Improved overall survival in melanoma with combined dabrafenib and trametinib

Combination of immunotherapy and other targeted therapies in advanced cutaneous melanoma

Cutaneous Melanoma (CM) is an aggressive cancer whose incidence is increasing worldwide. However, the knowledge of its biology and genes driving cell growth and survival allowed to develop new drugs that have improved PFS and OS of advanced disease. Both BRAF targeting agents and immune checkpoint inhibitors (ICIs) have been adopted for the treatment of metastatic disease and the adjuvant setting. Several melanoma patients show innate or acquired drug-resistance and thus new strategies are required for overcoming this complication. New ICIs have been developed, and strategies of combination or sequencing are under investigation in ongoing clinical trials. In addition, pre-clinical data have demonstrated that many strategies induce the release of neoantigens within the tumor microenvironment, thus suggesting the combination of new agents with ICIs. Here, we review the ongoing strategies in advanced CM including a dedicated section on treatment of brain metastases.

Melanoma: An immunotherapy journey from bench to bedside

Melanoma gave science a window into the role immune evasion plays in the development of malignancy. The entire spectrum of immune focused anti-cancer therapies has been subjected to clinical trials in this disease, with limited success until the immune checkpoint blockade era. That revolution launched first in melanoma, heralded a landscape change throughout cancer that continues to reverberate today.

Acceptability of Drugs in the Treatment of Unresectable/Metastatic BRAF V600-Mutant Melanoma: A Systematic Review and Network Meta-Analysis

Background

Although many novel regimens have entered the treatment paradigm for unresectable/metastatic BRAF V600-mutant melanoma, there is still a lack of head-to-head comparison in terms of security. We conducted a network meta-analysis to compare the risk of adverse events (AEs) across different treatments and to provide an acceptability ranking for patients.

Methods

A systematic literature review was conducted in Embase, PubMed, WHO International Clinical Trials Registry Platform, and Clinical Trials.gov with a time frame from database inception to December 24, 2021. We retrieved evidence on the cumulative incidence of any-grade AEs means grades 1-5 AEs (regardless of severity) and severe AEs based on the pooled risk ratios (RRs) and 95% credible intervals (95% CrI).

Results

Twelve publications and thirteen treatments enrolling 5,803 patients were included. For any-grade AEs, the acceptability of combined dabrafenib and trametinib is superior to the combination of vemurafenib and cobimetinib (RR: 0.94; Crl: 0.89, 0.98). Furthermore, nivolumab combined with ipilimumab increases any-grade AEs than single-agent ipilimumab (RR: 0.90; Crl: 0.83, 0.96) or nivolumab (RR: 0.90; Crl: 0.84, 0.97). For severe AEs, dabrafenib has the best acceptability than single-agent vemurafenib (RR: 0.66; Crl: 0.50, 0.87) or encorafenib (RR: 0.64; Crl: 0.43, 0.94). In addition, ipilimumab (SUCRA: 0.87) ranks first in the acceptability for any-grade AEs, and nivolumab (SUCRA: 0.95) ranks first in the acceptability for severe AEs. The ranking of the combination of vemurafenib and cobimetinib (SUCRA: 0.66) is superior to encorafenib in combination with binimetinib (SUCRA: 0.39) and combination of vemurafenib and cobimetinib (SUCRA: 0.18).

Conclusions

We identified the lowest AE risk treatment options for BRAF V600-mutant melanoma patients. In general, immunotherapy (ipilimumab or nivolumab) has better acceptability than most targeted therapies, and triplet therapies are related with the worst acceptability. Moreover, single-agent dabrafenib can be used as the first choice in monotherapy, and the combination of dabrafenib and trametinib is the preferred combination therapy. Overall, the combination of immunotherapy drugs increases any-grade and severe AEs than a single agent, whereas the condition of targeted therapy drugs cannot be simply generalized. Therefore, this information can facilitate evidence-based decision-making and support optimizing treatment and outcomes in clinical practice.

Mechanisms of Immunotherapy Resistance in Cutaneous Melanoma: Recognizing a Shapeshifter

Melanoma is one of the seven most common cancers in the United States, and its incidence is still increasing. Since 2011, developments in targeted therapies and immunotherapies have been essential for significantly improving overall survival rates. Prior to the advent of targeted and immunotherapies, metastatic melanoma was considered a death sentence, with less than 5% of patients surviving more than 5 years. With the implementation of immunotherapies, approximately half of patients with metastatic melanoma now survive more than 5 years. Unfortunately, this also means that half of the patients with melanoma do not respond to current therapies and live less than 5 years after diagnosis. One major factor that contributes to lower response in this population is acquired or primary resistance to immunotherapies via tumor immune evasion. To improve the overall survival of melanoma patients new treatment strategies must be designed to minimize the risk of acquired resistance and overcome existing primary resistance. In recent years, many advances have been made in identifying and understanding the pathways that contribute to tumor immune evasion throughout the course of immunotherapy treatment. In addition, results from clinical trials focusing on treating patients with immunotherapy-resistant melanoma have reported some initial findings. In this review, we summarize important mechanisms that drive resistance to immunotherapies in patients with cutaneous melanoma. We have focused on tumor intrinsic characteristics of resistance, altered immune function, and systemic factors that contribute to immunotherapy resistance in melanoma. Exploring these pathways will hopefully yield novel strategies to prevent acquired resistance and overcome existing resistance to immunotherapy treatment in patients with cutaneous melanoma.

LncRNA LNCOC1 is Upregulated in Melanoma and Serves as a Potential Regulatory Target of miR-124 to Suppress Cancer Cell Invasion and Migration

Background

A cascade of genes and pathways have been reported in the precise regulation of malignant melanoma (MM). Previous study has demonstrated that lncRNA LNCOC1 is an oncogenic factor in the pathogenesis and development of various cancers. The present study explored the functionalities of LNCOC1 and its interactions with miR-124 in MM.

