Dabrafenib in BRAF-mutated metastatic melanoma: a multicentre, open-label, phase 3 randomised controlled trial

The efficacy of immune checkpoint blockade for melanoma in-transit with or without nodal metastases - A multicenter cohort study

PURPOSE

Guidelines addressing melanoma in-transit metastasis (ITM) recommend immune checkpoint inhibitors (ICI) as a first-line treatment option, despite the fact that there are no efficacy data available from prospective trials for exclusively ITM disease. The study aims to analyze the outcome of patients with ITM treated with ICI based on data from a large cohort of patients treated at international referral clinics.

METHODS

A multicenter retrospective cohort study of patients treated between January 2015 and December 2020 from Australia, Europe, and the USA, evaluating treatment with ICI for ITM with or without nodal involvement (AJCC8 N1c, N2c, and N3c) and without distant disease (M0). Treatment was with PD-1 inhibitor (nivolumab or pembrolizumab) and/or CTLA-4 inhibitor (ipilimumab). The response was evaluated according to the RECIST criteria modified for cutaneous lesions.

RESULTS

A total of 287 patients from 21 institutions in eight countries were included. Immunotherapy was first-line treatment in 64 (22%) patients. PD-1 or CTLA-4 inhibitor monotherapy was given in 233 (81%) and 23 (8%) patients, respectively, while 31 (11%) received both in combination. The overall response rate was 56%, complete response (CR) rate was 36%, and progressive disease (PD) rate was 32%. Median PFS was ten months (95% CI 7.4-12.6 months) with a one-, two-, and five-year PFS rate of 48%, 33%, and 18%, respectively. Median MSS was not reached, and the one-, two-, and five-year MSS rates were 95%, 83%, and 71%, respectively.

CONCLUSION

Systemic immunotherapy is an effective treatment for melanoma ITM. Future studies should evaluate the role of systemic immunotherapy in the context of multimodality therapy, including locoregional treatments such as surgery, intralesional therapy, and regional therapies.

18F-FDG PET/CT During Neoadjuvant Targeted Therapy in Prior Unresectable Stage III Melanoma Patients: Can (Early) Metabolic Imaging Predict Histopathologic Response or Recurrence?

PURPOSE

The aim of this study was to investigate whether 18F-FDG PET/CT can predict histopathological response or recurrence in BRAF-mutated unresectable locally advanced stage III melanoma treated with neoadjuvant BRAF/MEK inhibition followed by resection and the value of PET in detecting early recurrence after resection.

PATIENTS AND METHODS

Twenty BRAF-mutated, unresectable stage III melanoma patients received BRAF/MEK inhibitors before surgery. 18F-FDG PET/CT was performed at baseline and 2 and 8 weeks after initiation of therapy. After resection, PET/CT was performed at specific time points during 5 years of follow-up. Pathological response was assessed on the dissection specimen. Response monitoring was measured with SUVmax, SUVpeak, MATV, and TLG and according to EORTC and PERCIST criteria.

RESULTS

Pathological response was assessed in 18 patients. Nine patients (50%) had a pathologic complete or near-complete response, and 9 (50%) had a pathologic partial or no response. EORTC or PERCIST response measurements did not correspond with pathologic outcome. SUVmax, SUVpeak, MATV, and TLG at all time points and absolute or percentage change among the 3 initial time points did not differ between the groups.During follow-up, 8 of 17 patients with R0 resection developed a recurrence, 6 recurrences were detected with imaging only, 4 of which with PET/CT in less than 6 months after surgery. PET parameters before surgery did not predict recurrence.

CONCLUSIONS

Baseline 18F-FDG PET or PET response in previous unresectable stage III melanoma patients seems not useful to predict pathologic response after neoadjuvant BRAF/MEK inhibitors treatment. However, PET/CT seems valuable in detecting recurrence early after R0 resection.

Novel GLCCI1-BRAF fusion drives kinase signaling in a case of pheochromocytomatosis

INTRODUCTION

Recurrent and metastatic pheochromocytoma (PCC) are rare advanced endocrine neoplasms with limited treatment options. Insight into the pathogenic molecular alterations in patients with advanced PCC can provide therapeutic options for precisely targeting dysregulated pathways.

OBJECTIVE

We report the discovery and characterization of a novel BRAF-containing fusion transcript and its downstream molecular alterations in a patient with recurrent PCC with peritoneal seeding (pheochromocytomatosis).

METHODS

We reviewed the medical record of a patient with pheochromocytomatosis. A comprehensive pan-cancer molecular profiling using next-generation sequencing (NGS) as well as confirmatory real-time-quantitative PCR were performed on surgical specimens. BRAF rearrangement and downstream molecular changes were assayed using fluorescence in situ hybridization (FISH) and immunohistochemistry (IHC), respectively. Western blot was used to assess the in vitro activation of the mitogen-activated protein kinase (MAPK) signaling pathway and the EMT markers in transfected HEK-293 cells.

RESULTS

The NGS analysis of a specimen from a 72-year-old female patient with pheochromocytomatosis showed an in-frame fusion of exon 3 of Glucocorticoid Induced 1 (GLCCI1) to exon 9 of BRAF. The upstream auto-inhibitory domain of BRAF was excluded from the GLCCI1-BRAF fusion; however, the downstream BRAF kinase domain was intact. A BRAF rearrangement was confirmed via a BRAF-specific break-apart FISH assay. Four separate tumor foci harbored GLCCI1-BRAF fusion. IHC demonstrated increased phosphorylated MEK. HEK-293 cells transfected with the GLCCI1-BRAF fusion demonstrated increased phosphorylated MEK as well as higher expression of EMT markers SNAI1 and ZEB1 in vitro.

CONCLUSION

We demonstrate a novel pathogenic gene fusion of GLCCI1 with the oncogenic kinase domain of BRAF, resulting in an activation of the MAPK signaling pathway and EMT markers. Thus, this patient may benefit from clinically available MEK and/or BRAF inhibitors when systemic therapy is indicated.

SUMMARY STATEMENT

This report is the first of GLCCI1 fused to BRAF in a human neoplasm and only the second BRAF-containing fusion transcript in PCC. Detailed molecular characterization of PCC can be a valuable tool in managing patients with recurrent PCC and pheochromocytomatosis that represents a significant clinical challenge.

Co-Treatment of Chloroquine and Trametinib Inhibits Melanoma Cell Proliferation and Decreases Immune Cell Infiltration

Autophagy is characterized as a cytoprotective process and inhibition of autophagy with medicinally active agents, such as chloroquine (CQ) is proposed as a prospective adjuvant therapy for cancer. Here, we examined the preclinical effects of CQ combined with the MEK inhibitor trametinib (TRA) on melanoma. We found that cotreatment of CQ and TRA markedly slowed melanoma growth induced in Tyr-CreER.BrafCa.Ptenfl/fl mice. Immunostaining showed that trametinib decreased Ki-67+ proliferating cells, and increased TUNEL+ apoptotic cells. The combo treatment induced a further decrease of Ki-67+ proliferating cells. Consistent with the in vivo findings, CQ and TRA inhibited melanoma cell proliferation in vitro, which was correlated by decreased cyclin D1 expression. In addition, we found that tissues treated with CQ and TRA had significantly decreased numbers of CD4+ and CD8+ T-lymphocytes and F4/80+ macrophages. Together, these results indicate that cotreatment of CQ and TRA decreases cancer cell proliferation, but also dampens immune cell infiltration. Further study is warranted to understand whether CQ-induced immune suppression inadvertently affects therapeutic benefits.

