Long-Term Outcomes in BRAF-Mutated Melanoma Treated with Combined Targeted Therapy or Immune Checkpoint Blockade: Are We Approaching a True Cure?

An Automated Real-Time PCR Assay versus Next-Generation Sequencing in the Detection of BRAF V600 Mutations in Melanoma Tissue Samples

BACKGROUND

Next-generation sequencing (NGS) is the most commonly used method for determining BRAF mutational status in patients with advanced melanoma. Automated PCR-based methods, such as the IdyllaTM system, are increasingly used for mutation diagnostics, but it is unclear what impact the choice of diagnostic method has on the management of melanoma.

OBJECTIVES

To compare the concordance rate of BRAF V600 mutational analysis using IdyllaTM and NGS and to analyze the technical and clinical turnaround time. The clinical relevance is compared by analyzing the impact on the treatment decision.

METHODS

In this monocentric prospective cohort study, the BRAF mutation status of 51 patients was determined using both methods in parallel.

RESULTS

BRAF V600 mutation was detected in 23/51 cases (45%). IdyllaTM showed a 100% concordant result with a faster turnaround time (0.2 days) compared to NGS (12.2 days). In general, less tumor material was required for IdyllaTM than for NGS. Most patients received immunotherapy as a first-line therapy regardless of the BRAF V600 status.

CONCLUSIONS

IdyllaTM testing proved to be a reliable and rapid alternative to NGS in the determination of BRAF V600 mutation. Although BRAF. status was available earlier, this had no influence on the treatment decision in most cases.

Targeted therapy or immunotherapy in BRAF-mutated metastatic melanoma: a Spanish center's decade of experience

Background

Targeted therapies and immunotherapy are currently considered the mainstay first-line treatment for advanced BRAF-mutated melanoma. However, the impact of treatment (targeted therapy and immunotherapy) and the prognostic factors are still not clear.

Material and methods

Medical records of 140 patients diagnosed with advanced melanoma between 2011 and 2021 were retrospectively reviewed to extract demographic, BRAF status, treatment, performance status, and survival data. ORR, PFS, and OS were compared between patients diagnosed with advanced melanoma and treated with first-line IT or BRAF/MEKi. The prognostic factors were assessed using Cox regression models.

Results

In all patients and those treated with immunotherapy, we did not find any effect of BRAF status on ORR, PFS, or OS. In patients with BRAF-mutated melanoma, ORR was 43.8% vs. 70% (P=0.04), PFS was 19.2 vs. 11.5 months (p=0.22), and OS was 33.4 vs. 16.4 months for the immunotherapy and targeted therapy groups, respectively (P=0.04). ECOG, presence of brain metastases, and high LDH level from initiation of first-line treatment were all associated with differences in PFS and OS.

Conclusion

Patients with advanced BRAF-mutated melanoma treated with first-line immunotherapy had a significantly longer PFS and OS than those treated with first-line BRAF/MEKi; however, first-line BRAF/MEKi treatment had a significantly higher ORR than first-line immunotherapy.

A Thia-Analogous Indirubin N-Glycoside Disrupts Mitochondrial Function and Causes the Death of Human Melanoma and Cutaneous Squamous Cell Carcinoma Cells

Skin cancer is the most common malignant disease worldwide and, therefore, also poses a challenge from a pharmacotherapeutic perspective. Derivatives of indirubin are an interesting option in this context. In the present study, the effects of 3-[3'-oxo-benzo[b]thiophen-2'-(Z)-ylidene]-1-(β-d-glucopyranosyl)-oxindole (KD87), a thia-analogous indirubin N-glycoside, on the viability and mitochondrial properties of melanoma (A375) and squamous cell carcinoma cells (A431) of the skin were investigated. In both cell lines, KD87 caused decreased viability, the activation of caspases-3 and -7, and the inhibition of colony formation. At the mitochondrial level, a concentration-dependent decrease in both the basal and ATP-linked oxygen consumption rate and in the reserve capacity of oxidative respiration were registered in the presence of KD87. These changes were accompanied by morphological alterations in the mitochondria, a release of mitochondrial cytochrome c into the cytosol and significant reductions in succinate dehydrogenase complex subunit B (SDHB, subunit of complex II) in A375 and A431 cells and NADH:ubiquinone oxidoreductase subunit B8 (NDUFB8, subunit of complex I) in A375 cells. The effect of KD87 was accompanied by a significant upregulation of the enzyme heme oxygenase-1, whose inhibition led to a partial but significant reduction in the metabolic-activity-reducing effect of KD87. In summary, our data show a mitochondria-targeting effect of KD87 as part of the cytotoxic effect of this compound on skin cancer cells, which should be considered in future studies with this class of compounds.