Methods

A total of 65 melanoma patients were enrolled in this study. The expression of LNCOC1 and miR-124 after cell transfection were detected by RT-qPCR. The migration rates of SK-MEL-3 and A375 cells after transient transfection with LNCOC1 expression vector and miR-124 mimic was detected by trans-well assay.

Results

LNCOC1 was accumulated to high levels in melanoma, and it was significantly correlated with the low survival rate of melanoma patients. Our bioinformatics data showed that miR-124 could target LNCOC1. Overexpression of miR-124 could downregulate LNCOC1. However, up-regulated the expression of LNCOC1 did not affect the expression of miR-124. Our correlation analysis also revealed that the expression of LNCOC1 and miR-124 were inversely correlated in both melanoma tissues and non-tumor tissues. The trans-well invasion and migration assays indicated that overexpression of miR-124 inhibited the melanoma cell invasion and migration. However, overexpression of LNCOC1 promoted melanoma cell invasion and migration.

Conclusion

LNCOC1 is upregulated in melanoma, which can be considered as a potential target of miR-124 in modulating melanoma cell invasion and migration. LNCOC1 may also be an interfering target of MM therapy.

Long-term non-invasive drug treatments in adult zebrafish that lead to melanoma drug resistance

Zebrafish embryos are widely used for drug discovery, however, administering drugs to adult zebrafish is limited by current protocols that can cause stress. Here, we developed a drug formulation and administration method for adult zebrafish by producing food-based drug pellets that are consumed voluntarily. We applied this to zebrafish with BRAF-mutant melanoma, a model that has significantly advanced our understanding of melanoma progression, but not of drug resistance due to the limitations of current treatment methods. Zebrafish with melanomas responded to short-term, precise and daily dosing with drug pellets made with the BRAFV600E inhibitor, vemurafenib. On-target drug efficacy was determined by phospho-Erk staining. Continued drug treatment led to the emergence, for the first time in zebrafish, of acquired drug resistance and melanoma relapse, modelling the responses seen in melanoma patients. This method presents a controlled, non-invasive approach that permits long-term drug studies and can be widely applied to adult zebrafish models.

Genetic characterization of advanced conjunctival melanoma and response to systemic treatment

BACKGROUND

Conjunctival melanoma is a rare type of ocular melanoma, which is prone to local recurrence and metastasis and can lead to patient death. Novel therapeutic strategies have revolutionized cutaneous melanoma management. The efficacy of these therapies in conjunctival melanoma, however, has not been evaluated in larger patient cohorts.

METHODS

In this multi-center retrospective cohort study with additional screening of the ADOREG database, data were collected from 34 patients with metastatic conjunctival melanoma who received targeted therapy (TT) (BRAF ± MEK inhibitors) or immune checkpoint inhibitors (ICI) (anti-PD-1 ± anti-CTLA4). In 15 cases, tissue was available for targeted next-generation-sequencing (611 genes) and RNA sequencing. Driver mutations, tumor mutational burden, copy number variations and inflammatory/IFNγ gene expression signatures were determined.

RESULTS

Genetic characterization identified frequent BRAF (46.7%, 7/15), NRAS (26.7%, 4/15), NF1 (20%, 3/15), and TERT promoter (46.7%, 7/15) mutations. UV associated C>T and CC>TT mutations were common. Median follow-up time after start of first TT or ICI therapy was 13.2 months. In 26 patients receiving first-line ICI, estimated one-year progression-free survival (PFS) rate was 42.0%, PFS and overall survival (OS) 6.2 and 18.0 months, respectively. First-line TT was given to 8 patients, estimated one-year PFS rate was 54.7%, median PFS and OS 12.6 and 29.1 months, respectively.

CONCLUSIONS

Our findings support the role of UV irradiation in conjunctival melanoma and the genetic similarity with cutaneous melanoma. Conjunctival melanoma patients with advanced disease benefit from both targeted therapies (BRAF ± MEK inhibitors) and immune checkpoint inhibitors.

Cancer proteogenomics: current impact and future prospects

Genomic analyses in cancer have been enormously impactful, leading to the identification of driver mutations and development of targeted therapies. But the functions of the vast majority of somatic mutations and copy number variants in tumours remain unknown, and the causes of resistance to targeted therapies and methods to overcome them are poorly defined. Recent improvements in mass spectrometry-based proteomics now enable direct examination of the consequences of genomic aberrations, providing deep and quantitative characterization of tumour tissues. Integration of proteins and their post-translational modifications with genomic, epigenomic and transcriptomic data constitutes the new field of proteogenomics, and is already leading to new biological and diagnostic knowledge with the potential to improve our understanding of malignant transformation and therapeutic outcomes. In this Review we describe recent developments in proteogenomics and key findings from the proteogenomic analysis of a wide range of cancers. Considerations relevant to the selection and use of samples for proteogenomics and the current technologies used to generate, analyse and integrate proteomic with genomic data are described. Applications of proteogenomics in translational studies and immuno-oncology are rapidly emerging, and the prospect for their full integration into therapeutic trials and clinical care seems bright.

Impact of electrochemotherapy in metastatic cutaneous melanoma: a contemporary systematic review and meta-analysis

BACKGROUND

Electrochemotherapy (ECT) harnesses electric pulses to enhance cytotoxic drug delivery into tumors and has entered the armamentarium to treat superficially metastatic melanoma. We performed a systematic review and meta-analysis to assess treatment patterns and patient outcomes.

METHODS

PubMed, Medline, Embase, and the Cochrane Library databases were queried for publication from inception to September 2020. Primary outcome measures were overall and complete response rate (ORR and CRR); secondary outcomes included local control rate (LCR) and overall survival (OS).

