BRAFV600-mutant Melanoma Research Articles

Abstract B047: Monitoring treatment response and toxicity in BRAF V600-mutant metastatic melanoma with circulating cell-free DNA

Abstract Background: The DREAMseq trial (EA6134, NCT02224781) was a national multi-center randomized phase III trial coordinated by ECOG-ACRIN that found that immune checkpoint inhibitor (IO) treatment achieves improved survival outcomes compared to targeted therapy (TT) in patients with BRAF V600-mutant metastatic melanoma. Still, approximately 40% of patients do not respond to IO, and existing biomarkers fail to distinguish this subset of patients who do not benefit from IO therapy. Additionally, as many as 80% of patients may experience immune- related adverse events (irAEs), which range from mild dermatological symptoms to life- threatening myocarditis. Here, we explore the use of the methylation status of cell-free DNA (cfDNA) in serially collected blood samples to measure response and toxicity in the context of IO- and TT-treated metastatic melanoma. Methods: Serial serum samples were collected from patients with BRAF V600-mutant metastatic melanoma treated with ipilimumab/nivolumab (IO) or dabrafenib/trametinib (TT). Circulating cfDNA was isolated from serially collected serum samples, enriched for regions of interest by hybridization capture and sequenced using enzymatic methyl-seq. Cell-type deconvolution was performed to determine the abundance of cell type- specific methylation patterns of cfDNA molecules in patient serum at different time points of treatment. The BRAF V600 mutation abundance in total cfDNA was also assessed. Results: We identified melanocyte lineage-specific DNA methylation regions and demonstrate that the methylation status of these regions remains conserved in malignant melanoma. We characterized the changes in abundance of the melanocyte-lineage cfDNA over the course of treatment and show that these changes distinguish responders from non-responders to either IO or TT. Furthermore, we track the abundance of cell type-specific DNA from normal tissues to identify markers indicative of adverse effects or disease progression. Conclusions: We established melanocyte-lineage methylation markers and evaluated the use of cell-type specific DNA methylation to monitor treatment effects of immune checkpoint or BRAF/MEK inhibitors in metastatic melanoma using serially collected blood samples. Citation Format: Sidharth S Jain, A. Patrick IV McDeed, Megan E McNamara, Amber R Alley, Dori S Rosenstrauch, Harry Sun, Natalie Thompson, John M Kirkwood, Geoffrey T Gibney, Michael B Atkins, Anton Wellstein. Monitoring treatment response and toxicity in BRAF V600-mutant metastatic melanoma with circulating cell-free DNA [abstract]. In: Proceedings of the AACR Special Conference: Liquid Biopsy: From Discovery to Clinical Implementation; 2024 Nov 13-16; San Diego, CA. Philadelphia (PA): AACR; Clin Cancer Res 2024;30(21_Suppl):Abstract nr B047.

PHGDH Induction by MAPK is Essential for Melanoma Formation and Creates an Actionable Metabolic Vulnerability.

Overexpression of PHGDH, the rate-limiting enzyme in the serine synthesis pathway, promotes melanomagenesis, melanoma cell proliferation, and survival of metastases in serine-low environments such as the brain. Here, we found that PHGDH is universally increased in melanoma cells and required for melanomagenesis. While PHGDH amplification explained PHGDH overexpression in a subset of melanomas, oncogenic BRAFV600E also promoted PHGDH transcription through mTORC1-mediated translation of ATF4. Importantly, depletion of PHGDH in genetic mouse melanoma models blocked tumor formation. In addition to BRAFV600E-mediated upregulation, PHGDH was further induced by exogenous serine restriction. Surprisingly, BRAFV600E inhibition diminished serine restriction-mediated PHGDH expression by preventing ATF4 induction. Consequently, melanoma cells could be specifically starved of serine by combining BRAFV600E inhibition with exogenous serine restriction, which promoted cell death in vitro and attenuated melanoma growth in vivo. In summary, this study identified that PHGDH is essential for melanomagenesis and regulated by BRAFV600E, revealing a targetable vulnerability in BRAFV600E-mutant melanoma.

Concurrent involvement of the bone marrow by BRAF V600E-mutant melanoma and hairy cell leukemia.

Concurrent involvement of the bone marrow by BRAF V600E-mutant melanoma and hairy cell leukemia.

INEAS's Cost-Effectiveness Analysis of Vemurafenib: Paving the Way for Value-Based Pricing in Tunisia.