Safety of combining dabrafenib plus trametinib in elderly BRAF V600 mutation-positive advanced melanoma patients: real-world data analysis of Spanish patients (ELDERLYMEL)

Efficacy and safety of dabrafenib and trametinib in metastatic melanoma have been demonstrated in two-phase III and one-phase I/II clinical trials. However, patients at least 75 years old (y.o.) were largely underrepresented. Additionally, the safety profile of dabrafenib and trametinib based on age is unknown. ELDERLYMEL is a retrospective noninterventional multicenter study, describing the effectiveness and safety of at least 75 y.o. patients compared with less than 75 y.o. patients with advanced BRAF V600-mutated melanoma treated with dabrafenib plus trametinib or dabrafenib monotherapy. A total of 159 patients were included, 130 less than 75 y.o. and 29 at least 75 y.o. Clinical features were similar between the groups, except in the number of comorbidities, number of metastatic sites, Eastern Cooperative Oncology Group (ECOG) performance status, and BRAF V600-mutation type. Five patients per group received dabrafenib monotherapy. There were no differences in adverse events (AEs) rate or grade between the groups. However, AE profiles were different between the groups, being pyrexia infrequent in patients at least 75 y.o. (13.8% vs. 42.3%; P = 0.005). Dabrafenib and trametinib dose intensities were lower in at least 75 y.o. patients (P = 0.018 and P = 0.020), but there were no differences in effectiveness between the groups. Finally, in a multivariate analysis, sex (female) was the only variable independently associated with an increased risk of AE grade ≥3. Data from the ELDERLYMEL study demonstrate that dabrafenib plus trametinib is safe and effective in at least 75 y.o. patients with advanced BRAF V600-mutated melanoma without increasing toxicity. Additionally, we describe a different safety profile depending on age and sex.

Impact of Previous Local Treatment for Brain Metastases on Response to Molecular Targeted Therapy in BRAF-Mutant Melanoma Brain Metastasis: A Systematic Review and Meta-Analysis

Background

Melanoma brain metastases (BMs) are associated with poor prognosis and are the main cause of mortality in melanoma patients. BRAF inhibitors have shown intracranial activity in both treatment-naïve and previously treated BM patients. We aimed to investigate if there was any difference in response of BRAF inhibitors in these two cohorts.

Materials and Methods

Electronic database search included PubMed, Medline, and Cochrane library until March 2021 for studies with desired comparative outcomes. Outcomes of interest that were obtained for meta-analysis included intracranial response rate as the primary outcome and survival and safety outcomes as the secondary outcomes. Review Manager version 5.4 was used for data analysis.

Results

Three studies comprising 410 BRAF-mutated melanoma patients with BMs were included according to eligibility criteria. The comparative cohort included patients with treatment-naïve BMs (TN cohort; n = 255) and those who had progressive disease after receiving local brain treatment for BMs (PT cohort; n = 155). Meta-analysis revealed that BRAF inhibitors (vemurafenib and dabrafenib) and BRAF/MEK inhibitor combination (dabrafenib and trametinib) induced significantly higher intracranial disease control (OR 0.58 [95% CI: 0.34, 0.97], p = 0.04) and a trend toward improved progression-free survival (PFS) (HR 1.22 [95% CI: 0.98, 1.52], p = 0.08) in the PT cohort as compared to the TN cohort. Overall survival was not significantly different between the cohorts (HR 1.16 [95% CI: 0.89, 1.51], p = 0.28). Subgroup analysis revealed that PFS was significantly improved (HR 1.67 [95% CI: 1.06, 2.62], p = 0.03), and a trend toward improved OS (HR 1.62 [95% CI: 0.95, 2.75], p = 0.08) was achieved in patients receiving BRAF/MEK inhibitor combination and patients with BRAFv600K mutation receiving dabrafenib alone. No increase in overall adverse events (AEs), grade 3/4 AEs, and severe adverse events (SAEs) was observed between the cohorts.

Conclusions

BRAF inhibitors (plus MEK inhibitor) may achieve better intracranial disease stability in BRAF-mutant melanoma patients who have received previous local treatment for BMs.

Systematic Review Registration

https://www.crd.york.ac.uk/prospero/), identifier CRD42020185984.

Acquired resistance to BRAF inhibitors is mediated by BRAF splicing variants in BRAF V600E mutation-positive colorectal neuroendocrine carcinoma

Neuroendocrine carcinomas (NECs), a poorly differentiated subtype of neuroendocrine neoplasms, are aggressive and have a poor prognosis. Colorectal neuroendocrine carcinomas (CRC-NECs) are observed in about 0.6% of all patients with CRC. Interestingly, patients with CRC-NECs show higher frequencies of BRAF mutation than typical CRC. BRAF V600E mutation-positive CRC-NECs were shown to be sensitive to BRAF inhibitors and now are treated by BRAF inhibitors. Similar to the other BRAF V600E mutated cancers, resistances against BRAF inhibitors have been observed, but the resistance mechanisms are still unclear. In this study, we established BRAF V600E mutated CRC-NEC cell line directly from surgical specimens and experimentally obtained BRAF inhibitor dabrafenib resistant cell lines. The resistant cells are revealed to express at least three types of BRAF splicing variants harboring V600E-mutation, and contribute to RAF/MEK/ERK pathway activation. In these cells, MEK and ERK inhibitors but not dabrafenib significantly suppressed cell growth and survival. Thus, in BRAF V600E mutation-positive CRC-NECs, BRAF splicing variants activate the RAF/MEK/ERK pathway and contribute to acquire BRAF inhibitor resistance. Hence, MEK or ERK are potential therapeutic targets to overcome BRAF resistance.

La résistance aux inhibiteurs de BRAF

La voie de signalisation MAPK/ERK est une voie centrale de la signalisation intracellulaire. Sa dérégulation participe à la transformation et la progression tumorales. Dans plusieurs cancers, la découverte de mutations activatrices de BRAF, à l’origine de l’activation de cette voie, a ouvert de nouvelles perspectives thérapeutiques avec le développement d’inhibiteurs spécifiques de la protéine. Selon les cancers, ces inhibiteurs ont cependant montré soit une efficacité insuffisante, due à la résistance primaire des cellules tumorales, soit une efficacité transitoire, due à l’apparition d’une résistance acquise. Dans cette revue, nous revenons sur les découvertes qui ont conduit au développement de ces inhibiteurs de BRAF. Nous détaillons également les mécanismes moléculaires et cellulaires de la résistance à ces inhibiteurs observée dans différents types de cancers. Comprendre ces mécanismes est en effet primordial pour développer des stratégies thérapeutiques qui soient plus efficaces.

Neoadjuvant Systemic Therapy (NAST) in Patients with Melanoma: Surgical Considerations by the International Neoadjuvant Melanoma Consortium (INMC)

Exciting advances in melanoma systemic therapies have presented the opportunity for surgical oncologists and their multidisciplinary colleagues to test the neoadjuvant systemic treatment approach in high-risk, resectable metastatic melanomas. Here we describe the state of the science of neoadjuvant systemic therapy (NAST) for melanoma, focusing on the surgical aspects and the key role of the surgical oncologist in this treatment paradigm. This paper summarizes the past decade of developments in melanoma treatment and the current evidence for NAST in stage III melanoma specifically. Issues of surgical relevance are discussed, including the risk of progression on NAST prior to surgery. Technical aspects, such as the definition of resectability for melanoma and the extent and scope of routine surgery are presented. Other important issues, such as the utility of radiographic response evaluation and method of pathologic response evaluation, are addressed. Surgical complications and perioperative management of NAST related adverse events are considered. The International Neoadjuvant Melanoma Consortium has the goal of harmonizing NAST trials in melanoma to facilitate rapid advances with new approaches, and facilitating the comparison of results across trials evaluating different treatment regimens. Our ultimate goals are to provide definitive proof of the safety and efficacy of NAST in melanoma, sufficient for NAST to become an acceptable standard of care, and to leverage this platform to allow more personalized, biomarker-driven, tailored approaches to subsequent treatment and surveillance.

STARBOARD: encorafenib + binimetinib + pembrolizumab for first-line metastatic/unresectable BRAF V600-mutant melanoma

Despite the significant progress in the treatment of unresectable or metastatic BRAF V600-mutant melanoma, there remains two primary treatment options: targeted therapy and immunotherapy. Targeted therapy or immunotherapy alone is associated with efficacy limitations including efficacy limited to select patient subsets. With separate mechanisms of action and different response patterns, the combination of targeted agents and immunotherapy to treat patients with BRAF V600-mutant melanoma may further improve patient outcomes. Current treatment guidelines recommend treatment with targeted agents alone, immunotherapy, or the combination of targeted agents and immunotherapy. The randomized, double-blind STARBOARD trial aims to evaluate efficacy and safety of encorafenib, binimetinib and pembrolizumab in treatment-naive patients with metastatic or unresectable locally advanced BRAF V600-mutant melanoma in comparison to pembrolizumab.

