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

Phase I study of [131I] ICF01012, a targeted radionuclide therapy, in metastatic melanoma: MELRIV-1 protocol

Background

Benzamide-based radioligands targeting melanin were first developed for imaging melanoma and then for therapeutic purpose with targeted radionuclide therapy (TRT).

[¹³¹I]ICF01012 presents a highly favorable pharmacokinetics profile in vivo for therapy. Tumour growth reduction and increase survival have been established in preclinical models of melanoma. According the these preclinical results, we initiate a first-in-human study aimed to determine the recommended dose of [¹³¹I]ICF01012 to administer for the treatment of patients with pigmented metastatic melanoma.

Methods

The MELRIV-1 trial is an open-label, multicentric, dose-escalation phase I trial. The study is divided in 2 steps, a selection part with an IV injection of low activity of [¹³¹I]ICF01012 (185 MBq at D0) to select patients who might benefit from [¹³¹I]ICF01012 TRT in therapeutic part, i.e. patient presenting at least one tumour lesion with [¹³¹I]ICF01012 uptake and an acceptable personalized dosimetry to critical organs (liver, kidney, lung and retina). According to dose escalation scheme driven by a Continual Reassessment Method (CRM) design, a single therapeutic injection of 800 MBq/m², or 1600 MBq/m², or 2700 MBq/m² or 4000 MBq/m² of [¹³¹I]ICF01012 will be administered at D11 (± 4 days). The primary endpoint is the recommended therapeutic dose of [¹³¹I]ICF01012, with DLT defined as any grade 3-4 NCI-CT toxicity during the 6 weeks following therapeutic dose. Safety, pharmacokinetic, biodistribution (using planar whole body and SPECT-CT acquisitions), sensitivity / specificity of [¹³¹I]ICF01012, and therapeutic efficacy will be assessed as secondary objectives. Patients who received therapeutic injection will be followed until 3 months after TRT. Since 6 to 18 patients are needed for the therapeutic part, up to 36 patients will be enrolled in the selection part.

Discussion

This study is a first-in-human trial evaluating the [¹³¹I]ICF01012 TRT in metastatic malignant melanomas with a diagnostic dose of the [¹³¹I]ICF01012 to select the patients who may benefit from a therapeutic dose of [¹³¹I]ICF01012, with at least one tumor lesion with [¹³¹I]ICF01012 uptake and an acceptable AD to healthy organ.

Trial registration

Clinicaltrials.gov: NCT03784625. Registered on December 24, 2018.

Identifier in French National Agency for the Safety of Medicines and Health Products (ANSM): N°EudraCT 2016-002444-17.

Discovery of SHR2415, a Novel Pyrrole-Fused Urea Scaffold ERK1/2 Inhibitor

ERK1/2 kinase is a key downstream node of the RAS-RAF-MEK-ERK signaling pathway. A highly potent and selective ERK1/2 inhibitor is a promising option for cancer treatment that will provide a potential solution for overcoming drug resistance. Herein we designed and synthesized a novel scaffold featuring a pyrrole-fused urea template. The lead compound, SHR2415, was shown to be a highly potent ERK1/2 inhibitor that exhibited high cell potency based on the Colo205 assay. In addition, SHR2415 displayed favorable PK profiles across species as well as robust in vivo efficacy in a mouse Colo205 xenograft model.

How I treat refractory/relapsed hairy cell leukemia with BRAF inhibitors

Hairy cell leukemia (HCL) responds very well to frontline chemotherapy with purine analogs (cladribine and pentostatine). However, approximately half of patients experience 1 or more relapses, which become progressively resistant to these myelotoxic and immunosuppressive agents. At progression, standard therapeutic options include a second course of purine analogs alone or in combination with rituximab and, upon second relapse, therapy with the anti-CD22 immunotoxin moxetumomab pasudotox. Furthermore, blockade of the mutant BRAF-V600E kinase (the pathogenetic hallmark of HCL) through orally available specific inhibitors (vemurafenib or dabrafenib) effaces the peculiar morphologic, phenotypic, and molecular identity of this disease and its typical antiapoptotic behavior and is emerging as an attractive chemotherapy-free strategy in various clinical scenarios. These include patients with, or at risk of, severe infections and, in a highly effective combination with rituximab, patients with relapsed or refractory HCL. Other treatments explored in clinical trials are BTK inhibition with ibrutinib and co-inhibition of BRAF (through dabrafenib or vemurafenib) and its downstream target MEK (through trametinib or cobimetinib). Here, we focus on our experience with BRAF inhibitors in clinical trials and as off-label use in routine practice by presenting 3 challenging clinical cases to illustrate their management in the context of all available treatment options.

Targeted Therapy for Melanomas Without BRAF V600 Mutations

Modern therapy of advanced melanoma offers effective targeted therapeutic options in the form of BRAF plus MEK inhibition for patients with BRAF V600 mutations. For patients lacking these mutations, checkpoint inhibition remains the only first-line choice for treatment of metastatic disease. However, approximately half of patients do not respond to immunotherapy, requiring effective options for a second-line treatment. Advances in genetic profiling have found other possible target molecules, especially a wide array of rare non-V600 BRAF mutations which may respond to available targeted therapy.

More information on the characteristics of such mutants is needed to further assess the efficacy of targeted therapies in the metastatic and adjuvant setting of advanced melanoma. Thus, it may be helpful to classify known BRAF mutations by their kinase activation status and dependence on alternative signaling pathways. While BRAF V600 mutations appear to have an overall more prominent role of kinase activity for tumor growth, non-V600 BRAF mutations show great differences in kinase activation and, hence, response to BRAF plus MEK inhibition. When BRAF-mutated melanomas rely on additional signaling molecules such as RAS for tumor growth, greater benefit may be expected from MEK inhibition than BRAF inhibition. In other cases, mutations of c-kit or NRAS may serve as important pharmacological targets in advanced melanoma. However, since benefit from currently available targeted therapies for non-V600 mutants is usually inferior regarding response and long-term outcome, checkpoint inhibitors remain the standard recommended first-line therapy for these patients.

Herein, we review the current clinical data for characteristics and response to targeted therapy of melanomas lacking a V600 BRAF mutation.

Triplet Therapy in Melanoma - Combined BRAF/MEK Inhibitors and Anti-PD-(L)1 Antibodies

PURPOSE OF REVIEW

We provide an updated review of clinical trials evaluating the combination of BRAF/MEK inhibitors with anti-PD-(L)1 therapy (triplet therapy) for patients with advanced BRAF-mutant melanoma, accompanied by a summary of the biological evidence supporting this combination.

RECENT FINDINGS

Resistance to BRAF/MEK inhibition and comparatively low response rates to immune checkpoint inhibitors remain clinical challenges in the treatment of melanoma. Preclinical data demonstrates that targeted therapy is immune-modulatory and synergises with immune checkpoint inhibition. Several randomised controlled trials have evaluated the combination of targeted therapy with immune checkpoint inhibition. Triplet therapy has shown improvements in progression-free survival and durability of response compared to BRAF/MEK inhibition alone; however, questions remain regarding the best clinical scenario for implementation of this regimen in the era of front-line immunotherapy.

SEOM-GEINO clinical guideline of systemic therapy and management of brain central nervous system metastases (2021)

Central nervous system (CNS) dissemination is a severe complication in cancer and a leading cause of cancer-related mortality. Brain metastases (BMs) are the most common types of malignant intracranial tumors and are reported in approximately 25% of patients with metastatic cancers. The recent increase in incidence of BMs is due to several factors including better diagnostic assessments and the development of improved systemic therapies that have lower activity on the CNS. However, newer systemic therapies are being developed that can cross the blood-brain barrier giving us additional tools to treat BMs. The guidelines presented here focus on the efficacy of new targeted systemic therapies and immunotherapies on CNS BMs from breast, melanoma, and lung cancers.

Mechanisms of immune activation and regulation: lessons from melanoma

Melanoma, a skin cancer that develops from pigment cells, has been studied intensively, particularly in terms of the immune response to tumours, and has been used as a model for the development of immunotherapy. This is due, in part, to the high mutational burden observed in melanomas, which increases both their immunogenicity and the infiltration of immune cells into the tumours, compared with other types of cancers. The immune response to melanomas involves a complex set of components and interactions. As the tumour evolves, it accumulates an increasing number of genetic and epigenetic alterations, some of which contribute to the immunogenicity of the tumour cells and the infiltration of immune cells. However, tumour evolution also enables the development of resistance mechanisms, which, in turn, lead to tumour immune escape. Understanding the interactions between melanoma tumour cells and the immune system, and the evolving changes within the melanoma tumour cells, the immune system and the microenvironment, is essential for the development of new cancer therapies. However, current research suggests that other extrinsic factors, such as the microbiome, may play a role in the immune response to melanomas. Here, we review the mechanisms underlying the immune response in the tumour and discuss recent advances as well as strategies for treatment development.