RESULTS

Twenty-seven studies met the selection criteria for a total of 1161 individuals (mean age 71 years) and 5308 tumors (weighted mean size 14 mm). The majority of patients (n = 1124) underwent bleomycin-ECT. Aggregate ORR was 77.6% (95% confidence interval [CI] 71.0 - 83.2%) and CRR 48% (95% CI 42 - 54%), with no significant difference between the route of bleomycin administration (ORR, 69.2 vs. 81.9% following intravenous or intratumoral bleomycin, p = .37) and tumor size (p = .69). When reported (n = 8 studies), 1- and 2-year LCR ranged from 54 to 89% and 72 to 74%, respectively, and 1-year OS (n = 3 studies) from 67 to 89%.

CONCLUSIONS

ECT with either intratumoral or intravenous bleomycin confers a high therapeutic response in cutaneous metastatic melanoma. Moderate evidence supports its low toxicity and durability of local control.HighlightsElectrochemotherapy (ECT) is associated with a 77% overall response rate (ORR).Intravenous and intratumoral bleomycin are equally effective.There are no relevant toxicity concerns.One-year local tumor control rate ranges from 54 to 89%.Current literature has significant variation in reporting.

Pharmacokinetic Interaction Between the MEK1/MEK2 Inhibitor Trametinib and Oral Contraceptives Containing Norethindrone and Ethinyl Estradiol in Female Patients With Solid Tumors

This phase 1 postapproval study assessed the effect of the mitogen-activated protein kinase kinase enzyme 1/enzyme 2 inhibitor trametinib (2 mg once daily, repeat dosing) on the pharmacokinetics of combined oral contraceptives (COCs) containing norethindrone (NE; 1 mg daily) and ethinyl estradiol (EE; 0.035 mg daily) in 19 female patients with solid tumors. Compared with NE/EE administered without trametinib, NE/EE administered with steady-state trametinib was associated with a clinically nonrelevant 20% increase in NE exposure (area under the curve [AUC]) and no effect on EE exposure (geometric mean ratio [geo-mean] of NE/EE + trametinib to NE/EE [90%CI]: NE AUC calculated to the end of a dosing interval at steady-state [AUCtau ] 1.20 [1.02-1.41]; NE AUC from time zero to the last measurable concentration sampling time [AUClast ] 1.2 [0.999-1.45]; EE AUCtau 1.06 [0.923-1.22]; EE AUClast 1.05 [0.883-1.25]). Maximum serum concentration (Cmax ) of NE increased by 13% and Cmax of EE decreased by 8.5% when dosed with steady-state trametinib compared with COCs administered alone (geo-mean ratio [90%CI]: NE Cmax 1.13 [0.933-1.36]; EE Cmax 0.915 [0.803-1.04]). These results indicate that repeat-dose trametinib does not lower exposure to NE or EE and, hence, is unlikely to impact the contraceptive efficacy of COCs. The pharmacokinetic parameters of trametinib and its metabolite M5 were consistent with historic data of trametinib alone. Coadministration of trametinib and COCs was generally well tolerated in this study, with observed safety signals consistent with the known safety profile of trametinib and no new reported safety events. Overall, the findings indicate that hormonal COCs can be coadministered in female patients who receive trametinib monotherapy without compromising the contraceptive efficacy.

Establishment and characterization of an immortalized human giant congenital melanocytic nevi cell line

Treatments for giant congenital melanocytic nevi (GCMN) are extremely limited. Thus, there is an urgent need for development of relevant targeted therapies. However, current lack of preclinical cell models restricts progress in GCMN research. In this study, we aimed to establish and characterize an immortalized GCMN cell line. GCMN cells were successfully immortalized by means of lentivirus-mediated simian virus 40 large T transfection. The immortalized GNC cell line (ImGNC) showed lower proliferation rate and higher melanin content than primary melanocytes. Expression levels of the differentiation gene MITF and stemness genes TWIST1, SNAI1, and FOXD3 were elevated in ImGNCs; however, the established ImGNC cell line was immortalized but not transformed. Sanger sequencing detected the heterozygous NRAS^Q61K mutation in ImGNCs, but not the BRAF^V600E mutation. Despite carrying the NRAS^Q61K allele, ImGNCs demonstrated suppressed MAPK activation and elevated PI3K/Akt activation, as compared with primary melanocytes. Drug sensitivity analysis showed that ImGNCs are more sensitive to PI3K/Akt and Bcl-2 inhibitors than to MEK or ERK inhibitors. Unlike the proliferation-inhibiting effect of PI3K/Akt inhibitors, the Bcl-2 inhibitor navitoclax promptly promoted apoptosis in ImGNCs. Considering the low proliferation characteristics of GCMN in vivo, Bcl-2 may be a potential therapeutic target that warrants further research.

Challenges of modelling approaches for network meta-analysis of time-to-event outcomes in the presence of non-proportional hazards to aid decision making: Application to a melanoma network

BACKGROUND

Synthesis of clinical effectiveness from multiple trials is a well-established component of decision-making. Time-to-event outcomes are often synthesised using the Cox proportional hazards model assuming a constant hazard ratio over time. However, with an increasing proportion of trials reporting treatment effects where hazard ratios vary over time and with differing lengths of follow-up across trials, alternative synthesis methods are needed.

OBJECTIVES

To compare and contrast five modelling approaches for synthesis of time-to-event outcomes and provide guidance on key considerations for choosing between the modelling approaches.

METHODS

The Cox proportional hazards model and five other methods of estimating treatment effects from time-to-event outcomes, which relax the proportional hazards assumption, were applied to a network of melanoma trials reporting overall survival: restricted mean survival time, generalised gamma, piecewise exponential, fractional polynomial and Royston-Parmar models.

RESULTS

All models fitted the melanoma network acceptably well. However, there were important differences in extrapolations of the survival curve and interpretability of the modelling constraints demonstrating the potential for different conclusions from different modelling approaches.

