MEK inhibitors for pre-treated, NRAS-mutated metastatic melanoma: A multi-centre, retrospective study

Recurrent Melanoma in a Patient with Chronic Lymphocytic Leukemia (CLL) Presenting with an Apparent Co-Existing NRAS and BRAF Mutation: A Diagnostic and Treatment Conundrum

Melanoma is the fifth most common cancer in the United States. The advent of immunotherapy and molecular targeted therapy has improved progression-free and overall survival in many patients with advanced disease. However, the selection of therapeutic choices requires a nuanced approach, especially when considering molecularly targeted agents. This case report highlights a diagnostic and therapeutic challenge in managing a patient with a history of chronic lymphocytic leukemia (CLL) and recurrent melanoma. Molecular testing suggested discordant BRAF V600E testing and a simultaneous NRAS G12D mutation. After a careful literature review, repetition of his molecular testing, and analysis of the timelines and results of all his molecular testing, we concluded that the BRAF V600E mutation result was falsely positive. The patient was treated with two cycles of ipilimumab (1 mg/kg) and nivolumab (3 mg/kg) as per the NADINA trial and had a complete radiographic response. He then underwent resection demonstrating a pathologic partial response ranging from 20% to 95% tumor necrosis, dependent on the satellite examined. This case report underscores the importance of precise molecular diagnostics in guiding melanoma treatment and demonstrates the complexities of managing a patient with a coexisting malignancy.

Genomic landscape and comparative analysis of tissue and liquid-based NGS in Taiwanese anaplastic thyroid carcinoma

Anaplastic thyroid carcinoma (ATC) is an aggressive cancer that requirements rapid diagnosis and multimodal treatment. Next-generation sequencing (NGS) aids in personalized therapies and improved trial enrollment. The role of liquid-based NGS in ATC remains unclear. This study analyzed ATC samples using tissue-based NGS, liquid-based NGS, or both platforms. Genetic alterations showed highly heterogeneity, including mutations in RAS/RAF/MEK/ERK, PI3K/AKT/mTOR, cell cycle regulation, other receptor tyrosine kinases, DNA damage response, mismatch repair, and chromatin remodeling. TP53 (65.4%) and BRAF (30.8%) were the most frequently mutated genes in tissue NGS. In paired samples, the concordance rates were 69.2% for TP53 and 84.6% for BRAF. One of two patients treated with dabrafenib and trametinib showed a copy number gain in post-treatment tissue NGS, potentially indicating resistance. Liquid biopsy provides valuable supplementary information when tissue samples are insufficient. Further studies are necessary to understand resistance mechanisms and develop strategies to overcome them in BRAF-targeted therapy.

Molecularly matched targeted therapy: a promising approach for refractory metastatic melanoma

BACKGROUND

Only a fraction of patients with metastatic melanoma derive durable benefit from approved treatments. The clinical impact of personalized medicine strategies for melanoma, apart from BRAF, NRAS, or CKIT targeting, has rarely been reported.

MATERIALS AND METHODS

By means of the Group of Cutaneous Oncology of the French Society of Dermatology, we retrospectively included all patients with advanced melanoma aged 18 years and older for whom molecular testing identified one or more actionable molecular alterations and who accordingly received molecularly matched therapy. We excluded patients with only BRAF, NRAS, or CKIT alterations and patients who received molecularly matched therapy for less than 15 days.

RESULTS

We included 26 patients with a median follow-up of 8 months (1-54), a median age of 63 years (24-89), and a sex ratio of 2.7. These patients had been heavily pretreated, and 64% had elevated LDH levels. The disease control rate was 38%, with 4 cases of partial response (overall response rate: 15%) and 6 of stable disease for at least 6 months. The median duration of treatment was 3.1 months (0.9-13.5). Among patients with disease control, the median duration of control was 6.6 months (2.6-13.5) and 3 cases were ongoing at the end of the study. Patients with controlled disease had GNA11, MAP2K1, FYCO1-RAF1, HRAS, ATM, CCND1, MDM2/CDK4, and CDKN2A/NRAS alterations.

CONCLUSIONS

High-throughput sequencing followed by matched targeted therapy is a promising approach for patients with advanced melanoma refractory to approved treatments.