Translational drug-interaction corpus

The discovery of drug-drug interactions (DDIs) that have a translational impact among in vitro pharmacokinetics (PK), in vivo PK and clinical outcomes depends largely on the quality of the annotated corpus available for text mining. We have developed a new DDI corpus based on an annotation scheme that builds upon and extends previous ones, where an abstract is fragmented and each fragment is then annotated along eight dimensions, namely, focus, polarity, certainty, evidence, directionality, study type, interaction type and mechanism. The guideline for defining these dimensions has undergone refinement during the annotation process. Our DDI corpus comprises 900 positive DDI abstracts and 750 that are not directly relevant to DDI. The abstracts in corpus are separated into eight categories of DDI or non-DDI evidence: DDI with pharmacokinetic (PK) mechanism, in vivo DDI PK, DDI clinical, drug-nutrition interaction, single drug, not drug related, in vitro pharmacodynamic (PD) and case report. Seven annotators, three annotators with drug-interaction research experience and four annotators with less drug-interaction research experience independently annotated the DDI corpus, where two researchers independently annotated each abstract. After two rounds of annotations with additional training in between, agreement improved from (0.79, 0.96, 0.86, 0.70, 0.91, 0.65, 0.78, 0.90) to (0.93, 0.99, 0.96, 0.94, 0.95, 0.93, 0.96, 0.97) for focus, certainty, evidence, study type, interaction type, mechanisms, polarity and direction, respectively. The novice-level annotators improved from 0.83 to 0.96, while the expert-level annotators stayed in high performance with some improvement, from 0.90 to 0.96. In summary, we achieved 96% agreement among each pair of annotators with regard to the eight dimensions. The annotated corpus is now available to the community for inclusion in their text-mining pipelines. Database URL https://github.com/zha204/DDI-Corpus-Database/tree/master/DDI%20corpus.

Melanoma Brain Metastases: An Update on the Use of Immune Checkpoint Inhibitors and Molecularly Targeted Agents

Brain metastases from melanoma are no longer uniformly associated with dismal outcomes. Impressive tumor tissue-based (craniotomy) translational research has consistently shown that distinct patient subgroups may have a favorable prognosis. This review provides a historical overview of the standard-of-care treatments until the early 2010s. It subsequently summarizes more recent advances in understanding the biology of melanoma brain metastases (MBMs) and treating patients with MBMs, mainly focusing upon prospective clinical trials of BRAF/MEK and PD-1/CTLA-4 inhibitors in patients with previously untreated MBMs. These additional systemic treatments have provided effective complementary treatment approaches and/or alternatives to radiation and craniotomy. The current role of radiation therapy, especially in conjunction with systemic therapies, is also discussed through the lens of various retrospective studies. The combined efficacy of systemic treatments with radiation has improved overall survival over the last 10 years and has sparked considerable research interest regarding optimal dosing and sequencing of radiation treatments with systemic treatments. Finally, the review describes ongoing clinical trials in patients with MBMs.

Potential Biomarkers of Skin Melanoma Resistance to Targeted Therapy—Present State and Perspectives

Simple Summary

Around 5–10% of advanced melanoma patients progress early on anti-BRAF targeted therapy and 20–30% respond only with the stabilization of the disease. Presumably, these patients could benefit more from first-line immunotherapy. Resistance to BRAF/MEK inhibitors is generated by genetic and non-genetic factors inherent to a tumor or acquired during therapy. Some of them are well documented as a cause of treatment failure. They are potential predictive markers that could improve patients’ selection for both standard and also alternative therapy as some of them have therapeutic potential. Here, a summary of the most promising predictive and therapeutic targets is presented. This up-to-date knowledge may be useful for further study on implementing more accurate genetic/molecular tests in melanoma treatment.

Abstract

Melanoma is the most aggressive skin cancer, the number of which is increasing worldwide every year. It is completely curable in its early stage and fatal when spread to distant organs. In addition to new therapeutic strategies, biomarkers are an important element in the successful fight against this cancer. At present, biomarkers are mainly used in diagnostics. Some biological indicators also allow the estimation of the patient’s prognosis. Still, predictive markers are underrepresented in clinics. Currently, the only such indicator is the presence of the V600E mutation in the BRAF gene in cancer cells, which qualifies the patient for therapy with inhibitors of the MAPK pathway. The identification of response markers is particularly important given primary and acquired resistance to targeted therapies. Reliable predictive tests would enable the selection of patients who would have the best chance of benefiting from treatment. Here, up-to-date knowledge about the most promising genetic and non-genetic resistance-related factors is described. These are alterations in MAPK, PI3K/AKT, and RB signaling pathways, e.g., due to mutations in NRAS, RAC1, MAP2K1, MAP2K2, and NF1, but also other changes activating these pathways, such as the overexpression of HGF or EGFR. Most of them are also potential therapeutic targets and this issue is also addressed here.

Discovery of Raf Family Is a Milestone in Deciphering the Ras-Mediated Intracellular Signaling Pathway

The Ras-Raf-MEK-ERK signaling pathway, the first well-established MAPK pathway, plays essential roles in cell proliferation, survival, differentiation and development. It is activated in over 40% of human cancers owing to mutations of Ras, membrane receptor tyrosine kinases and other oncogenes. The Raf family consists of three isoforms, A-Raf, B-Raf and C-Raf. Since the first discovery of a truncated mutant of C-Raf as a transforming oncogene carried by a murine retrovirus, forty years of extensive studies have provided a wealth of information on the mechanisms underlying the activation, regulation and biological functions of the Raf family. However, the mechanisms by which activation of A-Raf and C-Raf is accomplished are still not completely understood. In contrast, B-Raf can be easily activated by binding of Ras-GTP, followed by cis-autophosphorylation of the activation loop, which accounts for the fact that this isoform is frequently mutated in many cancers, especially melanoma. The identification of oncogenic B-Raf mutations has led to accelerated drug development that targets Raf signaling in cancer. However, the effort has not proved as effective as anticipated, inasmuch as the mechanism of Raf activation involves multiple steps, factors and phosphorylation of different sites, as well as complex interactions between Raf isoforms. In this review, we will focus on the physiological complexity of the regulation of Raf kinases and their connection to the ERK phosphorylation cascade and then discuss the role of Raf in tumorigenesis and the clinical application of Raf inhibitors in the treatment of cancer.

Insights Into Vascular Anomalies, Cancer, and Fibroproliferative Conditions: The Role of Stem Cells and the Renin-Angiotensin System

Cells exhibiting embryonic stem cell (ESC) characteristics have been demonstrated in vascular anomalies (VAs), cancer, and fibroproliferative conditions, which are commonly managed by plastic surgeons and remain largely unsolved. The efficacy of the mTOR inhibitor sirolimus, and targeted therapies that block the Ras/BRAF/MEK/ERK1/2 and PI3KCA/AKT/mTOR pathways in many types of cancer and VAs, further supports the critical role of ESC-like cells in the pathogenesis of these conditions. ESC-like cells in VAs, cancer, and fibroproliferative conditions express components of the renin-angiotensin system (RAS) – a homeostatic endocrine signaling cascade that regulates cells with ESC characteristics. ESC-like cells are influenced by the Ras/BRAF/MEK/ERK1/2 and PI3KCA/AKT/mTOR pathways, which directly regulate cellular proliferation and stemness, and interact with the RAS at multiple points. Gain-of-function mutations affecting these pathways have been identified in many types of cancer and VAs, that have been treated with targeted therapies with some success. In cancer, the RAS promotes tumor progression, treatment resistance, recurrence, and metastasis. The RAS modulates cellular invasion, migration, proliferation, and angiogenesis. It also indirectly regulates ESC-like cells via its direct influence on the tissue microenvironment and by its interaction with the immune system. In vitro studies show that RAS inhibition suppresses the hallmarks of cancer in different experimental models. Numerous epidemiological studies show a reduced incidence of cancer and improved survival outcomes in patients taking RAS inhibitors, although some studies have shown no such effect. The discovery of ESC-like cells that express RAS components in infantile hemangioma (IH) underscores the paradigm shift in the understanding of its programmed biologic behavior and accelerated involution induced by β-blockers and angiotensin-converting enzyme inhibitors. The findings of SOX18 inhibition by R-propranolol suggests the possibility of targeting ESC-like cells in IH without β-adrenergic blockade, and its associated side effects. This article provides an overview of the current knowledge of ESC-like cells and the RAS in VAs, cancer, and fibroproliferative conditions. It also highlights new lines of research and potential novel therapeutic approaches for these unsolved problems in plastic surgery, by targeting the ESC-like cells through manipulation of the RAS, its bypass loops and converging signaling pathways using existing low-cost, commonly available, and safe oral medications.

