Long-term outcome in BRAF(V600E) melanoma patients treated with vemurafenib: Patterns of disease progression and clinical management of limited progression

Management of In-transit Disease: Regional Therapies, Intralesional Therapies, and Systemic Therapy

In-transit (IT) melanoma represents a distinct, heterogeneous pattern of disease that arises as superficial tumors along the track between the primary site and the draining regional lymph node basin. Many therapies have been explored for treatment of this disease with the goal of maximizing delivery of the therapeutic agent to the tumor while minimizing systemic toxicities. These include regional chemotherapies, intralesional injections, checkpoint inhibitors, immunomodulators, and vaccines in various combinations or as monotherapy. Here, we review the general managemnt of patients with ITmelanoma, the range of currently available treatment options, and recommendations for specific therapies for individual patients.

Design, synthesis, anticancer and in silico assessment of 8-caffeinyl chalcone hybrid conjugates

In this paper, we report the design, synthesis, and characterization of novel 8-caffeinyl chalcone hybrid conjugates, which were studied for their anticancer properties, toxicity, and in silico behavior. The synthesized compounds consist of 8-caffeinyl and chalcone structures with diverse substituents. The synthesis involved three main stages: bromination of caffeine to produce 8-BC, synthesis of chalcones, and subsequent coupling of these chalcones with 8-BC. The anticancer activity of the resulting compounds was evaluated in vitro against breast cancer MCF-7 and melanoma A-375 cell lines, revealing certain compounds to have significant efficacy compared to the reference drug methotrexate. Toxicity assessments using a healthy cell line indicated that most compounds displayed some level of toxicity, with only a few exceptions. Molecular docking studies indicated robust binding affinities of selected compounds to B-RAF kinase and hDHFR enzymes. In silico analyses of pharmacokinetic and physicochemical properties demonstrated that the majority of the compounds adhered to Lipinski's rule of five. Furthermore, density functional theory (DFT) studies were performed to gain deeper insights into the properties of the intermediates used throughout the research.

Extracellular vesicles promote migration despite BRAF inhibitor treatment in malignant melanoma cells

Extracellular vesicles (EVs) constitute a vital component of intercellular communication, exerting significant influence on metastasis formation and drug resistance mechanisms. Malignant melanoma (MM) is one of the deadliest forms of skin cancers, because of its high metastatic potential and often acquired resistance to oncotherapies. The prevalence of BRAF mutations in MM underscores the importance of BRAF-targeted therapies, such as vemurafenib and dabrafenib, alone or in combination with the MEK inhibitor, trametinib. This study aimed to elucidate the involvement of EVs in MM progression and ascertain whether EV-mediated metastasis promotion persists during single agent BRAF (vemurafenib, dabrafenib), or MEK (trametinib) and combined BRAF/MEK (dabrafenib/trametinib) inhibition.Using five pairs of syngeneic melanoma cell lines, we assessed the impact of EVs - isolated from their respective supernatants - on melanoma cell proliferation and migration. Cell viability and spheroid growth assays were employed to evaluate proliferation, while migration was analyzed through mean squared displacement (MSD) and total traveled distance (TTD) measurements derived from video microscopy and single-cell tracking.Our results indicate that while EV treatments had remarkable promoting effect on cell migration, they exerted only a modest effect on cell proliferation and spheroid growth. Notably, EVs demonstrated the ability to mitigate the inhibitory effects of BRAF inhibitors, albeit they were ineffective against a MEK inhibitor and the combination of BRAF/MEK inhibitors. In summary, our findings contribute to the understanding of the intricate role played by EVs in tumor progression, metastasis, and drug resistance in MM.

Revisiting the Role of B-RAF Kinase as a Therapeutic Target in Melanoma

Malignant melanoma is the rarest but most aggressive and deadly skin cancer. Melanoma is the result of a malignant transformation of melanocytes, which leads to their uncontrolled proliferation. Mutations in the mitogen-activated protein kinase (MAPK) pathway, which are crucial for the control of cellular processes, such as apoptosis, division, growth, differentiation, and migration, are one of its most common causes. BRAF kinase, as one of the known targets of this pathway, has been known for many years as a prominent molecular target in melanoma therapy, and the following mini-review outlines the state-of-the-art knowledge regarding its structure, mutations and mechanisms.

Overall survival of patients with hepatocellular carcinoma treated with sintilimab and disease outcome after treatment discontinuation

BACKGROUND

The use of Anti-PD-1 therapy has yielded promising outcomes in hepatocellular carcinoma (HCC). However, limited research has been conducted on the overall survival (OS) of patients with varying tumor responses and treatment duration.

METHODS

This retrospective study analyzed HCC patients who received sintilimab between January 2019 and December 2020 at four centers in China. The evaluation of tumor progression was based on Response Evaluation Criteria in Solid Tumors version 1.1. The study investigated the correlation between tumor response and OS, and the impact of drug use on OS following progressive disease (PD).

RESULTS

Out of 441 treated patients, 159 patients satisfied the inclusion criteria. Among them, 77 patients with disease control exhibited a significantly longer OS compared to the 82 patients with PD (median OS 26.0 vs. 11.3 months, P < 0.001). Additionally, the OS of patients with objective response (OR) was better than that of patients with stable disease (P = 0.002). Among the 47 patients with PD who continued taking sintilimab, the OS was better than the 35 patients who discontinued treatment (median OS 11.4 vs. 6.9 months, P = 0.042).

CONCLUSIONS

In conclusion, the tumor response in HCC patients who received sintilimab affects OS, and patients with PD may benefit from continued use of sintilimab.

Design, synthesis, anticancer and in silico assessment of 8-piperazinyl caffeinyl-triazolylmethyl hybrid conjugates

In this paper, we have assessed the design, synthesis, characterization, anticancer properties, toxicity, and in silico study of 8-piperazinyl caffeinyl-triazolylmethyl derivatives as new caffeine hybrid conjugates. These compounds consist of four moieties comprising 8-caffeinyl, piperazinyl, 1,2,3-triazolyl, and alkyl substituents. The synthesis of these compounds was started by bromination of caffeine to attain 8-BC, SNAr reaction with piperazine to acquire 8-PC, N-propargylation of 8-PC and finally click Huisgen cycloaddition with diverse alkyl azides. These compounds were in vitro tested against two significant cancer cell lines comprising breast cancer MCF-7 (ATCC HTB-22) and melanoma cancer A-375 (ATCC CRL-1619) cell lines and activities compared with methotrexate (MTX) as a reference drug. Anticancer assessments indicated 12j (IC50 = 323 ± 2.6) and 12k (IC50 = 175 ± 3.2) were the most potent compounds against A-375 and MCF-7 cell growth, respectively and their activities were even stronger than MTX (IC50 = 418 ± 2 for A375 and IC50 = 343 ± 3.6 for MCF-7). Toxicities were determined by screening compounds against normal cell line HEK-293 (ATCC CRL-11268) and indicated that except 12i (IC50 = 371 ± 2.3), 12j (IC50 = 418 ± 2.4), and MTX (IC50 = 199 ± 2.4), all compounds are non-toxic. Docking was conducted for 12j and 12k and determined the strong binding affinities to B-RAF kinase and hDHFR enzymes, respectively. In silico pharmacokinetic and physiochemical profiles of tested compounds were investigated which indicated that most compounds obeyed Lipinski's rule of five (RO5). The DFT study on M06-2X/6-311G (d,p) was used to indicate HOMO, LUMO, MEP, and other parameters for a better understanding of 12j and 12k reactivity. Owing to anticancer properties, toxicity, and in silico data, 12j and 12k can be proposed for further research in the future.