The Tunisian Health Technology Assessment (HTA) body, INEAS, conducted a cost-effectiveness analysis (CEA) of vemurafenib in the treatment of locally advanced or metastatic BRAF V600-mutated melanoma. The objective of this analysis was to enable the use of value-based pricing as a new approach to price negotiation. This study was part of a broader HTA report that was prepared in response to a joint request from the regulatory authorities and the CNAM, Tunisia's compulsory insurance scheme. Our analysis was based on a probabilistic Markov cohort model that calculated the costs and quality-adjusted life years (QALY) associated with vemurafenib compared to the standard of care from a public payer perspective. The CEA indicated that vemurafenib provides a gain of 0.38 life years (1.78 vs. 1.4) for an incremental cost of USD 101,106.62 from the perspective of the main public payer (CNAM). This study revealed an incremental cost-effectiveness ratio (ICER) of 163,311.40 USD/QALY and 163,911.46 USD/QALY, respectively, from the CNAM and public health facilities' perspectives. Vemurafenib cannot be considered cost-effective in terms of what has normally been considered a reasonable willingness to pay (WTP) in Tunisia. A significant price reduction would be necessary to bring the incremental cost-effectiveness ratio to an acceptable level.

MEK Pathway Inhibitor-Mediated Response in BRAF V600-Mutant Melanoma with Brain Parenchymal and Leptomeningeal Metastases.

MEK Pathway Inhibitor-Mediated Response in BRAF V600-Mutant Melanoma with Brain Parenchymal and Leptomeningeal Metastases.

Sequencing of Checkpoint or BRAF/MEK Inhibitors on Brain Metastases in Melanoma

BackgroundThe impact of the order of treatment with checkpoint inhibitors or BRAF/MEK inhibitors on the development of brain metastases in patients with metastatic unresectable BRAFV600-mutant melanoma is unknown. The SECOMBIT trial examined the impact of the order of receipt of these treatments in such patients.MethodsIn this three-arm trial, we reviewed patients without brain metastases who received the BRAF/MEK inhibitors encorafenib and binimetinib until they had progressive disease followed by the immune checkpoint inhibitors ipilimumab and nivolumab (arm A); or treatment with ipilimumab and nivolumab until they had progressive disease followed by encorafenib and binimetinib (arm B); or treatment with encorafenib and binimetinib for 8 weeks followed by ipilimumab and nivolumab until they had progressive disease followed by retreatment with encorafenib arm binimetinib (arm C).ResultsBrain metastases were discovered during the trial in 23/69 patients in arm A, 11/69 in arm B, and 9/68 in arm C. At a median follow-up of 56 months, the 60-month brain metastases–free survival rates were 56% for arm A, 80% for arm B (hazard ratio [HR] vs. A: 0.40, 95% confidence interval [CI] 0.23 to 0.58), and 85% for arm C (HR vs. A: 0.35, 95% CI 0.16 to 0.76).ConclusionsIn patients with unresectable metastatic melanoma, the treatment sequence of immune checkpoint inhibition followed by BRAF/MEK inhibitors was associated with longer periods of new brain metastases–free survival than the reverse sequence. A regimen in which immune checkpoint inhibition was sandwiched between BRAF/MEK inhibition also appeared to be protective against brain metastases. (ClinicalTrials.gov number NCT02631447.)

The Evaluation of Immune Checkpoint Inhibitors and BRAF/MEK Inhibitors in Different Therapy Lines for Metastatic Melanoma: A Retrospective Study.

Background: Nivolumab plus ipilimumab (nivo/ipi) combination therapy is highly effective in treating advanced melanoma, but serious immune-related adverse events (irAEs) are prevalent. The overall response rate (ORR) of the BRAF inhibitor plus MEK inhibitor (BRAFi/MEKi) combination therapy for BRAFV600-mutant advanced melanoma surpasses that of immune checkpoint inhibitors (ICIs). However, the OS and PFS of BRAFi/MEKi combination therapy are inferior to those of ICIs. Methods: We retrospectively evaluated 22 melanoma patients treated with nivo/ipi therapy and 13 patients treated with encorafenib plus binimetinib (enco/bini) between November 2018 and July 2023. Results: The ORR of nivo/ipi for metastatic melanoma patients was significantly higher in the first-line cohort [60.0% (95% CI: 31.2-83.3%)] than in the second-line or beyond cohort [8.3% (95% CI: 0-37.5%)], whereas the ORR of enco/bini was comparable between the first-line cohort [75.0% (95% CI: 28.9-96.6%)] and the second-line or beyond cohort [77.8% (95% CI: 44.3-94.7%)]. The median PFS of nivo/ipi significantly improved in the first-line cohort [7.7 months (95% CI: 2.0-11.9)] compared to the second-line or beyond cohort [2.3 months (95% CI: 0.5-6.0)] (p = 0.0109). In addition to efficacy, the incidence of grade 3 or greater AEs was comparable in the first-line and second-line or beyond cohorts. Conclusions: Although our present data are based on a small number of cases, they suggest that nivo/ipi should be administered as the first-line therapy for the treatment of BRAFV600-mutant metastatic melanoma, rather than enco/bini, aligning with findings from previous clinical trials.

Advancements and Challenges in Personalized Therapy for BRAF-Mutant Melanoma: A Comprehensive Review.