Therapeutic advances of targeting receptor tyrosine kinases in cancer

Receptor tyrosine kinases (RTKs), a category of transmembrane receptors, have gained significant clinical attention in oncology due to their central role in cancer pathogenesis. Genetic alterations, including mutations, amplifications, and overexpression of certain RTKs, are critical in creating environments conducive to tumor development. Following their discovery, extensive research has revealed how RTK dysregulation contributes to oncogenesis, with many cancer subtypes showing dependency on aberrant RTK signaling for their proliferation, survival and progression. These findings paved the way for targeted therapies that aim to inhibit crucial biological pathways in cancer. As a result, RTKs have emerged as primary targets in anticancer therapeutic development. Over the past two decades, this has led to the synthesis and clinical validation of numerous small molecule tyrosine kinase inhibitors (TKIs), now effectively utilized in treating various cancer types. In this manuscript we aim to provide a comprehensive understanding of the RTKs in the context of cancer. We explored the various alterations and overexpression of specific receptors across different malignancies, with special attention dedicated to the examination of current RTK inhibitors, highlighting their role as potential targeted therapies. By integrating the latest research findings and clinical evidence, we seek to elucidate the pivotal role of RTKs in cancer biology and the therapeutic efficacy of RTK inhibition with promising treatment outcomes.

BRAF and MEK inhibitor combinations induce potent molecular and immunological effects in NRAS-mutant melanoma cells: Insights into mode of action and resistance mechanisms

About 25% of melanoma harbor activating NRAS mutations, which are associated with aggressive disease therefore requiring a rapid antitumor intervention. However, no efficient targeted therapy options are currently available for patients with NRAS-mutant melanoma. MEK inhibitors (MEKi) appear to display a moderate antitumor activity and also immunological effects in NRAS-mutant melanoma, providing an ideal backbone for combination treatments. In our study, the MEKi binimetinib, cobimetinib and trametinib combined with the BRAF inhibitors (BRAFi) encorafenib, vemurafenib and dabrafenib were investigated for their ability to inhibit proliferation, induce apoptosis and alter the expression of immune modulatory molecules in sensitive NRAS-mutant melanoma cells using two- and three-dimensional cell culture models as well as RNA sequencing analyses. Furthermore, NRAS-mutant melanoma cells resistant to the three BRAFi/MEKi combinations were established to characterize the mechanisms contributing to their resistance. All BRAFi induced a stress response in the sensitive NRAS-mutant melanoma cells thereby significantly enhancing the antiproliferative and proapoptotic activity of the MEKi analyzed. Furthermore, BRAFi/MEKi combinations upregulated immune relevant molecules, such as ICOS-L, components of antigen-presenting machinery and the "don't eat me signal" molecule CD47 in the melanoma cells. The BRAFi/MEKi-resistant, NRAS-mutant melanoma cells counteracted the molecular and immunological effects of BRAFi/MEKi by upregulating downstream mitogen-activated protein kinase pathway molecules, inhibiting apoptosis and promoting immune escape mechanisms. Together, our study reveals potent molecular and immunological effects of BRAFi/MEKi in sensitive NRAS-mutant melanoma cells that may be exploited in new combinational treatment strategies for patients with NRAS-mutant melanoma.

Augmenting MEK inhibitor efficacy in BRAF wild-type melanoma: synergistic effects of disulfiram combination therapy

BACKGROUND

MEK inhibitors (MEKi) were shown to be clinically insufficiently effective in patients suffering from BRAF wild-type (BRAF WT) melanoma, even if the MAPK pathway was constitutively activated due to mutations in NRAS or NF-1. Thus, novel combinations are needed to increase the efficacy and duration of response to MEKi in BRAF WT melanoma. Disulfiram and its metabolite diethyldithiocarbamate are known to have antitumor effects related to cellular stress, and induction of endoplasmic reticulum (ER) stress was found to synergize with MEK inhibitors in NRAS-mutated melanoma cells. Therefore, we investigated the combination of both therapeutics to test their effects on BRAF-WT melanoma cells and compared them with monotherapy using the MEKi trametinib.

METHODS

The effects of combined therapy with disulfiram or its metabolite diethyldithiocarbamate and the MEKi trametinib were evaluated in a series of BRAF-WT melanoma cell lines by measuring cell viability and apoptosis induction. Cytotoxicity was additionally assessed in 3D spheroids, ex vivo melanoma slice cultures, and in vivo xenograft mouse models. The response of melanoma cells to treatment was studied at the RNA and protein levels to decipher the mode of action. Intracellular and intratumoral copper measurements were performed to investigate the role of copper ions in the antitumor cytotoxicity of disulfiram and its combination with the MEKi.

RESULTS

Diethyldithiocarbamate enhanced trametinib-induced cytotoxicity and apoptosis induction in 2D and 3D melanoma culture models. Mechanistically, copper-dependent induction of oxidative stress and ER stress led to Janus kinase (JNK)-mediated apoptosis in melanoma cells. This mechanism was also detectable in patient-derived xenograft melanoma models and resulted in a significantly improved therapeutic effect compared to monotherapy with the MEKi trametinib.

CONCLUSIONS

Disulfiram and its metabolite represent an attractive pharmaceutical approach to induce ER stress in melanoma cells that potentiates the antitumor effect of MEK inhibition and may be an interesting candidate for combination therapy of BRAF WT melanoma.