Targeting UGCG Overcomes Resistance to Lysosomal Autophagy Inhibition

Lysosomal autophagy inhibition (LAI) with hydroxychloroquine or DC661 can enhance cancer therapy, but tumor regrowth is common. To elucidate LAI resistance, proteomics and immunoblotting demonstrated that LAI induced lipid metabolism enzymes in multiple cancer cell lines. Lipidomics showed that LAI increased cholesterol, sphingolipids, and glycosphingolipids. These changes were associated with striking levels of GM1+ membrane microdomains (GMM) in plasma membranes and lysosomes. Inhibition of cholesterol/sphingolipid metabolism proteins enhanced LAI cytotoxicity. Targeting UDP-glucose ceramide glucosyltransferase (UGCG) synergistically augmented LAI cytotoxicity. Although UGCG inhibition decreased LAI-induced GMM and augmented cell death, UGCG overexpression led to LAI resistance. Melanoma patients with high UGCG expression had significantly shorter disease-specific survival. The FDA-approved UGCG inhibitor eliglustat combined with LAI significantly inhibited tumor growth and improved survival in syngeneic tumors and a therapy-resistant patient-derived xenograft. These findings nominate UGCG as a new cancer target, and clinical trials testing UGCG inhibition in combination with LAI are warranted.

SIGNIFICANCE

We discovered UGCG-dependent lipid remodeling drives resistance to LAI. Targeting UGCG with a drug approved for a lysosomal storage disorder enhanced LAI antitumor activity without toxicity. LAI and UGCG inhibition could be tested clinically in multiple cancers. This article is highlighted in the In This Issue feature, p. 247.

Design, synthesis, anticancer and in silico assessment of 8-caffeinyl-triazolylmethoxy hybrid conjugates

In this research the synthesis, characterization, anticancer and the cytotoxicity assessments of novel 8-caffeinyl-triazolylmethoxy hybrid conjugates have been described. These compounds are the first caffeine-1,2,3-triazolyl hybrid molecules that structurally are composed of three compartments comprising caffeinyl, 1,2,3-triazolyl and N-alkyl/aryl residues. The in vitro evaluations of synthesized compounds on cancer cell lines, including two breast cancer cell lines MDA-MB-468 (ATCC HTB-22), MCF-7 (ATCC HTB-22), melanoma cell line A-375 (ATCC CRL-1619) and normal cell line HEK-293 (ATCC CRL-11268) have determined that 22c (IC50 < 12.5 μM) demonstrated potent activity against A375 and its toxicity is even stronger than methotrexate (MTX) as a standard drug. Additionally, 22c involves more selectivity than MTX regarding its non-toxicity for the HEK-293 cell line. Among the tested compounds against two breast cancer cell lines, 22f (IC50 = 136 ± 0.2 and 126 ± 0.6 μM for MCF-7 and MDA-MB-468, respectively) and 22i (IC50 = 165 ± 1.8 and 175 ± 1.4 μM for MCF-7 and MDA-MB-468, respectively) were the most potent compounds but their activities were less than MTX, moreover 22f showed more selectivity regarding its lower toxicity against HEK-293. Overall, 22f displayed general toxicity and selectivity on all tested cancer cell lines. The in silico physicochemical properties, pharmacokinetic profile, and drug likeness predictions were also carried out for all the studied compounds. Most new compounds exhibited zero violation of Lipinski's rule (RO5). A molecular docking study was also conducted to predict the binding mode and the interaction of 22c as the most active anti-melanoma entry with B-RAF V600E kinase enzyme. The docking results determined that 22c exhibited a strong binding affinity to the active site of the enzyme. These findings demonstrated 22c and 22f as potential future anticancer drug candidates.

Cabozantinib beyond progression improves survival in advanced renal cell carcinoma patients: the CABEYOND study (Meet-URO 21)

BACKGROUND

Cabozantinib improves survival in metastatic renal cell carcinoma (mRCC) after prior antiangiogenics. The best treatment at disease progression (PD) is unknown. Being also a AXL/MET inhibitor, involved in acquired resistance, we hypothesized a prolonged tumor growth control in patients continuing cabozantinib despite PD.

RESEARCH DESIGN AND METHODS

This retrospective multicenter study enrolled patients receiving cabozantinib after the first line between 2014 and 2020. We compared patients maintaining cabozantinib after first PD due to clinical benefit and good tolerability with those who changed therapy. The postprogression survival (PPS) of both was our primary endpoint.

RESULTS

We analyzed 89 patients: 45 received cabozantinib beyond PD and 44 switched therapy. 40.4%, 31.5%, and 28.1% of patients received 1, 2, or >2 prior treatment, respectively. 84.3% were intermediate-poor International Metastatic Renal Cell Carcinoma Database risk. Patients continuing cabozantinib showed a higher response rate to cabozantinib before PD (46.7% vs 25%, p = 0.03) and were more heavily pretreated. Continuing cabozantinib showed a significantly longer PPS compared with switching therapy (median PPS 16.9 vs 13.2 months, HR 0.66, 95%CI 0.48-0.92, p = 0.011).

CONCLUSIONS

We observed longer PPS in patients continuing cabozantinib beyond PD, suggesting that this could be an effective option.

Ligand-based drug design and molecular docking simulation studies of some novel anticancer compounds on MALME-3M melanoma cell line

Background

Melanoma cancer causes serious health problem worldwide because of its rapid invasion to other organs and lack of satisfactory chemotherapy. The pGI50 anticancer activity values of 70 compounds from the NCI (National Cancer Institute) on MALME-3M cell line was modeled to describe the quantitative structure-activity relationships (QSARs) of the compounds, and some selected compounds were docked.

Results

The generated QSAR model was found to be statistically significant based on the obtained values of the validation keys such as R2 (0.885), $$ {R}_{\mathrm{adjusted}}^2 $$ R adjusted 2 (0.868), Q2cv (0.842), and $$ {R}_{pred}^2 $$ R pred 2 (0.738) required to evaluate the strength and robustness of QSAR model. Compound 39 was selected as a template due to its good pGI50 (9.205) and was modified to design new potent compounds. The predicted pGI50 activity of the designed compounds by the built model was N1 (9.836), N2 (12.876), N3 (10.901), and N4 (11.263) respectively. These proposed compounds were docked with V600E-BRAF receptor and the result shows that, N1, N2, N3, and N4 with free binding energy (FBE) of − 11.7 kcal mol−1, − 12.8 kcal mol−1, − 12.7 kcal mol−1, and − 12.9 kcal mol−1 respectively were better than the parent structure of the template (compound 39, FBE = − 7.0 kcal mol−1) and the standard V600E-BRAF inhibitor (Vemurafenib, FBE = − 11.3 kcal mol−1). Additionally, these compounds passed the drug-likeness criteria successfully to be orally bioavailable.

Conclusion

The proposed compounds were considered optimal as their performances are comparable to vemurafenib and possessed enhanced physicochemical properties. Thus recommends further research such as synthesis, in vivo, and ex-vivo evaluation.

Clinical benefit of continuing pembrolizumab treatment beyond progression in patients with metastatic urothelial carcinoma

BACKGROUND

There has been no clinical evidence to justify continued pembrolizumab therapy beyond progression in patients with metastatic urothelial carcinoma (UC).

MATERIALS AND METHODS

We conducted a multicenter retrospective study evaluating the clinical efficacy of continued use of pembrolizumab beyond progression in patients with metastatic UC. Data from 51 patients with metastatic UC, who developed progression during second-line pembrolizumab therapy, were analyzed. Progression was defined based on the Immunotherapy Response Evaluation Criteria in Solid Tumors. The outcome was overall survival (OS). The association between continued treatment, OS, and the risk of all-cause mortality was tested using log-rank test, conventional and time-dependent Cox regression models.

RESULTS

No significant difference in patient characteristics was noted between patients continuing pembrolizumab beyond progression (N = 21) and those discontinuing pembrolizumab (N = 30). Median OS was significantly longer in the continuation group (17.8 vs. 8.8 months; P = 0.038). A multivariable conventional Cox regression model identified continued pembrolizumab administration as a significant independent prognostic factor of all-cause mortality (hazard ratio [HR]: 0.21, 95% confidence interval [CI]: 0.05-0.90, P = 0.036), irrespective of the time from treatment initiation to progression and concurrent clinical progression. Further, longer duration of pembrolizumab treatment beyond progression was independently associated with a reduced risk of all-cause mortality in a multivariable time-dependent Cox regression model, when used as a time-dependent variable (HR: 0.07, 95% CI: 0.01-0.45, P = 0.006).

CONCLUSIONS

Continued pembrolizumab administration beyond progression might be beneficial in patients with metastatic UC who were clinically stable.