Characterization of anticancer drug resistance by reverse-phase protein array: new targets and strategies

INTRODUCTION

Drug resistance is the main barrier to achieving cancer cures with medical therapy. Cancer drug resistance occurs, in part, due to adaptation of the tumor and microenvironment to therapeutic stress at a proteomic level. Reverse-phase protein arrays (RPPA) are well suited to proteomic analysis of drug resistance due to high sample throughput, sensitive detection of phosphoproteins, and validation for a large number of critical cellular pathways.

AREAS COVERED

This review summarizes contributions of RPPA to understanding and combating drug resistance. In particular, contributions of RPPA to understanding resistance to PARP inhibitors, BRAF inhibitors, immune checkpoint inhibitors, and breast cancer investigational therapies are discussed. Articles reviewed were identified by MEDLINE, Scopus, and Cochrane search for keywords 'proteomics,' 'reverse-phase protein array,' 'drug resistance,' 'PARP inhibitor,' 'BRAF inhibitor,' 'immune checkpoint inhibitor,' and 'I-SPY' spanning October 1, 1960 - October 1, 2021.

EXPERT OPINION

Precision oncology has thus far failed to convert the armament of targeted therapies into durable responses for most patients, highlighting that genetic sequencing alone is insufficient to guide therapy selection and overcome drug resistance. Combined genomic and proteomic analyses paired with creative drug combinations and dosing strategies hold promise for maturing precision oncology into an era of improved patient outcomes.

Novel Therapeutic Approaches with DNA Damage Response Inhibitors for Melanoma Treatment

Targeted therapies against components of the mitogen-activated protein kinase (MAPK) pathway and immunotherapies, which block immune checkpoints, have shown important clinical benefits in melanoma patients. However, most patients develop resistance, with consequent disease relapse. Therefore, there is a need to identify novel therapeutic approaches for patients who are resistant or do not respond to the current targeted and immune therapies. Melanoma is characterized by homologous recombination (HR) and DNA damage response (DDR) gene mutations and by high replicative stress, which increase the endogenous DNA damage, leading to the activation of DDR. In this review, we will discuss the current experimental evidence on how DDR can be exploited therapeutically in melanoma. Specifically, we will focus on PARP, ATM, CHK1, WEE1 and ATR inhibitors, for which preclinical data as single agents, taking advantage of synthetic lethal interactions, and in combination with chemo-targeted-immunotherapy, have been growing in melanoma, encouraging the ongoing clinical trials. The overviewed data are suggestive of considering DDR inhibitors as a valid therapeutic approach, which may positively impact the future of melanoma treatment.

Targeting mutations in cancer

Targeted therapies have come to play an increasingly important role in cancer therapy over the past two decades. This success has been made possible in large part by technological advances in sequencing, which have greatly advanced our understanding of the mutational landscape of human cancer and the genetic drivers present in individual tumors. We are rapidly discovering a growing number of mutations that occur in targetable pathways, and thus tumor genetic testing has become an important component in the choice of appropriate therapies. Targeted therapy has dramatically transformed treatment outcomes and disease prognosis in some settings, whereas in other oncologic contexts, targeted approaches have yet to demonstrate considerable clinical efficacy. In this Review, we summarize the current knowledge of targetable mutations that occur in a range of cancers, including hematologic malignancies and solid tumors such as non-small cell lung cancer and breast cancer. We outline seminal examples of druggable mutations and targeting modalities and address the clinical and research challenges that must be overcome to maximize therapeutic benefit.

Somatic Genomic Testing in Patients With Metastatic or Advanced Cancer: ASCO Provisional Clinical Opinion

PURPOSE

An ASCO provisional clinical opinion offers timely clinical direction to ASCO's membership following publication or presentation of potentially practice-changing data from major studies. This provisional clinical opinion addresses the appropriate use of tumor genomic testing in patients with metastatic or advanced solid tumors.

CLINICAL CONTEXT

An increasing number of therapies are approved to treat cancers harboring specific genomic biomarkers. However, there is a lack of clarity as to when tumor genomic sequencing should be ordered, what type of assays should be performed, and how to interpret the results for treatment selection.

PROVISIONAL CLINICAL OPINION

Patients with metastatic or advanced cancer should undergo genomic sequencing in a certified laboratory if the presence of one or more specific genomic alterations has regulatory approval as biomarkers to guide the use of or exclusion from certain treatments for their disease. Multigene panel-based assays should be used if more than one biomarker-linked therapy is approved for the patient's disease. Site-agnostic approvals for any cancer with a high tumor mutation burden, mismatch repair deficiency, or neurotrophic tyrosine receptor kinase (NTRK) fusions provide a rationale for genomic testing for all solid tumors. Multigene testing may also assist in treatment selection by identifying additional targets when there are few or no genotype-based therapy approvals for the patient's disease. For treatment planning, the clinician should consider the functional impact of the targeted alteration and expected efficacy of genomic biomarker-linked options relative to other approved or investigational treatments.Additional information is available at www.asco.org/assays-and-predictive-markers-guidelines.

Partial response to dabrafenib and trametinib in relapsed BRAF V600E-Mutated multiple myeloma and possible mechanisms of resistance

BRAF V600E mutations are detected in 3%–10% of patients with multiple myeloma (MM) and are associated with more aggressive disease, higher frequency of extramedullary growth and shorter survival. Monotherapy with the BRAF inhibitor vemurafenib has been disappointing in MM. In patients with BRAF-mutated melanoma, MEK and BRAF inhibition has been a successful approach. Here we describe a very good partial response and possible mechanisms of resistance to a combination of the BRAF inhibitor dabrafenib and the MEK inhibitor trametinib in a patient with BRAF V600E-mutant refractory MM.

Characterization of the treatment-naive immune microenvironment in melanoma with BRAF mutation

BACKGROUND

Patients with BRAF-mutant and wild-type melanoma have different response rates to immune checkpoint blockade therapy. However, the reasons for this remain unknown. To address this issue, we investigated the precise immune composition resulting from BRAF mutation in treatment-naive melanoma to determine whether this may be a driver for different response to immunotherapy.

METHODS

In this study, we characterized the treatment-naive immune context in patients with BRAF-mutant and BRAF wild-type (BRAF-wt) melanoma using data from single-cell RNA sequencing, bulk RNA sequencing, flow cytometry and immunohistochemistry (IHC).

RESULTS

In single-cell data, BRAF-mutant melanoma displayed a significantly reduced infiltration of CD8+ T cells and macrophages but also increased B cells, natural killer (NK) cells and NKT cells. We then validated this finding using bulk RNA-seq data from the skin cutaneous melanoma cohort in The Cancer Genome Atlas and deconvoluted the data using seven different algorithms. Interestingly, BRAF-mutant tumors had more CD4+ T cells than BRAF-wt samples in both primary and metastatic cohorts. In the metastatic cohort, BRAF-mutant melanoma demonstrated more B cells but less CD8+ T cell infiltration when compared with BRAF-wt samples. In addition, we further investigated the immune cell infiltrate using flow cytometry and multiplex IHC techniques. We confirmed that BRAF-mutant melanoma metastases were enriched for CD4+ T cells and B cells and had a co-existing decrease in CD8+ T cells. Furthermore, we then identified B cells were associated with a trend for improved survival (p=0.078) in the BRAF-mutant samples and Th2 cells were associated with prolonged survival in the BRAF-wt samples.

