Therapy In Melanoma Patients Research Articles

Eravacycline improves the efficacy of anti-PD1 immunotherapy via AP1/CCL5 mediated M1 macrophage polarization in melanoma

Screening approved library is a promising and safe strategy to overcome the limitation of low response rate and drug resistance in immunotherapy. Accumulating evidence showed that the application of antibiotics has been considered to reduce the effectiveness of anti-PD1 immunotherapy in tumor treatment, however, in this study, an antibiotic drug (Eravacycline, ERV) was identified to improve the efficacy of anti-PD1 immunotherapy in melanoma through screening approved library. Administration of ERV significantly attenuated melanoma cells growth as well as directly or indirectly benefited M1 macrophage polarization. Meanwhile, ERV treatment significantly induced cellular autophagy via damage of mitochondria, leading to up-regulation of ROS production, subsequently, raised CCL5 secretion through elevation AP1 binding to CCL5 promoter via p38 or JNK1/2 activation. Knockdown of Ccl5 expression attenuated ERV triggered M1 macrophage polarization in melanoma cells. Clinical analysis revealed a positive association between high expression of CCL5 and improved prognosis as well as a favorable anti-PD1 therapy in melanoma patients. As expected, application of ERV improved the efficacy of anti-PD1. Overall, our results approved that ERV enhances the efficacy of anti-PD1 immunotherapy in melanoma by promoting the polarization of M1 macrophages, which provided novel therapeutic strategy for improving the effectiveness of melanoma anti-PD1 immunotherapy.

Evaluation of colitis induced by immune-checkpoint inhibitors therapy in melanoma patients by an overall grading scale.

Colitis was the third most common immune-related adverse effect in melanoma patients treated with immune-checkpoint inhibitor (ICI). With the limitation of real-world data in the UK population, this study was conducted in a UK hospital where a fresh colitis guidance was introduced to evaluate the overall grading (OG) to assess colitis severity and guide the treatment. This study aimed to investigate colitis severity by Common Terminology Criteria for Adverse Events (CTCAE) grade and overall grade at time of presentation. Colitis treatment and outcome were evaluated to compare the impact of these two categories. A single-center, retrospective observational study was performed in melanoma patient developing colitis symptoms. A total of 44 advanced melanoma patient with colitis symptoms were included. Median time to colitis onset was 67 days (range 4-890). Majority of patients developed G1/ G2 of CTCAE scale (70.4%) but moderate or severe overall grade (84.1%). There were 65.9% of patients treated with steroids, and 38.2% with infliximab and 4.5% with vedolizumab. The median time of colitis resolution was 28 days (range 0-282). Both treatment modality and time to resolution were associated with severity of colitis assessed by complete OG(p<0.0001) rather than CTCAE grading (p>0.05). This study provided a comprehensive description about ICI-induced colitis management in a single center of the UK. The more completed OG was proposed to stratify colitis patient and guide the investigation and treatment decision at presenting time, replacing the old CTCAE grading.

Efficiency and tolerance of second-line triple BRAF inhibitor/MEK inhibitor/anti-PD1 combined therapy in BRAF mutated melanoma patients with central nervous system metastases occurring during first-line combined targeted therapy: a real-life survey.

Although current systemic therapies significantly improved the outcome of advanced melanoma, the prognosis of patient with central nervous system (CNS) metastases remains poor especially when clinically symptomatic. We aimed to investigate the efficiency of CNS targets and tolerance of second-line combined anti-PD1/dual-targeted anti-BRAF/anti-MEK therapy implemented in patients with CNS progression after initially efficient first-line combined targeted therapy in patients with BRAF-mutated melanoma in a real-life setting. A monocentric retrospective analysis including all such patients treated from January 2017 to January 2022 was conducted in our tertiary referral center. The response of CNS lesions to second-line triple therapy was assessed through monthly clinical and at least quarterly morphological (according to RECIST criteria) evaluation. Tolerance data were also collected. Seventeen patients were included with a mean follow-up of 2.59 (±2.43) months. Only 1 patient displayed a significant clinical and morphological response. No statistically significant difference was observed between patients receiving or not additional local therapy (mainly radiotherapy) as to response achievement. Immunotherapy was permanently discontinued in 1 patient owing to grade 4 toxicity. Mean PFS and OS after CNS progression were 2.59 and 4.12 months, respectively. In this real-life survey, the subsequent addition of anti-PD1 to combined targeted therapy in melanoma patients with upfront CNS metastases did not result in significant response of CNS targets in most BRAF mutated melanoma patients with secondary CNS progression after initially successful first-line combined targeted therapy.