Integrative Genomic Analyses of Patient-Matched Intracranial and Extracranial Metastases Reveal a Novel Brain-Specific Landscape of Genetic Variants in Driver Genes of Malignant Melanoma

BACKGROUND

Development of brain metastases in advanced melanoma patients is a frequent event that limits patients' quality of life and survival. Despite recent insights into melanoma genetics, systematic analyses of genetic alterations in melanoma brain metastasis formation are lacking. Moreover, whether brain metastases harbor distinct genetic alterations beyond those observed at different anatomic sites of the same patient remains unknown.

EXPERIMENTAL DESIGN AND RESULTS

In our study, 54 intracranial and 18 corresponding extracranial melanoma metastases were analyzed for mutations using targeted next generation sequencing of 29 recurrently mutated driver genes in melanoma. In 11 of 16 paired samples, we detected nucleotide modifications in brain metastases that were absent in matched metastases at extracranial sites. Moreover, we identified novel genetic variants in ARID1A, ARID2, SMARCA4 and BAP1, genes that have not been linked to brain metastases before; albeit most frequent mutations were found in ARID1A, ARID2 and BRAF. Conclusion: Our data provide new insights into the genetic landscape of intracranial melanoma metastases supporting a branched evolution model of metastasis formation.

Clinical Implications of Acquired BRAF Inhibitors Resistance in Melanoma

Understanding the role of mitogen-activated protein kinase (MAPK) pathway-activating mutations in the development and progression of melanoma and their possible use as therapeutic targets has substantially changed the management of this neoplasm, which, until a few years ago, was burdened by severe mortality. However, the presence of numerous intrinsic and extrinsic mechanisms of resistance to BRAF inhibitors compromises the treatment responses’ effectiveness and durability. The strategy of overcoming these resistances by combination therapy has proved successful, with the additional benefit of reducing side effects derived from paradoxical activation of the MAPK pathway. Furthermore, the use of other highly specific inhibitors, intermittent dosing schedules and the association of combination therapy with immune checkpoint inhibitors are promising new therapeutic strategies. However, numerous issues related to dose, tolerability and administration sequence still need to be clarified, as is to be expected from currently ongoing trials. In this review, we describe the clinical results of using BRAF inhibitors in advanced melanoma, with a keen interest in strategies aimed at overcoming resistance.

ESMO consensus conference recommendations on the management of metastatic melanoma: under the auspices of the ESMO Guidelines Committee

The European Society for Medical Oncology (ESMO) held a consensus conference on melanoma on 5-7 September 2019 in Amsterdam, The Netherlands. The conference included a multidisciplinary panel of 32 leading experts in the management of melanoma. The aim of the conference was to develop recommendations on topics that are not covered in detail in the current ESMO Clinical Practice Guideline and where available evidence is either limited or conflicting. The main topics identified for discussion were (i) the management of locoregional disease; (ii) targeted versus immunotherapies in the adjuvant setting; (iii) targeted versus immunotherapies for the first-line treatment of metastatic melanoma; (iv) when to stop immunotherapy or targeted therapy in the metastatic setting; and (v) systemic versus local treatment for brain metastases. The expert panel was divided into five working groups to each address questions relating to one of the five topics outlined above. Relevant scientific literature was reviewed in advance. Recommendations were developed by the working groups and then presented to the entire panel for further discussion and amendment before voting. This manuscript presents the results relating to the management of metastatic melanoma, including findings from the expert panel discussions, consensus recommendations and a summary of evidence supporting each recommendation. All participants approved the final manuscript.

Melanoma Brain Metastases in the Era of Target Therapies: An Overview

Malignant melanoma is the third most common type of tumor that causes brain metastases. Patients with cerebral involvement have a dismal prognosis and their treatment is an unmet medical need. Brain involvement is a multistep process involving several signaling pathways such as Janus kinase/signal Transducer and Activator of Transcription (JAK/STAT), Phosphoinositide 3-kinase/Protein Kinase B (PI3K/AKT), Vascular Endothelial Growth Factor and Phosphatase and Tensin Homolog (PTEN). Recently therapy that targets the MAPK signaling (BRAF/MEK inhibitors) and immunotherapy (anti-CTLA4 and anti-PD1 agents) have changed the therapeutic approaches to stage IV melanoma. In contrast, there are no solid data about patients with brain metastases, who are usually excluded from clinical trials. Retrospective data showed that BRAF-inhibitors, alone or in combination with MEK-inhibitors have interesting clinical activity in this setting. Prospective data about the combinations of BRAF/MEK inhibitors have been recently published, showing an improved overall response rate. Short intracranial disease control is still a challenge. Several attempts have been made in order to improve it with combinations between local and systemic therapies. Immunotherapy approaches seem to retain promising activity in the treatment of melanoma brain metastasis as showed by the results of clinical trials investigating the combination of anti-CTL4 (Ipilimumab) and anti-PD1(Nivolumab). Studies about the combination or the sequential approach of target therapy and immunotherapy are ongoing, with immature results. Several clinical trials are ongoing trying to explore new approaches in order to overcome tumor resistance. At this moment the correct therapeutic choices for melanoma with intracranial involvement is still a challenge and new strategies are needed.

An evaluation of encorafenib for the treatment of melanoma

Introduction: In the treatment of advanced BRAF-mutant melanoma, selective regulation of the MAPK pathway with BRAF and MEK inhibition has emerged as one of the mainstays of therapy.Areas covered: The authors present the current data on encorafenib as a compound, its pharmacokinetic and pharmacodynamics properties. This review includes current data on encorafenib therapy as a single agent as well as in combination with the MEK-inhibitor binimetinib and other systemic therapies.Expert opinion: BRAF inhibition with encorafenib exhibits substantial antitumor activity with less paradoxical MAPK pathway activation leading to treatment resistance. Combination therapy with MEK inhibitors improves response rate, progression-free survival, and overall survival in patients with BRAF-mutant metastatic melanoma compared to prior treatment regimens. Serious adverse events, including the development of cutaneous malignancies, are reported at lower rates with combination therapy, while less severe events such as pyrexia can be more common. Existing data is lacking for a recommendation of triplet therapy, although results from multiple ongoing trials are highly anticipated.

Surveillance imaging with FDG-PET/CT in the post-operative follow-up of stage 3 melanoma

Background

As early detection of recurrent melanoma maximizes treatment options, patients usually undergo post-operative imaging surveillance, increasingly with FDG-PET/CT (PET). To assess this, we evaluated stage 3 melanoma patients who underwent prospectively applied and sub-stage-specific schedules of PET surveillance.

Patients and methods

From 2009, patients with stage 3 melanoma routinely underwent PET +/- MRI brain scans via defined schedules based on sub-stage-specific relapse probabilities. Data were collected regarding patient characteristics and outcomes. Contingency analyses were carried out of imaging outcomes.

Results

One hundred and seventy patients (stage 3A: 34; 3B: 93; 3C: 43) underwent radiological surveillance. Relapses were identified in 65 (38%) patients, of which 45 (69%) were asymptomatic. False-positive imaging findings occurred in 7%, and 6% had treatable second (non-melanoma) malignancies. Positive predictive values (PPV) of individual scans were 56%-83%. Negative scans had predictive values of 89%-96% for true non-recurrence [negative predictive values (NPV)] until the next scan. A negative PET at 18 months had NPVs of 80%-84% for true non-recurrence at any time in the 47-month (median) follow-up period. Sensitivity and specificity of the overall approach of sub-stage-specific PET surveillance were 70% and 87%, respectively. Of relapsed patients, 33 (52%) underwent potentially curative resection and 10 (16%) remained disease-free after 24 months (median).

Conclusions

Application of sub-stage-specific PET in stage 3 melanoma enables asymptomatic detection of most recurrences, has high NPVs that may provide patient reassurance, and is associated with a high rate of detection of resectable and potentially curable disease at relapse.

Principles of Targeted Therapy for Melanoma

Targeted BRAF and MEK inhibition has become an appropriate first-line treatment of BRAF-mutant advanced cutaneous melanoma. The authors present an overview of the MAPK pathway as well as the other major pathways implicated in melanoma development. Melanoma brain metastases are a devastating complication of melanoma that can be traced to derangements in cell signaling pathways, and the current evidence for targeted therapy is reviewed. Finally, activating KIT mutations are rarely found to cause melanomas and may provide an actionable target for therapy. The authors review the current evidence for targeted KIT therapy and summarize the ongoing clinical trials.

