments including stage, the survival difference was no longer significant. No survival difference between the second generation immigrant group and Swedish-born patients were observed. In conclusion, a worse CMM-specific survival in women from former Yugoslavia was associated with more advanced stages of CMM at diagnosis. Secondary prevention efforts focusing on specific groups may be needed to further improve the CMM prognosis.

Molecular diagnostics and anaplastic thyroid carcinoma: the time has come to harvest the high hanging fruit

Targeted therapies have played a major role in cancer therapeutics, starting with the discovery of a drug against BCR–ABL rearrangements in chronic myelogenous leukemia. This led to the first approval of a targeted agent in cancer and since, many others have followed. Anaplastic thyroid cancer (ATC) is an aggressive carcinoma with few curative options. Although previous cytotoxic chemotherapy and kinase inhibitor therapies have not proven efficacious in ATC, some of the newer drugs appear to be promising. A case report and a comprehensive review of the current standard of care, genetics, modern therapeutic drugs and clinical trials are presented, in order to outline where we currently stand and where the future lies in the quest for a cure for ATC.

Combined Therapy with Dabrafenib and Trametinib in BRAF-Mutated Metastatic Melanoma in a Real-Life Setting: The INT Milan Experience

Purpose

Combination therapy with dabrafenib and trametinib is safer and more effective than BRAF inhibitor-based monotherapy for metastatic melanoma.

Methods

We retrospectively analyzed BRAF-mutated metastatic melanoma patients treated at our institution with daily oral dabrafenib 300 mg and trametinib 2 mg from November 2013 to April 2016. This clinical record included both untreated and previously treated stage IV melanomas. Physical examination and laboratory examinations were performed monthly and disease re-evaluations were performed every 3 months.

Results

A total of 48 patients (24 male, 24 female) with BRAF-mutated metastatic melanoma received dabrafenib and trametinib; median age was 48 years (range 23-75). Median follow-up was 362.5 days (range 72-879). Best overall response rate consisted of 6.2% (3 patients) complete response, 64.6% (31) partial response, and 25% ( 12 ) stable disease; median time to best response was 11 weeks (range 5.7-125.5). Progression of disease was seen in 19 patients (39.6%), with median time to progression (TTP) of 26 weeks (range 8-54). A total of 15 patients (31.2%) died due to progression of disease. Median progression-free survival and median overall survival were not reached. To date, 30 patients (62.5%) are still under treatment. A total of 27 (56.2%) patients had at least one adverse event (AE); grade 3-4 AEs were seen in 4 cases (8.3%). The main toxicities were fever (25%), skin rash (14.6%), arthralgias (10.4%), and aspartate aminotransferase/alanine aminotransferase increase (8.3%). Treatment dose was reduced in 7 subjects (14.6%), with only one case of discontinuation due to AE.

Conclusions

Our data, using combined targeted therapy, are in line with the scientific literature in terms of both safety and effectiveness in a real-life setting.

Ipilimumab in melanoma

INTRODUCTION

The treatment of melanoma is evolving rapidly over the past few years. Patients with BRAFv600 mutations can be treated with a combination of a BRAF-inhibitor and an MEK-inhibitor. Patients with BRAF wild-type tumors and BRAFv600 mutated tumors can be treated with immunotherapy i.e. check point inhibitors.

AREAS COVERED

We conducted a comprehensive review of the literature on the efficacy and predictive markers, safety, and pharmacoeconomics of ipilimumab in melanoma Expert commentary: Ipilimumab was the first check point inhibitor reaching the clinic, gaining FDA and EMA approval for metastatic melanoma in 2011. Ipilimumab was also approved by FDA in the adjuvant setting for patients with high risk, stage III melanoma. The anti-PD1 directed antibodies pembrolizumab and nivolumab are superior to single agent ipilimumab, which is no longer considered the standard first line treatment in metastatic melanoma. The addition ipilimumab to nivolumab is associated with a higher response rate and a better PFS, particularly in patients with PD-L1 negative tumors, albeit at the cost of a steep increase in grade 3-4 adverse event rate. Definitive survival data on this combination are pending and the selection of patients potentially requiring the combination and its pharmacoeconomic implications are to be elucidated.