CONCLUSIONS

In conclusion, treatment-naive BRAF-mutant melanoma has a distinct immune context compared with BRAF-wt melanoma, with significantly decreased CD8+ T cells and increased B cells and CD4+ T cells in the tumor microenvironment. These findings indicate that further mechanistic studies are warranted to reveal how this difference in immune context leads to improved outcome to combination immune checkpoint blockade in BRAF-mutant melanoma.

Real-world frequency of BRAF testing and utilization of therapies in patients with advanced melanoma

Both BRAF/MEK targeted agents and immunotherapy are approved for the treatment of advanced melanoma. BRAF testing is recommended at the time of advanced melanoma diagnosis. In addition, little is known regarding the treatment trends for patients with BRAF mutated tumors. This investigation aims to assess the real-world prevalence of molecular testing and treatment trends for patients with BRAF mutated tumors. Using a de-identified database, patients of age ≥18 years with advanced melanoma from 2013 to 2018 were examined. Molecular testing performed within 3 months of advanced diagnosis was considered to have the test performed at the time of diagnosis. Test prevalence was calculated and compared in groups stratified by the patient, tumor and treatment factors. In total 4459 patients were included; 1936 (43.4%) stage III, 1191 (26.7%) stage IV and 1332 (29.9%) recurrent. Totally 50.4% of patients received systemic treatment; 76.4% stage IV, 71% recurrent patients and 26.7% stage III patients. However, 73.5% received first-line immunotherapy. In total 73.8% of patients had molecular testing, and 50.5% had tested at the time of advanced diagnosis. Of those tested 42% had a BRAF mutated tumor. In total 48% of these patients received first-line immunotherapy whereas 43% received a BRAF inhibitor, with increasing immunotherapy use seen over time. The majority of patients with advanced melanoma undergo molecular testing at the time of advanced diagnosis. Immunotherapy is the most commonly prescribed treatment regardless of BRAF mutational status. These results provide real-world data on the frequency of molecular testing and treatment trends for patients with advanced melanoma.

Nectin-4: a Novel Therapeutic Target for Skin Cancers

OPINION STATEMENT

Nectin-4 is a tumor-associated antigen that is highly expressed on various cancer cells, and it has been further proposed to have roles in tumor development and propagation ranging from cellular proliferation to motility and invasion. Nectin-4 blockade reduces tumor proliferation and induces apoptosis in several malignancies. Nectin-4 has been used as a potential target in antibody-drug conjugate (ADC) development. Enfortumab vedotin, an ADC against Nectin-4, has demonstrated efficacy against solid tumor malignancies. Enfortumab vedotin has received US Food and Drug Administration approval for treating urothelial cancer. Furthermore, the efficacy of ADCs against Nectin-4 against solid tumors other than urothelial cancer has been demonstrated in preclinical studies, and clinical trials examining the effects of enfortumab vedotin are ongoing. Recently, Nectin-4 was reported to be highly expressed in several skin cancers, including malignant melanoma, cutaneous squamous cell carcinoma, and extramammary Paget's disease, and involved in tumor progression and survival in retrospective studies. Nectin-4-targeted therapies and ADCs against Nectin-4 could therefore be novel therapeutic options for skin cancers. This review highlights current knowledge on Nectin-4 in malignant tumors, the efficacy of enfortumab vedotin in clinical trials, and the prospects of Nectin-4-targeted agents against skin cancers.

Comprehensive Analysis of the Prognostic Signature of Mutation-Derived Genome Instability-Related lncRNAs for Patients With Endometrial Cancer

Background: Emerging evidence shows that genome instability-related long non-coding RNAs (lncRNAs) contribute to tumor–cell proliferation, differentiation, and metastasis. However, the biological functions and molecular mechanisms of genome instability-related lncRNAs in endometrial cancer (EC) are underexplored.

Methods: EC RNA sequencing and corresponding clinical data obtained from The Cancer Genome Atlas (TCGA) database were used to screen prognostic lncRNAs associated with genomic instability via univariate and multivariate Cox regression analysis. The genomic instability-related lncRNA signature (GILncSig) was developed to assess the prognostic risk of high- and low-risk groups. The prediction performance was analyzed using receiver operating characteristic (ROC) curves. The immune status and mutational loading of different risk groups were compared. The Genomics of Drug Sensitivity in Cancer (GDSC) and the CellMiner database were used to elucidate the relationship between the correlation of prognostic lncRNAs and drug sensitivity. Finally, we used quantitative real-time PCR (qRT-PCR) to detect the expression levels of genomic instability-related lncRNAs in clinical samples.

Results: GILncSig was built using five lncRNAs (AC007389.3, PIK3CD-AS2, LINC01224, AC129507.4, and GLIS3-AS1) associated with genomic instability, and their expression levels were verified using qRT-PCR. Further analysis revealed that risk score was negatively correlated with prognosis, and the ROC curve demonstrated the higher accuracy of GILncSig. Patients with a lower risk score had higher immune cell infiltration, a higher immune score, lower tumor purity, higher immunophenoscores (IPSs), lower mismatch repair protein expression, higher microsatellite instability (MSI), and a higher tumor mutation burden (TMB). Furthermore, the level of expression of prognostic lncRNAs was significantly related to the sensitivity of cancer cells to anti-tumor drugs.

Conclusion: A novel signature composed of five prognostic lncRNAs associated with genome instability can be used to predict prognosis, influence immune status, and chemotherapeutic drug sensitivity in EC.

The Current State of Treatment and Future Directions in Cutaneous Malignant Melanoma

Malignant melanoma is the leading cause of death among cutaneous malignancies. While its incidence is increasing, the most recent cancer statistics show a small but clear decrease in mortality rate. This trend reflects the introduction of novel and more effective therapeutic regimens, including the two cornerstones of melanoma therapy: immunotherapies and targeted therapies. Immunotherapies exploit the highly immunogenic nature of melanoma by modulating and priming the patient's own immune system to attack the tumor. Treatments combining immunotherapies with targeted therapies, which disable the carcinogenic products of mutated cancer cells, have further increased treatment efficacy and durability. Toxicity and resistance, however, remain critical challenges to the field. The present review summarizes past treatments and novel therapeutic interventions and discusses current clinical trials and future directions.

Impact of Cannabinoid Compounds on Skin Cancer

Drugs targeting the endocannabinoid system are of interest as potential systemic chemotherapeutic treatments and for palliative care in cancer. In this context, cannabinoid compounds have been successfully tested as a systemic therapeutic option in preclinical models over the past decades. Recent findings have suggested an essential function of the endocannabinoid system in the homeostasis of various skin functions and indicated that cannabinoids could also be considered for the treatment and prophylaxis of tumour diseases of the skin. Cannabinoids have been shown to exert their anticarcinogenic effects at different levels of skin cancer progression, such as inhibition of tumour growth, proliferation, invasion and angiogenesis, as well as inducing apoptosis and autophagy. This review provides an insight into the current literature on cannabinoid compounds as potential pharmaceuticals for the treatment of melanoma and squamous cell carcinoma.

Immune Landscape and an RBM38-Associated Immune Prognostic Model with Laboratory Verification in Malignant Melanoma

Simple Summary

The primary treatment of malignant melanoma is a classical regimen of surgery combined with chemotherapy, targeted drugs, and immunotherapy. The purpose of this study was to explore the immune response mechanism of RNA binding protein RBM38 in the development of melanoma with the screening of effective immunodiagnostic models and targeted therapy. We found that RBM38, as an oncogene, promotes the proliferation, invasion, and migration of melanoma cells and is associated with immune infiltration and pathways. Our investigation presented the prognostic significance of RBM38-associated immune signature. In addition, this model may provide a potential strategy for improving the survival and immunotherapy of melanoma patients.