First-Line Genomic Profiling in Previously Untreated Advanced Solid Tumors for Identification of Targeted Therapy Opportunities

IMPORTANCE

Precision oncology using comprehensive genomic profiling (CGP) by next-generation sequencing is aimed at companion diagnosis and genomic profiling. The clinical utility of CGP before the standard of care (SOC) is still not resolved, and more evidence is needed.

OBJECTIVE

To investigate the clinical utility of next-generation CGP (FoundationOne CDx [F1CDx]) in patients with previously untreated metastatic or recurrent solid tumors.

DESIGN, Setting, and Participants

This multicenter, prospective, observational cohort study enrolled patients with previously untreated advanced solid tumors between May 18, 2021, and February 16, 2022, with follow-up through August 16, 2022. The study was conducted at 6 hospitals in Japan. Eligible patients were aged 20 years or older and had Eastern Cooperative Oncology Group performance status of 0 to 1 with previously untreated metastatic or recurrent cancers in the gastrointestinal or biliary tract; pancreas, lung, breast, uterus, or ovary; and malignant melanoma.

EXPOSURE

Comprehensive genomic profiling testing before SOC for advanced solid tumors.

MAIN OUTCOMES AND MEASURES

Proportion of patients with actionable or druggable genomic alterations and molecular-based recommended therapy (MBRT).

RESULTS

A total of 183 patients met the inclusion criteria and 180 patients (92 men [51.1%]) with a median age of 64 years (range, 23-88 years) subsequently underwent CGP (lung [n = 28], colon/small intestine [n = 27], pancreas [n = 27], breast [n = 25], biliary tract [n = 20], gastric [n = 19], uterus [n = 12], esophagus [n = 10], ovary [n = 6], and skin melanoma [n = 6]). Data from 172 patients were available for end point analyses. Actionable alterations were found in 172 patients (100.0%; 95% CI, 97.9%-100.0%) and druggable alternations were identified in 109 patients (63.4%; 95% CI, 55.7%-70.6%). The molecular tumor board identified MBRT for 105 patients (61.0%; 95% CI, 53.3%-68.4%). Genomic alterations included in the companion diagnostics list of the CGP test were found in 49 patients (28.5%; 95% CI, 21.9%-35.9%) in a tumor-agnostic setting. After a median follow-up of 7.9 months (range, 0.5-13.2 months), 34 patients (19.8%; 95% CI, 14.1%-26.5%) received MBRT.

CONCLUSIONS AND RELEVANCE

The findings of this study suggest that CGP testing before SOC for patients with advanced solid tumors may be clinically beneficial to guide the subsequent anticancer therapies, including molecularly matched treatments.

Immune checkpoint inhibition in patients with NRAS mutated and NRAS wild type melanoma: a multicenter Dermatologic Cooperative Oncology Group study on 637 patients from the prospective skin cancer registry ADOREG

BACKGROUND

Melanomas frequently harbour somatic mutations in BRAF (40%) or NRAS (20%). Impact of NRAS mutations on the therapeutic outcome of immune checkpoint inhibitors (ICI) remains controversial. Potential correlation of the NRAS mutational status and programmed cell death ligand-1 (PD-L1) expression in melanoma is unknown.

PATIENTS AND METHODS

Advanced, non-resectable melanoma patients with known NRAS mutation status treated with first-line ICI between 06/2014 and 05/2020 in the prospective multicenter skin cancer registry ADOREG were included. Overall response rate (ORR), progression-free survival (PFS), and overall survival (OS) according to NRAS status were analysed. A multivariate Cox model was used to analyse factors associated with PFS and OS; survival was analysed using the Kaplan-Meier approach.

RESULTS

Among 637 BRAF wild-type patients, 310 (49%) had an NRAS mutation with Q61R (41%) and Q61K (32%). NRAS-mutated (NRASmut) melanomas were significantly more often located on the lower extremities and trunk (p = 0.001); nodular melanoma was the most common subtype (p < 0.0001). No significant differences were found for PFS and OS for anti-PD1 monotherapy (2-year PFS 39%, [95% confidence interval (CI), 33-47] in NRASmut patients and 41% [95% CI, 35-48] in NRAS-wild type (NRASwt) patients; 2-year OS was 54% [95% CI, 48-61] in NRASmut patients and 57% [95% CI, 50-64] in NRASwt patients) and anti-PD1 plus anti-CTLA4 therapy between both cohorts (2-year PFS was 54% [95% CI, 44-66] in NRASmut patients and 53% [95% CI, 41-67] in NRASwt patients; 2-year OS was 58% [95% CI, 49-70] in NRASmut patients and 62% [95% CI, 51-75] in NRASwt patients). The ORR to anti-PD1 was 35% for NRASwt patients and 26% for NRASmut patients and 34% compared to 32% for combinational therapy. Data on PD-L1 expression was available in 82 patients (13%). PD-L1 expression (>5%) was not correlated to NRAS mutational status. In multivariate analysis, elevated lactate dehydrogenase, Eastern Cooperative Oncology Group performance status ≥ 1, and brain metastases were significantly associated with a higher risk of death in all patients.