The Management of Oligoprogression in the Landscape of New Therapies for Metastatic Melanoma

Background: A limited degree of progression after a response to treatment is labelled as oligoprogression and is a hot topic of metastatic melanoma (MM) management. Rogue progressive metastases could benefit from local treatment, which could allow the continuation of ongoing systemic therapy, also known as treatment beyond progression (TBP). Methods: We retrospectively reviewed 214 selected MM patients who developed oligoprogression during treatment with v-Raf murine sarcoma viral oncogene homolog B (BRAF)/mitogen-activated-extracellular signal-regulated kinase (MEK) or programmed cell death protein 1 (PD-1) inhibitors and received a local treatment continuing TBP. We performed univariate and multivariable analyses to assess the association between therapy outcomes and a series of clinical and biological features. Results: We identified 27 (10%) oligoprogressed patients treated locally with surgery (14), radiosurgery (11), and electrochemotherapy (2). TBP included PD-1 inhibitors (13) and BRAF/MEK inhibitors (14). The median progression-free survival post oligoprogression (PFSPO) was 14 months (5-19 95% confidence interval (C.I.)). In the univariate analysis, a significantly longer PFSPO was associated with complete response (CR), Eastern Cooperative Oncology Group (ECOG) performance status (PS) of 0, neutrophils/lymphocytes ratio (N/L) <2, and progression-free survival (PFS) at oligoprogression >11 months. Nevertheless, in the multivariable analysis, only CR and N/L <2 were found to be associated with longer PFSPO. Conclusions: In selected patients, local treatments contribute to controlling oligoprogression for a long time, allowing the continuation of systemic treatment and prolongation of overall survival (OS). Increasing biological and clinical knowledge is improving the accuracy in identifying patients to apply for local ablative therapies.

Application of CO2 laser evaporation in locally advanced melanoma

Aim

This study aims to investigate the role of CO₂ laser evaporation in the treatment of melanoma patients with satellite or in-transit metastases.

Materials & methods

Patients who underwent CO₂ laser evaporation were retrospectively included between November 2002 and August 2018. The Sharplan 40C CO₂ laser was used with a high pulse wave mode. Data concerning patient and tumor characteristics, CO₂ laser evaporation and subsequent therapies were collected.

Results

A total of 26 patients were included. Median duration of local control was 5.5 months. The median number of lesions evaporated per treatment was three (1-16); patients received a median of three (1-19) treatments.

Conclusion

In a selected group of melanoma patients with satellite or in-transit metastases, CO₂ laser evaporation should be considered as treatment for local control.

Contemporary Approaches to In-Transit Melanoma

In-transit melanoma represents a distinct disease pattern of heterogeneous superficial tumors. Many treatments have been developed specifically for this type of disease, including regional chemotherapy and a variety of directly injectable agents. Novel strategies include the intralesional delivery of oncolytic viruses and immunocytokines. The combination of intralesional or regional chemotherapy with systemic immune checkpoint inhibitors also is a promising approach. In the current review, we examine the general management of the workup of patients with in-transit disease, the range of available therapies, and recommendations for specific therapies for an individual patient.

Activation of TAp73 and inhibition of TrxR by Verteporfin for improved cancer therapy in TP53 mutant pancreatic tumors

Aim:

TAp73 is a tumor suppressor, which compensates for p53 loss and induces apoptosis in tumors in response to genotoxic stress or small-molecule treatments. Pancreatic ductal adenocarcinoma has a late onset of the disease, responds poorly to the existing therapies and has a very low survival rates.

Result:

Here, using drug-repurposing approach, we found that protoporphyrin IX (PpIX) and benzoporphyrin derivative (BPD) monoacid ring A activate TAp73 and induce apoptosis in pancreatic cancer cells. PpIX and BPD induce reactive oxygen species and inhibit thioredoxin reductase 1.

Conclusion:

Thus, PpIX and BPD target cancer cells’ vulnerabilities namely activate TAp73 tumor suppressor and inhibit oncogenic Trx1. Our findings may contribute to faster repurposing of PpIX and BPD to treat pancreatic tumors.

Despite all efforts, pancreatic cancer remains one of the most aggressive tumors. Late diagnoses, often linked with the asymptomatic disease progression, make pancreatic cancer extremely difficult to treat. We have assessed drugs that are already clinically used in the photodynamic therapy of actinic keratosis and age-related macular degeneration and showed that the compounds induce apoptotic death of cancer cells. The mechanism is via activation of the p73 tumor suppressor and inhibition of the oncogenic thioredoxin reductase. Molecules with a complementary mechanism of action inducing cell death might be very promising candidates for improved cancer therapy in pancreatic cancer patients.

Two pathways leading to the induction of potent apoptosis by protoporphyrin IX and Verteporfin in mutant TP53 pancreatic cancer cells. One pathway is through inhibition of TAp73/MDM2 interactions and induction of TAp73-related apoptosis and the second pathway converges on inhibition of oncogenic TrxR and accumulation of reactive oxygen species.

Prognostic significance of distant metastasis-free interval in patients with relapsed melanoma treated with BRAF with or without MEK inhibitors

This retrospective cohort study assessed the prognostic significance of distant metastasis-free interval (DMFI) in patients with relapsed BRAF-mutant melanoma treated with BRAF with or without MEK inhibitors (BRAFi ± MEKi). Patients with a DMFI of up to 24 months were compared with those with DMFI of more than 24 months, with regard to their postrelapse progression-free survival (PR-PFS) and overall survival (PR-OS). In total, 109 patients were included in the study. Median DMFI was 25.3 (range: 3.4-188.2) months. Median PR-PFS in patients with DMFI of more than 24 months was 7.9 months [95% confidence interval (CI): 6.2-9.7] compared with 5.4 (95% CI: 4.2-6.7) months of those with shorter DMFI (P = 0.016). Median PR-OS was 15.6 months (95% CI: 13.6-17.6) in patients with DMFI of more than 24 months and 12.0 months (95% CI: 9.0-15.0) with DMFI of up to 24 months (P = 0.289). Multivariate Cox regression analysis showed that DMFI was independently and strongly associated with improved PR-PFS (adjusted hazard ratio = 3.21, 95% CI: 1.78-5.77, ≤ 24 vs. > 24 months) and longer PR-OS (adjusted hazard ratio: 2.09, 95% CI: 1.15-3.80, ≤ 24 vs. > 24 months). The present cohort study is one of the first to confirm the association of DMFI of more than 24 months with an indolent disease course, as shown by longer PR-PFS and PR-OS, in patients with relapsed stage IV melanoma treated by BRAF inhibitor/MEK inhibitor.

New Era in the Management of Melanoma Brain Metastases

The remarkable advances in the systemic therapy of metastatic melanoma have now extended the 1-year overall survival rate from 25% to nearing 85%. Systemic treatment in the form of BRAF-targeted therapy and immunotherapy is slowly but surely proving its efficacy in the treatment of metatstatic brain metastases (MBM). Single-agent BRAF inhibitors provide an intracranial response rate of 25% to 40%, whereas the combination of BRAFi/MEKi leads to responses in up to 58%. However, the durability of responses induced by BRAFi/MEKi seems to be even shorter than in extracranial disease. On the other hand, single-agent ipilimumab provides comparable clinical benefit in MBMs as it does in extracranial metastases. Single-agent PD-1 anitbodies induce response rates of approximately 20%, and those responses appear durable. Similarly the combination of CTLA-4+ PD-1 antibodies induces durable responses at an impressive rate of 55% and is safe to administer. Although the local treatment approaches with radiation and surgery remain important and are critically needed in the management of MBM, systemic therapy offers a new dimension that can augment the impact of those therapies and come at a potentially lower cost of neurocognitive impairment. Considerations for combining those modalities are direly needed, in addition to considering novel systemic combinations that target mechanisms specific to MBM. In this report, we will discuss the underlying biology of melanoma brain metastases, the clinical outcomes from recent clinical trials of targeted and immunotherapy, and their impact on clinical practice in the context of existing local therapeutic modalities.