Over the past several decades, advancements in the treatment of BRAF-mutant melanoma have led to the development of BRAF inhibitors, BRAF/MEK inhibitor combinations, anti-PD-1 therapy, and anti-CTLA4 therapy. Although these therapies have shown substantial efficacy in clinical trials, their sustained effectiveness is often challenged by the tumor microenvironment, which is a highly heterogeneous and complex milieu of immunosuppressive cells that affect tumor progression. The era of personalized medicine holds substantial promise for the tailoring of treatments to individual genetic profiles. However, tumor heterogeneity and immune evasion mechanisms contribute to the resistance to immunotherapy. Despite these challenges, tumor-infiltrating lymphocyte (TIL) therapy, as exemplified by lifileucel, has demonstrated notable efficacy against BRAF V600-mutant melanoma. Additionally, early response biomarkers, such as COX-2 and MMP2, along with FDG-PET imaging, offer the potential to improve personalized immunotherapy by predicting patient responses and determining the optimal treatment duration. Future efforts should focus on reducing the T-cell harvesting periods and costs associated with TIL therapy to enhance efficiency and accessibility.

In vivo vulnerabilities to GPX4 and HDAC inhibitors in drug-persistent versus drug-resistant BRAFV600E lung adenocarcinoma

The current targeted therapy for BRAFV600E-mutant lung cancer consists of a dual blockade of RAF/MEK kinases often combining dabrafenib/trametinib (D/T). This regimen extends survival when compared to single-agent treatments, but disease progression is unavoidable. By using whole-genome CRISPR screening and RNA sequencing, we characterize the vulnerabilities of both persister and D/T-resistant cellular models. Oxidative stress together with concomitant induction of antioxidant responses is boosted by D/T treatment. However, the nature of the oxidative damage, the choice of redox detoxification systems, and the resulting therapeutic vulnerabilities display stage-specific differences. Persister cells suffer from lipid peroxidation and are sensitive to ferroptosis upon GPX4 inhibition invivo. Biomarkers of lipid peroxidation are detected in clinical samples following D/T treatment. Acquired alterations leading to mitogen-activated protein kinase (MAPK) reactivation enhance cystine transport to boost GPX4-independent antioxidant responses. Similarly to BRAFV600E-mutant melanoma, histone deacetylase (HDAC) inhibitors decrease D/T-resistant cell viability and extend therapeutic response invivo.

Real-world use and outcomes of targeted therapy and immunotherapy for adjuvant treatment of BRAF -mutated melanoma patients in the United States.

Using a customized, harmonized US electronic health record database, real-world prescription patterns of first-line adjuvant immunotherapy and targeted therapy were retrospectively assessed for BRAF V600-mutated melanoma. Adults with BRAF V600 mutation-positive stage IIIA-D cutaneous melanoma who received first-line adjuvant immunotherapy (nivolumab or pembrolizumab) or targeted therapy (dabrafenib plus trametinib) between 1 January 2014 and 30 August 2020 in the NOBLE database were included. Patients were followed from first-line adjuvant therapy initiation for at least 6 months, until death, progression, follow-up loss, or data cutoff. Primary endpoints were proportion of patients receiving either therapy in first-line and second-line, treatment switching, treatment timing, and status at the end of first-line therapy. Secondary endpoints included discontinuation rates, recurrence-free survival (RFS), and overall survival (OS). Of 318 patients evaluated, 67.6% received nivolumab, 14.2% pembrolizumab, and 18.2% targeted therapy as first-line adjuvant therapy. Median treatment duration was longest for nivolumab (292 days) and shortest for targeted therapy (115 days). Reason for discontinuation was recorded for 195 of 274 patients who discontinued first-line therapy; most common reasons were treatment completion and treatment-related toxicity [87/158 (55.0%) and 29/158 (18.4%), respectively, in immunotherapy-treated patients; 9/37 (24.3%) and 21/37 (56.8%) in targeted therapy-treated patients]. Median RFS and OS for targeted therapy and nivolumab were not reached and were 34.6 and 38.1 months, respectively, for pembrolizumab. These results inform on prescription preferences and clinical outcomes for BRAF V600-mutated melanoma patients in the first-line adjuvant setting.

Encorafenib and binimetinib followed by radiotherapy for patients with BRAFV600-mutant melanoma and brain metastases (E-BRAIN/GEM1802 phase II study).