HSP90 inhibition overcomes resistance to molecular targeted therapy in BRAFV600E mutant high-grade glioma

PURPOSE

Molecular targeted therapy using BRAF and/or MEK inhibitors has been applied to BRAFV600E mutant high-grade gliomas (HGGs); however, the therapeutic effect is limited by the emergence of drug resistance.

EXPERIMENTAL DESIGN

We established multiple paired BRAFV600E mutant HGG patient-derived xenograft (PDX) models based on tissues collected prior to and at relapse after molecular targeted therapy. Using these models, we dissected treatment resistant mechanisms for molecular targeted therapy and explored therapeutic targets to overcome resistance in BRAFV600E HGG models in vitro and in vivo.

RESULTS

We found that, despite causing no major genetic and epigenetic changes, BRAF and/or MEK inhibitor treatment deregulated multiple negative feedback mechanisms, which led to the re-activation of the MAPK pathway through c-Raf and AKT signaling. This altered oncogenic signaling primarily mediated resistance to molecular targeted therapy in BRAFV600E mutant HGG. To overcome this resistance mechanism, we performed a high-throughput drug screening to identify therapeutic agents that potently induce additive cytotoxicity with BRAF and MEK inhibitors. We discovered that HSP90 inhibition combined with BRAF/MEK inhibition coordinately deactivated the MAPK and AKT/mTOR pathways, and subsequently induced apoptosis via dephosphorylation of GSK3β (Ser9) and inhibition of Bcl-2 family proteins. This mediated potent cytotoxicity in vitro and in vivo in refractory models with acquired resistance to molecular-targeted therapy.

CONCLUSIONS

The combination of an HSP90 inhibitor with BRAF or MEK inhibitors can overcome the limitations of the current therapeutic strategies for BRAFV600E mutant HGG.

Discoidin Domain Receptor 2 orchestrates melanoma resistance combining phenotype switching and proliferation

Combined therapy with anti-BRAF plus anti-MEK is currently used as first-line treatment of patients with metastatic melanomas harboring the somatic BRAF V600E mutation. However, the main issue with targeted therapy is the acquisition of tumor cell resistance. In a majority of resistant melanoma cells, the resistant process consists in epithelial-to-mesenchymal transition (EMT). This process called phenotype switching makes melanoma cells more invasive. Its signature is characterized by MITF low, AXL high, and actin cytoskeleton reorganization through RhoA activation. In parallel of this phenotype switching phase, the resistant cells exhibit an anarchic cell proliferation due to hyper-activation of the MAP kinase pathway. We show that a majority of human melanoma overexpress discoidin domain receptor 2 (DDR2) after treatment. The same result was found in resistant cell lines presenting phenotype switching compared to the corresponding sensitive cell lines. We demonstrate that DDR2 inhibition induces a decrease in AXL expression and reduces stress fiber formation in resistant melanoma cell lines. In this phenotype switching context, we report that DDR2 control cell and tumor proliferation through the MAP kinase pathway in resistant cells in vitro and in vivo. Therefore, inhibition of DDR2 could be a new and promising strategy for countering this resistance mechanism.

Combined HP 13C Pyruvate and 13C-Glucose Fluxomic as a Potential Marker of Response to Targeted Therapies in YUMM1.7 Melanoma Xenografts

A vast majority of BRAF V600E mutated melanoma patients will develop resistance to combined BRAF/MEK inhibition after initial clinical response. Resistance to targeted therapy is described to be accompanied by specific metabolic changes in melanoma. The aim of this work was to evaluate metabolic imaging using ¹³C-MRS (Magnetic Resonance Spectroscopy) as a marker of response to BRAF/MEK inhibition in a syngeneic melanoma model. Tumor growth was significantly delayed in mice bearing YUMM1.7 melanoma xenografts treated with the BRAF inhibitor vemurafenib, and/or with the MEK inhibitor trametinib, in comparison with the control group. ¹³C-MRS was performed in vivo after injection of hyperpolarized (HP) ¹³C-pyruvate, at baseline and 24 h after treatment, to evaluate dynamic changes in pyruvate-lactate exchange. Furthermore, ex vivo ¹³C-MRS steady state metabolic tracing experiments were performed after U-¹³C-glucose or 5-¹³C-glutamine injection, 24 h after treatment. The HP ¹³C-lactate-to-pyruvate ratio was not modified in response to BRAF/MEK inhibition, whereas the production of ¹³C-lactate from ¹³C-glucose was significantly reduced 24 h after treatment with vemurafenib, trametinib, or with the combined inhibitors. Conversely, ¹³C-glutamine metabolism was not modified in response to BRAF/MEK inhibition. In conclusion, we identified ¹³C-glucose fluxomic as a potential marker of response to BRAF/MEK inhibition in YUMM1.7 melanoma xenografts.

NRF2 and Key Transcriptional Targets in Melanoma Redox Manipulation

Melanocytes are dendritic, pigment-producing cells located in the skin and are responsible for its protection against the deleterious effects of solar ultraviolet radiation (UVR), which include DNA damage and elevated reactive oxygen species (ROS). They do so by synthesizing photoprotective melanin pigments and distributing them to adjacent skin cells (e.g., keratinocytes). However, melanocytes encounter a large burden of oxidative stress during this process, due to both exogenous and endogenous sources. Therefore, melanocytes employ numerous antioxidant defenses to protect themselves; these are largely regulated by the master stress response transcription factor, nuclear factor erythroid 2-related factor 2 (NRF2). Key effector transcriptional targets of NRF2 include the components of the glutathione and thioredoxin antioxidant systems. Despite these defenses, melanocyte DNA often is subject to mutations that result in the dysregulation of the proliferative mitogen-activated protein kinase (MAPK) pathway and the cell cycle. Following tumor initiation, endogenous antioxidant systems are co-opted, a consequence of elevated oxidative stress caused by metabolic reprogramming, to establish an altered redox homeostasis. This altered redox homeostasis contributes to tumor progression and metastasis, while also complicating the application of exogenous antioxidant treatments. Further understanding of melanocyte redox homeostasis, in the presence or absence of disease, would contribute to the development of novel therapies to aid in the prevention and treatment of melanomas and other skin diseases.

The PIK3CA H1047R Mutation Confers Resistance to BRAF and MEK Inhibitors in A375 Melanoma Cells through the Cross-Activation of MAPK and PI3K-Akt Pathways

The targeting of the Mitogen-Activated Protein Kinase (MAPK) signalling pathway in melanoma improves the prognosis of patients harbouring the V-Raf Murine Sarcoma Viral Oncogene Homolog B1 (BRAF) mutation. However, a fraction of these patients may experience tumour progression due to resistance to targeted therapy. Mutations affecting the Phosphoinositol-3-Kinase (PI3K)–Akt pathway may favour the onset of drug resistance, suggesting the existence of a crosstalk between the MAPK and PI3K–Akt pathways. We hypothesized that the inhibition of both pathways may be a therapeutic option in resistant melanoma. However, conflicting data have been generated in this context. In this study, three different A375 cell melanoma models either overexpressing or not expressing the wild-type or mutated form of the PhosphatidylInositol-4,5-bisphosphate 3-Kinase Catalytic Subunit Alpha (PIK3CA) gene were used to clarify the therapeutic response of melanoma to BRAF, Mitogen-Activated Protein Kinase Kinase 1 (MEK), and PI3K inhibitors in the presence of the PIK3CA H1047R mutation. Our data strongly support the notion that the crosstalk between the MAPK and PI3K–Akt pathways is one of the main mechanisms associated with melanoma development and progression and that the combination of MAPK and PI3K inhibitors may sensitize melanoma cells to therapy.

MET Exon 14 Splice-Site Mutations Preferentially Activate KRAS Signaling to Drive Tumourigenesis

Simple Summary

MET exon 14 splice-site mutations occur in ~3–4% of lung adenocarcinoma cases, defining a cohort of patients which might benefit from anti-MET targeted therapy. Such therapies have yielded mixed results, however, pointing to the need for better treatment design. Our study sought to aid this by characterizing key changes in mutant MET signaling behaviour. We first compared the transcriptional profiles of lung tumours with either METΔex14 or wild-type MET-amplification. METΔex14-mutant tumours exhibited increased activation of the Ras-MAPK pathway, consistent with our observations in an isogenic model system. Furthermore, sustained activity of this pathway is necessary for proliferation and maintenance of METΔex14 tumours, while forced reactivation of this pathway is sufficient to restore growth in the absence of MET activity. Our findings suggest that the MAPK pathway represents a main effector of METΔex14-driven cancer, lending credence to the possibility of combined MET-MAPK inhibition to improve therapeutic outcomes.