Molecular modeling, dynamics simulations, and binding efficiency of berberine derivatives: A new group of RAF inhibitors for cancer treatment

RAF kinases are a family of enzymes in the MAP kinase pathway that contribute to the development of different types of cancer. BRAF is the most important member of RAF kinases. BRAF mutations have been detected in 7% of all cancers and 66% of melanomas; as such, the FDA has approved a few BRAF inhibitor drugs to date. However, BRAF can activate CRAF leading to resistance to BRAF inhibitors. Berberine (BBR) is an alkaloid that is widely distributed in different plant species. Several studies have been carried out on the anti-cancer effects of BBR but direct targets of BBR are unknown. In this study, interactions of BBR derivatives against BRAF and CRAF kinases were modeled and predicted using an in silico-based approach. To analyze and identify the residues important in BRAF docking, we modeled interactions of ATP, the universal substrate of BRAF, and found that Lys483 and Asp594 are the most important residues involved in both ATP and BBR binding [(The average score = -11.5 kcal/mol (ATP); Range of scores = -7.78 to -9.55 kcal/mol (BBR)]. In addition to these polar residues, Trp530 and Phe583 are also applicable to the molecular docking of BRAF. We also observed that Asp593 was excluded from the enzyme cavity, while Phe594 was included inside the cavity, making the enzyme inactive. Finally, three alternatives for BBR were identified with dual RAF inhibition effects [The best scores against BRAF = -11.62 kcal/mol (BBR-7), -10.64 kcal/mol (BBR-9), and -11.01 kcal/mol (BBR-10); the best scores against CRAF = -9.68 kcal/mol (BBR-7), -9.60 kcal/mol (BBR-9), and -9.20 kcal/mol (BBR-10)]. Direct effects of BBR derivatives against BRAF and CRAF kinases had not yet been reported previously, and, thus, for the first time, we report three cycloprotoberberines as lead compounds against RAF kinases.

Long-term survival with modern therapeutic agents against metastatic melanoma-vemurafenib and ipilimumab in a daily life setting

Despite new therapeutic options, metastatic melanoma remains to be one of the most fatal tumors. With the development of BRAF inhibitors and immune checkpoint inhibitors, overall survival could be prolonged significantly for the first time. Clinical studies implied that even long-term survival is possible with both types of drugs, but predictive markers are so far missing. In this study, we analyzed survival data from patients that received the first-in-class substances vemurafenib and ipilimumab, respectively, during the time period from registration of the drugs until availability of combination treatments. We aimed to evaluate the possibility of long-term survival in a daily life setting and to characterize patients that benefit from these drugs in order to gain insight into predictive attributes. Eighty patients were evaluated who were treated with either vemurafenib (n = 40) or ipilimumab (n = 40), and overall survival was analyzed. Subgroup analysis was performed for patients who were still alive 24 months after induction of therapy (long-term survival). Median overall survival (OS) was 8.0 months for patients treated with vemurafenib and 10.0 months for patients treated with ipilimumab (log-rank P value = 0.689). Long-term survival was achieved in 32.5% of patients (42.3% vemurafenib, 57.7% ipilimumab). Negative predictors of long-term survival in the vemurafenib group were brain and liver metastases, as well as elevated LDH, S100ß and liver enzymes. For ipilimumab, an increase in lymphocytes and eosinophils during course of treatment correlated with long-term survival. Our real-life experience shows that long-term survival is possible with using both therapeutic agents, vemurafenib and ipilimumab. Pattern of metastases and laboratory values might be of interest in decision making for a specific therapeutic approach. Combination of drugs and observational studies in larger patient cohorts are necessary to further validate our findings.

A Retrospective Analysis of the Efficacy of Pembrolizumab in Melanoma Patients With Brain Metastasis

A total of 50% of patients with melanoma will develop brain metastasis (BM). Pembrolizumab was approved for treatment of metastatic melanoma on the basis of significant systemic antitumor activity. Because of low enrollment of patients with BM in pembrolizumab trials, efficacy against melanoma BM remains unknown. We reviewed records of 89 consecutive patients with melanoma treated with pembrolizumab at our institution between May 1, 2014 and October 31, 2015 to determine the time to progression. Thirty-six (40%) patients had BM before pembrolizumab. Twenty-six (72%) patients with BM had received prior treatment for BM. With median follow-up of 17.2 months, 54 patients (61%) developed progressive disease on pembrolizumab. Intracranial progression occurred in 19 patients (21%), 3 of whom did not have BM before treatment. Median time to progression at any site was 6 months for those without BM (n=53), 5 months for those with treated BM (n=26), and 1.2 months for patients with untreated BM (n=10). Using a Cox regression model adjusted for baseline factors, there was a statistically significant (Wald χ P=0.003) reduction in the hazard of progression for patients without BM [hazard ratio, 0.19; 90% confidence interval, 0.08-0.42) and patients with treated BM (hazard ratio, 0.27; 90% confidence interval, 0.12-0.64) compared with those with untreated BM. In conclusion, melanoma patients with pretreated BM can have durable systemic responses to pembrolizumab. Large, prospective studies are needed to evaluate the intracranial antitumor activity of pembrolizumab in melanoma patients with untreated BM.

Progression patterns under BRAF inhibitor treatment and treatment beyond progression in patients with metastatic melanoma

Despite markedly improved treatment options for metastatic melanoma, resistance to targeted therapies such as BRAF inhibitors (BRAFi) or BRAFi plus MEK inhibitors (MEKi) remains a major problem. Our aim was to characterize progression on BRAFi therapy and outcome of subsequent treatment. One hundred and eighty patients with BRAF-mutant metastatic melanoma who had progressed on treatment with single-agent BRAFi from February 2010 to April 2015 were included in a retrospective data analysis focused on patterns of progression, treatment beyond progression (TBP) and subsequent treatments after BRAFi therapy. Analysis revealed that 51.1% of patients progressed with both new and existing metastases opposed to progression of only preexisting (28.3%) or only new (20.6%) metastases. Exclusive extracranial progression occurred in 50.6% of patients compared to both extra- and intracranial (29.4%) or sole cerebral progression (20%). Multivariable analyses demonstrated that single site progression and primary response to BRAFi were associated with improved progression-free survival. Progression with exclusively new or only existing metastases and a baseline Eastern Cooperative Oncology Group (ECOG) of 0 were associated with prolonged overall survival (OS). TBP had no significant impact on OS. Other subsequent treatments showed low efficacy with the exception of anti-PD-1 antibodies. In conclusion we identified specific patterns of progression which significantly correlate with further prognosis after progression on BRAFi treatment. In contrast to previously published data, we could not demonstrate a significant survival benefit for BRAFi TBP. Subsequent therapies had strikingly low efficacy except for PD-1 inhibitors.

Incidence and relative risk of cutaneous squamous cell carcinoma with single-agent BRAF inhibitor and dual BRAF/MEK inhibitors in cancer patients: a meta-analysis

BACKGROUND

BRAF inhibitor and dual BRAF/MEK inhibitors have been approved for the treatment of BRAF-mutated melanoma. Cutaneous squamous cell carcinoma (cuSCC) is an adverse event associated with these drugs. The contribution of BRAF inhibitor and dual BRAF/MEK inhibitors to cuSCC are still unknown. We performed this meta-analysis to determine the overall incidence and relative risk of cuSCC in cancer patients treated with these drugs.

RESULTS

A total of 7,442 patients from 24 primary studies were included. The incidences of all-grade and high-grade cuSCC in cancer patients treated with BRAF inhibitor were 12.5% (95% CI: 10.8-14.6%) and 11.6% (95% CI: 9.8-13.8%), and dual BRAF/MEK inhibitors were 3.0% (95% CI: 2.0-4.5%) and 2.8% (95% CI: 1.9-4.0%), respectively. On subgroup analysis and meta-regression, the incidence of cuSCC did not vary with tumor type, study design and specific drug used. The use of single agent BRAF inhibitor significantly increased the risk of developing cuSCC comparing with dual BRAF/MEK inhibitors for all-grade (RR 4.72, 95% CI: 2.42-9.20) and high-grade (RR 4.92, 95% CI: 2.64-9.16) in cancer patients.