Efficacy of Pembrolizumab in Advanced Melanoma: A Narrative Review

Pembrolizumab has been shown to increase survival in patients with metastatic melanoma. Considering the numerous oncoming studies, we decided to conduct a narrative review of the latest efficacy evidence regarding the use of pembrolizumab, alone or in combination, in patients with metastatic melanoma. A search was conducted in PubMed using "pembrolizumab," and "metastatic melanoma" as keywords, considering studies from 2022 onward. We reviewed pembrolizumab and associations, cost-effectiveness, virus, advanced acral melanoma, long-term outcomes, real-life data, biomarkers, obesity, and vaccines. In conclusion, pembrolizumab is a fundamental option in the therapy of metastatic melanoma. However, a certain group of patients do not respond and, therefore, new combination options need to be evaluated. In particular, the use of vaccines tailored to tumor epitopes could represent a breakthrough in the treatment of resistant forms. Further studies with larger sample numbers are needed to confirm the preliminary results.

Making In Vitro Tumor Models Whole Again

As a reductionist approach, patient-derived in vitro tumor models are inherently still too simplistic for personalized drug testing as they do not capture many characteristics of the tumor microenvironment (TME), such as tumor architecture and stromal heterogeneity. This is especially problematic for assessing stromal-targeting drugs such as immunotherapies in which the density and distribution of immune and other stromal cells determine drug efficacy. On the other end, in vivo models are typically costly, low-throughput, and time-consuming to establish. Ex vivo patient-derived tumor explant (PDE) cultures involve the culture of resected tumor fragments that potentially retain the intact  TME of the original tumor. Although developed decades ago, PDE cultures have not been widely adopted likely because of their low-throughput and poor long-term viability. However, with growing recognition of the importance of patient-specific TME in mediating drug response, especially in the field of immune-oncology, there is an urgent need to resurrect these holistic cultures. In this Review, the key limitations of patient-derived tumor explant cultures are outlined and technologies that have been developed or could be employed to address these limitations are discussed. Engineered holistic tumor explant cultures may truly realize the concept of personalized medicine for cancer patients.

Clinical and molecular overview of immunotherapeutic approaches for malignant skin melanoma: Past, present and future

Traditional therapeutic approaches for malignant melanoma, have proved to be limited and/or ineffective, especially with respect to their role in improving patient survival and tumor recurrence. In this regard, immunotherapy has been demonstrated to be a promising therapeutic alternative, boosting antitumor responses through the modulation of cell signaling pathways involved in the effector mechanisms of the immune system, particularly, the so-called "immunological checkpoints". Clinical studies on the efficacy and safety of immunotherapeutic regimens, alone or in combination with other antitumor approaches, have increased dramatically in recent decades, with very encouraging results. Hence, this review will discuss the current immunotherapeutic regimens used to treat malignant melanoma, as well as the molecular and cellular mechanisms involved. In addition, current clinical studies that have investigated the use, efficacy, and adverse events of immunotherapy in melanoma will also be discussed.

Addressing the unmet needs of patients with BRAF-mutated melanoma in Latin America: Expert perspective

Melanoma represents an increasing public health burden with extensive unmet needs in Latin America (LA). A mutation in the BRAF gene is present in approximately 50% of all melanomas in White populations and is a target of precision medicine, with the potential to dramatically improve patient outcomes. Thus, increased access to BRAF testing and therapy is LA must be explored. At a multi-day conference, a panel of Latin American experts in oncology and dermatology were provided with questions to address the barriers limiting access to testing for BRAF mutation in patients with melanoma in LA, who may be eligible for targeted therapy to improve their prognosis. During the conference, responses were discussed and edited until a consensus on addressing the barriers was achieved. Identified challenges included ignorance of BRAF-status implications, limited human and infrastructural resources, affordability and reimbursement, fragmented care delivery, pitfalls in the sample journey, and lack of local data. Despite the clear benefits of targeted therapies for BRAF-mutated melanoma in other regions, there is no clear path to prepare LA for a sustainable personalized medicine approach to this disease. Due to melanoma’s time-sensitive nature, LA must aim to provide early access to BRAF testing and consider mutational status within treatment decision making. To this end, recommendations are provided and include establishing multidisciplinary teams and melanoma referral centers and improving access to diagnosis and treatment.

Incidence of BRAF mutations in cutaneous melanoma: histopathological and molecular analysis of a Ukrainian population

Aim

This study aimed to investigate the incidence of BRAF mutation in cutaneous melanoma in the Ukrainian population with respect to clinical and histopathological data.

Materials & methods

This single-center retrospective cohort study enrolled 299 primary CM with known BRAF status assessed by RT-PCR.

Results

The overall BRAF mutation rate was 56.5% in CM and demonstrated a link with the younger age (p < 0.001), anatomical site (p < 0.001) and histological type of CM (p = 0.022). BRAF-positive CM possessed a slightly higher mitotic rate (p = 0.015) and Breslow thickness (p = 0.028) but did not relate to tumor-infiltrating lymphocytes.