Encorafenib plus binimetinib (EB) is a standard of care treatment for advanced BRAFV600-mutant melanoma. We assessed efficacy and safety of encorafenib plus binimetinib in patients with BRAFV600-mutant melanoma and brain metastasis (BM) and explored if radiotherapy improves the duration of response. E-BRAIN/GEM1802 was a prospective, multicenter, single arm, phase II trial that enrolled patients with melanoma BRAFV600-mutant and BM. Patients received encorafenib 450mg once daily plus binimetinib 45mg BID, and those who achieved partial response or stable disease at first tumor assessment were offered radiotherapy. Treatment continued until progression.Primary endpoint was intracranial response rate (icRR) after 2 months of EB, establishing a futility threshold of 60%. The study included 25 patients with no BM symptoms and 23 patients with BM symptoms regardless of using corticosteroids. Among them, 31 patients (64.6%) received sequential radiotherapy. After two months, icRR was 70.8% (95% CI: 55.9-83.1); 10.4% complete response. Median intracranial PFS and OS were 8.5 (95% CI: 6.4-11.8) and 15.9 (95% CI: 10.7-21.4) months, respectively (8.3 months for icPFS and 13.9 months OS for patients receiving RDT). Most common grade 3-4 treatment-related adverse event was alanine aminotransferase (ALT) increased (10.4%). Encorafenib plus binimetinib showed promising clinical benefit in terms of icRR, and tolerable safety profile with low frequency of high grade TRAEs, in patients with BRAFV600-mutant melanoma and BM, including those with symptoms and need for steroids. Sequential radiotherapy is feasible but it does not seem to prolong response.

Neoadjuvant pembrolizumab, dabrafenib and trametinib in BRAFV600-mutant resectable melanoma: the randomized phase 2 NeoTrio trial

Immune checkpoint inhibitors and BRAF-targeted therapy each improve survival in melanoma. Immune changes early during targeted therapy suggest the mechanisms of each drug class could work synergistically. In the non-comparative, randomized, phase 2 NeoTrio trial, we investigated whether targeted therapy could boost the proportion of patients achieving long-term recurrence-free survival with neoadjuvant immunotherapy in resectable stage III BRAFV600-mutant melanoma. Sixty patients (42% females) were randomized to pembrolizumab alone (n = 20), sequential therapy (dabrafenib plus trametinib followed by pembrolizumab; n = 20) or concurrent (triple) therapy (n = 20), followed by surgery and adjuvant therapy. The primary outcome was pathological response; secondary outcomes included radiographic response, recurrence-free survival, overall survival, surgical outcomes, peripheral blood and tumor analyses and safety. The pathological response rate was 55% (11/20; including six pathological complete responses (pCRs)) with pembrolizumab, 50% (10/20; three pCRs) with sequential therapy and 80% (16/20; ten pCRs) with concurrent therapy, which met the primary outcome in each arm. Treatment-related adverse events affected 75–100% of patients during neoadjuvant treatment, with seven early discontinuations (all in the concurrent arm). At 2 years, event-free survival was 60% with pembrolizumab, 80% with sequential therapy and 71% with concurrent therapy. Recurrences after major pathological response were more common in the targeted therapy arms, suggesting a reduction in response ‘quality’ when targeted therapy is added to neoadjuvant immunotherapy. Risking the curative potential of immunotherapy in melanoma cannot be justified. Pending longer follow-up, we suggest that immunotherapy and targeted therapy should not be combined in the neoadjuvant setting for melanoma. ClinicalTrials.gov registration: NCT02858921.

A phase II study of tunlametinib in combination with vemurafenib in patients with BRAF V600-mutant advanced melanoma.

e21519 Background: The new MEK inhibitor tunlametinib combined with the BRAF inhibitor vemurafenib showed promising clinical activity in patients (pts) with BRAF V600-mutant solid tumors in a previous Phase I study (NCT03976050). Based on the result, we designed a phase IIa study to evaluate the efficacy and safety of tunlametinib plus vemurafenib in Chinese pts with BRAF V600 mutant melanoma. Methods: This open-label, single arm, multiple-center phase IIa study enrolled Chinese pts with BRAF V600E-mutant advanced melanoma, without restriction on the disease subtype (e.g., acral, mucosal, or cutaneous melanoma). Prior treatment was permitted, excluding BRAF/MEK inhibitors. Pts received oral tunlametinib at a dose of 9 mg twice daily and vemurafenib 720 mg twice daily. The primary endpoint was the objective response rate (ORR) per RECIST v1.1. Results: Between October 15, 2021, and June 22nd, 2022, 17 pts were enrolled and included in the analysis. Thirteen (76.5%) pts had received previous systemic antitumor therapy, with 12 (70.6%) receiving immunotherapy. Seven (41.2%) pts had acral melanoma, 8 (47.1%) pts had skin melanoma (non-acral) and 2 (11.8%) pts had mucosal melanoma. All pts had metastatic disease. With a median follow-up of 15.3 months (95%CI: 6.8; NE), 12 (70.6%) pts achieved confirmed partial response (PR), resulting in a confirmed ORR of 70.6% (95% CI: 44.0%-89.7%). The disease control rate was 100% (95% CI: 80.5%, 100.0%). The median progression-free survival (PFS) was 10.0 months (95% CI: 5. 5, NE). the duration of response (DOR) was 20.1 (95% CI: 4.2, NE). The overall survival (OS) was 21.6 months (95% CI: 14.5, NE), with a 12-months OS rate of 87.4% (95% CI: 58.1%, 96.7%). Subgroup analysis revealed that in pre-treated pts, the confirmed ORR was 76.9% (95% CI: 46.2%, 95.0%), the median PFS was 10.0 months (95% CI: 5.5, NE), while in previous untreated pts, the mPFS was 14.0 months (95% CI: 9.9, NE). In pts with skin melanoma, the confirmed ORR was 87.5% (47.3%, 99.7%), the mPFS was 10.0 months (95% CI: 5.5, NE), the mOS was 21.6 months (95% CI: 5.7, NE). In pts with acral melanoma, the ORR was 57.1% (95% CI: 18.4%,90.1%), the mPFS was 18.1 months (95% CI: 2.8, NE), the mOS not reached (12.3, NE). The most common adverse events included rash, pyrexia, and elevated blood creatin phosphokinase, most of which were of grade 1-2 severity. Grade 3 or higher TRAEs occurred in 12 (70.6%) pts, of which 41.2% were rash. Most AEs were manageable with supportive therapy or dose interruption. No treatment-related deaths were reported. Conclusions: The addition of a MEK inhibitor tunlametinib to vemurafenibexhibited promising clinical efficacy in Chinese patients with BRAF V600-mutant advanced melanoma, with a manageable safety profile. Additionally, notable effects were observed in pts with acral melanoma. The efficacy in pre-treated patients was comparable to that of similar agents in previous untreated patients. Clinical trial information: NCT05263453 .