Abstract

Targeted therapies for MET exon 14-skipping (METΔex14)-driven lung cancers have generated some promising results but response rates remain below that seen for other kinase-driven cancers. One strategy for improving treatment outcomes is to employ rational combination therapies to enhance the suppression of tumour growth and delay or prevent the emergence of resistance. To this end, we profiled the transcriptomes of MET-addicted lung tumours and cell lines and identified the RAS-mitogen-activated protein kinase (MAPK) pathway as a critical effector required for METΔex14-dependent growth. Ectopic expression of MET in an isogenic cell line model showed that overexpression of the mutant MET receptor led to higher levels of MAPK phosphorylation and nuclear import, resulting in increased expression and phosphorylation of nuclear MAPK targets. In comparison, other known MET effectors were unaffected. Inhibition of this pathway by KRAS knockdown in MET-addicted cells in vitro led to decreased viability in only the METΔex14-mutant cells. Conversely, decoupling RAS-MAPK axis, but not other effector pathways, from MET activity via the introduction of constitutively active mutants conferred resistance to MET inhibitors in vitro. Our results suggest that aberrant hyperactivity of the MET receptor caused by the exon 14-skipping mutation does not uniformly upregulate all known downstream effectors, rather gaining a predilection for aberrantly activating and subsequently relying on the RAS-MAPK pathway. These findings provide a rationale for the co-targeting of the RAS-MAPK pathway alongside MET to prolong therapeutic response and circumvent resistance to improve patient survival.

The Predictive Value of MAP2K1/2 Mutations on Efficiency of Immunotherapy in Melanoma

Background

MAP2K1/2 genes are mutated in approximately 8% of melanoma patients; however, the impact of MAP2K1/2 gene alterations on the efficiency of immunotherapy has not been clarified. This study focused on the correlation between MAP2K1/2 gene mutations and the treatment response.

Methods

Six metastatic melanoma clinical cohorts treated with immune checkpoint inhibitors [anti-cytotoxic T lymphocyte antigen-4 (CTLA-4) or anti-programmed cell death-1 (PD-1)] were recruited in this study. RNA expression profiling results from each of these six cohorts and the Cancer Genome Atlas (TCGA) melanoma cohort were analysed to explore the mechanism related to immune activation.

Results

Compared to patients with wild-type MAP2K1/2, those with MAP2K1/2 mutations in an independent anti-CTLA-4-treated cohort had higher objective response rates, longer progression-free survival, and longer overall survival (OS). These findings were further validated in a pooled anti-CTLA-4-treated cohort in terms of the OS. However, there was no correlation between MAP2K1/2 mutations and OS in the anti-PD-1-treated cohort. Subgroup Cox regression analysis suggested that patients with MAP2K1/2 mutations received fewer benefits from anti-PD-1 monotherapy than from anti-CTLA-4 treatment. Furthermore, transcriptome profiling analysis revealed that melanoma tumours with MAP2K mutation was enriched in CD8⁺ T cells, B cells, and neutrophil cells, also expressed high levels of CD33 and IL10, implying a potential mechanism underlying the benefit of melanoma patients with MAP2K1/2 mutations from anti-CTLA-4 treatment.

Conclusions

MAP2K1/2 mutations were identified as an independent predictive factor for anti-CTLA-4 therapy in melanoma patients. Anti-CTLA-4 treatment might be more effective than anti-PD-1 therapy for patients with MAP2K1/2-mutated melanoma.

Not so 'rare'-an example of malignant melanoma in India: report from a tertiary cancer centre

Purpose

Malignant melanoma (MM) is rare in India. Indian data on demography and treatment outcome on advanced MM is very limited in the literature.

Materials & methods

This is a retrospective study of advanced MM treated between January 2013 and December 2020. We evaluated the clinicopathologic features, mutational profiles, survival outcome and prognostic factors in advanced MM patients.

Results

Out of a total 460 patients, 185 (42%) had metastatic disease at presentation and were enrolled in this study with a median age of 63 years (range: 28–93) and male:female ratio of 94:91. The mucosal primary was predominant (n = 110, 59%) than cutaneous primary (38%) and anorectum was the most common site (n = 84, 45%). Tumour mutational analysis was performed in 65 (35%) patients. BRAF mutations were detected in 12 patients and KIT mutations in 7 patients. Thirteen patients didn’t have any mutations and 22 patients had mutations other than KIT & BRAF. Only 59 (32%) patients took any systemic treatment – immune checkpoint inhibitors (ICIs) in 17, temozolomide in 18 and paclitaxel/carboplatin in 18, tyrosine kinase inhibitors in 6 patients. After a median follow-up of 26 months (95% confidence interval (CI): 11.6–not reached), median progression-free survival (PFS) was 7.1 months (95% CI: 4.4–9.1) and median overall survival was 14.8 months (95% CI: 7.7–18.2 months). The use of ICI emerged as an only significant good prognostic factor (p ≤ 0.001) for PFS, on multivariate analysis.

Conclusion

Mucosal origin was more common than cutaneous primary with anorectum being the most common site. BRAF mutation was less as compared to published literature. Very few patients received systemic therapy and the use of ICI showed superior PFS.

Prediction of Drug-Drug Interaction Between Dabrafenib and Irinotecan via UGT1A1-Mediated Glucuronidation

BACKGROUND

Dabrafenib and irinotecan are two drugs that can be utilized to treat melanoma. A previous in vivo study has shown that dabrafenib enhances the antitumor activity of irinotecan in a xenograft model with unclear mechanism.

OBJECTIVES

This study aims to investigate the inhibition of dabrafenib on SN-38 (the active metabolite of irinotecan) glucuronidation, trying to elucidate the possible mechanism underlying the synergistic effect and to provide a basis for further development and optimization of this combination in clinical research.

METHODS

Recombinant human uridine diphosphate glucuronosyltransferase 1A1 (UGT1A1) and human liver microsomes (HLMs) were employed to catalyze the glucuronidation of SN-38 in vitro. Inhibition kinetic analysis and quantitative prediction study were combined to predict drug-drug interaction (DDI) potential in vivo.

RESULTS

Dabrafenib noncompetitively inhibited SN-38 glucuronidation in pooled HLMs and recombinant UGT1A1 with unbound inhibitor constant (K_i,u) values of 12.43 ± 0.28 and 3.89 ± 0.40 μM, respectively. Based on the in vitro K_i,u value and estimation of kinetic parameters, dabrafenib administered at 150 mg twice daily may result in about a 1-2% increase in the area under the curve (AUC) of SN-38 in vivo. However, the ratios of intra-enterocyte concentration of dabrafenib to K_i,u ([I]_gut/K_i,u) are 2.73 and 8.72 in HLMs and recombinant UGT1A1, respectively, indicating a high risk of intestinal DDI when dabrafenib was used in combination with irinotecan.

CONCLUSION

Dabrafenib is a potent noncompetitive inhibitor of UGT1A1 and may bring potential risk of DDI when combined with irinotecan.

Phase I pharmacokinetic study of single agent trametinib in patients with advanced cancer and hepatic dysfunction

BACKGROUND

Trametinib is an oral MEK 1/2 inhibitor, with a single agent recommended phase 2 dose (RP2D) of 2 mg daily (QD). This study was designed to evaluate RP2D, maximum tolerated dose (MTD), and pharmacokinetic (PK) profile of trametinib in patients with advanced solid tumors who had various degrees of hepatic dysfunction (HD).

METHODS

Advanced cancer patients were stratified into 4 HD groups based on Organ Dysfunction Working Group hepatic function stratification criteria: normal (Norm), mild (Mild), moderate (Mod), severe (Sev). Dose escalation was based on "3 + 3" design within each HD group. PK samples were collected at cycle 1 days 15-16.