CONCLUSION

The restricted mean survival time, generalised gamma, piecewise exponential, fractional polynomial and Royston-Parmar models can accommodate non-proportional hazards and differing lengths of trial follow-up within a network meta-analysis of time-to-event outcomes. We recommend that model choice is informed using available and relevant prior knowledge, model transparency, graphically comparing survival curves alongside observed data to aid consideration of the reliability of the survival estimates, and consideration of how the treatment effect estimates can be incorporated within a decision model.

Pembrolizumab versus placebo as adjuvant therapy in completely resected stage IIB or IIC melanoma (KEYNOTE-716): a randomised, double-blind, phase 3 trial

BACKGROUND

Pembrolizumab prolongs progression-free and overall survival among patients with advanced melanoma and recurrence-free survival in resected stage III disease. KEYNOTE-716 assessed pembrolizumab as adjuvant therapy in patients with completely resected, high-risk, stage II melanoma. We report results from the planned first and second interim analyses for recurrence-free survival.

METHODS

In this double-blind, randomised, placebo-controlled phase 3 study, involving 160 academic medical centres and hospitals in 16 countries (Australia, Belgium, Brazil, Canada, Chile, France, Germany, Israel, Italy, Japan, Poland, South Africa, Spain, Switzerland, the UK, and the USA), patients aged 12 years or older with newly diagnosed, completely resected stage IIB or IIC melanoma (TNM stage T3b or T4 with a negative sentinel lymph node biopsy) were recruited. Eligible patients were randomly assigned (1:1), in blocks of four and stratified by T-category (3b, 4a, and 4b) and paediatric status (age 12-17 years vs ≥18 years), using an interactive response technology system to intravenous pembrolizumab 200 mg (2 mg/kg in paediatric patients) or placebo every 3 weeks for 17 cycles or until disease recurrence or unacceptable toxicity. All patients, clinical investigators, and analysts were masked to treatment assignment. The primary endpoint was investigator-assessed recurrence-free survival (defined as time from randomisation to recurrence or death) in the intention-to-treat (ITT) population (ie, all patients randomly assigned to treatment). The primary endpoint was met if recurrence-free survival was significantly improved for pembrolizumab versus placebo at either the first interim analysis (after approximately 128 patients had events) or second interim analysis (after 179 patients had events) under multiplicity control. Safety was assessed in all patients randomly assigned to treatment who received at least one dose of study treatment. This study is registered with ClinicalTrials.gov, NCT03553836, and is closed to accrual.

FINDINGS

Between Sept 23, 2018, and Nov 4, 2020, 1182 patients were screened, of whom 976 were randomly assigned to pembrolizumab (n=487) or placebo (n=489; ITT population). The median age was 61 years (IQR 52-69) and 387 (40%) patients were female and 589 (60%) were male. 874 (90%) of 976 patients were White and 799 (82%) were not Hispanic or Latino. 483 (99%) of 487 patients in the pembrolizumab group and 486 (99%) of 489 in the placebo group received assigned treatment. At the first interim analysis (data cutoff on Dec 4, 2020; median follow-up of 14·4 months [IQR 10·2-18·7] in the pembrolizumab group and 14·3 months [10·1-18·7] in the placebo group), 54 (11%) of 487 patients in the pembrolizumab group and 82 (17%) of 489 in the placebo group had a first recurrence of disease or died (hazard ratio [HR] 0·65 [95% CI 0·46-0·92]; p=0·0066). At the second interim analysis (data cutoff on June 21, 2021; median follow-up of 20·9 months [16·7-25·3] in the pembrolizumab group and 20·9 months [16·6-25·3] in the placebo group), 72 (15%) patients in the pembrolizumab group and 115 (24%) in the placebo group had a first recurrence or died (HR 0·61 [95% CI 0·45-0·82]). Median recurrence-free survival was not reached in either group at either assessment timepoint. At the first interim analysis, grade 3-4 treatment-related adverse events occurred in 78 (16%) of 483 patients in the pembrolizumab groups versus 21 (4%) of 486 in the placebo group. At the first interim analysis, four patients died from an adverse event, all in the placebo group (one each due to pneumonia, COVID-19-related pneumonia, suicide, and recurrent cancer), and at the second interim analysis, one additional patient, who was in the pembrolizumab group, died from an adverse event (COVID-19-related pneumonia). No deaths due to study treatment occurred.

INTERPRETATION

Pembrolizumab as adjuvant therapy for up to approximately 1 year for stage IIB or IIC melanoma resulted in a significant reduction in the risk of disease recurrence or death versus placebo, with a manageable safety profile.

FUNDING

Merck Sharp & Dohme, a subsidiary of Merck & Co, Kenilworth, NJ, USA.

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.

On the development of B-Raf inhibitors acting through innovative mechanisms

B-Raf is a protein kinase participating to the regulation of many biological processes in cells. Several studies have demonstrated that this protein is frequently upregulated in human cancers, especially when it bears activating mutations. In the last years, few ATP-competitive inhibitors of B-Raf have been marketed for the treatment of melanoma and are currently under clinical evaluation on a variety of other types of cancer. Although the introduction of drugs targeting B-Raf has provided significant advances in cancer treatment, responses to ATP-competitive inhibitors remain limited, mainly due to selectivity issues, side effects, narrow therapeutic windows, and the insurgence of drug resistance.

Impressive research efforts have been made so far towards the identification of novel ATP-competitive modulators with improved efficacy against cancers driven by mutant Raf monomers and dimers, some of them showing good promises. However, several limitations could still be envisioned for these compounds, according to literature data. Besides, increased attentions have arisen around approaches based on the design of allosteric modulators, polypharmacology, proteolysis targeting chimeras (PROTACs) and drug repurposing for the targeting of B-Raf proteins. The design of compounds acting through such innovative mechanisms is rather challenging. However, valuable therapeutic opportunities can be envisioned on these drugs, as they act through innovative mechanisms in which limitations typically observed for approved ATP-competitive B-Raf inhibitors are less prone to emerge. In this article, current approaches adopted for the design of non-ATP competitive inhibitors targeting B-Raf are described, discussing also on the possibilities, ligands acting through such innovative mechanisms could provide for the obtainment of more effective therapies.