Atezolizumab (A), cobimetinib (C), and vemurafenib (V) in patients (pts) with BRAFV600 mutation–positive melanoma with central nervous system (CNS) metastases (mets): Final results and exploratory biomarker analysis from the phase 2 TRICOTEL study.

9550 Background: Primary analysis results from the phase 2 TRICOTEL study showed intracranial activity with the triplet combination of A + C + V in pts with BRAFV600-mutated melanoma with CNS mets (1). Here, we report final analysis results and exploratory biomarker analyses for pts with BRAFV600-mutated melanoma in the triplet combination cohort from TRICOTEL. Methods: Eligible pts were aged ≥18 y and had melanoma, MRI-confirmed CNS mets ≥5 mm in ≥1 dimension, and no prior systemic treatment for metastatic disease. Pts received A (840 mg on days 1 and 15 of each 28-d cycle) + C (60 mg once daily for 21 d on, 7 d off) + V (720 mg twice daily) except in cycle 1, during which A was withheld. Tumor tissue and circulating tumor DNA (ctDNA) samples collected at baseline (cycle 1, day 1) and ctDNA at the time of progressive disease (PD) were profiled for mutations using next-generation sequencing. Tumor tissue was profiled using a pipeline programmed for MelArray, and ctDNA was measured based on the tissue genetic profile. Results: A total of65 pts were enrolled in the triplet combination cohort. At final analysis, median follow-up was 12.4 mo. Per independent review committee (IRC) assessment, intracranial ORR (confirmed by assessments ≥4 wk apart) was 38% (95% CI, 27–51) and median intracranial PFS was 5.1 mo (95% CI, 3.7–6.9) (Table). Median OS was 13.4 mo (95% CI, 10.7–16.9). No new safety signals were observed since primary analysis. Mutations were detected in baseline ctDNA samples of 60 pts (5 pts not reported) and showed high prevalence of NF1, NRAS, and GNAI2 mutations; relative to tumor tissue, 11 additional BRAF mutations were detected in ctDNA at baseline. Acquired mutations in AKT1 were detected in ctDNA at PD. Median OS shortened in pts with >2 versus ≤2 mutated MAPK pathway genes in ctDNA at baseline (9.1 vs 14.5 mo; hazard ratio, 2.0 [95% CI, 1.0–3.7]; p<0.05). In tumor tissue, baseline mutations in PIK3C2A and PLEKHG4 were enriched in nonresponders, while RAD51B mutations were enriched in responders. Conclusions: Combination A + C + V had clinical intracranial activity in pts with BRAFV600-mutated melanoma with CNS mets. Exploratory biomarker analyses in this small cohort demonstrate the presence of ctDNA in pts with melanoma and CNS mets and provide insight into mutations associated with response and resistance to the triplet combination. 1. Dummer R et al, Lancet Oncol 2023. Clinical trial information: NCT03625141 . [Table: see text]

A randomized, controlled, multicenter, phase 3 study of vusolimogene oderparepvec (VO) combined with nivolumab vs treatment of physician’s choice in patients with advanced melanoma that has progressed on anti–PD-1 and anti–CTLA-4 therapy (IGNYTE-3).