RESULTS

Forty-six patients were enrolled with 44 evaluable for safety [Norm=17, Mild=7, Mod (1.5 mg)=4, Mod (2 mg)=5, Sev (1 mg)=9, Sev (1.5 mg)=2] and 22 for PK analysis. Treatment related adverse events were consistent with prior trametinib studies. No treatment related deaths occurred. Dose limiting toxicities (DLTs) were evaluable in 15 patients (Mild=6, Mod (1.5 mg)=3, Mod (2 mg)=2, Sev (1 mg)=3 and Sev (1.5 mg)=1). One DLT (grade 3 acneiform rash) was observed in a Sev patient (1.5 mg). Dose interruptions or reductions due to treatment related adverse events occurred in 15 patients (34%) [Norm=9, 53%; Mild=2, 29%; Mod (1.5 mg)=1, 33%; Mod (2 mg)=2, 33%; Sev (1 mg)=1, 11%; Sev (1.5 mg)=1; 50%]. There were no significant differences across HD groups for all PK parameters when trametinib was normalized to 2 mg. However, only limited PK data were available for the Mod (n = 3) and Sev (n = 3) groups compared to Norm (n = 10) and Mild (n = 6) groups. Trametinib is heavily protein bound, with no correlation between serum albumin level and unbound trametinib fraction (p = 0.26).

CONCLUSIONS

RP2D for trametinib in Mild HD patients is 2 mg QD. There are insufficient number of evaluable patients due to difficulty of patient accrual to declare RP2D and MTD for Mod and Sev HD groups. DLTs were not observed in the highest dose cohorts that reached three evaluable patients - 1.5 mg QD in Mod group, and 1 mg QD in Sev group.

TRIAL REGISTRATION

This study was registered in the ClinicalTrials.gov website ( NCT02070549 ) on February 25, 2014. .

Recommended first-line management of brain metastases from melanoma: A multicenter survey of clinical practice

BACKGROUND

Radiotherapy (RT) and surgery (Sx) are effective in treating brain metastases. However, immune checkpoint inhibitors (ICI) have shown activity against asymptomatic melanoma brain metastases (MBM). BRAF/MEK inhibitors can be used to treat BRAF V600 mutation positive (BRAF+) MBM.

METHOD

We conducted an international survey among experts from medical oncology (MO), clinical oncology (CO), radiation oncology (RO), and neurosurgery (NS) about treatment recommendations for patients with asymptomatic BRAF+ or BRAF mutation negative (BRAF-) MBM. Eighteen specific clinical scenarios were presented and a total of 267 responses were collected. Answers were grouped and compared using Fisher's exact test.

RESULTS

In most MBM scenarios, survey respondents, regardless of specialty, favored RT in addition to systemic therapy. However, for patients with BRAF+ MBM, MO and CO were significantly more likely than RO and NS to recommend BRAF/MEK inhibitors alone, without the addition of RT, including the majority of MO (51%) for patients with 1-3 MBM, all <2cm. Likewise, for BRAF- MBM, MO and CO more commonly recommended single or dual agent ICI only and dual agent ICI therapy alone was the most common recommendation from MO or CO for MBM <2cm. When at least 1 of 3 MBM (BRAF+ or BRAF-) was >2cm, upfront Sx was recommended by all groups with the exception that MO and RO recommended RT for BRAF- MBM.

CONCLUSIONS

In most clinical settings involving asymptomatic MBM, experts recommended RT in addition to systemic therapy. However, recommendations varied significantly according to specialty, with MO and CO more commonly recommending dual systemic therapy alone for up to 9 BRAF- MBM <2cm.

Impressive Rapid Complete Response on FDG PET/CT to BRAF Inhibitors in a Metastatic Melanoma With Massive Tumor Burden

ABSTRACT

Recent advances in the development of innovative treatments for MM (metastatic melanoma) significantly improved survival. BRAF inhibitor-targeted therapies are also indicated in stage IV BRAF-mutant melanoma, especially dabrafenib and trametinib in combination. The authors present here an impressive rapid (1 month) complete metabolic response on FDG PET/CT to BRAF inhibitors of an MM with a massive tumor burden estimated at more than 10 kg.

Mechanistically Coupled PK (MCPK) Model to Describe Enzyme Induction and Occupancy Dependent DDI of Dabrafenib Metabolism

Dabrafenib inhibits the cell proliferation of metastatic melanoma with the oncogenic BRAF(V600)-mutation. However, dabrafenib monotherapy is associated with pERK reactivation, drug resistance, and consequential relapse. A clinical drug-dose determination study shows increased pERK levels upon daily administration of more than 300 mg dabrafenib. To clarify whether such elevated drug concentrations could be reached by long-term drug accumulation, we mechanistically coupled the pharmacokinetics (MCPK) of dabrafenib and its metabolites. The MCPK model is qualitatively based on in vitro and quantitatively on clinical data to describe occupancy-dependent CYP3A4 enzyme induction, accumulation, and drug–drug interaction mechanisms. The prediction suggests an eight-fold increase in the steady-state concentration of potent desmethyl-dabrafenib and its inactive precursor carboxy-dabrafenib within four weeks upon 150 mg b.d. dabrafenib. While it is generally assumed that a higher dose is not critical, we found experimentally that a high physiological dabrafenib concentration fails to induce cell death in embedded 451LU melanoma spheroids.

Adjuvant treatment of high-risk melanoma - cost-effectiveness analysis of treatment options for BRAF 600 mutated tumors

INTRODUCTION

Until recently, adjuvant treatment options for higher stage resectable cutaneous melanoma were limited. Two studies with a similar set-up, published 2017, led to registration of targeted therapy for BRAF-mutated melanoma with dabrafenib and trametinib as well as of the immunotherapy with nivolumab irrespective of BRAF-mutation status. Both options have been positively assessed in Germany since 2019 for the adjuvant treatment of BRAF-V600 mutated melanoma. This study evaluates the cost-effectiveness of both treatment alternatives (dabrafenib/trametinib and nivolumab) against observation as a comparative therapy from the perspective of German statutory health funds.

METHODS

Partitioned survival analysis based on published survival curves for the investigated treatment options was used for a cohort model for the health states relapse free survival, progression, and death. The partitioned survival analysis approach was based on the survival curves published for the key studies Combi AD and Checkmate-238. The modelling was performed for the remaining lifetime for a cohort with starting age of 50 years. For extrapolation of the survival curves, convergence to general population mortality rates was assumed in the long term. Within the progression state, a Markov model uses three levels of progressions (locoregional, distant metastases with 1st and 2nd line treatment). Lifetime treatment costs were calculated using the German statutory health fund reimbursement scheme. Quality adjusted life years (QALYs) associated to the health states were adopted from previously published utilities based on the Combi AD study.

RESULTS

The treatment with dabrafenib/trametinib yielded an increase in quality adjusted life years of 2.28 QALY at an incremental lifetime cost of 86.1 T€. The incremental cost effectiveness ratio of dabrafenib/trametinib and nivolumab was comparable with 37.8 T€/QALY and 30.0 T€/QALY, respectively. Several sensitivity analyses proved the result to be insensitive. General model parameters like discount rate and length of the time horizon had stronger influence. For nivolumab, the model showed lower discounted lifetime costs (118.1 T€) compared to dabrafenib/trametinib [155.1 T€], associated with a lower gain in QALYs (1.64 years) compared to observation.

CONCLUSION

Both dabrafenib/trametinib and nivolumab turned out to be cost effective within internationally accepted Incremental Cost Effectiveness Ratio (ICER) thresholds with comparable cost effectiveness ratios.

Immunotherapy for Melanoma

Melanoma is the leading cause of death from skin cancer and is responsible for over 7000 deaths in the USA each year alone. For many decades, limited treatment options were available for patients with metastatic melanoma; however, over the last decade, a new era in treatment dawned for oncologists and their patients. Targeted therapy with BRAF and MEK inhibitors represents an important cornerstone in the treatment of metastatic melanoma; however, this chapter carefully reviews the past and current therapy options available, with a significant focus on immunotherapy-based approaches. In addition, we provide an overview of the results of recent advances in the adjuvant setting for patients with resected stage III and stage IV melanoma, as well as in patients with melanoma brain metastases. Finally, we provide a brief overview of the current research efforts in the field of immuno-oncology for melanoma.