CONCLUSIONS

The PFS and OS were not affected by NRAS mutational status in patients treated with anti-PD1-based ICI. Similar ORR was seen in NRASwt and NRASmut patients. Tumour PD-L1 expression did not correlate with NRAS mutational status.

Real-life use of trametinib after immunotherapy failure in BRAF wild-type advanced melanoma

BRAFV600 wild-type advanced melanomas quickly reach a therapeutic dead-end, after immunotherapy failure. Even if preclinical studies have suggested sensitivity to MEK inhibitors such as trametinib in NRAS, NF1 or GNA mutated melanoma, therapeutic options are limited for these patients. We present a retrospective monocentric study of 22 patients with advanced melanoma treated by trametinib after immunotherapy resistance. Melanomas harboured NRAS (20), NF1 (1) or GNA11 (1) mutations. For most of them (18), anti-PD1 was associated with trametinib. A disease-control was reported in 36% of patients (8/22), with six stable diseases and two partial responses according to Response Evaluation Criteria in Solid Tumors (RECIST) criteria. Median progression-free survival was 2 months (1-14) and median overall survival was 6.5 months (2-24). In patients with progressive disease (14/22), dissociated radiologic responses and clinical benefits such as pain reduction were seen in five patients. High blood level of lactate dehydrogenase (LDH) seemed associated with trametinib failure, without significance (P = 0.06). Adverse events (grade 1-3) occurred in 91% of patients during the first weeks of treatment, mainly papulo-pustular rashes (77%), leg oedemas (36%), asthenia (18%) and diarrhoea (14%). This real-life study showed that trametinib may benefit some metastatic melanoma that progressed after chemotherapy and immune checkpoint inhibitors. Objective disease control (partial response or stable disease) using RECIST criteria was observed in 36% of patients. Because of frequent side-effects which can alter the quality of life and the short response duration, this off-label option has to be discussed with the patient. Studies with combination therapy with trametinib to improve relapse-free survival and lower side-effects are ongoing.

Clinical response under MEK inhibitor alone in metastatic melanoma with a novel fusion involving the RAF1 gene

Currently, in the absence of BRAFV600 mutation, the management of advanced melanomas is based on immunotherapies, but only half of the patients are responders. RAF1 (also named CRAF) fusions occur in 1-2.1% of wild-type melanomas. Preclinical data suggest that the presence of RAF fusion may be sensitive to MEK inhibitors. We report the case of a patient with an advanced melanoma harboring an EFCC1-RAF1 fusion who showed a clinical benefit from and a partial response to a MEK inhibitor.

A first-in-human, phase 1a dose-escalation study of the selective MEK1/2 inhibitor FCN-159 in patients with advanced NRAS-mutant melanoma

BACKGROUND

A phase 1a first-in-human study evaluated the safety/tolerability, preliminary antitumour activity and pharmacokinetics of the oral MEK1/2 inhibitor FCN-159 in Chinese patients with advanced, NRAS-mutant melanoma.

PATIENTS AND METHODS

Patients received a single FCN-159 dose at assigned levels, proceeding to continuous dosing (once daily [QD] for 28-day cycles) if no dose-limiting toxicities (DLTs) occurred within the next 3 days. Dose escalation was initiated after review of data for the previous dose level. The primary end-point was incidence of DLTs after the first dose.

RESULTS

Thirty-three patients were enrolled across nine FCN-159 dose groups (0.2-15 mg QD). One DLT occurred: grade 3 folliculitis in the 15-mg group. There was one grade >3 treatment-emergent adverse event (TEAE), death of unknown aetiology (not FCN-159 related). The most common FCN-159-related TEAE was rash (36.4%), and the incidence of grade ≥3 FCN-159-related TEAEs was 15.2%. Antitumour activity at QD doses <6 mg was limited; therefore, efficacy data are presented only for doses ≥6 mg (n = 21). The objective response and clinical benefit rates were 19.0% (four partial responses) and 52.4%, respectively. Median (95% confidence interval) duration of response and progression-free survival were 4.8 months (2.8-not reached) and 3.8 months (1.8-5.6), respectively. FCN-159 exposure increased dose-proportionately; geometric mean terminal half-life was 29.9-56.9 h.

CONCLUSIONS

FCN-159 was well tolerated and demonstrated promising antitumour activity at doses ≥6 mg QD in patients with advanced, NRAS-mutant melanoma. The recommended phase 2 dose was 12 mg QD.

CLINICALTRIALS

GOV IDENTIFIER

NCT03932253. https://clinicaltrials.gov/ct2/show/NCT03932253.