TPS9604 Background: Melanoma is the 5th most common cancer type, with ~100,000 new cases and ~8,000 deaths estimated in the US for 2024. First-line systemic treatment with immune checkpoint inhibitors improved the objective response rate (ORR) and extended progression-free survival (PFS) and overall survival (OS) for patients with advanced disease. The combination of anti–PD-1 nivolumab (nivo) + anti–CTLA-4 ipilimumab (ipi) therapy is associated with the highest ORR and best PFS and OS in this setting. However, only about half of patients respond, and there is no standard of care for patients who progress after anti–PD-1–based therapy. VO (also referred to as RP1) is a selectively replication-competent HSV-1 oncolytic virus that expresses human GM-CSF and a fusogenic glycoprotein (GALV-GP-R–). Preliminary data from the phase 1/2 study (IGNYTE) showed that intratumoral (IT) VO plus intravenous (IV) nivolumab (nivo) was well tolerated and had meaningful antitumor activity (ORR, 31.4%) with durable responses in patients with advanced melanoma who progressed on prior anti–PD-1 therapy. This phase 3 study will evaluate the overall survival and clinical benefit as well as the safety of VO plus nivo for patients with advanced melanoma whose disease has progressed after receiving anti–PD-1 and anti–CTLA-4 therapy (or who are not eligible for anti–CTLA-4 therapy in addition to anti–PD-1) versus physician’s choice. Methods: This is a randomized, controlled, multicenter, phase 3 clinical trial comparing VO in combination with nivo vs physician’s choice of treatment in patients with unresectable or metastatic melanoma. Key eligibility criteria include age ≥12 years, stage IIIb–IV/M1a–M1d cutaneous melanoma, confirmed disease progression on an anti–PD–1 and anti–CTLA-4 treatment (administered in combination or in sequence with anti–PD-1 last), at least 1 measurable tumor (≥1 cm), and adequate hematologic, hepatic, and renal function. Patients who are not candidates for anti–CTLA-4 therapy may enroll if they have confirmed progression on anti–PD-1 therapy. Patients with BRAF V600 mutant melanoma must have received an anti-BRAF + anti-MEK targeted therapy prior to enrollment. Patients (N = ~400) will be randomized 1:1 to receive VO plus nivo or physician’s choice (nivo + relatlimab, anti–PD–1 monotherapy rechallenge [nivo or pembrolizumab], or single-agent chemotherapy [dacarbazine, temozolomide, or paclitaxel/albumin-bound paclitaxel]). VO is given IT Q2W; nivo is administered IV at 240 mg Q2W or 480 mg Q4W starting with the 2nd dose of VO. The primary endpoint of the study is OS; the key secondary endpoints are PFS and ORR. Additional endpoints include complete response rate, duration of response, disease control rate, and safety. Clinical trial information: NCT06264180 .

Neoadjuvant immune checkpoint inhibitors for patients with resectable stage III/IV melanoma: A nationwide real-life study in France (NEOMEL).

9578 Background: Several studies have shown the efficacy of neoadjuvant treatment (NT) with immune checkpoint inhibitors (ICI) for resectable stage III/IV melanoma. However, real-life data are lacking. Methods: NEOMEL is a national multicenter retrospective study assessing the efficacy and tolerability of NT with ICI (NT-ICI) for resectable metastatic melanoma in a real-life setting. Data were obtained in patients (pts) with resectable stage III/IV melanoma who initiated NT-ICI (at least one infusion). Primary endpoint was pathologic complete response (pCR) (i.e no residual tumor) rate. Secondary endpoints were pathologic response (pR) according to INMC, radiologic response (RECIST), safety profile (CTCAE) and survival outcomes. Results: A total of 166 pts with resectable stage III/IV melanoma were included. Median age was 67 years (range, 24-96). Most pts had primary cutaneous melanoma (n=157, 89%), stage IIIB-D disease (n=156, 94%); a BRAF V600-mutant melanoma was observed in 47% (n=78); 8% (n=14) pts had received a previous systemic treatment. The median number of infusions of NT-ICI was 3 (range, 1-5). ICI regimens were anti-PD-1 monotherapy (n=122, 73%) or nivolumab + ipilimumab (NIVO + IPI) (n=44, 27%). Median follow-up was 6.5 months (range, 1-85). Overall, 143 pts (86%) underwent surgery. A pCR was observed in 44% of pts (n=63/143), including 52% (n=51/99) treated with anti-PD-1 monotherapy, and 27% (n=12/44) treated with NIVO + IPI. Of note, 78 pts (54%) were treated with 3 infusions of pembrolizumab (PBZ) (according to SWOG 1801 protocol) and had a pCR in 45% (n=35). A pR was assessed according to INMC criteria in 58% of pts (n=83/143): 51% of pCR (n=42), 8% of near-pCR (n=7) corresponding to a major pR of 59% (n=49/83), 16% of pathologic partial response (n=13) and 25% of pathologic non-response (n=21). Twenty-three pts (14%) did not undergo surgery because of progressive disease (n=10), clinical and radiologic responses (8 complete responses, 1 partial response, 1 stable disease), toxicity (n=2) or patient’s choice (n=1). Radiologic overall response rate according to RECIST (data available after NT in 49% of pts) was 54% (n = 44/82). All grade immune-related adverse events (irAEs) of NT-ICI occurred in 31% (n=51) of pts, including grade 3-4 irAEs in 10% (n=17) and one grade 5 irAE (pneumonitis with PBZ). Severe irAEs (grade 3 or more) were observed in 4% (n=4/99) of pts treated with anti-PD1 monotherapy and 32% (n=14/44) of pts treated with NIVO + IPI. Adjuvant treatment was started for 120 pts (84%). At last follow-up, 26 pts (18%) have had recurrence after surgery, including 3 pts with a pCR and 23 pts with a non-pCR to NT-ICI. Survival data are not yet available. Conclusions: NT-ICI for advanced melanoma demonstrated its efficacy with high rates of pCR in a real-life setting and an acceptable safety profile, particularly NT anti-PD1 monotherapy.