Abstract

Background: Current studies have revealed that RNA-binding protein RBM38 is closely related to tumor development, while its role in malignant melanoma remains unclear. Therefore, this research aimed to investigate the function of RBM38 in melanoma and the prognosis of the disease. Methods: Functional experiments (CCK-8 assay, cell colony formation, transwell cell migration/invasion experiment, wound healing assay, nude mouse tumor formation, and immunohistochemical analysis) were applied to evaluate the role of RBM38 in malignant melanoma. Immune-associated differentially expressed genes (DEGs) on RBM38 related immune pathways were comprehensively analyzed based on RNA sequencing results. Results: We found that high expression of RBM38 promoted melanoma cell proliferation, invasion, and migration, and RBM38 was associated with immune infiltration. Then, a five-gene (A2M, NAMPT, LIF, EBI3, and ERAP1) model of RBM38-associated immune DEGs was constructed and validated. Our signature showed superior prognosis capacity compared with other melanoma prognostic signatures. Moreover, the risk score of our signature was connected with the infiltration of immune cells, immune-regulatory proteins, and immunophenoscore in melanoma. Conclusions: We constructed an immune prognosis model using RBM38-related immune DEGs that may help evaluate melanoma patient prognosis and immunotherapy modalities.

Antagonism of the transient receptor potential melastatin‑2 channel leads to targeted antitumor effects in primary human malignant melanoma cells

Melanoma continues to be the most aggressive and devastating form of skin cancer for which the development of novel therapies is required. The present study aimed to determine the effects of antagonism of the transient receptor potential melastatin‑2 (TRPM2) ion channel in primary human malignant melanoma cells. TRPM2 antagonism via use of the antifungal agent, clotrimazole, led to decreases in cell proliferation, as well as dose‑dependent increases in cell death in all melanoma cell lines investigated. The targeting of TRPM2 channels was verified using TRPM2 knockdown, where treatment with TRPM2 small‑interfering RNA led to similar levels of cell death in all melanoma cell lines when compared with clotrimazole treatment. Minimal effects on proliferation and cell death were observed following antagonism or knockdown of TRPM2 in non‑cancerous human keratinocytes. Moreover, characteristics of TRPM2 were explored in these melanoma cells and the results demonstrated that TRPM2, localized to the plasma membrane as a non‑specific ion channel in non‑cancerous cells, displayed a nuclear localization in all human melanoma cell lines analyzed. Additional characterization of these melanoma cell lines confirmed that each expressed one or more established multidrug resistance genes. Results of the present study therefore indicated that antagonism of the TRPM2 channel led to antitumor effects in human melanoma cells, including those that are potentially unresponsive to current treatments due to the expression of drug resistance genes. The unique cellular localization of TRPM2 and the specificity of the antitumor effects elicited by TRPM2 antagonism suggested that TRPM2 possesses a unique role in melanoma cells. Collectively, the targeting of TRPM2 represents a potentially novel, efficacious and readily accessible treatment option for patients with melanoma.

The value of anticancer drugs - a regulatory view

The high prices of new anticancer drugs and the marginal added benefit perceived by some stakeholders have fuelled a debate on the value of anticancer drugs in the European Union, even though an agreed definition of what constitutes a drug's value does not exist. In this Perspective, we discuss the value of drugs from different viewpoints and objectives of decision makers: for regulators, assessment of the benefit-risk balance of a drug is a cornerstone for approval; payers rely on cost-effectiveness analyses carried out by health technology assessment agencies for reimbursement decisions; for patients, treatment choices are based on personal preferences and attitudes to risk; and clinicians can use several scales (such as the ESMO Magnitude of Clinical Benefit Scale (ESMO-MCBS)) that have been developed as an attempt to measure value objectively. Although a unique definition that fully captures the concept of value is unlikely to emerge, herein we discuss the importance of understanding different perspectives, and how regulators can help to inform different decision makers.

Economic and health care resource utilization burden of central nervous system metastases in patients with metastatic melanoma

BACKGROUND: In patients with metastatic melanoma, central nervous system (CNS) involvement is associated with poor prognosis, increased costs, and higher health care resource utilization (HCRU); however, previous cost-estimate studies were conducted before widespread use of targeted therapies and immunotherapies. OBJECTIVE: To estimate costs and HCRU in patients with metastatic melanoma with and without CNS metastases in the current treatment era following introduction of targeted therapies and immunotherapies. METHODS: This real-world retrospective cohort study used data from the IQVIA PharMetrics Plus claims database to estimate and compare costs and HCRU in patients with metastatic melanoma by presence or absence of CNS metastases between January 2011 and June 2019. Patients with at least 2 melanoma claims, at least 2 metastatic claims, and continuous enrollment at least 6 months before and at least 1 month after first metastatic diagnosis were included. Mean per-patient-per-month (PPPM) costs are reported in 2019 US dollars. Analyses were also conducted by time period of first metastatic diagnosis: 2011-2014 (reflecting BRAF inhibitor monotherapy and anti-CTLA-4 therapy) and 2015-2019 (reflecting availability of BRAF and MEK inhibitor combinations and anti-PD-1/PD-L1 therapies). RESULTS: Of 4,078 patients, 1,253 (30.7%) had CNS metastases. Patients with CNS metastases were more likely to receive any treatment (89.1% vs 58.9%; P < 0.001), including systemic treatment (73.3% vs 55.4%; P < 0.001) and radiation (65.8% vs 11.8%; P < 0.001), and to have brain imaging any time after metastatic diagnosis (98.3% vs 67.2%; P < 0.001). In patients with CNS metastases, 40.0% had dexamethasone 4 mg within 30 days of CNS metastatic diagnosis. Patients with CNS metastases incurred higher total mean PPPM costs ($29,953 vs $14,996; P < 0.001). The largest contributors were total radiology ($2,351 vs $1,110), targeted therapies ($2,499 vs $638), and immunotherapies ($7,398 vs $5,036). HCRU and costs were higher in patients with vs without CNS metastases regardless of time period of first metastatic diagnosis. In patients with CNS metastases, use of any systemic treatment was increased in 2015-2019 vs 2011-2014 (81.2% vs 64.5%; P < 0.001), including chemotherapy (68.1% vs 50.0%; P < 0.001), immunotherapy (60.9% vs 30.1%; P < 0.001), and/or targeted therapies (32.7% vs 27.4%; P = 0.05). Mean total PPPM costs for patients with CNS metastases increased from $28,183 in 2011-2014 to $31,569 in 2015-2019 (P < 0.001); main drivers were immunotherapies and targeted therapies. CONCLUSIONS: CNS metastases occur frequently in patients with metastatic melanoma and are associated with significantly increased economic burden compared with patients without CNS metastases; the largest contributors to total costs in the current treatment era are radiology, targeted therapies, and immunotherapies. Brain imaging remains underused, and there is an opportunity to improve outcomes through early detection of CNS metastases, potentially reducing the high HCRU and costs associated with CNS metastases. DISCLOSURES: This study was funded by F. Hoffmann-La Roche Ltd. The sponsor was involved in the study design, data collection, data analysis, manuscript preparation, and publication decisions. Seetasith and Lee are employed by and report stock ownership in Genentech, Inc. Bartley and McKenna were employed by Genentech, Inc., at the time of this study and report stock ownership. Tawbi reports grants and personal fees from Genentech/Roche, Novartis, BMS, and Merck; grants from GSK and Celgene; and personal fees from Eisai, outside the submitted work. Kent, Burton, and Haydu have nothing to disclose. The results of this study were presented in part at the AMCP Nexus 2020 Virtual Meeting, October 19-23, 2020.

Naturally occurring, natural product inspired and synthetic heterocyclic anti-cancer drugs

This chapter describes the importance and activity of a huge number of commercially available naturally occurring, natural product derived or synthetic heterocyclic anti-cancer drugs.

Novel treatment strategy for NRAS-mutated melanoma through a selective inhibitor of CD147/VEGFR-2 interaction

More than 70% of human NRAS^mut melanomas are resistant to MEK inhibitors highlighting the crucial need for efficient therapeutic strategies for these tumors. CD147, a membrane receptor, is overexpressed in most cancers including melanoma and is associated with poor prognosis. We show here that CD147i, a specific inhibitor of CD147/VEGFR-2 interaction represents a potential therapeutic strategy for NRAS^mut melanoma cells. It significantly inhibited the malignant properties of NRAS^mut melanomas ex vivo and in vivo. Importantly, NRAS^mut patient's-derived xenografts, which were resistant to MEKi, became sensitive when combined with CD147i leading to decreased proliferation ex vivo and tumor regression in vivo. Mechanistic studies revealed that CD147i effects were mediated through STAT3 pathway. These data bring a proof of concept on the impact of the inhibition of CD147/VEGFR-2 interaction on melanoma progression and represents a new therapeutic opportunity for NRAS^mut melanoma when combined with MEKi.