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.

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.

Melanomas with concurrent BRAF non-p.V600 and NF1 loss-of-function mutations are targetable by BRAF/MEK inhibitor combination therapy

Although combination BRAF/MEK inhibition has produced significant survival benefits for BRAF p.V600 mutant melanomas, targeted therapies approved for BRAF non-p.V600 mutant melanomas remain limited. Through the analysis of 772 cutaneous melanoma exomes, we reveal that BRAF non-p.V600 mutations co-occurs more frequently with NF1 loss, but not with oncogenic NRAS mutations, than expected by chance. We present cell signaling data, which demonstrate that BRAF non-p.V600 mutants can signal as monomers and dimers within an NF1 loss context. Concordantly, BRAF inhibitors that inhibit both monomeric and dimeric BRAF synergize with MEK inhibition to significantly reduce cell viability in vitro and tumor growth in vivo in BRAF non-p.V600 mutant melanomas with co-occurring NF1 loss-of-function mutations. Our data suggest that patients harboring BRAF non-p.V600 mutant melanomas may benefit from current FDA-approved BRAF/MEK inhibitor combination therapy currently reserved for BRAF p.V600 mutant patients.

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.

Treat Now or Treat Later: Comparative Effectiveness of Adjuvant Therapy in Resected Stage IIIA Melanoma

BACKGROUND

Adjuvant therapy for most sentinel-node-positive (stage IIIA) melanoma may have limited clinical benefit for older patients given the competing risk of non-cancer death. The objective of this study is to model the clinical effect and cost of adjuvant therapy in stage IIIA melanoma across age groups.

STUDY DESIGN

A Markov decision analysis model simulated the overall survival of patients with resected stage IIIA melanoma treated with adjuvant therapy vs observation. In the adjuvant approach, patients are modeled to receive adjuvant pembrolizumab (BRAF wild type) or dabrafenib/trametinib (BRAF mutant). In the observation approach, treatment is deferred until recurrence. Transition variables were derived from landmark randomized trials in adjuvant and salvage therapy. The model was analyzed for age groups spanning 40 to 89 years. The primary outcome was the number needed to treat (NNT) to prevent one melanoma-related death at 10 years. Cost per mortality avoided was estimated using Medicare reimbursement rates.

RESULTS

Projections for NNT among BRAF wild type patients increased by age from 14.71 (age 40 to 44) to 142.86 (age 85 to 89), with patients in cohorts over the age of 75 having an NNT over 25. The cost per mortality avoided ranged from $2.75 million (M) (age 40 to 44) to $27.57M (age 85 to 89). Corresponding values for BRAF mutant patients were as follows: NNT 18.18 to 333.33; cost per mortality avoided ranged from $2.75M to $54.70M.

CONCLUSION

Universal adjuvant therapy for stage IIIA melanoma is costly and provides limited clinical benefit in patients older than 75 years.

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.

MAPKinase inhibition after failure of immune checkpoint blockade in patients with advanced melanoma - An evaluation of the multicenter prospective skin cancer registry ADOREG

OBJECTIVES

Forty to sixty percent of patients with advanced melanoma show primary resistance to PD-1-based immunotherapy, 30-40% of initial responders also progress. Here, we evaluated the outcome of second-line targeted therapy (TT) after progression on PD-1-based immune checkpoint inhibition (ICI) in BRAFV600-mutated melanoma. In addition, we report data on the activity of re-exposure with PD-1-based regimes.

METHODS

Patients with advanced (non-resectable stage III or IV, AJCC 2017, 8th edition) melanoma progressing on PD-1-based ICI (nivolumab, pembrolizumab or ipilimumab plus nivolumab) and receiving second-line BRAF plus MEK inhibition were identified from the prospective multicenter skin cancer registry ADOREG.

RESULTS

We identified 108 patients with unresectable stage III or stage IV melanoma progressing on first-line ICI (nivolumab, pembrolizumab or ipilimumab plus nivolumab) and receiving second-line combined BRAF/MEK inhibition. Seventy-three percent of the cohort presented with primary PD-1 resistant disease. Median progression-free survival (PFS) on ICI was 2.6 (95% CI 2.2-2.9) months. Median PFS on subsequent TT was 6.6 (95% CI 5.4-7.8) months. Median OS from start of second-line TT was 16.0 (95% CI 11.2-20.8) months. The 3-year PFS and OS rates on second-line TT were 16% and 30%. The objective response rate (ORR) and disease control rate (DCR) to TT were 42.6% and 55.6%. In patients with brain metastases, the ORR and DCR were 31.4% and 43.1%. Patients without brain metastases showed an ORR and DCR of 52.6% and 66.7%, respectively. Response to first-line ICI was associated with a numerically higher ORR and DCR to second-line TT and improved OS on TT. Twenty-three patients received third-line ICI of whom two patients showed an objective response.

CONCLUSIONS

BRAF plus MEK inhibition shows meaningful activity and outcome in patients with advanced melanoma resistant to anti-PD-1-based immunotherapy. Rates of long-term benefit and survival in our study were similar to those reported for treatment-naïve patients receiving first-line MAPKi.