High-throughput ex vivo drug testing identifies potential drugs and drug combinations for NRAS-positive malignant melanoma

Therapy options for patients with metastatic melanoma (MM) have considerably improved over the past decade. However, many patients still need effective therapy after unsuccessful immunotherapy, especially patients with BRAF-negative tumors who lack the option of targeted treatment second line. Therefore, the elucidation of efficient and personalized therapy options for these patients is required. In this study, three patient-derived cancer cells (PDCs) were established from NRAS Q61-positive MM patients. The response of PDCs and five established melanoma cell lines (two NRAS-positive, one wild type, and two BRAF V600-positive) was evaluated toward a panel of 527 oncology drugs using high-throughput drug sensitivity and resistance testing. The PDCs and cell lines displayed strong responses to MAPK inhibitors, as expected. Additionally, the PDCs and cell lines were responsive to PI3K/mTOR, mTOR, and PLK1 inhibitors among other effective drugs currently undergoing clinical trials. Combinations with a MEK inhibitor were tested with other targeted agents to identify effective synergies. MEK inhibitor showed synergy with multikinase inhibitor ponatinib, ABL inhibitor nilotinib, PI3K/mTOR inhibitor pictilisib, and pan-RAF inhibitor LY3009120. The application of the patients' cancer cells for functional drug testing ex vivo is one step further in the process of identifying potential agents and agent combinations to personalize treatment for patients with MM. Our preliminary study results suggest that this approach has the potential for larger-scale drug testing and personalized treatment applications in our expansion trial. Our results show that drug sensitivity and resistance testing may be implementable in the treatment planning of patients with MM.

OUP accepted manuscript

Background

The prognosis of patients with metastatic malignant melanoma is very poor and partly due to resistance to conventional chemotherapies. The study’s objectives were to assess the activity and tolerability of apatinib, an oral small molecule anti-angiogenesis inhibitor, in patients with recurrent advanced melanoma.

Methods

This was a single-arm, single-center phase II trial. The primary endpoint was progression-free survival (PFS) and the secondary endpoints were objective response rate (ORR), disease control rate (DCR), and overall survival (OS). Eligible patients had received at least one first-line therapy for advanced melanoma and experienced recurrence. Apatinib (500 mg) was orally administered daily.

Results

Fifteen patients (V660E BRAF status: 2 mutation, 2 unknown, 11 wild type) were included in the analysis. The median PFS was 4.0 months. There were two major objective responses, for a 13.3% response rate. Eleven patients had stable disease, with a DCR of 86.7%. The median OS was 12.0 months. The most common treatment-related adverse events of any grade were hypertension (80.0%), mucositis oral (33.3%), hand-foot skin reaction (26.7%), and liver function abnormalities, hemorrhage, diarrhea (each 20%). The only grade ≥3 treatment-related adverse effects that occurred in 2 patients was hypertension (6.7%) and mucositis (6.7%). No treatment-related deaths occurred.

Conclusion

Apatinib showed antitumor activity as a second- or above-line therapy in patients with malignant melanoma. The toxicity was manageable.

ClinicalTrials.gov Identifier

NCT03383237

Re-thinking therapeutic development for CNS metastatic disease

There has been unprecedented progress in the development of systemic therapies for patients with metastatic melanoma over the last decade. There is now tremendous potential and momentum to further and markedly reduce the impact of this disease. However, developing more effective treatments for metastases to the CNS remains a critical challenge for patients with melanoma. Melanoma patients with active CNS metastases have largely been excluded from both early-phase and registration trials for all currently approved targeted and immune therapies for this disease. While this exclusion has generally been justified in clinical research due to concerns about poor prognosis, lack of CNS penetration of agents and/or risk of toxicities, recent post-approval trials have shown the feasibility, safety and clinical benefit of clinical investigation in these patients. These trials have also identified key areas for which more effective strategies are needed. In parallel, recent translational and preclinical research has provided insights into novel immune, molecular and metabolic features of melanoma brain metastases that may mediate the aggressive biology and therapeutic resistance of these tumors. Together, these advances suggest the need for new paradigms for therapeutic development for melanoma patients with CNS metastasis.

Genomic and Transcriptomic Correlates of Thyroid Carcinoma Evolution after BRAF Inhibitor Therapy

Targeted inhibition of BRAF V600E achieves tumor control in a subset of advanced thyroid tumors. Nearly all tumors develop resistance, and some have been observed to subsequently undergo dedifferentiation. The molecular alterations associated with thyroid cancer dedifferentiation in the setting of BRAF inhibition are unknown. We analyzed targeted next-generation sequencing data from 639 advanced, recurrent and/or metastatic thyroid carcinomas, including 15 tumors that were treated with BRAF inhibitor drugs and had tissue sampled during or posttreatment, 8 of which had matched pretherapy samples. Pre- and posttherapy tissues from one additional patient were profiled with whole-exome sequencing and RNA expression profiling. Mutations in genes comprising the SWI/SNF chromatin remodeling complex and the PI3K-AKT-mTOR, MAPK, and JAK-STAT pathways all increased in prevalence across more dedifferentiated thyroid cancer histologies. Of 7 thyroid cancers that dedifferentiated after BRAF inhibition, 6 had mutations in these pathways. These mutations were mostly absent from matched pretreatment samples and were rarely detected in tumors that did not dedifferentiate. Additional analyses in one of the vemurafenib-treated tumors before and after anaplastic transformation revealed the emergence of an oncogenic PIK3CA mutation, activation of ERK signaling, dedifferentiation, and development of an immunosuppressive tumor microenvironment. These findings validate earlier preclinical data implicating these genetic pathways in resistance to BRAF inhibitors, and suggest that genetic alterations mediating acquired drug resistance may also promote thyroid tumor dedifferentiation. IMPLICATIONS: The possibility that thyroid cancer dedifferentiation may be attributed to selective pressure applied by BRAF inhibitor-targeted therapy should be investigated further.

Targeting protein arginine methyltransferase 5 sensitizes glioblastoma to trametinib

BACKGROUND

The prognosis of glioblastoma (GBM) remains dismal because therapeutic approaches have limited effectiveness. A new targeted treatment using MEK inhibitors, including trametinib, has been proposed to improve GBM therapy. Trametinib had a promising preclinical effect against several cancers, but its adaptive treatment resistance precluded its clinical translation in GBM. Previously, we have demonstrated that protein arginine methyltransferase 5 (PRMT5) is upregulated in GBM and its inhibition promotes apoptosis and senescence in differentiated and stem-like tumor cells, respectively. We tested whether inhibition of PRMT5 can enhance the efficacy of trametinib against GBM.

METHODS

Patient-derived primary GBM neurospheres (GBMNS) with transient PRMT5 knockdown were treated with trametinib and cell viability, proliferation, cell cycle progression, ELISA, and western blot were analyzed. In vivo, NSG mice were intracranially implanted with PRMT5-intact and -depleted GBMNS, treated with trametinib by daily oral gavage, and observed for tumor progression and mice survival rate.

RESULTS

PRMT5 depletion enhanced trametinib-induced cytotoxicity in GBMNS. PRMT5 knockdown significantly decreased trametinib-induced AKT and ERBB3 escape pathways. However, ERBB3 inhibition alone failed to block trametinib-induced AKT activity suggesting that the enhanced antitumor effect imparted by PRMT5 knockdown in trametinib-treated GBMNS resulted from AKT inhibition and not ERBB3 inhibition. In orthotopic murine xenograft models, PRMT5-depletion extended the survival of tumor-bearing mice, and combination with trametinib further increased survival.

CONCLUSION

Combined PRMT5/MEK inhibition synergistically inhibited GBM in animal models and is a promising strategy for GBM therapy.

Ipilimumab in a real-world population: A prospective Phase IV trial with long-term follow-up

Ipilimumab was the first treatment that improved survival in advanced melanoma. Efficacy and toxicity in a real-world setting may differ from clinical trials, due to more liberal eligibility criteria and less intensive monitoring. Moreover, high costs and lack of biomarkers have raised cost-benefit concerns about ipilimumab in national healthcare systems and limited its use. Here, we report the prospective, interventional study, Ipi4 (NCT02068196), which aimed to investigate the toxicity and efficacy of ipilimumab in a real-world population with advanced melanoma. This national, multicentre, phase IV trial included 151 patients. Patients received ipilimumab 3 mg/kg intravenously and were followed for at least 5 years or until death. Treatment interruption or cessation occurred in 38%, most frequently due to disease progression (19%). Treatment-associated grade 3 to 4 toxicity was observed in 28% of patients, and immune-related toxicity in 56%. The overall response rate was 9%. Median overall survival was 12.1 months (95% CI: 8.3-15.9); and progression-free survival 2.7 months (95% CI: 2.6-2.8). After 5 years, 20% of patients were alive. In a landmark analysis from 6 months, improved survival was associated with objective response (HR 0.16, P = .001) and stable disease (HR 0.49, P = .005) compared to progressive disease. Poor performance status, elevated lactate dehydrogenase and C-reactive protein were identified as biomarkers. This prospective trial represents the longest reported follow-up of a real-world melanoma population treated with ipilimumab. Results indicate safety and efficacy comparable to phase III trials and suggest that the use of ipilimumab can be based on current cost-benefit estimates.