Conclusion

The high rate of BRAF mutations in CM patients in the Ukrainian cohort was associated with superficial spreading histology, higher depth of invasion and proliferation.

Classic and new strategies for the treatment of advanced melanoma and non-melanoma skin cancer

Advanced melanoma and non-melanoma skin cancers (NMSCs) are burdened with a dismal prognosis. To improve the survival of these patients, studies on immunotherapy and target therapies in melanoma and NMSCs are rapidly increasing. BRAF and MEK inhibitors improve clinical outcomes, and anti-PD1 therapy demonstrates better results than chemotherapy or anti-CTLA4 therapy in terms of the survival of patients with advanced melanoma. In recent years, the combination therapy of nivolumab plus ipilimumab has gained ground in studies for its survival and response rate benefits in patients with advanced melanoma. In addition, neoadjuvant treatment for stages III and IV melanoma, either as monotherapy or combination therapy, has recently been discussed. Another promising strategy evaluated in recent studies is the triple combination of anti-PD-1/PD-L1 immunotherapy and anti-BRAF plus anti-MEK targeted therapy. On the contrary, in advanced and metastatic BCC, successful therapeutic strategies, such as vismodegib and sonidegib, are based on the inhibition of aberrant activation of the Hedgehog signaling pathway. In these patients, anti-PD-1 therapy with cemiplimab should be reserved as the second-line therapy in case of disease progression or poor response. In patients with locally advanced or metastatic SCC, who are not candidates for surgery or radiotherapy, anti-PD1 agents such as cemiplimab, pembrolizumab, and cosibelimab (CK-301) have shown significant results in terms of response rate. PD-1/PD-L1 inhibitors, such as avelumab, have also been used in Merkel carcinoma, achieving responses in half of the patients with advanced disease. The latest prospect emerging for MCC is the locoregional approach involving the injection of drugs that can stimulate the immune system. Two of the most promising molecules used in combination with immunotherapy are cavrotolimod (a Toll-like receptor 9 agonist) and a Toll-like receptor 7/8 agonist. Another area of study is cellular immunotherapy with natural killer cells stimulated with an IL-15 analog or CD4/CD8 cells stimulated with tumor neoantigens. Neoadjuvant treatment with cemiplimab in CSCCs and nivolumab in MCCs has shown promising results. Despite the successes of these new drugs, the new challenges ahead will be to select patients who will benefit from these treatments based on biomarkers and parameters of the tumor microenvironment.

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.

The Role of Treatment Sequencing with Immune-Checkpoint Inhibitors and BRAF/MEK Inhibitors for Response and Survival of Patients with BRAFV600-Mutant Metastatic Melanoma—A Retrospective, Real-World Cohort Study

The advent of immune-checkpoint inhibitors (CPI) and BRAF/MEK-directed targeted therapy (TT) has improved the treatment landscape of patients with BRAFV600-mutant metastatic melanoma. While TT allows for rapid disease control, the development of secondary TT resistance limits the duration of responses. Responses to CPI have a slower onset but can be durable in a subset of patients. To date, little prospective data is available for the optimal sequencing of these agents in melanoma patients. In this retrospective, single-center, real-world analysis, we identified 135 patients with BRAF-mutated, metastatic melanoma who received consecutive treatment with TT followed by CPI, or vice versa, as first and second-line therapy, respectively. We collected data on clinical-pathological factors, treatment duration, best overall response, progression-free survival and overall survival (OS). Our data revealed that front-line treatment with CPI, followed by TT, showed a non-significant trend towards better OS compared to front-line TT (median OS: 35.0 vs. 18.0 months, p = 0.070). This association was confirmed in a subgroup of patients without systemic pre-treatments (median OS: 41.0 vs. 14.0 months, p = 0.02). Further, we observed significantly better objective response rates to second-line treatments for patients receiving front-line CPI (18.4 vs. 37.8%, p = 0.024). Last, our results indicated that rapid disease progression was less common in patients treated with front-line CPI (27.6% vs. 16.2%) and that subsequent treatment with TT resulted in favorable survival outcomes. Our real-world data indicate that sequential treatment with front-line CPI is associated with favorable tumor control and overall survival in a subgroup of previously untreated BRAF-mutant metastatic melanoma patients.