Re-establishing the comprehension of phytomedicine and nanomedicine in inflammation-mediated cancer signaling

Recent mounting evidence has revealed extensive genetic heterogeneity within tumors that drive phenotypic variation affecting key cancer pathways, making cancer treatment extremely challenging. Diverse cancer types display resistance to treatment and show patterns of relapse following therapy. Therefore, efforts are required to address tumor heterogeneity by developing a broad-spectrum therapeutic approach that combines targeted therapies. Inflammation has been progressively documented as a vital factor in tumor advancement and has consequences in epigenetic variations that support tumor instigation, encouraging all the tumorigenesis phases. Increased DNA damage, disrupted DNA repair mechanisms, cellular proliferation, apoptosis, angiogenesis, and its incursion are a few pro-cancerous outcomes of chronic inflammation. A clear understanding of the cellular and molecular signaling mechanisms of tumor-endorsing inflammation is necessary for further expansion of anti-cancer therapeutics targeting the crosstalk between tumor development and inflammatory processes. Multiple inflammatory signaling pathways, such as the NF-κB signaling pathway, JAK-STAT signaling pathway, MAPK signaling, PI3K/AKT/mTOR signaling, Wnt signaling cascade, and TGF-β/Smad signaling, have been found to regulate inflammation, which can be modulated using various factors such as small molecule inhibitors, phytochemicals, recombinant cytokines, and nanoparticles in conjugation to phytochemicals to treat cancer. Researchers have identified multiple targets to specifically alter inflammation in cancer therapy to restrict malignant progression and improve the efficacy of cancer therapy. siRNA-and shRNA-loaded nanoparticles have been observed to downregulate STAT3 signaling pathways and have been employed in studies to target tumor malignancies. This review highlights the pathways involved in the interaction between tumor advancement and inflammatory progression, along with the novel approaches of nanotechnology-based drug delivery systems currently used to target inflammatory signaling pathways to combat cancer.

BRAF inhibitors and their immunological effects in malignant melanoma

INTRODUCTION

The treatment of cutaneous melanoma has been revolutionised by the development of small molecule inhibitors targeting the MAPK pathway, including inhibitors of BRAF (BRAFi) and MEK (MEKi), and immune checkpoint blockade antibodies, occurring in tandem. Despite these advances, the 5-year survival rate for patients with advanced melanoma remains only around 50%. Although not designed to alter immune responses within the tumour microenvironment (TME), MAPK pathway inhibitors (MAPKi) exert a range of effects on the host immune compartment which may offer opportunities for therapeutic interventions.

AREAS COVERED

We review the effects of MAPKi especially BRAFi, on the TME, focussing on alterations in inflammatory cytokine secretion, the recruitment of immune cells and their functions, both during response to BRAFi treatment and as resistance develops. We outline potential combinations of MAPKi with established and experimental treatments.

EXPERT OPINION

MAPKi in combination or in sequence with established treatments such as checkpoint inhibitors, anti-angiogenic agents, or new therapies such as adoptive cell therapies, may augment their immunological effects, reverse tumour-associated immune suppression and offer the prospect of longer-lived clinical responses. Refining therapeutic tools at our disposal and embracing "old friends" in the melanoma treatment arsenal, alongside new target identification, may improve the chances of therapeutic success.

Management of In-Transit Metastases

PURPOSE OF REVIEW

The purpose of this study is to discuss the current knowledge and future perspectives regarding the treatment options for in-transit metastases (ITM), along with the optimal algorithms for patients presenting with this adverse manifestation of melanoma.

RECENT FINDINGS

In addition to procedures historically accepted for the management of ITM, encompassing surgery and regional techniques, novel medications in the form of immune checkpoint inhibitors (ICI) and targeted therapies now represent standard options, allowing for the possibility of combined approaches, with an expanding role of systemic therapies. Melanoma in-transit metastases consist of intralymphatic neoplastic implants distributed between the primary site and the regional nodal basin, within the subepidermal and dermal lymphatics. Distinct risk factors may influence the development of ITM, and the clinical presentation can be highly heterogeneous, enhancing the complexity of the management of ITM. Surgical resection, when feasible, continues to represent a standard approach for patients with curative intent. Patients with extensive or unresectable disease may also benefit from regional approaches that include isolated limb perfusion or infusion, electrochemotherapy, and a wide variety of intralesional therapies. Over the past decade, regimens with ICI and BRAF/MEK inhibitors dramatically expanded the benefit of systemic treatments for patients with melanoma, both in the adjuvant setting and for those with advanced disease, and the combination of these modalities with regional treatments, as well as neoadjuvant approaches, may represent the future for the treatment of patients with ITM.

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.

Recent Developments of Circulating Tumor Cell Analysis for Monitoring Cutaneous Melanoma Patients

Simple Summary

Circulating tumor cells (CTCs) originating from cutaneous melanoma patients have been studied for several decades as surrogates for real-time clinical status and disease outcomes. Here, we will review clinical studies from the last 15 years that assessed CTCs and disease outcomes for melanoma patients. Assessment of multiple molecular melanoma-associated antigen (MAA) markers by quantitative reverse transcriptase-polymerase chain reaction (RT-PCR) was the most common assay allowing for the improvement of assay sensitivity, to address tumor heterogeneity, and to predict patient outcomes. Multicenter studies demonstrate the utility of CTC assays reducing the bias observed in single-center trials. Recent development of CTC enrichment platforms has provided reproducible methods. CTC assessment enables both multiple mRNAs and DNAs genomic profiling. CTC provides specific important translational information on tumor progression, prediction of treatment response, and survival outcomes for cutaneous melanoma patients.

Abstract

Circulating tumor cells (CTCs) have been studied using multiple technical approaches for interrogating various cancers, as they allow for the real-time assessment of tumor progression, disease recurrence, treatment response, and tumor molecular profiling without the need for a tumor tissue biopsy. Here, we will review studies from the last 15 years on the assessment of CTCs in cutaneous melanoma patients in relation to different clinical outcomes. The focus will be on CTC detection in blood samples obtained from cutaneous melanoma patients of different clinical stages and treatments utilizing multiple platforms. Assessment of multiple molecular melanoma-associated antigen (MAA) markers by quantitative reverse transcriptase-polymerase chain reaction (RT-PCR) was the most common assay allowing for the improvement of assay sensitivity, tumor heterogeneity, and to predict patient outcomes. Multicenter studies demonstrate the utility of CTC assays reducing the bias observed in single- center trials. The recent development of CTC enrichment platforms has provided reproducible methods. CTC assessment enables both multiple mRNAs and DNAs genomic aberration profiling. CTC provides specific important translational information on tumor progression, prediction of treatment response, and survival outcomes for cutaneous melanoma patients. The molecular studies on melanoma CTCs have provided and may set standards for other solid tumor CTC analyses.

Regulation of LncRNAs in Melanoma and Their Functional Roles in the Metastatic Process

Long non-coding RNAs (lncRNAs) are key regulators of numerous intracellular processes leading to tumorigenesis. They are frequently deregulated in cancer, functioning as oncogenes or tumor suppressors. As they act through multiple mechanisms, it is not surprising that they may exert dual functions in the same tumor. In melanoma, a highly invasive and metastatic tumor with the propensity to rapidly develop drug resistance, lncRNAs play different roles in: (i) guiding the phenotype switch and leading to metastasis formation; (ii) predicting the response of melanoma patients to immunotherapy; (iii) triggering adaptive responses to therapy and acquisition of drug resistance phenotypes. In this review we summarize the most recent findings on the lncRNAs involved in melanoma growth and spreading to distant sites, focusing on their role as biomarkers for disease diagnosis and patient prognosis, or targets for novel therapeutic approaches.