Neoadjuvant B-RAF and MEK Inhibitor Targeted Therapy for Adult Papillary Craniopharyngiomas: A New Treatment Paradigm

BACKGROUND

Surgical and clinical management of craniopharyngiomas is associated with high long-term morbidity especially in the case of hypothalamic involvement. Improvements in knowledge of craniopharyngioma molecular biology may offer the possibility of safe and effective medical neoadjuvant treatments in a subset of patients harboring papillary subtype tumors with a BRAFV600E mutation.

METHOD

We report herein two cases of tubero-infundibular and ventricular Papillary Craniopharyngiomas in which BRAF/MEK inhibitor combined therapy was used as adjuvant (Case 1) or neoadjuvant (Case 2) treatment, with a 90% reduction in tumor volume observed after only 5 months. In Case 2 the only surgical procedure used was a minimal invasive biopsy by the trans-ventricular neuroendoscopic approach. As a consequence, targeted therapy was administered in purely neoadjuvant fashion. After shrinkage of the tumor, both patients underwent fractionated radiotherapy on the small tumor remnant to achieve long-term tumor control. A review of a previously reported case has also been performed.

RESULT

This approach led to tumor control with minimal long-term morbidity in both cases. No side effects or complications were reported after medical treatment and adjuvant radiotherapy.

CONCLUSION

Our experience and a review of the literature argue for a change in the current treatment paradigm for Craniopharyngiomas (CPs). In giant and invasive tumors, confirmation of BRAFV600E mutated PCPs by biopsy and BRAF/MEK inhibitor therapy before proposing other treatments may be useful to improve long term outcomes for patients.

Adaptive chromatin remodeling and transcriptional changes of the functional kinome in tumor cells in response to targeted kinase inhibition

Pharmacological inhibition of protein kinases induces adaptive reprogramming of tumor cell regulatory networks by altering expression of genes that regulate signaling, including protein kinases. Adaptive responses are dependent on transcriptional changes resulting from remodeling of enhancer and promoter landscapes. Enhancer and promoter remodeling in response to targeted kinase inhibition is controlled by changes in open chromatin state and by activity of specific transcription factors, such as c-MYC. This review focuses on the dynamic plasticity of protein kinase expression of the tumor cell kinome and the resulting adaptive resistance to targeted kinase inhibition. Plasticity of the functional kinome has been shown in patient window trials where triple-negative and human epidermal growth factor receptor 2–positive breast cancer patient tumors were characterized by RNAseq after biopsies before and after 1 week of therapy. The expressed kinome changed dramatically during drug treatment, and these changes in kinase expression were shown in cell lines and xenografts in mice to be correlated with adaptive tumor cell drug resistance. The dynamic transcriptional nature of the kinome also differs for inhibitors targeting different kinase signaling pathways (e.g., BRAF-MEK-ERK versus PI3K-AKT) that are commonly activated in cancers. Heterogeneity arising from differences in gene regulation and mutations represents a challenge to therapeutic durability and prevention of clinical drug resistance with drug-tolerant tumor cell populations developing and persisting through treatment. We conclude that understanding the heterogeneity of kinase expression at baseline and in response to therapy is imperative for development of combinations and timing intervals of therapies making interventions durable.

Reliability of BRAF mutation detection using plasma sample: A systematic review and meta-analysis

BACKGROUND

Testing of B-Raf proto-oncogene (BRAF) mutation in tumor is necessary before targeted therapies are given. When tumor samples are not available, plasma samples are commonly used for the testing of BRAF mutation. The aim of this study was to investigate the diagnostic accuracy of BRAF mutation testing using plasma sample of cancer patients.

METHODS

Databases of Pubmed, Embase, and Cochrane Library were searched for eligible studies investigating BRAF mutation in paired tissue and plasma samples of cancer patients. A total of 798 publications were identified after database searching. After removing 229 duplicated publications, 569 studies were screened using the following exclusion criteria: (1) BRAF mutation not measured in plasma or in tumor sample; (2) lacking BRAF-wildtype or BRAF-mutated samples; (3) tissue and plasma samples not paired; (4) lacking tumor or plasma samples; (5) not plasma sample; (6) not cancer; (7) un-interpretable data. Accuracy data and relevant information were extracted from each eligible study by 2 independent researchers and analyzed using statistical software.

RESULTS

After pooling the accuracy data from 3943 patients of the 53 eligible studies, the pooled sensitivity, specificity, and diagnostic odds ratio of BRAF mutation testing using plasma sample were 69%, 98%, and 55.78, respectively. Area under curve of summary receiver operating characteristic curve was 0.9435. Subgroup analysis indicated that BRAF mutation testing using plasma had overall higher accuracy (diagnostic odds ratio of 89.17) in colorectal cancer, compared to melanoma and thyroid carcinoma. In addition, next-generation sequencing had an overall higher accuracy in detecting BRAF mutation using plasma sample (diagnostic odds ratio of 63.90), compared to digital polymerase chain reaction (PCR) and conventional PCR, while digital PCR showed the highest sensitivity (74%) among the 3 techniques.

CONCLUSION

BRAF testing using plasma sample showed an overall high accuracy compared to paired tumor tissue sample, which could be used for cancer genotyping when tissue sample is not available. Large prospective studies are needed to further investigate the accuracy of BRAF mutation testing in plasma sample.

Signal pathways of melanoma and targeted therapy

Melanoma is the most lethal skin cancer that originates from the malignant transformation of melanocytes. Although melanoma has long been regarded as a cancerous malignancy with few therapeutic options, increased biological understanding and unprecedented innovations in therapies targeting mutated driver genes and immune checkpoints have substantially improved the prognosis of patients. However, the low response rate and inevitable occurrence of resistance to currently available targeted therapies have posed the obstacle in the path of melanoma management to obtain further amelioration. Therefore, it is necessary to understand the mechanisms underlying melanoma pathogenesis more comprehensively, which might lead to more substantial progress in therapeutic approaches and expand clinical options for melanoma therapy. In this review, we firstly make a brief introduction to melanoma epidemiology, clinical subtypes, risk factors, and current therapies. Then, the signal pathways orchestrating melanoma pathogenesis, including genetic mutations, key transcriptional regulators, epigenetic dysregulations, metabolic reprogramming, crucial metastasis-related signals, tumor-promoting inflammatory pathways, and pro-angiogenic factors, have been systemically reviewed and discussed. Subsequently, we outline current progresses in therapies targeting mutated driver genes and immune checkpoints, as well as the mechanisms underlying the treatment resistance. Finally, the prospects and challenges in the development of melanoma therapy, especially immunotherapy and related ongoing clinical trials, are summarized and discussed.

First-line Advanced Cutaneous Melanoma Treatments: Where Do We Stand?

Cutaneous melanoma has always been a dreaded diagnosis because of its high mortality rate and its proclivity for invasiveness and metastasis. Historically, advanced melanoma treatment has been limited to chemotherapy and nonspecific immunotherapy agents that display poor curative potential and high toxicity. However, during the last decade, the evolving understanding of the mutational burden of melanoma and immune system evasion mechanisms has led to the development of targeted therapy and specific immunotherapy agents that have transformed the landscape of advanced melanoma treatment. Despite the considerable strides in understanding the clinical implications of these agents, there is a scarcity of randomized clinical trials that directly compare the efficacy of the aforementioned agents; hence, there are no clear preferences among the available first-line options. In addition, the introduction of these agents was associated with a variety of dermatologic adverse events, some of which have shown a detrimental effect on the continuity of treatment. This holds especially true in light of the current fragmentation of care provided by the managing health care professionals. In this study, we attempt to summarize the current understanding of first-line treatments. In addition, the paper describes the indirect comparative evidence that aids in bridging the gap in the literature. Furthermore, this paper sheds light on the impact of the scarcity of dermatology specialist input in the management of dermatologic adverse events associated with advanced melanoma treatment. It also looks into the potential avenues where dermatologic input can bridge the gap in the care provided by oncologists, thus standardizing the care provided to patients with melanoma presenting with dermatologic adverse events.

Pulmonary metastatic melanoma: current state of diagnostic imaging and treatments

Melanoma is the deadliest form of skin cancer with an estimated incidence of over 160,000 cases annually and about 41,000 melanoma-related deaths per year worldwide. Malignant melanoma (MM) primarily occurs in the skin but has been described in other organs. Although the respiratory system is generally afflicted by tumors such as lung cancer, it is also rarely affected by primary MM. The estimated incidence of pulmonary MM of the lung accounts for 0.01% of all primary lung tumors. The current understanding of pulmonary MM of the lung pathophysiology and its management are not well established. We aim to survey current clinical modalities with a focus on diagnostic imaging and therapeutic intervention to guide providers in the management of patients with a high index of suspicion.