Evaluating cost benefits of combination therapies for advanced melanoma

BACKGROUND

Although a number of monoimmunotherapies and targeted therapies are available to treat BRAF+ advanced melanoma, response rates remain relatively low in the range of 22-53% with progression-free survival (PFS) in the range of 4.8-8.8 months. Recently, combination targeted therapies have improved response rates to about 66-69%, PFS to 11.0-12.6 months and overall survival (OS) to 25.1-25.6 months. While combination immunotherapies have improved response rates of 67 compared with 19-29% with monotherapies and improved PFS of 11.7 compared with 4.4-5.8 months with monotherapies, the OS benefit is yet to be established in phase 3 trials. As healthcare costs continue to rise, US payers have a predominant interest in assessing the value of available treatments. Therefore, a cost-benefit model was developed to evaluate the value of treating BRAF+ advanced melanoma with two combination therapies: nivolumab + ipilimumab (N+I) and dabrafenib + trametinib (D+T).

SCOPE

The model was used to estimate total costs, total costs by expenditure category, cost per month of PFS and cost per responder for the payer, and societal perspectives of treating advanced melanoma patients with the BRAF V600 mutation using combination targeted therapy (D+T) or combination immunotherapy (N+I). The model followed patients from initiation of treatment to the point of progression or death. Deterministic and probabilistic sensitivity analyses were conducted to evaluate the robustness of the results and to understand the dispersion of simulated results.

FINDINGS

Based on a hypothetical payer with one million covered lives, it was expected that fourteen metastatic melanoma patients with the BRAF V600 mutation would be treated each year. Cost-benefit with N+I and D+T was simulated from the payer perspective. The cost per month of PFS for N+I was $22,162, while that for D+T was $17,716 (-$4,446 cost difference); the cost per responder for N+I was $388,746 and that for D+T was $282,429 (-$106,316 cost difference). The cost per month of PFS and per responder from the societal perspective resembled the patterns observed from the payer's perspective: the cost per month of PFS for N+I was $22,843, while that for D+T was $18,283 (-$4,560 cost difference). The cost per responder for N+I was $400,695 and that for D+T was $291,473 (-$109,222 cost difference). The totals of travel and treatment time for N+I and D+T were 58 hours and 3.9 hours per patient, respectively, of which total infusion time for N+I accounted for a majority - 59% - of the 58 hours. Sensitivity analyses indicated that results were most sensitive to model inputs for median PFS, body weight, and drug cost. Moreover, D+T is likely associated with a lower cost per month of PFS and cost per responder than N+I, except at low body weights (less than 57 kg).

CONCLUSION

The model presented in this study was used to analyze the clinical and economic benefit of using combination therapies in advanced melanoma patients with the BRAF V600 mutation. This analysis suggests D+T therapy is associated with less patient time and lower costs relative to N+I to gain similar PFS and overall response rate (ORR) benefits.

Combined vemurafenib and fotemustine in patients with BRAF V600 melanoma progressing on vemurafenib

Background

BRAF inhibitor vemurafenib achieves high response rate and an improvement in survival in patients with BRAF-mutated metastatic melanoma. However, median progression-free survival is only 6.9 months in the phase 3 study. Retrospective analyses suggest that treatment with BRAF inhibitors beyond initial progression might be associated with improved overall survival. We aimed to prospectively investigate the activity of prolonged treatment with vemurafenib and the addition of fotemustine in patients with systemic progression on prior single-agent BRAF inhibitor.

Patients and Methods

In this two-centres, single-arm Phase 2 trial, we enrolled patients with systemic progressive disease during single-agent vemurafenib treatment. Participants received vemurafenib 960 mg twice daily or dose administered at time of disease progression with vemurafenib previous treatment and fotemustine 100 mg/m2 intravenously every three weeks. The primary endpoint was PFS.

Results

Thirty-one patients were enrolled in the study; 16 patients had brain metastases at baseline. Median PFS was 3.9 months and 19 patients (61.3%) achieved disease control (1 CR, 4 PR, 14 SD). For patients achieving disease control, median duration of treatment was 6 months. Median OS was 5.8 months from enrolment and 15.4 months from start of previous vemurafenib. Five patients (16.1%) had a G3-4 AE, the most common being thrombocytopenia, which occurred in 3 patients.

This trial is registered with ClinicalTrials.gov number NCT01983124.

Conclusion

The combination of vemurafenib plus fotemustine has clinical activity and an acceptable safety profile in BRAF-refractory patients.