Real-World Evidence of Systemic Therapy Sequencing on Overall Survival for Patients with Metastatic BRAF-Mutated Cutaneous Melanoma

Aim: To evaluate optimal systemic therapy sequencing (first-line targeted therapy (1L-TT) vs. first-line immunotherapy (1L-IO)) in patients with BRAF-mutated metastatic melanoma. Methods: Nation-wide prospective data of patients with newly diagnosed BRAF-mutated metastatic melanoma were retrieved from the Canadian Melanoma Research Network. Results: Our study included 79 and 107 patients in the 1L-IO and 1L-TT groups, respectively. There were more patients with ECOG 0−1 (91% vs. 72%, p = 0.023) in the 1L-IO group compared to the 1L-TT group. Multivariable Cox analysis suggested no OS differences between the two groups (HR 0.838, 95%CI 0.502−1.400, p = 0.500). However, patients who received 1L-TT then 2L-IO had the longest OS compared to 1L-IO without 2L therapy, 1L-IO then 2L-TT, and 1L-TT without 2L therapy (38.3 vs. 32.2 vs. 16.9 vs. 6.3 months, p < 0.001). For patients who received 2L therapy, those who received 2L-IO had a trend towards OS improvement compared with the 2L-TT group (21.7 vs. 8.9 months, p = 0.053). Conclusions: Our nation-wide prospective study failed to establish any optimal systemic therapy sequencing in advanced BRAF-mutant melanoma patients. Nevertheless, we provided evidence that immunotherapy has durable efficacy in advanced BRAF-mutant melanoma patients, regardless of treatment line, and that Canadian medical oncologists were selecting the appropriate treatment sequences in a real-world setting, based on patients’ clinical and tumour characteristics.

Loxl3 Promotes Melanoma Progression and Dissemination Influencing Cell Plasticity and Survival

Simple Summary

Malignant melanoma is the most lethal skin cancer due to its aggressive clinical behavior and therapeutic resistance. A comprehensive knowledge of the molecular mechanisms underlying melanoma progression is urgently needed to improve the survival of melanoma patients. Phenotypic plasticity of melanoma cells has emerged as a key process in melanomagenesis and therapy resistance. This phenotypic plasticity is sustained by an epithelial-to-mesenchymal (EMT)-like program that favors multiple intermediate states and allows adaptation to changing microenvironments along melanoma progression. Given the essential role of lysyl oxidase-like 3 (LOXL3) in human melanoma cell survival and its contribution to EMT, we generated mice with conditional melanocyte-specific targeting of Loxl3, concomitant to Braf activation and Pten deletion. Our results supported a key role of Loxl3 for melanoma progression, metastatic dissemination, and genomic stability, and supported its contribution to melanoma phenotypic plasticity by modulating the expression of several EMT transcription factors (EMT-TFs).

Abstract

Malignant melanoma is a highly aggressive tumor causing most skin cancer-related deaths. Understanding the fundamental mechanisms responsible for melanoma progression and therapeutic evasion is still an unmet need for melanoma patients. Progression of skin melanoma and its dissemination to local or distant organs relies on phenotypic plasticity of melanoma cells, orchestrated by EMT-TFs and microphthalmia-associated TF (MITF). Recently, melanoma phenotypic switching has been proposed to uphold context-dependent intermediate cell states benefitting malignancy. LOXL3 (lysyl oxidase-like 3) promotes EMT and has a key role in human melanoma cell survival and maintenance of genomic integrity. To further understand the role of Loxl3 in melanoma, we generated a conditional Loxl3-knockout (KO) melanoma mouse model in the context of BrafV600E-activating mutation and Pten loss. Melanocyte-Loxl3 deletion increased melanoma latency, decreased tumor growth, and reduced lymph node metastatic dissemination. Complementary in vitro and in vivo studies in mouse melanoma cells confirmed Loxl3’s contribution to melanoma progression and metastasis, in part by modulating phenotypic switching through Snail1 and Prrx1 EMT-TFs. Importantly, a novel LOXL3-SNAIL1-PRRX1 axis was identified in human melanoma, plausibly relevant to melanoma cellular plasticity. These data reinforced the value of LOXL3 as a therapeutic target in melanoma.

Neratinib kills B-RAF V600E melanoma via ROS-dependent autophagosome formation and death receptor signaling

Melanoma cells expressing mutant B-RAF V600E are susceptible to treatment with the combination of a B-RAF inhibitor and a MEK1/2 inhibitor. We investigated the impact of the ERBB family and MAP4K inhibitor neratinib on the biology of PDX isolates of cutaneous melanoma expressing B-RAF V600E. Neratinib synergized with HDAC inhibitors to kill melanoma cells at their physiologic concentrations. Neratinib activated ATM, AMPK, ULK1, and PERK and inactivated mTORC1/2, ERK1/2, eIF2 alpha, and STAT3. Neratinib increased expression of Beclin1, ATG5, CD95, and FAS-L and decreased levels of multiple toxic BH3 domain proteins, MCL1, BCL-XL, FLIP-s, and ERBB1/2/4. ATG13 S318 phosphorylation and autophagosome formation was dependent upon ATM, and activation of ATM was dependent on reactive oxygen species. Reduced expression of ERBB1/2/4 required autophagosome formation and reduced MCL1/BCL-XL levels required eIF2 alpha phosphorylation. Maximal levels of eIF2 alpha phosphorylation required signaling by ATM-AMPK and autophagosome formation. Knock down of eIF2 alpha, CD95, FAS-L, Beclin1, and ATG5 or over-expression of FLIP-s significantly reduced killing. Combined knock down of Beclin1 and CD95 abolished cell death. Our data demonstrate that PDX melanoma cells expressing B-RAF V600E are susceptible to being killed by neratinib and more so when combined with HDACi.