MATERIALS AND METHODS

The databases of PubMed, Embase and abstracts published in ASCO proceedings were searched for relevant studies from January 2000 to June 2017. Summary incidences, relative risks (RRs) and 95% confidence intervals (CIs) were calculated by using either random effects or fixed effect models according to the heterogeneity of included studies.

CONCLUSIONS

BRAF inhibitor significantly increases the risk of developing cuSCC compared with dual BRAF/MEK inhibitors in cancer patients. Clinicians should be aware of the risks of cuSCC with the administration of these drugs in cancer patients.

Overcoming resistance to BRAF inhibitors

The discovery of activating mutations in the serine/threonine (S/T) kinase BRAF followed by a wave of follow-up research manifested that the MAPK-pathway plays a critical role in melanoma initiation and progression. BRAF and MEK inhibitors produce an unparalleled response rate in melanoma, but it is now clear that most responses are transient, and while some patients show long lasting responses the majority progress within 1 year. In accordance with the key role played by the MAPK-pathway in BRAF mutant melanomas, disease progression is mostly due to the appearance of drug-resistance mechanisms leading to restoration of MAPK-pathway activity. In the present article we will review the development, application and clinical effects of BRAF and MEK inhibitors both, as single agent and in combination in the context of targeted therapy in melanoma. We will then describe the most prominent mechanisms of resistance found in patients progressed on these targeted therapies. Finally we will discuss strategies for further optimizing the use of MAPK inhibitors and will describe the potential of alternative combination therapies to either delay the onset of resistance to MAPK inhibitors or directly target specific mechanisms of resistance to BRAF/MEK inhibitors.

New Combination Strategies Using Programmed Cell Death 1/Programmed Cell Death Ligand 1 Checkpoint Inhibitors as a Backbone

The discovery of immune checkpoints and subsequent clinical development of checkpoint inhibitors have revolutionized the field of oncology. The durability of the antitumor immune responses has raised the hope for long-term patient survival and potential cure; however, currently, only a minority of patients respond. Combination strategies to help increase antigen release and T-cell priming, promote T-cell activation and homing, and improve the tumor immune microenvironment, all guided by predictive biomarkers, can help overcome the tumor immune-evasive mechanisms and maximize efficacy to ultimately benefit the majority of patients. Great challenges remain because of the complex underlying biology, unpredictable toxicity, and accurate assessment of response. Carefully designed clinical trials guided by translational studies of paired biopsies will be key to develop reliable predictive biomarkers to choose which patients would most likely benefit from each strategy.

Isolation and detection of circulating tumour cells from metastatic melanoma patients using a slanted spiral microfluidic device

Circulating Tumour Cells (CTCs) are promising cancer biomarkers. Several methods have been developed to isolate CTCs from blood samples. However, the isolation of melanoma CTCs is very challenging as a result of their extraordinary heterogeneity, which has hindered their biological and clinical study. Thus, methods that isolate CTCs based on their physical properties, rather than surface marker expression, such as microfluidic devices, are greatly needed in melanoma. Here, we assessed the ability of the slanted spiral microfluidic device to isolate melanoma CTCs via label-free enrichment. We demonstrated that this device yields recovery rates of spiked melanoma cells of over 80% and 55%, after one or two rounds of enrichment, respectively. Concurrently, a two to three log reduction of white blood cells was achieved with one or two rounds of enrichment, respectively. We characterised the isolated CTCs using multimarker flow cytometry, immunocytochemistry and gene expression. The results demonstrated that CTCs from metastatic melanoma patients were highly heterogeneous and commonly expressed stem-like markers such as PAX3 and ABCB5. The implementation of the slanted microfluidic device for melanoma CTC isolation enables further understanding of the biology of melanoma metastasis for biomarker development and to inform future treatment approaches.

Open-label, multicentre safety study of vemurafenib in 3219 patients with BRAFV600 mutation-positive metastatic melanoma: 2-year follow-up data and long-term responders' analysis

BACKGROUND

The orally available BRAF kinase inhibitor vemurafenib is an effective and tolerable treatment option for patients with metastatic melanoma harbouring BRAF^V600 mutations. We assessed the safety of vemurafenib in a large population of patients with few alternative treatment options; we report updated 2-year safety.

METHODS

This was an open-label, multicentre study of vemurafenib (960 mg bid) in patients with previously treated or untreated BRAF mutation-positive metastatic melanoma (cobas^® 4800 BRAF V600 Mutation Test). The primary end-point was safety; efficacy end-points were secondary. An exploratory analysis was performed to assess safety outcomes in patients with long duration of response (DOR) (≥12 or ≥24 months).

RESULTS

After a median follow-up of 32.2 months (95% CI, 31.1-33.2 months), 3079/3219 patients (96%) had discontinued treatment. Adverse events (AEs) were largely consistent with previous reports; the most common all-grade treatment-related AEs were arthralgia (37%), alopecia (25%) and hyperkeratosis (23%); the most common grade 3/4 treatment-related AEs were squamous cell carcinoma of the skin (8%) and keratoacanthoma (8%). In the exploratory analysis, patients with DOR ≥12 months (n = 287) or ≥24 months (n = 133) were more likely to experience grade 3/4 AEs than the overall population. No new specific safety signals were observed with longer vemurafenib exposure.

CONCLUSIONS

After 2 years' follow-up, safety was maintained in this large group of patients with BRAF^V600 mutation-positive metastatic melanoma who are more representative of routine clinical practice than typical clinical trial populations. These data suggest that long-term vemurafenib treatment is effective and tolerable without the development of new safety signals.

Integrin β1 activation induces an anti-melanoma host response

TGF-β is a cytokine thought to function as a tumor promoter in advanced malignancies. In this setting, TGF-β increases cancer cell proliferation, survival, and migration, and orchestrates complex, pro-tumorigenic changes in the tumor microenvironment. Here, we find that in melanoma, integrin β1-mediated TGF-β activation may also produce tumor suppression via an altered host response. In the A375 human melanoma cell nu/nu xenograft model, we demonstrate that cell surface integrin β1-activation increases TGF-β activity, resulting in stromal activation, neo-angiogenesis and, unexpectedly for this nude mouse model, increase in the number of intra-tumoral CD8⁺ T lymphocytes within the tumor microenvironment. This is associated with attenuation of tumor growth and long-term survival benefit. Correspondingly, in human melanomas, TGF-β1 correlates with integrin β1/TGF-β1 activation and the expression of markers for vasculature and stromal activation. Surprisingly, this integrin β1/TGF-β1 transcriptional footprint also correlates with the expression of markers for tumor-infiltrating lymphocytes, multiple immune checkpoints and regulatory pathways, and, importantly, better long-term survival of patients. These correlations are unique to melanoma, in that we do not observe similar associations between β1 integrin/TGF-β1 activation and better long-term survival in other human tumor types. These results suggest that activation of TGF-β1 in melanoma may be associated with the generation of an anti-tumor host response that warrants further study.

Treatment Beyond Progression in Patients with Advanced Renal Cell Carcinoma Treated with Nivolumab in CheckMate 025

BACKGROUND

Response patterns to nivolumab differ from those seen with other approved targeted therapies.

OBJECTIVE

To investigate the efficacy of nivolumab in previously treated patients with advanced renal cell carcinoma who were treated beyond (Response Evaluation Criteria In Solid Tumors) RECIST progression.

DESIGN, SETTING, AND PARTICIPANTS

This was a subgroup analysis of patients treated with nivolumab in the phase 3 CheckMate 025 study. Patients continuing to tolerate therapy and exhibiting investigator-assessed clinical benefit were eligible to be treated beyond RECIST progression (TBP) and received therapy for ≥4 wk after first progression; patients not treated beyond RECIST progression (NTBP) received 0 wk to <4 wk of therapy after progression.

INTERVENTIONS

Nivolumab 3mg/kg intravenously every 2 wk.