The Use of ctDNA for BRAF Mutation Testing in Routine Clinical Practice in Patients with Advanced Melanoma

Assessment of BRAF mutation status is mandatory in advanced, treatment-naïve melanoma patients. Liquid biopsy can be an alternative in cases with inadequate or unavailable tumor tissue. The aim of our study was to evaluate the clinical utility of plasma circulating tumor DNA analysis for BRAF mutation testing and to assess outcomes of therapy with BRAF/MEK inhibitors initiated based on the liquid biopsy results. This was a retrospective single-center analysis of 46 patients (21 female, 25 male) with advanced melanoma who underwent circulating tumor DNA (ctDNA) BRAF mutation testing. A BRAF mutation was found in 45.7% (21/46) of liquid biopsies and 44.8% (13/29) of tissue samples. In patients with both ctDNA and tissue samples (n = 29), the concordance between the results of both tests was 82.8%. A BRAF mutation was detected in 7/17 (41.2%) patients with only ctDNA analysis. In 18 patients, therapy with BRAF/MEK inhibitors was initiated on the basis of the result of liquid biopsy. The objective response rate was 77.8 %, and the median PFS was 6.0 months. Our study confirms the clinical utility of BRAF mutation detection in plasma ctDNA. This study provides initial real-world data showing that treatment with BRAF/MEK inhibitors could be commenced based on liquid biopsy results.

Classical RAS proteins are not essential for paradoxical ERK activation induced by RAF inhibitors

RAF inhibitors unexpectedly induce ERK activation in normal and oncogenic RAS tumor cells, making them unsuitable for treating RAS-driven cancers. The precise mechanism of this paradox is not fully understood but is believed to be RAS dependent. In this study, we discovered that classical RAS proteins are not essential for RAF inhibitor-induced ERK activation in H/N/KRAS-less mouse embryonic fibroblasts. We further showed that the MRAS/SHOC2 complex is required for the classical RAS-independent paradoxical ERK activation. Our findings provide new insights into the mechanism of paradoxical ERK activation by RAF inhibitors, and they have important therapeutic implications for developing effective RAF inhibitors.

RAF inhibitors unexpectedly induce ERK signaling in normal and tumor cells with elevated RAS activity. Paradoxical activation is believed to be RAS dependent. In this study, we showed that LY3009120, a pan-RAF inhibitor, can unexpectedly cause paradoxical ERK activation in KRAS^G12C-dependent lung cancer cell lines, when KRAS is inhibited by ARS1620, a KRAS^G12C inhibitor. Using H/N/KRAS-less mouse embryonic fibroblasts, we discovered that classical RAS proteins are not essential for RAF inhibitor-induced paradoxical ERK signaling. In their absence, RAF inhibitors can induce ERK phosphorylation, ERK target gene transcription, and cell proliferation. We further showed that the MRAS/SHOC2 complex is required for this process. This study highlights the complexity of the allosteric RAF regulation by RAF inhibitors, and the importance of other RAS-related proteins in this process.

RAS pathway regulation in melanoma

Activating mutations in RAS genes are the most common genetic driver of human cancers. Yet, drugging this small GTPase has proven extremely challenging and therapeutic strategies targeting these recurrent alterations have long had limited success. To circumvent this difficulty, research has focused on the molecular dissection of the RAS pathway to gain a more-precise mechanistic understanding of its regulation, with the hope to identify new pharmacological approaches. Here, we review the current knowledge on the (dys)regulation of the RAS pathway, using melanoma as a paradigm. We first present a map of the main proteins involved in the RAS pathway, highlighting recent insights into their molecular roles and diverse mechanisms of regulation. We then overview genetic data pertaining to RAS pathway alterations in melanoma, along with insight into other cancers, that inform the biological function of members of the pathway. Finally, we describe the clinical implications of RAS pathway dysregulation in melanoma, discuss past and current approaches aimed at drugging the RAS pathway, and outline future opportunities for therapeutic development.

Summary: This Review describes the molecular regulation of the RAS pathway, presents the clinical consequences of its pathological activation in human cancer, and highlights recent advances towards its therapeutic inhibition, using melanoma as an example.

Precision medicine for metastatic colorectal cancer in clinical practice

Globally, metastatic colorectal cancer is one of the leading causes for cancer-related death. Treatment limited to conventional chemotherapeutics extended life for only a few months. However, advances in surgical approaches and medical treatment regimens have greatly increased survival, even leading to long-term remission in selected patients. Advances in multiomics analysis of tumors have built a foundation for molecular-targeted therapies. Furthermore, immunotherapies are on the edge of revolutionizing oncological practice. This review summarizes recent advances in the growing toolbox of personalized treatment for patients with metastatic colorectal cancer. We provide an overview of current multimodal therapy and explain novel immunotherapy and targeted therapy approaches in detail. We emphasize clinically relevant therapies, such as inhibitors of MAPK signaling, and give recommendations for clinical practice. Finally, we describe the potential predictive impact of molecular subtypes and provide an outlook on novel concepts, such as functional precision medicine.

Recent advances in B-RAF inhibitors as anticancer agents

The significance of B-RAF in the promotion of cell proliferation and motility was explored by the researchers in the past. However, in 2002, several researchers found that mutation in B-RAF leads to cancer. Extensive research on B-RAF mutations suggested B-RAF V600E mutation as a critical predictive, prognostic and diagnostic biomarker in numerous cancers such as melanoma, thyroid, and colorectal cancers. Based on the significance of B-RAF kinase and associated mutation, the present review will give a brief overview about structure and functions of B-RAF enzyme, its role in different types of cancer, available drugs in the market for B-RAF inhibition, chemical classification and SAR studies of reported investigational B-RAF inhibitors in patented and non-patented literature during last decade. The SAR provided for all the reported inhibitors will help researchers to gain knowledge about the possible structural features required for selective B-RAF inhibition. This insightful analysis of B-RAF will certainly help researchers to develop novel anticancer agents in the future.

Emerging Novel Therapeutic Approaches for Treatment of Advanced Cutaneous Melanoma

The prognosis of patients with advanced cutaneous melanoma has radically changed in the past decade. Nevertheless, primary or acquired resistance to systemic treatment occurs in many cases, highlighting the need for novel treatment strategies. This review has the purpose of summarizing the current area of interest for the treatment of metastatic or unresectable advanced cutaneous melanoma, including data from recently completed or ongoing clinical trials. The main fields of investigation include the identification of new immune checkpoint inhibitors (anti-LAG3, GITR agonist and anti-TIGIT), adoptive cell therapy, vaccines, engineered TCR therapy, IL-2 agonists, novel targets for targeted therapy (new MEK or RAF inhibitors, HDAC, IDO, ERK, Axl, ATR and PARP inhibitors), or combination strategies (antiangiogenetic agents plus immune checkpoint inhibitors, intra-tumoral immunotherapy in combination with systemic therapy). In many cases, only preliminary efficacy data from early phase trials are available, which require confirmation in larger patient cohorts. A more in-depth knowledge of the biological effects of the molecules and identifying predictive biomarkers remain crucial for selecting patient populations most likely to benefit from novel emerging treatment strategies.

Using Optical Tweezers to Dissect Allosteric Communication Networks in Protein Kinases

Mutations in protein kinases are often associated with the development of cancer, and application of mutant-specific inhibitors as therapeutic measures have shown a remarkable improvement in prolonging patient survival. However, it has also been observed that tumors bearing certain mutation types are more resistant to current approved drugs. Importantly, many resistant mutations are located in regions outside substrate or inhibitor binding sites, indicating allosteric effects. Understanding how mutations trigger effects over a distant site of the protein requires a deeper investigation of the molecular origin of allosteric regulation networks in kinases. In this chapter, we show the application of single-molecule optical tweezers to selectively manipulate specific regions of proteins to trace allosteric signals, thereby allowing the elucidation of allosteric communication networks. We illustrate this approach using as model system the regulatory subunit of protein kinase A. This single-molecule optical tweezers approach, however, can be readily applicable to study other kinases, and can be further expanded to screen potential allosteric drugs for future therapeutics.