Circulating tumour DNA (ctDNA) in metastatic melanoma, a systematic review and meta-analysis

INTRODUCTION

Circulating tumour DNA (ctDNA) is an emerging biomarker in melanoma. We performed a systematic review and meta-analysis to explore its clinical utility as a prognostic, pharmacodynamic (PD) and predictive biomarker.

METHODS

A systematic search was conducted from Jan 2015 to April 2021, of the electronic databases PubMed, Cochrane Library and Ovid MEDLINE to identify studies. Studies were restricted to those published in English within the last 5 years, evaluating ctDNA in humans in ≥10 patients. Survival data were extracted for meta-analysis using pooled treatment effect (TE), i.e. log hazard ratios (HRs) and corresponding standard error of TE for progression-free survival or overall survival differences in patients who were ctDNA positive or negative. PRISMA statement guidelines were followed.

RESULTS

A meta-analysis of 19 studies grouped according to methodology of ctDNA detection, revealed a combined estimate for HR of progression-free survival (13 studies using droplet digital Polymerase Chain Reaction (ddPCR) methodology (N = 1002) of 2.10 (95% CI: 1.71-2.59) revealing a poorer prognosis when ctDNA was detected. This result was confirmed in the smaller analysis of (non-ddPCR, N = 347) five studies: HR = 2.45 (95% CI: 1.29-4.63). Similar findings were found in the overall survival analysis of nine studies (ddPCR methodology, N = 841) where the combined HR was 2.78 (95% CI: 2.21-3.49) and of the five studies (non-ddPCR methodology, N = 326) where the combined HR was 2.58 (95% CI: 1.74-3.84). Serial ctDNA levels on treatment showed a pharmacodynamic role reflecting response or resistance earlier than radiological assessment.

CONCLUSIONS

Circulating tumour DNA is a predictive, prognostic and PD biomarker in melanoma. Technical standardisation of assays is required before clinical adoption.

Discontinuation of BRAF/MEK-Directed Targeted Therapy after Complete Remission of Metastatic Melanoma-A Retrospective Multicenter ADOReg Study

The advent of BRAF/MEK inhibitors (BRAFi/MEKi) has significantly improved progression-free (PFS) and overall survival (OS) for patients with advanced BRAF-V600-mutant melanoma. Long-term survivors have been identified particularly among patients with a complete response (CR) to BRAF/MEK-directed targeted therapy (TT). However, it remains unclear which patients who achieved a CR maintain a durable response and whether treatment cessation might be a safe option in these patients. Therefore, this study investigated the impact of treatment cessation on the clinical course of patients with a CR upon BRAF/MEK-directed-TT. We retrospectively selected patients with BRAF-V600-mutant advanced non-resectable melanoma who had been treated with BRAFi ± MEKi therapy and achieved a CR upon treatment out of the multicentric skin cancer registry ADOReg. Data on baseline patient characteristics, duration of TT, treatment cessation, tumor progression (TP) and response to second-line treatments were collected and analyzed. Of 461 patients who received BRAF/MEK-directed TT 37 achieved a CR. TP after initial CR was observed in 22 patients (60%) mainly affecting patients who discontinued TT (n = 22/26), whereas all patients with ongoing TT (n = 11) maintained their CR. Accordingly, patients who discontinued TT had a higher risk of TP compared to patients with ongoing treatment (p < 0.001). However, our data also show that patients who received TT for more than 16 months and who discontinued TT for other reasons than TP or toxicity did not have a shorter PFS compared to patients with ongoing treatment. Response rates to second-line treatment being initiated in 21 patients, varied between 27% for immune-checkpoint inhibitors (ICI) and 60% for BRAFi/MEKi rechallenge. In summary, we identified a considerable number of patients who achieved a CR upon BRAF/MEK-directed TT in this contemporary real-world cohort of patients with BRAF-V600-mutant melanoma. Sustained PFS was not restricted to ongoing TT but was also found in patients who discontinued TT.