Systematic identification of biomarker-driven drug combinations to overcome resistance

The ability to understand and predict variable responses to therapeutic agents may improve outcomes in patients with cancer. We hypothesized that the basal gene-transcription state of cancer cell lines, coupled with cell viability profiles of small molecules, might be leveraged to nominate specific mechanisms of intrinsic resistance and to predict drug combinations that overcome resistance. We analyzed 564,424 sensitivity profiles to identify candidate gene-compound pairs, and validated nine such relationships. We determined the mechanism of a novel relationship, in which expression of the serine hydrolase enzymes monoacylglycerol lipase (MGLL) or carboxylesterase 1 (CES1) confers resistance to the histone lysine demethylase inhibitor GSK-J4 by direct enzymatic modification. Insensitive cell lines could be sensitized to GSK-J4 by inhibition or gene knockout. These analytical and mechanistic studies highlight the potential of integrating gene-expression features with small-molecule response to identify patient populations that are likely to benefit from treatment, to nominate rational candidates for combinations and to provide insights into mechanisms of action.

Identification of New Vulnerabilities in Conjunctival Melanoma Using Image-Based High Content Drug Screening

Recent evidence suggests that numerous similarities exist between the genomic landscapes of both conjunctival and cutaneous melanoma. Since alterations of several components of the MAP kinases, PI3K/mTOR, and cell cycle pathways have been reported in conjunctival melanoma, we decided to assess the sensitivity of conjunctival melanoma to targeted inhibition mostly of kinase inhibitors. A high content drug screening assay based on automated fluorescence microscopy was performed in three conjunctival melanoma cell lines with different genomic backgrounds with 489 kinase inhibitors and 53 other inhibitors. IC50 and apoptosis induction were respectively assessed for 53 and 48 compounds. The genomic background influenced the response to MAK and PI3K/mTOR inhibition, more specifically cell lines with BRAF V600E mutations were more sensitive to BRAF/MEK inhibition, while CRMM2 bearing the NRASQ61L mutation was more sensitive to PI3k/mTOR inhibition. All cell lines demonstrated sensitivity to cell cycle inhibition, being more pronounced in CRMM2, especially with polo-like inhibitors. Our data also revealed new vulnerabilities to Hsp90 and Src inhibition. This study demonstrates that the genomic background partially influences the response to targeted therapy and uncovers a large panel of potential vulnerabilities in conjunctival melanoma that may expand available options for the management of this tumor.

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.

The Prognostic Relevance of PMCA4 Expression in Melanoma: Gender Specificity and Implications for Immune Checkpoint Inhibition

PMCA4 is a critical regulator of Ca2+ homeostasis in mammalian cells. While its biological and prognostic relevance in several cancer types has already been demonstrated, only preclinical investigations suggested a metastasis suppressor function in melanoma. Therefore, we studied the expression pattern of PMCA4 in human skin, nevus, as well as in primary and metastatic melanoma using immunohistochemistry. Furthermore, we analyzed the prognostic power of PMCA4 mRNA levels in cutaneous melanoma both at the non-metastatic stage as well as after PD-1 blockade in advanced disease. PMCA4 localizes to the plasma membrane in a differentiation dependent manner in human skin and mucosa, while nevus cells showed no plasma membrane staining. In contrast, primary cutaneous, choroidal and conjunctival melanoma cells showed specific plasma membrane localization of PMCA4 with a wide range of intensities. Analyzing the TCGA cohort, PMCA4 mRNA levels showed a gender specific prognostic impact in stage I-III melanoma. Female patients with high transcript levels had a significantly longer progression-free survival. Melanoma cell specific PMCA4 protein expression is associated with anaplasticity in melanoma lung metastasis but had no impact on survival after lung metastasectomy. Importantly, high PMCA4 transcript levels derived from RNA-seq of cutaneous melanoma are associated with significantly longer overall survival after PD-1 blockade. In summary, we demonstrated that human melanoma cells express PMCA4 and PMCA4 transcript levels carry prognostic information in a gender specific manner.

Die Systemtherapie des malignen Melanoms

In den vergangenen 10 Jahren wurde die Systemtherapie des malignen Melanoms durch die Zulassung neuer Substanzen revolutioniert. In der vorliegenden Übersicht werden zunächst die aktuellen adjuvanten Therapiemöglichkeiten beschrieben, anschließend werden der Kenntnisstand zur neoadjuvanten Therapie dargestellt und schließlich die Behandlungsoptionen im inoperablen Stadium beleuchtet.

Tumors carrying BRAF-mutations over-express NAMPT that is genetically amplified and possesses oncogenic properties

Background

Nicotinamide phosphoribosyltransferase (NAMPT), the rate-limiting enzyme in nicotinamide adenine dinucleotide (NAD) biosynthesis, is up-regulated in several cancers, including metastatic melanoma (MM). The BRAF oncogene is mutated in different cancer types, among which MM and thyroid carcinoma (THCA) are prominent. Drugs targeting mutant BRAF are effective, especially in MM patients, even though resistance rapidly develops. Previous data have linked NAMPT over-expression to the acquisition of BRAF resistance, paving the way for therapeutic strategies targeting the two pathways.

Methods

Exploiting the TCGA database and a collection of MM and THCA tissue microarrays we studied the association between BRAF mutations and NAMPT expression. BRAF wild-type (wt) cell lines were genetically engineered to over-express the BRAF V600E construct to demonstrate a direct relationship between over-activation of the BRAF pathway and NAMPT expression. Responses of different cell line models to NAMPT (i)nhibitors were studied using dose–response proliferation assays. Analysis of NAMPT copy number variation was performed in the TCGA dataset. Lastly, growth and colony forming assays were used to study the tumorigenic functions of NAMPT itself.

Results

The first finding of this work is that tumor samples carrying BRAF-mutations over-express NAMPT, as demonstrated by analyzing the TCGA dataset, and MM and THC tissue microarrays. Importantly, BRAF wt MM and THCA cell lines modified to over-express the BRAF V600E construct up-regulated NAMPT, confirming a transcriptional regulation of NAMPT following BRAF oncogenic signaling activation. Treatment of BRAF-mutated cell lines with two different NAMPTi was followed by significant reduction of tumor growth, indicating NAMPT addiction in these cells. Lastly, we found that several tumors over-expressing the enzyme, display NAMPT gene amplification. Over-expression of NAMPT in BRAF wt MM cell line and in fibroblasts resulted in increased growth capacity, arguing in favor of oncogenic properties of NAMPT.