A case of primary malignant melanoma of the esophagogastric junction with abscopal effect after nivolumab administration

BACKGROUND

The abscopal effect is a rare phenomenon in which local irradiation causes tumor regression outside the irradiated area. There have been no reports of abscopal effect in patients with gastrointestinal melanoma with metastasis. Here, we report a case of primary malignant melanoma of the esophagogastric junction with abscopal effect after long-term treatment with nivolumab.

CASE PRESENTATION

A 75-year-old woman was referred to our hospital with a gastroesophageal lesion. Upper gastrointestinal endoscopy revealed a raised lesion on the posterior wall of the greater curvature of the cardia and tenderness in the lower esophagus. Immunostaining of the tumor biopsy showed positive staining for Melan-A, human melanoma black-45 (HMB45), and S-100, indicating malignant melanoma of the esophagogastric junction. Contrast-enhanced computed tomography (CT) of the abdomen showed a mildly stained lesion protruding into the cardiac part of stomach and enlarged surrounding lymph nodes. The patient was diagnosed with malignant melanoma of the esophagogastric junction and proximal gastrectomy with lower esophagus resection was performed. Histological examination showed large, round tumor cells with nuclear atypia. Immunostaining was positive for Melan A, HMB45, S-100 protein, and SRY-box transcription factor 10, and the final diagnosis was malignant melanoma of the esophagogastric junction, with regional lymph node metastases. Three months after surgery, follow-up CT indicated left pleural metastasis; therefore, the patient was administered nivolumab, an immune checkpoint inhibitor (ICI). Following three courses of nivolumab, the patient exhibited grade 3 renal dysfunction (Common Terminology Criteria for Adverse Events version 5.0). After that, we have not administered nivolumab treatment. Five months after the development of renal dysfunction, a CT scan demonstrated an unstained nodule within the pancreatic, and the patient was diagnosed with pancreatic metastasis; intensity-modulated radiotherapy was performed. Six months later, CT revealed pancreatic nodule and pleural metastasis was shrunk; after an additional 2 months, pleural metastasis and effusion had disappeared. The patient is alive with no additional lesions.

CONCLUSIONS

We report a case of primary malignant melanoma of the esophagogastric junction with an abscopal effect following nivolumab treatment. The findings of this case report suggest that ICIs in combination with radiotherapy may be effective for treating metastatic or recurrent malignant melanoma of the gastrointestinal tract.

Oxidative Stress-Related Mechanisms in Melanoma and in the Acquired Resistance to Targeted Therapies

Melanoma is a highly aggressive cancer with the poorest prognosis, representing the deadliest form of skin cancer. Activating mutations in BRAF are the most frequent genetic alterations, present in approximately 50% of all melanoma cases. The use of specific inhibitors towards mutant BRAF variants and MEK, a downstream signaling target of BRAF in the MAPK pathway, has significantly improved progression-free and overall survival in advanced melanoma patients carrying BRAF mutations. Nevertheless, despite these improvements, resistance still develops within the first year of therapy in around 50% of patients, which is a significant problem in managing BRAF-mutated advanced melanoma. Understanding these mechanisms is one of the mainstreams of the research on BRAFi/MEKi acquired resistance. Both genetic and epigenetic mechanisms have been described. Moreover, in recent years, oxidative stress has emerged as another major force involved in all the phases of melanoma development, from initiation to progression until the onsets of the metastatic phenotype and chemoresistance, and has thus become a target for therapy. In the present review, we discuss the current knowledge on oxidative stress and its signaling in melanoma, as well as the oxidative stress-related mechanisms in the acquired resistance to targeted therapies.

Intermittent BRAF inhibition in advanced BRAF mutated melanoma results of a phase II randomized trial

Combination treatment with BRAF (BRAFi) plus MEK inhibitors (MEKi) has demonstrated survival benefit in patients with advanced melanoma harboring activating BRAF mutations. Previous preclinical studies suggested that an intermittent dosing of these drugs could delay the emergence of resistance. Contrary to expectations, the first published phase 2 randomized study comparing continuous versus intermittent schedule of dabrafenib (BRAFi) plus trametinib (MEKi) demonstrated a detrimental effect of the “on−off” schedule. Here we report confirmatory data from the Phase II randomized open-label clinical trial comparing the antitumoral activity of the standard schedule versus an intermittent combination of vemurafenib (BRAFi) plus cobimetinib (MEKi) in advanced BRAF mutant melanoma patients (NCT02583516). The trial did not meet its primary endpoint of progression free survival (PFS) improvement. Our results show that the antitumor activity of the experimental intermittent schedule of vemurafenib plus cobimetinib is not superior to the standard continuous schedule. Detection of BRAF mutation in cell free tumor DNA has prognostic value for survival and its dynamics has an excellent correlation with clinical response, but not with progression. NGS analysis demonstrated de novo mutations in resistant cases.

Whether intermittent strategies of delivering drugs can improve cancer patients survival is still unclear. Here, the authors reports the results of a randomized phase II clinical trial aimed to compare the efficacy and safety of two dosing regimens (continuous and intermittent) of vemurafenib and cobimetinib combination as first-line treatment of patients with unresectable or metastatic advanced melanoma with BRAFV600 mutation

Dermatologic toxicities of targeted antineoplastic agents and immune checkpoint inhibitor therapy in pediatric patients: A systematic review

Cutaneous adverse events (cAEs) from targeted antineoplastic agents and immune checkpoint inhibitors are common in children with cancer and may lead to dose reduction or cessation of critical oncologic treatment. Timely diagnosis and proper management of cAEs in pediatric oncology patients is essential to optimize ongoing cancer-directed therapy and improve quality of life. This systematic review of published studies summarizes dermatologic toxicities to targeted anticancer treatments and immune checkpoint inhibitors.

Retrospective analysis of adjuvant therapy using dabrafenib plus trametinib in Japanese patients with advanced melanoma: analysis of 36 cases

Patients with resected stage IIIB, IIIC and IIID melanomas have a high risk of recurrence. Therefore, an appropriate protocol for stage III melanoma is needed. Since adjuvant dabrafenib plus trametinib (D+T) combined therapy and anti-PD1 antibody (Ab) therapy reduce the risk of recurrence in patients with resected stage III BRAF-mutated melanoma, selecting the adjuvant therapy for BRAF-mutated melanoma is controversial. The efficacy and safety profiles of D+T combined therapy in the adjuvant setting were retrospectively analyzed in 36 Japanese. BRAF-mutated advanced melanoma patients. The relapse-free rate (RFR) at 12 months was 82.1% (95% confidential interval (CI), 63.9-92.6%). In the 21 patients who completed the protocol, the RFR at 12 months was 85.7% (95% CI, 64.5-95.9%). In the seven patients whose protocol was interrupted by adverse events, the RFR was 71.4% (95% CI, 35.2-92.4%). The incidence rate of any AEs for all patients was 69.7% (95% CI, 52.5-82.8%), including 13 cases of pyrexia, five cases of skin rash and four cases of liver dysfunction. The present study suggested that D+T therapy in the adjuvant setting is a useful and very tolerable protocol for BRAF-mutated melanoma in the Japanese population.

Should Targeted Therapy Be Continued in BRAF-Mutant Melanoma Patients after Complete Remission?

BACKGROUND

Targeted therapy is used to treat patients with a BRAF-mutated metastatic melanoma and is continued until disease progression or severe toxicity. No robust data on the management of patients achieving a complete remission (CR) are available.

MAIN OBJECTIVE

To determine the relapse rate in the first year after targeted therapy discontinuation in patients in CR.

SECONDARY OBJECTIVES

To determine the relapse rates throughout the follow-up and to identify prognostic factors for relapse at 1 year.

METHODS

A retrospective, monocentric observational study was conducted in patients with advanced melanoma included in the RIC-Mel database who discontinued targeted therapy after achieving a CR confirmed by CT scan and PET/CT scan.

RESULTS

Twenty-nine patients were included. Seventeen (58.6%) patients were treated with BRAF inhibitor (BRAFi) alone and 12 (41.4%) with a BRAFi combined with a MEK inhibitor (BRAFi + MEKi). The median treatment duration was 9.7 months. The relapse rates after discontinuation were 69% at 12 months (BRAFi: 70.6%; BRAFi + MEKi: 66.7%) and 76% at 36 months (BRAFi: 76.5%; BRAFi + MEKi: 75%). A non-significant trend towards a higher risk of relapse was found in women (p = 0.1; RR 3.36; 95% CI 0.77-17.07), in patients with an LDH level greater than the upper limits of normal (p = 0.58; RR 2.43; 95% CI 0.10-56.71), and when more than two metastatic sites were involved (p = 0.19; RR 4.6; 95% CI 0.46-46.51). After relapse, targeted therapy was resumed in 17 patients (7 with BRAFi; 10 with BRAFi + MEKi) with a response rate of 53%.