GZ17-6.02 Interacts With [MEK1/2 and B-RAF Inhibitors] to Kill Melanoma Cells

We defined the lethal interaction between the novel therapeutic GZ17-6.02 and the standard of care combination of the MEK1/2 inhibitor trametinib and the B-RAF inhibitor dabrafenib in PDX isolates of cutaneous melanoma expressing a mutant B-RAF V600E protein. GZ17-6.02 interacted with trametinib/dabrafenib in an additive fashion to kill melanoma cells. Regardless of prior vemurafenib resistance, the drugs when combined interacted to prolong ATM S1981/AMPK T172 and eIF2α S51 phosphorylation and prolong the reduced phosphorylation of JAK2 Y1007, STAT3 Y705 and STAT5 Y694. In vemurafenib-resistant cells GZ17-6.02 caused a prolonged reduction in mTORC1 S2448, mTORC2 S2481 and ULK1 S757 phosphorylation; regardless of vemurafenib resistance, GZ17-6.02 caused a prolonged elevation in CD95 and FAS-L expression. Knock down of eIF2α, Beclin1, ATG5, ATM, AMPKα, CD95 or FADD significantly reduced the ability of GZ17-6.02 to kill as a single agent or when combined with the kinase inhibitors. Expression of activated mTOR, activated STAT3, activated MEK1 or activated AKT significantly reduced the ability of GZ17-6.02 to kill as a single agent or when combined with kinase inhibitors; protective effects that were significantly less pronounced in cells treated with trametinib/dabrafenib. Regardless of vemurafenib resistance, the drugs alone or in combination all reduced the expression of PD-L1 and increased the levels of MHCA, which was linked to degradation of multiple HDAC proteins. Our findings support the use of GZ17-6.02 in combination with trametinib/dabrafenib in the treatment of melanomas expressing mutant B-RAF V600E proteins.

A matching-adjusted indirect comparison of combination nivolumab plus ipilimumab with BRAF plus MEK inhibitors for the treatment of BRAF-mutant advanced melanoma☆

Background

Approved first-line treatments for patients with BRAF V600–mutant advanced melanoma include nivolumab (a programmed cell death protein 1 inhibitor) plus ipilimumab (a cytotoxic T lymphocyte antigen-4 inhibitor; NIVO+IPI) and the BRAF/MEK inhibitors dabrafenib plus trametinib (DAB+TRAM), encorafenib plus binimetinib (ENCO+BINI), and vemurafenib plus cobimetinib (VEM+COBI). Results from prospective randomized clinical trials (RCTs) comparing these treatments have not yet been reported. This analysis evaluated the relative efficacy and safety of NIVO+IPI versus DAB+TRAM, ENCO+BINI, and VEM+COBI in patients with BRAF-mutant advanced melanoma using a matching-adjusted indirect comparison (MAIC).

Patients and methods

A systematic literature review identified RCTs for DAB+TRAM, ENCO+BINI, and VEM+COBI in patients with BRAF-mutant advanced melanoma. Individual patient-level data for NIVO+IPI were derived from the phase III CheckMate 067 trial (BRAF-mutant cohort) and restricted to match the inclusion/exclusion criteria of the comparator trials. Treatment effects for overall survival (OS) and progression-free survival (PFS) were estimated using Cox proportional hazards and time-varying hazard ratio (HR) models. Safety outcomes (grade 3 or 4 treatment-related adverse events) with NIVO+IPI and the comparators were compared.

Results

In the Cox proportional hazards analysis, NIVO+IPI showed improved OS compared with DAB+TRAM (HR = 0.53; 95% confidence interval [CI], 0.39-0.73), ENCO+BINI (HR = 0.60; CI, 0.42-0.85), and VEM+COBI (HR = 0.50; CI, 0.36-0.70) for the overall study period. In the time-varying analysis, NIVO+IPI was associated with significant improvements in OS and PFS compared with the BRAF/MEK inhibitors 12 months after treatment initiation. There were no significant differences between NIVO+IPI and BRAF/MEK inhibitor treatment from 0 to 12 months. Safety outcomes favored DAB+TRAM over NIVO+IPI, whereas NIVO+IPI was comparable to VEM+COBI.

Conclusion

Results of this MAIC demonstrated durable OS and PFS benefits for patients with BRAF-mutant advanced melanoma treated with NIVO+IPI compared with BRAF/MEK inhibitors, with the greatest benefits noted after 12 months.

•

First-line treatments for BRAF V600-mutant melanoma include NIVO+IPI and BRAF/MEK inhibitors.

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Results from prospective RCTs comparing NIVO+IPI and BRAF/MEK inhibitors have not yet been reported.

•

This MAIC evaluated NIVO+IPI versus BRAF/MEK inhibitors for BRAF-mutant advanced melanoma.

•

OS and PFS benefits were noted with NIVO+IPI versus BRAF/MEK inhibitors beginning at 12 months.

•

These findings may provide information relevant to the selection of treatments for BRAF-mutant advanced melanoma.

A monocentric phase I study of vemurafenib plus cobimetinib plus PEG-interferon (VEMUPLINT) in advanced melanoma patients harboring the V600BRAF mutation

BACKGROUND

Studies carried out in vitro and in a mouse model have shown that BRAF inhibitors enhance the effects of IFN-α on BRAFV600E melanoma cells through the inhibition of ERK. Therefore, the combination of vemurafenib and IFN-α in patients with BRAFV600E melanoma may provide therapeutic benefits; MEK inhibition may prevent the reactivation of the MAPK pathway induced by BRAF inhibitor resistance.