Conclusions

Overall, the association between BRAF mutations and NAMPT expression identifies a subset of tumors more sensitive to NAMPT inhibition opening the way for novel combination therapies including NAMPTi with BRAFi/MEKi, to postpone and/or overcome drug resistance. Lastly, the over-expression of NAMPT in several tumors could be a key and broad event in tumorigenesis, substantiated by the finding of NAMPT gene amplification.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12967-022-03315-9.

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.

Anti-tumor treatment and healthcare consumption near death in the era of novel treatment options for patients with melanoma brain metastases

Background

Effective systemic treatments have revolutionized the management of patients with metastatic melanoma, including those with brain metastases. The extent to which these treatments influence disease trajectories close to death is unknown. Therefore, this study aimed to gain insight into provided treatments and healthcare consumption during the last 3 months of life in patients with melanoma brain metastases.

Methods

Retrospective, single-center study, including consecutive patients with melanoma brain metastases diagnosed between June-2015 and June-2018, referred to the medical oncologist, and died before November-2019. Patient and tumor characteristics, anti-tumor treatments, healthcare consumption, presence of neurological symptoms, and do-not-resuscitate status were extracted from medical charts.

Results

100 patients were included. A BRAF-mutation was present in 66 patients. Systemic anti-tumor therapy was given to 72% of patients during the last 3 months of life, 34% in the last month, and 6% in the last week. Patients with a BRAF-mutation more frequently received systemic treatment during the last 3 (85% vs. 47%) and last month (42% vs. 18%) of life than patients without a BRAF-mutation. Furthermore, patients receiving systemic treatment were more likely to visit the emergency room (ER, 75% vs. 36%) and be hospitalized (75% vs. 36%) than those who did not.

Conclusion

The majority of patients with melanoma brain metastases received anti-tumor treatment during the last 3 months of life. ER visits and hospitalizations occurred more often in patients on anti-tumor treatment. Further research is warranted to examine the impact of anti-tumor treatments close to death on symptom burden and care satisfaction.

Neoadjuvant therapy for melanoma: rationale for neoadjuvant therapy and pivotal clinical trials

The treatment of malignant melanoma has drastically changed over the past decade with the advent of immune checkpoint blockade, targeted therapy with BRAF/MEK inhibition, and other novel therapies such as oncolytic virus intralesional therapy. Despite improvements in patient response rates and survival with these new treatments, there exists a large portion of patients with surgically resectable disease that are high risk for relapse. Patients with high-risk resectable melanoma account for up to 20% of newly diagnosed cases. For this high-risk group of patients, neoadjuvant therapy has many purposed advantages over adjuvant therapy, including a more robust immune response due to abundant tumor antigens at treatment initiation, the ability to assess pathologic response to therapy, tumor downstaging leading to increased disease resectability, and a potential decreased need for extensive lymphadenectomies. These findings have been backed by preclinical models and multiple neoadjuvant trials are underway. In this review, we will discuss the trials that have set the foundation for the current treatment standards and discuss the role and rationale for neoadjuvant therapy for high-risk malignant melanomas.

Adaptive translational reprogramming of metabolism limits the response to targeted therapy in BRAFV600 melanoma

Despite the success of therapies targeting oncogenes in cancer, clinical outcomes are limited by residual disease that ultimately results in relapse. This residual disease is often characterized by non-genetic adaptive resistance, that in melanoma is characterised by altered metabolism. Here, we examine how targeted therapy reprograms metabolism in BRAF-mutant melanoma cells using a genome-wide RNA interference (RNAi) screen and global gene expression profiling. Using this systematic approach we demonstrate post-transcriptional regulation of metabolism following BRAF inhibition, involving selective mRNA transport and translation. As proof of concept we demonstrate the RNA processing kinase U2AF homology motif kinase 1 (UHMK1) associates with mRNAs encoding metabolism proteins and selectively controls their transport and translation during adaptation to BRAF-targeted therapy. UHMK1 inactivation induces cell death by disrupting therapy induced metabolic reprogramming, and importantly, delays resistance to BRAF and MEK combination therapy in multiple in vivo models. We propose selective mRNA processing and translation by UHMK1 constitutes a mechanism of non-genetic resistance to targeted therapy in melanoma by controlling metabolic plasticity induced by therapy.

Different adaptive mechanisms have been reported to reduce the efficacy of mutant BRAF inhibition in melanoma. Here, the authors show BRAF inhibition induces the translational regulation of metabolic genes leading to acquired therapy resistance.

Translational advances in pancreatic ductal adenocarcinoma therapy

Pancreatic ductal adenocarcinoma (PDAC) is an aggressive cancer that is most frequently detected at advanced stages, limiting treatment options to systemic chemotherapy with modest clinical responses. Here, we review recent advances in targeted therapy and immunotherapy for treating subtypes of PDAC with diverse molecular alterations. We focus on the current preclinical and clinical evidence supporting the potential of these approaches and the promise of combinatorial regimens to improve the lives of patients with PDAC.

Adjuvant Pembrolizumab versus IFNα2b or Ipilimumab in Resected High-Risk Melanoma

We conducted a randomized phase III trial to evaluate whether adjuvant pembrolizumab for one year (647 patients) improved recurrence-free survival (RFS) or overall survival (OS) in comparison with high-dose IFNα-2b for one year or ipilimumab for up to three years (654 patients), the approved standard-of-care adjuvant immunotherapies at the time of enrollment for patients with high-risk resected melanoma. At a median follow-up of 47.5 months, pembrolizumab was associated with significantly longer RFS than prior standard-of-care adjuvant immunotherapies [HR, 0.77; 99.62% confidence interval (CI), 0.59-0.99; P = 0.002]. There was no statistically significant association with OS among all patients (HR, 0.82; 96.3% CI, 0.61-1.09; P = 0.15). Proportions of treatment-related adverse events of grades 3 to 5 were 19.5% with pembrolizumab, 71.2% with IFNα-2b, and 49.2% with ipilimumab. Therefore, adjuvant pembrolizumab significantly improved RFS but not OS compared with the prior standard-of-care immunotherapies for patients with high-risk resected melanoma.