RESULTS AND LIMITATIONS

Of 406 nivolumab-treated patients, 316 (78%) progressed by RECIST criteria. Of those who progressed, 48% were TBP, 52% were NTBP. Before being TBP, objective response rate (95% confidence interval) was 20% (14-28) and 14% (9-21) in patients TBP and NTBP, respectively. Differences in clinical characteristics assessed at first progression between patients TBP versus NTBP included better Karnofsky performance status, less deterioration in Karnofsky performance status, shorter time to response, lower incidence of new bone lesions, and improved quality of life. Postprogression, 13% of all patients TBP (20/153) had ≥30% tumor burden reduction including patients with preprogression and postprogression tumor measurements (n=142) and complete/partial response (28%, 8/29), stable disease (6%, 3/47), and progressive disease (14%, 9/66) as their best response before being TBP. Incidence of treatment-related adverse events in patients TBP was lower after (59%) versus before (71%) progression. Limitations included potential bias from the nonrandomized nature of the analysis.

CONCLUSIONS

A subset of patients with advanced renal cell carcinoma and RECIST progression experienced tumor reduction postprogression with nivolumab, and had an acceptable safety profile. Clinical judgment remains essential when switching therapy. ClinicalTrials.gov Identifier: NCT01668784.

PATIENT SUMMARY

A subset of patients with advanced renal cell carcinoma and disease progression may continue to benefit from nivolumab treatment beyond progression as evidenced by tumor reduction postprogression and an acceptable safety profile.

A phase I study of TPI 287 in combination with temozolomide for patients with metastatic melanoma

TPI 287 is a synthetic taxane derivative with structural modifications allowing for central nervous system penetration and potential circumvention of multidrug resistance efflux pump mechanisms. The aim of this phase I study was to determine the maximum tolerated dose of the combination of TPI 287 and temozolomide in metastatic melanoma. Patients with stage IV unresectable or recurrent stage III melanoma were eligible. Stable untreated or treated brain metastases were allowed. Patients with previous taxane exposure were excluded. TPI 287 was administered intravenously on days 1, 8, and 15 and temozolomide was taken orally daily on days 1-5 of a 28-day cycle. Responses were assessed every two cycles according to WHO criteria. A total of 21 patients were enrolled. The maximum tolerated dose of the combination at this schedule was determined to be 125 mg/m intravenous of TPI 287 and 110 mg/m of oral temozolomide. The dose-limiting toxicity was neuropathy and six patients experienced grade III neuropathy. All patients were evaluable for tumor response. There were no complete responses; there were two partial responses and seven patients had stable disease (overall response rate 9.5% and disease control rate 42.9%). Three patients had stable disease in the brain despite progressive extracranial disease. The combination of TPI 287 and temozolomide is well tolerated in patients with metastatic melanoma, with the exception of neuropathy. The central nervous system penetration of both agents makes this a rational combination for further testing in primary and metastatic brain lesions.

Treatment of brain metastases in the modern genomic era

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

A Pilot Trial of the Combination of Vemurafenib with Adoptive Cell Therapy in Patients with Metastatic Melanoma

PURPOSE

This pilot feasibility clinical trial evaluated the coadministration of vemurafenib, a small-molecule antagonist of BRAF^V600 mutations, and tumor-infiltrating lymphocytes (TIL) for the treatment of metastatic melanoma.

EXPERIMENTAL DESIGN

A metastatic tumor was resected for growth of TILs, and patients were treated with vemurafenib for 2 weeks, followed by resection of a second lesion. Patients then received a nonmyeloablative preconditioning regimen, infusion of autologous TILs, and high-dose interleukin-2 administration. Vemurafenib was restarted at the time of TIL infusion and was continued for 2 years or until disease progression. Clinical responses were evaluated by Response Evaluation Criteria in Solid Tumors (RECIST) 1.0. Metastases resected prior to and after 2 weeks of vemurafenib were compared using TCRB deep sequencing, immunohistochemistry, proliferation, and recognition of autologous tumor.

RESULTS

The treatment was well tolerated and had a safety profile similar to that of TIL or vemurafenib alone. Seven of 11 patients (64%) experienced an objective clinical response, and 2 patients (18%) had a complete response for 3 years (one response is ongoing at 46 months). Proliferation and viability of infusion bag TILs and peripheral blood T cells were inhibited in vitro by research-grade vemurafenib (PLX4032) when approaching the maximum serum concentration of vemurafenib. TCRB repertoire (clonotypes numbers, clonality, and frequency) did not significantly change between pre- and post-vemurafenib lesions. Recognition of autologous tumor by T cells was similar between TILs grown from pre- and post-vemurafenib metastases.

CONCLUSIONS

Coadministration of vemurafenib and TILs was safe and feasible and generated objective clinical responses in this small pilot clinical trial. Clin Cancer Res; 23(2); 351-62. ©2016 AACRSee related commentary by Cogdill et al., p. 327.

miR-579-3p controls melanoma progression and resistance to target therapy

Therapy of melanoma patients harboring activating mutations in the BRAF (V-raf murine sarcoma viral oncogene homolog B1) oncogene with a combination of BRAF and MEK inhibitors is plagued by the development of drug resistance. Mutational events, as well as adaptive mechanisms, contribute to the development of drug resistance. In this context we uncover here the role of a miRNA, miR-579-3p. We first show that low expression of miR-579-3p is a negative prognostic factor correlating with poor survival. Expression levels of miR-579-3p decrease from nevi to stage III/IV melanoma samples and even further in cell lines resistant to BRAF/MEK inhibitors. Mechanistically, we demonstrate that miR-579-3p acts as an oncosuppressor by targeting the 3'UTR of two oncoproteins: BRAF and an E3 ubiquitin protein ligase, MDM2. Moreover miR-579-3p ectopic expression impairs the establishment of drug resistance in human melanoma cells. Finally, miR-579-3p is strongly down-regulated in matched tumor samples from patients before and after the development of resistance to targeted therapies.

Endoplasmic reticulum stress-induced autophagy determines the susceptibility of melanoma cells to dabrafenib

Melanoma is one of the deadliest skin cancers and accounts for most skin-related deaths due to strong resistance to chemotherapy drugs. In the present study, we investigated the mechanisms of dabrafenib-induced drug resistance in human melanoma cell lines A375 and MEL624. Our studies support that both endoplasmic reticulum (ER) stress and autophagy were induced in the melanoma cells after the treatment with dabrafenib. In addition, ER stress-induced autophagy protects melanoma cells from the toxicity of dabrafenib. Moreover, inhibition of both ER stress and autophagy promote the sensitivity of melanoma cells to dabrafenib. Taken together, the data suggest that ER stress-induced autophagy determines the sensitivity of melanoma cells to dabrafenib. These results provide us with promising evidence that the inhibition of autophagy and ER stress could serve a therapeutic effect for the conventional dabrafenib chemotherapy.

Electrochemotherapy with bleomycin is effective in BRAF mutated melanoma cells and interacts with BRAF inhibitors

BACKGROUND

The aim of the study was to explore the effectiveness of electrochemotherapy (ECT) during the treatment of melanoma patients with BRAF inhibitors. Its effectiveness was tested on BRAF mutated and non-mutated melanoma cells in vitro and in combination with BRAF inhibitors.

MATERIALS AND METHODS

ECT with bleomycin was performed on two human melanoma cell lines, with (SK-MEL-28) or without (CHL-1) BRAF V600E mutation. Cell survival was determined using clonogenic assay to determine the effectiveness of ECT in melanoma cells of different mutation status. Furthermore, the effectiveness of ECT in concomitant treatment with BRAF inhibitor vemurafenib was also determined in BRAF mutated cells SK-MEL-28 with clonogenic assay.

RESULTS

The survival of BRAF V600E mutated melanoma cells was even lower than non-mutated cells, indicating that ECT is effective regardless of the mutational status of melanoma cells. Furthermore, the synergistic interaction between vemurafenib and ECT with bleomycin was demonstrated in the BRAF V600E mutated melanoma cells.

CONCLUSIONS

The effectiveness of ECT in BRAF mutated melanoma cells as well as potentiation of its effectiveness during the treatment with vemurafenib in vitro implies on clinical applicability of ECT in melanoma patients with BRAF mutation and/or during the treatment with BRAF inhibitors.

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

Background

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

Patients and Methods

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

Results

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

This trial is registered with ClinicalTrials.gov number NCT01983124.

Conclusion

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

The discovery of vemurafenib for the treatment of BRAF-mutated metastatic melanoma

INTRODUCTION

In the era of precision medicine and sophisticated modern genetics, the discovery of the BRAF(V600) inhibitor, vemurafenib, quickly became the model for targeted therapy in melanomas. As early as 2002, the majority of metastatic melanomas were described to harbor the BRAF(V600) mutation, setting the stage for an explosion of interest for targeting this protein as a novel therapeutic strategy. The highly selective BRAF(V600) inhibitor, vemurafenib, was identified initially through a large-scale drug screen.