PATIENTS AND METHODS

In a phase I study, adult patients with advanced BRAFV600-mutated melanoma were treated with vemurafenib + PEG-IFN-α-2b or vemurafenib + cobimetinib + PEG-IFN-α-2b, to assess the safety of the combination and the upregulation of IFN-α/β receptor-1 (IFNAR1).

RESULTS

Eight patients were treated; 59 adverse events with four serious ones (three related to study treatments) were reported. Patients with a pre-treatment IFNAR1 expression on ≤ 35% melanoma cells had a median progression-free survival of 12.0 months (range: 5.6-18.4 months) and a median overall survival of 31.0 months (range: 19.8-42.2 months), while patients with a pre-treatment IFNAR1 expression on > 35% of melanoma cells had a median progression-free survival of 4.0 months (range: 0-8.8; p = 0.03), and a median overall survival of 5 months (p = 0.02). Following treatment, responders had higher levels of growth-suppressor genes, including GAS1 and DUSP1, and genes involved in a metabolically robust immune response, including FAP.

CONCLUSION

Our study supports the overall safety of the vemurafenib + PEG-IFN-α-2b + cobimetinib combination. IFNAR1 expression levels correlated with response to treatment, including survival. Vemurafenib + PEG-IFN-α-2b + cobimetinib would have difficulty finding a niche in the current treatment scenario for advanced melanoma, but we speculate that our findings may contribute to identify subjects particularly responsive to treatment.

TRIAL REGISTRATION

The study was registered at clinicaltrials.gov (NCT01959633). Registered 10 October 2013, https://clinicaltrials.gov/ct2/show/NCT01959633.

Economic evaluation of adverse events of dabrafenib plus trametinib versus nivolumab in patients with advanced BRAF-mutant cutaneous melanoma for adjuvant therapy in Germany

Background: Adjuvant treatment options have become the standard therapy for stage III and IV resectable cutaneous melanoma. Two recent studies led to the registration of dabrafenib and trametinib as targeted therapies for BRAF-mutated melanoma, and of immunotherapy with nivolumab irrespective of BRAF-mutation status. Both therapies have different spectrums of adverse events. Objective: To estimate the financial impact of side effects from the perspective of the German statutory sick funds to compare both therapeutic options and to relate the burden to the overall costs of the treatment.

STUDY DESIGN AND SETTING

Thirty-six adverse event categories for the combination of dabrafenib and trametinib ('combi treatment') and for nivolumab were extracted from the original publications of the studies named COMBI-AD and CheckMate 238.

PATIENTS AND INTERVENTION

For all event categories a diagnosis and therapy recommendation were determined according to current national or international guidelines or from leading German textbooks.

MAIN OUTCOME MEASURE

The resulting diagnostic steps, treatments, and therapies were evaluated with unit costs based on the German fee schedule for ambulatory physicians, the German G-DRG scheme, and the German drug price list.

RESULTS

The number of events with nivolumab per one hundred treatments amounted to 3.8 mandatory hospitalizations, 3.5 emergency care events and 0.8 life-threatening events. For the combi treatment, the respective number of events per one hundred treatments was 2.7, 1.8, and 0.5. The overall cost burden was calculated as €899 for nivolumab and €861 for combi-treatment.

CONCLUSION

The treatment of adverse events resulting from adjuvant melanoma therapy showed comparable costs for both therapies.

Patient preferences for treatment of advanced melanoma: impact of comorbidities

BACKGROUND AND OBJECTIVES

Choice of treatment for advanced melanoma is crucially influenced by comorbidities and patient preferences. Our study aimed to investigate the impact of comorbidities on preferences.

PATIENTS AND METHODS

150 patients with melanoma stage IIC-IV completed a discrete choice experiment to determine preferences for outcome (overall response rate [ORR], 2-year survival, progression-free survival [PFS], time to response [TTR], kind of adverse events [AE], AE-related treatment discontinuation) and process attributes (frequency and route of administration [RoA], frequency of consultations) of systemic melanoma treatments. The impact of comorbidities was assessed by analysis of variance and multivariate regression.

RESULTS

Participants with hypertension and other cardiovascular diseases attached significantly greater importance to TTR and RoA than others. Respondents with arthropathy cared more about TTR (β = 0.179, P = 0.047) and RoA, but less about ORR (β = -0.209, P =  0.021). Individuals with diabetes considered AE (β = 0.185, P = 0.039) and frequency of consultations more essential, but ORR less relevant. Those with other malignancies were particularly worried about treatment discontinuation (β = 0.219, P =  0.008), but less about ORR (β = -0.202, P =  0.015). Participants with depression focused more on PFS (β = 0.201, P =  0.025) and less on TTR (β = -0.201, P =  0.023) and RoA (β = -0.167, P =  0.050).