SIGNIFICANCE

Adjuvant PD-1 blockade therapy decreases the rates of recurrence, but not survival, in patients with surgically resectable melanoma, substituting the prior standard-of-care immunotherapies for this cancer. See related commentary by Smithy and Shoushtari, p. 599. This article is highlighted in the In This Issue feature, p. 587.

Melanoma: An update on systemic therapies

Despite advances in early detection as described in part 1 of this continuing medical education series, melanoma continues to be a large contributor to cutaneous cancer-related mortality. In a subset of patients with unresectable or metastatic disease, surgical clearance is often not possible; therefore, systemic and local therapies are considered. The second article in this series provides dermatologists with an up-to-date working knowledge of the treatment options that may be prescribed by oncologists for patients with unresectable stage III, stage IV, and recurrent melanoma.

Amelanotic Malignant Melanoma with a BRAF V600E Mutation Mimicking Primary Lung Cancer

Amelanotic melanoma is a rare type of melanoma that shows little or no melanin pigmentation. When tumor lesions are not detected in cutaneous sites, the presence of melanin is the hallmark sign of malignant melanoma. We herein report a case of amelanotic melanoma with a BRAF V600E mutation mimicking primary lung cancer that was finally diagnosed on an autopsy. The current case suggests important caveats for the differential diagnosis of patients with BRAF V600E mutation-positive poorly differentiated lung tumors. In terms of the pathological diagnosis, routine immunohistochemical staining may be useful, especially in patients with a poorly differentiated lung tumor without TTF-1 expression.

Mechanistic and Clinical Overview Cardiovascular Toxicity of BRAF and MEK Inhibitors: JACC: CardioOncology State-of-the-Art Review

Rapidly accelerated fibrosarcoma B-type (BRAF) and mitogen-activated extracellular signal-regulated kinase (MEK) inhibitors have revolutionized melanoma treatment. Approximately half of patients with melanoma harbor a BRAF gene mutation with subsequent dysregulation of the RAF-MEK-ERK signaling pathway. Targeting this pathway with BRAF and MEK blockade results in control of cell proliferation and, in most cases, disease control. These pathways also have cardioprotective effects and are necessary for normal vascular and cardiac physiology. BRAF and MEK inhibitors are associated with adverse cardiovascular effects including hypertension, left ventricular dysfunction, venous thromboembolism, atrial arrhythmia, and electrocardiographic QT interval prolongation. These effects may be underestimated in clinical trials. Baseline cardiovascular assessment and follow-up, including serial imaging and blood pressure assessment, are essential to balance optimal anti-cancer therapy while minimizing cardiovascular side effects. In this review, an overview of BRAF/MEK inhibitor-induced cardiovascular toxicity, the mechanisms underlying these, and strategies for surveillance, prevention, and treatment of these effects are provided.

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.

Multiple Evanescent White Dot Syndrome and Choroidal Neovascularization following SARS-COV-2 Infection in a Patient on Dabrafenib and Trametinib

PURPOSE

to describe multimodal imaging and electrophysiology of multiple evanescent white dot syndrome (MEWDS) concomitant with COVID-19 infection in a patient on BRAF (B Rapidly Accelerated Fibrosarcoma) and MEK (Mitogen-activated Protein Kinase) inhibitors.

METHODS

observational case report and literature review.

RESULTS

a 37-year-old woman affected by cutaneous melanoma on BRAF and MEK inhibitors developed visual symptoms in the right eye simultaneously with a SARS-COV-2 infection. The right eye visual acuity was hand movement, and clinical examination disclosed vitreous cells, yellow-white retinal spots, and macular yellowish material. Fundus autofluorescence and angiograms were consistent with MEWDS. Angiograms, optical coherence tomography, and optical coherence tomography angiography revealed a macular choroidal neovascular membrane. The infectious and inflammatory work-up was negative. Electrodiagnostic tests revealed cone dysfunction. MEWDS resolved and anti-VEGF treatment allowed partial vision recovery.

CONCLUSION

the case illustrates the association of MEWDS and choroidal neovascularization developing after COVID-19 infection in the setting of immunotherapy.

The Extracellular Signal-Regulated Kinase Mitogen-Activated Protein Kinase Pathway in Osteoblasts

Extracellular signal-regulated kinases (ERKs) are evolutionarily ancient signal transducers of the mitogen-activated protein kinase (MAPK) family that have long been linked to the regulation of osteoblast differentiation and bone formation. Here, we review the physiological functions, biochemistry, upstream activators, and downstream substrates of the ERK pathway. ERK is activated in skeletal progenitors and regulates osteoblast differentiation and skeletal mineralization, with ERK serving as a key regulator of Runt-related transcription factor 2, a critical transcription factor for osteoblast differentiation. However, new evidence highlights context-dependent changes in ERK MAPK pathway wiring and function, indicating a broader set of physiological roles associated with changes in ERK pathway components or substrates. Consistent with this importance, several human skeletal dysplasias are associated with dysregulation of the ERK MAPK pathway, including neurofibromatosis type 1 and Noonan syndrome. The continually broadening array of drugs targeting the ERK pathway for the treatment of cancer and other disorders makes it increasingly important to understand how interference with this pathway impacts bone metabolism, highlighting the importance of mouse studies to model the role of the ERK MAPK pathway in bone formation.

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.