AREAS COVERED

Here we examine vemurafenib's journey from discovery to clinical use in metastatic melanoma. Topics covered include preclinical data, single agent Phase 1,2 and 3 clinical trials, resistance issues and mechanisms, adverse effects including the development of squamous cell cancers, and combination trials.

EXPERT OPINION

Due to its tolerance, low toxicity profile, rapid tumor response, and improved outcomes in melanoma patients with BRAF(V600) mutations, vemurafenib was advanced rapidly through clinical trials to receive FDA approval in 2011. While its efficacy is well documented, durability has become an issue for most patients who experience therapeutic resistance in approximately 6-8 months. In addition, a concerning toxicity observed in patients taking the drug include development of localized cutaneous squamous cell carcinomas (SCCs). It is hypothesized that drug resistance and SCC development result from a similar paradoxical activation of protein signaling pathways, specifically MAPK. Identification of these mechanisms has led to additional treatment strategies involving new combination therapies.

The evolution of combined molecular targeted therapies to advance the therapeutic efficacy in melanoma: a highlight of vemurafenib and cobimetinib

Metastatic melanoma is an aggressive, rapidly progressive disease which historically had very few effective treatment options. However, since 2011, the therapeutic landscape of melanoma has undergone a dramatic transformation with two distinct approaches and has catalyzed the successful advancement in the clinical field of immuno-oncology. In addition, the recognition of a key oncogenic driver mutation in melanoma, BRAF, stimulated the development of multiple potent kinase inhibitors which has also influenced the expansion and use of targeted agents in the practice of oncology. Vemurafenib, the initial BRAF inhibitor approved for the treatment of melanoma, was the first agent to demonstrate rapid clinical responses and significantly improved survival which was a clinical breakthrough in the treatment of melanoma. Although exciting and practice changing, the unparalleled responses with vemurafenib are usually not sustained. Further investigations delineated several mechanisms of acquired resistance which are most often mediated by the upregulation of the MAPK pathway. MEK inhibitors, another class of small-molecule inhibitors, were developed as an alternative agent to suppress the MAPK pathway downstream, independent from BRAF activation. Multiple studies have demonstrated the improvement in antitumor activity when MEK inhibitors are used in combination with BRAF inhibitors in the treatment of metastatic melanoma. This is a review of the investigations that led to the US Food and Drug Administration approval in 2015 of the combination of vemurafenib and cobimetinib, adding to the quickly growing armament for the treatment of advanced or metastatic melanoma with a BRAF V600 mutation.

Pembrolizumab for the treatment of advanced melanoma

INTRODUCTION

Since 2010 multiple targeted therapies and immunotherapies have been approved for the treatment of advanced melanoma. Pembrolizumab, a humanized monoclonal antibody directed against programed death receptor 1 has shown significant activity in advanced melanoma resulting in its approval first as post-ipilimumab and subsequently as frontline treatment.

AREAS COVERED

This article reviews the approved agents for the treatment of advanced melanoma with a focus on the preclinical and clinical evidence for the use of pembrolizumab in this setting. Primary emphasis is given to the clinical development of pembrolizumab, including phase I-III trials. Finally, we explore the role of pembrolizumab in combination with other therapies and ongoing investigations into its effectiveness in expanded patient populations.

EXPERT OPINION

Pembrolizumab provides durable responses and represents a major advancement in the treatment options for patients with advanced melanoma. Early studies of pembrolizumab in combination with other therapeutic agents have generated significant interest and further investigations including advanced clinical trials are warranted to evaluate safety and potential improved outcomes. Pembrolizumab and other immune checkpoint inhibitors are likely to play an expanded role in the treatment of advanced melanoma and other solid tumors over the next decade.

Immuno-oncology combinations: raising the tail of the survival curve

There have been exponential gains in immuno-oncology in recent times through the development of immune checkpoint inhibitors. Already approved by the U.S. Food and Drug Administration for advanced melanoma and non-small cell lung cancer, immune checkpoint inhibitors also appear to have significant antitumor activity in multiple other tumor types. An exciting component of immunotherapy is the durability of antitumor responses observed, with some patients achieving disease control for many years. Nevertheless, not all patients benefit, and efforts should thus now focus on improving the efficacy of immunotherapy through the use of combination approaches and predictive biomarkers of response and resistance. There are multiple potential rational combinations using an immunotherapy backbone, including existing treatments such as radiotherapy, chemotherapy or molecularly targeted agents, as well as other immunotherapeutics. The aim of such antitumor strategies will be to raise the tail on the survival curve by increasing the number of long term survivors, while managing any additive or synergistic toxicities that may arise with immunotherapy combinations. Rational trial designs based on a clear understanding of tumor biology and drug pharmacology remain paramount. This article reviews the biology underpinning immuno-oncology, discusses existing and novel immunotherapeutic combinations currently in development, the challenges of predictive biomarkers of response and resistance and the impact of immuno-oncology on early phase clinical trial design.

Primary and Metastatic Cutaneous Melanomas Express ALK Through Alternative Transcriptional Initiation

A number of common driver mutations have been identified in melanoma, but other genetic or epigenetic aberrations are also likely to play a role in the pathogenesis of melanoma and present potential therapeutic targets. Translocations of the anaplastic lymphoma kinase (ALK), for example, have been reported in spitzoid melanocytic neoplasms leading to kinase-fusion proteins that result in immunohistochemically detectable ALK expression. In this study, we sought to determine whether ALK was also expressed in nonspitzoid primary and metastatic cutaneous melanomas. ALK immunohistochemistry was performed on 603 melanomas (303 primary and 300 metastatic tumors) from 600 patients. ALK immunohistochemistry expression was identified in 7 primary and 9 metastatic tumors. In 5 of 7 primary tumors and in 6 of 9 metastatic lesions, the majority of tumor cells were immunoreactive for ALK. In the other 2 primary and 3 metastatic lesions, positive staining was identified in less than half of the tumor cells. ALK positivity was found in the presence or absence of BRAF or NRAS mutations. In contrast to prior observations with ALK-positive Spitz tumors, none of the ALK-positive melanomas harbored a translocation. Instead, the ALK-positive melanomas predominantly expressed the recently described ALK isoform, ALK, which lacks the extracellular and transmembrane domains of wild-type ALK, consists primarily of the intracellular tyrosine kinase domain, and originates from an alternative transcriptional initiation site within the ALK gene. The findings are clinically relevant as patients with metastatic melanoma who have ALK expression may potentially benefit from treatment with ALK kinase inhibitors.

The Complexity of the ERK/MAP-Kinase Pathway and the Treatment of Melanoma Skin Cancer

The central role played by the ERK/MAPK pathway downstream of RAS in human neoplasias is best exemplified in the context of melanoma skin cancer. Signaling through the MAPK pathway is crucial for the proliferation of melanocytes, the healthy pigment cells that give rise to melanoma. However, hyper-activation of the MAPK-pathway is found in over 90% of melanomas with approximately 50% of all patients displaying mutations in the kinase BRAF, and approximately 28% of all patients harboring mutations in the MAPK-pathway up-stream regulator NRAS. This finding has led to the development of BRAF and MEK inhibitors whose application in the clinic has shown unprecedented survival responses. Unfortunately the responses to MAPK pathway inhibitors are transient with most patients progressing within a year and a median progression free survival of 7-10 months. The disease progression is due to the development of drug-resistance based on various mechanisms, many of them involving a rewiring of the MAPK pathway. In this article we will review the complexity of MAPK signaling in melanocytic cells as well as the mechanisms of action of different MAPK-pathway inhibitors and their correlation with clinical response. We will reflect on mechanisms of innate and acquired resistance that limit patient's response, with a focus on the MAPK signaling network. Because of the resurgence of antibody-based immune-therapies there is a growing feeling of failure in the targeted therapy camp. However, recent studies have revealed new windows of therapeutic opportunity for melanoma sufferers treated with drugs targeting the MAPK pathway, and these opportunities will be discussed.