A phase 2 clinical trial of regorafenib in patients with advanced pretreated melanoma (RegoMel).

9518 Background: A majority of advanced melanoma patients (pts) will eventually progress despite treatment with PD-(L)1/CTLA-4/LAG-3 immune checkpoint- and BRAF-/MEK-inhibitors (BRAF-/MEKi; restricted to BRAFV600-mutant pts). Retrospective case observations indicate activity of regorafenib (REGO) in this setting (1). Methods: This single center, prospective, two-stage, phase 2 clinical trial, investigates REGO 80 mg QD (continuous dosing) in pts with advanced melanoma refractory to standard of care treatment. Objective response rate (ORR, by RECIST v1.1) served as the primary endpoint. The sample size (n=16) was determined according to a Simon’s two-stage minimax statistical design; the trial is considered positive if 3 or more responses are observed. Response assessments are performed every 6 weeks (q6w) during the first 24w, and q12w thereafter. Secondary endpoints are safety, progression free survival (PFS) and overall survival (OS). REGO treatment beyond first progression was permitted if considered to be of potential clinical benefit. Database lock was on Jan 9th, 2024. Results: From Oct 2022 to Sep 2023, 16 pts were enrolled (9 male, med age 61y; AJCC stage IIIC: 1; IV-M1a: 1; -M1c: 12, -M1d: 2, ECOG PS 0-1: 100%). Oncogenic driver mutations were identified in BRAFV600: 7-, KIT: 3-, NF1: 3-, NRASQ61K: 2-, RAF fusion: 1 pt. The ORR was 31% (: 5 partial responses (PR) - 4 confirmed in 3 KIT-,and 1 BRAFV600 -mut pt; and 1 unconfirmed in a BRAFV600-mut pt). One KIT-mut pt had previously progressed on imatinib. The median duration of response (DoR) was 29.7w (range 12-44). The disease control rate (DCR) was 56%. The median time on REGO monotherapy was 12.3w [95% CI 2.3-22.3], treatment is ongoing in 3 pts. At first progression, 6 BRAFV600-mut pts continued REGO in association with BRAF-/MEKi, in 5 response evaluable pts there is an ORR of 40% (2 PR with DoR of 24w and 30w) and DCR of 80%. At database lock, 11 pts were alive with a median follow up of 48.4w (range 24-63), 13 pts have progressed on REGO monotherapy (median PFS 11.9w [95% CI 3.5-20.3]; median OS was not reached). There were no grade ≥ 4 treatment related adverse events (TRAE); 56% of pts had at least one grade 3 TRAE, including hypertension (n=3) and maculo-papular rash (n=2). There was one toxicity-related REGO discontinuation. Conclusions: This phase 2 clinical trial on REGO monotherapy in advanced pretreated melanoma patients met its primary endpoint and demonstrated significant anti-tumor activity in KIT-mutant melanoma patients. In BRAFV600-mutant melanoma, continuation of REGO in combination with BRAF-/MEK-inhibitors demonstrated promising activity in patients who previously progressed on BRAF-/MEK-inhibitors for which further prospective investigation is ongoing. 1. Dirven I. et al. ESMO Meeting 2023. Clinical trial information: NCT05370807 .

Real-world effectiveness and safety of dabrafenib-trametinib as first-line of treatment for BRAF mutated metastatic melanoma: Results of the study GEM1801.