CONCLUSIONS

This real-life study provided long-term data in patients who discontinued targeted therapy after CR. Most patients experienced a relapse in the first year after targeted therapy discontinuation, of whom 50% were in the first 3 months. After targeted therapy resumption, 53% of relapsing patients achieved an objective response. Patients should be followed during the first year after treatment discontinuation. In addition, patients with less than 3 metastatic sites, a baseline LDH level with normal ranges, men, and patients responding rapidly to treatment would be more likely to maintain a CR after treatment discontinuation.

Individualized Treatment Strategy for Cutaneous Melanoma: Where Are We Now and Where Are We Going?

In the past several decades, innovative research in cancer biology and immunology has contributed to novel therapeutics, such as targeted therapy and immunotherapy, which have transformed the management of patients with melanoma. Despite the remarkable therapeutic outcomes of targeted treatments targeting MAPK signaling and immunotherapy that suppresses immune checkpoints, some individuals acquire therapeutic resistance and disease recurrence. This review summarizes the current understanding of melanoma genetic variations and discusses individualized melanoma therapy options, particularly for advanced or metastatic melanoma, as well as potential drug resistance mechanisms. A deeper understanding of individualized treatment will assist in improving clinical outcomes for patients with cutaneous melanoma.

Genomic sequencing to inform therapy in advanced pancreatic cancer: A systematic review and meta-analysis of prospective studies

PURPOSE

Current guidelines recommend somatic genomic sequencing for patients with advanced pancreatic cancer to identify targetable alterations amenable to targeted therapy. The benefit of somatic genomic sequencing in pancreatic cancer remains unclear. This study aims to assess the evidence supporting genomic sequencing to inform treatment selection for patients with advanced pancreatic cancer.

METHODS

A systematic review identified prospective studies of exocrine pancreatic cancer patients published before August 2020 which conducted genomic sequencing to inform treatment selection. Outcomes of interest included the proportion of patients with targetable alterations, the proportion that received targeted treatments, and the impact of targeted treatments on overall survival. Meta-analysis for proportions and hazard ratios was performed using Dersimonian and Laird random effect models.

RESULTS

19 studies (representing 2048 pancreatic cancer patients) were included. Sequencing methodologies, definitions of targetable alterations, and approaches treatment selection varied across studies and were incompletely reported. 590 of 1382 sequenced patients harboured a targetable alteration (random effects meta-analysis estimate of the proportion 0.46, 95% confidence interval 0.32-0.61). The proportion of patients with targetable alterations was highly heterogenous between studies (I² 93%, P < 0.001). 91 of 1390 patients received a matched therapy based on their targetable alterations (random effects meta-analysis estimate of the proportion 0.12, 95% CI 0.06-0.23). One observational study reported an overall survival benefit of matched therapy.

CONCLUSIONS

Genomic sequencing frequently identifies targetable alterations in pancreatic cancers. Further research is required to standardize the definitions of targetable alterations, the approach to treatment matching, and quantify the benefit of targeted therapy.

Combined BRAF-Targeted Therapy with Immunotherapy in BRAF-Mutated Advanced Melanoma Patients

PURPOSE OF REVIEW

To review evidence on the efficacy and safety of combined BRAF-targeted therapy and immune checkpoint inhibitors in patients with BRAF-mutated metastatic melanoma.

RECENT FINDINGS

Programmed death-1 pathway inhibitors administered with BRAF/MEK inhibitors showed promising anti-tumour activity in BRAF-mutated advanced melanoma and were investigated for safety and efficacy in three large international clinical trials. Although, in two out of those three randomized phase III studies, progression-free survival (PFS) did not reach statistical significance, results showed that duration of response (DOR) and overall survival (OS) were improved using combined therapy, sustaining the scientific rationale for its use at least in a subset of metastatic melanomas. However, the frequent occurrence of autoimmunity-induced toxicities should be considered since it is limiting the continuity and the wide application of these regimens. Novel treatment modalities combining targeted therapy with checkpoint inhibitors require further clinical investigation and elucidation of their effect on the immune system and cancer cell modulation.

BRAF Signaling Inhibition in Glioblastoma: Which Clinical Perspectives?

IDH-wild type (wt) glioblastoma (GB) accounts for approximately 90% of all GB and has a poor outcome. Surgery and adjuvant therapy with temozolomide and radiotherapy is the main therapeutic approach. Unfortunately, after relapse and progression, which occurs in most cases, there are very limited therapeutic options available. BRAF which plays a role in the oncogenesis of several malignant tumors, is also involved in a small proportion of IDH-wt GB. Previous successes with anti-B-Raf targeted therapy in tumors with V600E BRAF mutation like melanoma, combined with the poor prognosis and paucity of therapeutic options for GB patients is leading to a growing interest in the potential efficacy of this approach. This review is thus focused on dissecting the state of the art and future perspectives on BRAF pathway inhibition in IDH-wt GB. Overall, clinical efficacy is mostly described within case reports and umbrella trials, with promising but still insufficient results to draw more definitive conclusions. Further studies are needed to better define the molecular and phenotypic features that predict for a favorable response to treatment. In addition, limitations of B-Raf-inhibitors, in monotherapy or in combination with other therapeutic partners, to penetrate the blood-brain barrier and the development of acquired resistance mechanisms responsible for tumor progression need to be addressed.

Dermatologic adverse events associated with targeted therapies for melanoma

INTRODUCTION

The development of new targeted therapies has considerably changed the therapeutic paradigm of melanoma, significantly increasing overall survival (OS) and progression-free survival (PFS). However, skin-related adverse sequelae might occur and impact on patients' quality of life.

AREAS COVERED

In this article we will cover the most important dermatological toxicities related to BRAF and MEK-inhibitors, along with updated management strategies.

EXPERT OPINION

BRAF inhibitors have represented a revolution in the treatment of melanoma. They have improved the outcome of the disease and therefore represent an important option in the management and care of patients with advanced melanoma. Skin toxicity (especially the onset of squamous skin carcinomas) has been considered a major cutaneous side effect and, although the addition of MEK inhibitors in combination has significantly reduced the incidence of skin sequelae, serious skin adverse events might develop anyway and impact significantly on patients'quality of life and on national health system budget. The introduction of BRAF and MEK inhibitors as a new effective adjuvant treatment option for stage III and ulcerated melanoma has proved a significant impact on the risk of recurrence, and may have interesting developments in the near future as a further therapeutic tool.

Predictive Value of Baseline [18F]FDG PET/CT for Response to Systemic Therapy in Patients with Advanced Melanoma

Background/Aim: To evaluate the association between baseline [18F]FDG-PET/CT tumor burden parameters and disease progression rate after first-line target therapy or immunotherapy in advanced melanoma patients. Materials and Methods: Forty four melanoma patients, who underwent [18F]FDG-PET/CT before first-line target therapy (28/44) or immunotherapy (16/44), were retrospectively analyzed. Whole-body and per-district metabolic tumor volume (MTV) and total lesion glycolysis (TLG) were calculated. Therapy response was assessed according to RECIST 1.1 on CT scan at 3 (early) and 12 (late) months. PET parameters were compared using the Mann–Whitney test. Optimal cut-offs for predicting progression were defined using the ROC curve. PFS and OS were studied using Kaplan–Meier analysis. Results: Median (IQR) MTVwb and TLGwb were 13.1 mL and 72.4, respectively. Non-responder patients were 38/44, 26/28 and 12/16 at early evaluation, and 33/44, 21/28 and 12/16 at late evaluation in the whole-cohort, target, and immunotherapy subgroup, respectively. At late evaluation, MTVbone and TLGbone were higher in non-responders compared to responder patients (all p < 0.037) in the whole-cohort and target subgroup and MTVwb and TLGwb (all p < 0.022) in target subgroup. No significant differences were found for the immunotherapy subgroup. No metabolic parameters were able to predict PFS. Controversially, MTVlfn, TLGlfn, MTVsoft + lfn, TLGsoft + lfn, MTVwb and TLGwb were significantly associated (all p < 0.05) with OS in both the whole-cohort and target therapy subgroup. Conclusions: Higher values of whole-body and bone metabolic parameters were correlated with poorer outcome, while higher values of whole-body, lymph node and soft tissue metabolic parameters were correlated with OS.