CONCLUSIONS

Treatment preferences of melanoma patients vary significantly dependent on comorbidities.

Activated melanoma vessels: A sticky point for successful immunotherapy

Metastatic melanoma is a devastating disease with a marginal-albeit increasing-hope for cure. Melanoma has a high mutation rate which correlates to the expression of numerous neo-antigens and thus is associated with the potential to induce and strengthen effective antitumoral immunity. However, the incomplete and potentially insufficient response to established immunotherapies (response rates usually do not markedly exceed 60%) already points to the need of further studies to improve treatment strategies. Multiple tumor escape mechanisms that allow melanoma to evade from antitumoral immune responses have been characterized and must be overcome to achieve a better clinical efficacy of immunotherapies. Recently, promising progress has been made in targeting tumor vasculature to control and increase the infiltration of tumors with effector lymphocytes. It has been hypothesized that amplified lymphocytic infiltrates in melanoma metastases result in a switch of the tumor microenvironment from a non-inflammatory to an inflammatory state. In this view point essay, we discuss the requirements for successful homing of lymphocytes to melanoma tissue and we present a mouse melanoma xenograft model that allows the investigation of human tumor vessels in vivo. Furthermore, current clinical studies dealing with the activation of melanoma vasculature for enhanced effectiveness of immunotherapy protocols are presented and open questions for routine clinical application are addressed.

Intrinsic Balance between ZEB Family Members Is Important for Melanocyte Homeostasis and Melanoma Progression

It has become clear that cellular plasticity is a main driver of cancer therapy resistance. Consequently, there is a need to mechanistically identify the factors driving this process. The transcription factors of the zinc-finger E-box-binding homeobox family, consisting of ZEB1 and ZEB2, are notorious for their roles in epithelial-to-mesenchymal transition (EMT). However, in melanoma, an intrinsic balance between ZEB1 and ZEB2 seems to determine the cellular state by modulating the expression of the master regulator of melanocyte homeostasis, microphthalmia-associated transcription factor (MITF). ZEB2 drives MITF expression and is associated with a differentiated/proliferative melanoma cell state. On the other hand, ZEB1 is correlated with low MITF expression and a more invasive, stem cell-like and therapy-resistant cell state. This intrinsic balance between ZEB1 and ZEB2 could prove to be a promising therapeutic target for melanoma patients. In this review, we will summarise what is known on the functional mechanisms of these transcription factors. Moreover, we will look specifically at their roles during melanocyte-lineage development and homeostasis. Finally, we will overview the current literature on ZEB1 and ZEB2 in the melanoma context and link this to the 'phenotype-switching' model of melanoma cellular plasticity.

BRAF Inhibitors: Molecular Targeting and Immunomodulatory Actions

The BRAF inhibitors vemurafenib, dabrafenib and encorafenib are used in the treatment of patients with BRAF-mutant melanoma. They selectively target BRAF kinase and thus interfere with the mitogen-activated protein kinase (MAPK) signalling pathway that regulates the proliferation and survival of melanoma cells. In addition to their molecularly targeted activity, BRAF inhibitors have immunomodulatory effects. The MAPK pathway is involved in T-cell receptor signalling, and interference in the pathway by BRAF inhibitors has beneficial effects on the tumour microenvironment and anti-tumour immune response in BRAF-mutant melanoma, including increased immune-stimulatory cytokine levels, decreased immunosuppressive cytokine levels, enhanced melanoma differentiation antigen expression and presentation of tumour antigens by HLA 1, and increased intra-tumoral T-cell infiltration and activity. These effects promote recognition of the tumour by the immune system and enhance anti-tumour T-cell responses. Combining BRAF inhibitors with MEK inhibitors provides more complete blockade of the MAPK pathway. The immunomodulatory effects of BRAF inhibition alone or in combination with MEK inhibition provide a rationale for combining these targeted therapies with immune checkpoint inhibitors. Available data support the synergy between these treatment approaches, indicating such combinations provide an additional beneficial effect on the tumour microenvironment and immune response in BRAF-mutant melanoma.

Molecular T-Cell Repertoire Analysis as Source of Prognostic and Predictive Biomarkers for Checkpoint Blockade Immunotherapy

The T cells are key players of the response to checkpoint blockade immunotherapy (CBI) and monitoring the strength and specificity of antitumor T-cell reactivity remains a crucial but elusive component of precision immunotherapy. The entire assembly of T-cell receptor (TCR) sequences accounts for antigen specificity and strength of the T-cell immune response. The TCR repertoire hence represents a “footprint” of the conditions faced by T cells that dynamically evolves according to the challenges that arise for the immune system, such as tumor neo-antigenic load. Hence, TCR repertoire analysis is becoming increasingly important to comprehensively understand the nature of a successful antitumor T-cell response, and to improve the success and safety of current CBI.