e21515 Background: Dabrafenib-Trametinib (DT) is included in the therapeutic arsenal for BRAFV600-mutant metastatic melanoma. However, detailed effectiveness results for dabrafenib and trametinib depending on patient prognostic profile in the real-world are limited. Methods: GEM1801 is a prospective observational study that analyzes the clinical and pathological disease presentation patterns, the different lines of treatment choices and the health outcomes derived from treatments in patients with melanoma in Spain. Here we focus on patients receiving DT as first-line treatment in the metastatic melanoma. Based on previous studies, we defined 3 subgroups: good prognosis (normal LDH and < 3 metastatic sites), poor prognosis (high LDH and ≥3 metastatic sites), and intermediate prognosis (neither of good or poor prognosis). Results: From August 2018 to December 2022, 140 patients receiving DT were enrolled; 45 (32.1%) with good, 42 (30%) with intermediate and 34 (24.3%) with poor prognosis. Subgroup allocation was not possible for 19 patients due to missing info on LDH or metastatic sites. Overall survival (OS) was longer in patients with good versus poor prognosis (median 26.2 vs 10 months; p = 0.024), while those with intermediate prognosis showed a mixed profile with a median OS of 17.4 months. Response to treatment also showed correlation with OS (3-years OS rate: 57.1% vs 23% vs 46.9% vs 26.8% for CR, PR, SD and PD, respectively; p < 0.001). In patients who had a complete response, the 5-year OS rate was 58.3% (95% CI: 31.3-100) while the median overall survival was not reached. In patients with intermediate prognosis, the ECOG-PS was the main prognostic factor in multivariate analysis (hazard ratio: 4.6; 95% CI: 1.8-1.7; p = 0.002). The reported grade 3-5 toxicity was less than 5%. Treatment-related adverse events were reported in 5 (3.6%) patients, consisting of fever, mucositis, pneumonitis, neutropenia, ocular toxicity and retinal detachment. There were no differences across prognostic subgroups ( p = 0.741). Conclusions: DT in the Real-World has an acceptable effectiveness and safety profile. Prognostic groups could help in the selection of patients who could achieve a complete response, since it is the most important prognostic biomarker. Clinical trial information: NCT03605771 . [Table: see text]

Identification of BRAF Inhibitor Resistance-associated lncRNAs Using Genome-scale CRISPR-Cas9 Transcriptional Activation Screening.

Approximately 50% of melanomas harbor the BRAF V600E mutation and targeted therapies using BRAF inhibitors improve patient outcomes. Nonetheless, resistance to BRAF inhibitors develops rapidly and remains a challenge in melanoma treatment. In this study, we attempted to isolate long noncoding RNAs (lncRNAs) involved in BRAF inhibitor resistance using a comprehensive screening method. We used a CRISPR-Cas9 synergistic activation mediator (SAM) protein complex in a genome-scale transcriptional activation assay to screen for candidate lncRNA genes related to BRAF inhibitor resistance. Correlation analysis was performed between expression levels of isolated lncRNA genes and IC50 of dabrafenib in a BRAF-mutated melanoma cell line. Next, online databases were used to construct the lncRNA-miRNA-mRNA regulatory network. Finally, we evaluated the significance of the expression levels of these lncRNAs and mRNAs as biomarkers using clinical specimens. We isolated three BRAF inhibitor resistance-associated lncRNA genes, namely SNHG16, NDUFV2-AS1, and LINC01502. We constructed a lncRNA-miRNA-mRNA network of 13 nodes consisting of three lncRNAs, six miRNAs, and four mRNAs. The lncRNAs and target mRNAs from each regulatory axis significantly and positively correlated with each other. Finally, Kaplan-Meier analysis showed that higher expression levels of MITF, which was up-regulated by LINC01502, were significantly associated with worse prognosis in BRAF V600E-mutated melanoma. The identification of these BRAF inhibitor resistance-associated lncRNA genes at the genomic scale and the establishment of the lncRNA-miRNA-mRNA regulatory network provides new insights into the underlying mechanisms of BRAF inhibitor resistance in melanoma.

Simulating BRAFV600E-MEK-ERK signalling dynamics in response to vertical inhibition treatment strategies

In vertical inhibition treatment strategies, multiple components of an intracellular pathway are simultaneously inhibited. Vertical inhibition of the BRAFV600E–MEK-ERK signalling pathway is a standard of care for treating BRAFV600E-mutated melanoma where two targeted cancer drugs, a BRAFV600E-inhibitor, and a MEK inhibitor, are administered in combination. Targeted therapies have been linked to early onsets of drug resistance, and thus treatment strategies of higher complexities and lower doses have been proposed as alternatives to current clinical strategies. However, finding optimal complex, low-dose treatment strategies is a challenge, as it is possible to design more treatment strategies than are feasibly testable in experimental settings. To quantitatively address this challenge, we develop a mathematical model of BRAFV600E–MEK-ERK signalling dynamics in response to combinations of the BRAFV600E-inhibitor dabrafenib (DBF), the MEK inhibitor trametinib (TMT), and the ERK-inhibitor SCH772984 (SCH). From a model of the BRAFV600E–MEK–ERK pathway, and a set of molecular-level drug–protein interactions, we extract a system of chemical reactions that is parameterised by in vitro data and converted to a system of ordinary differential equations (ODEs) using the law of mass action. The ODEs are solved numerically to produce simulations of how pathway-component concentrations change over time in response to different treatment strategies, i.e., inhibitor combinations and doses. The model can thus be used to limit the search space for effective treatment strategies that target the BRAFV600E–MEK–ERK pathway and warrant further experimental investigation. The results demonstrate that DBF and DBF–TMT–SCH therapies show marked sensitivity to BRAFV600E concentrations in silico, whilst TMT and SCH monotherapies do not.