Multi-omics and tumor immune microenvironment characterization of a prognostic model based on aging-related genes in melanoma.

Melanoma is a common and fatal cutaneous malignancy with strong invasiveness and high mortality rate. Clinically, elderly melanoma patients tend to exhibit stronger invasion ability and poorer prognosis. Given the heterogeneity of tumors, we analyzed the prognosis and risk assessment of melanoma through aging-related genes rather than age stratification. FOXM1 and CCL4 were identified to be closely associated with melanoma prognosis. Single-cell transcriptome analysis showed that FOXM1 was significantly up-regulated in tumor cells, while CCL4 was markedly elevated in immune cells. A melanoma prognostic model was constructed based on the two independent prognostic factors. This model showed a high accuracy in predicting the mortality of melanoma patients over several years. The patients in low-risk group appeared to have more immune cell infiltration and better immune therapy efficacy. Cellular experiments showed that CCL4 could promote apoptosis of melanoma cells through immune cells, and apoptosis could regulate the expression of FOXM1. In addition, the results of the spatial transcriptome and immunohistochemistry suggested that CCL4 was highly expressed in macrophages and the expression of FOXM1 in melanoma cell was negatively correlated with immune cell infiltration, especially macrophages. Here, we established a novel prognostic model for melanoma, which showed promising predictive performance and may serve as a biomarker for the efficacy of immune checkpoint inhibition therapy in melanoma patients. In addition, we explored the function of two genes in the model in melanoma.

Potential Benefits and Challenges of mRNA Cancer Vaccines

Cancer is a complex and multifaceted disease that affects millions of people worldwide. One of the most promising advances in cancer treatment and prevention is the development of mRNA cancer vaccines. These vaccines are designed to harness the power of the immune system to target and eliminate cancer cells, offering a revolutionary approach to cancer therapy. Recently, one mRNA vaccine (mRNA-4157/v940) received FDA approval to be used as an adjuvant with Pembrolizumab therapy in melanoma patients. In addition, several mRNA cancer vaccines are in the development stage as follows.

TIGIT+ NK cells in combination with specific gut microbiota features predict response to checkpoint inhibitor therapy in melanoma patients

BackgroundComposition of the intestinal microbiota has been correlated to therapeutic efficacy of immune checkpoint inhibitors (ICI) in various cancer entities including melanoma. Prediction of the outcome of such therapy, however, is still unavailable. This prospective, non-interventional study was conducted in order to achieve an integrated assessment of the connection between a specific intestinal microbiota profile and antitumor immune response to immune checkpoint inhibitor therapy (anti-PD-1 and/or anti-CTLA-4) in melanoma patients.MethodsWe assessed blood and stool samples of 29 cutaneous melanoma patients who received immune checkpoint inhibitor therapy. For functional and phenotypical immune analysis, 12-color flow cytometry and FluoroSpot assays were conducted. Gut microbiome was analyzed with shotgun metagenomics sequencing. To combine clinical, microbiome and immune variables, we applied the Random Forest algorithm.ResultsA total of 29 patients was analyzed in this study, among whom 51.7% (n = 15) reached a durable clinical benefit. The Immune receptor TIGIT is significantly upregulated in T cells (p = 0.0139) and CD56high NK cells (p = 0.0037) of responders. Several bacterial taxa were associated with response (e.g. Ruminococcus torques) or failure (e.g. Barnesiella intestinihominis) to immune therapy. A combination of two microbiome features (Barnesiella intestinihominis and the Enterobacteriaceae family) and one immune feature (TIGIT+ CD56high NK cells) was able to predict response to ICI already at baseline (AUC = 0.85; 95% CI: 0.841–0.853).ConclusionsOur results reconfirm a link between intestinal microbiota and response to ICI therapy in melanoma patients and furthermore point to TIGIT as a promising target for future immunotherapies.

Tumour regression predicts better response to interferon therapy in melanoma patients: a retrospective single centre study.

We hypothesise that regression may have an impact on the effectiveness of adjuvant IFN therapy, based on its role in the host immune response. Our purpose is to investigate regression and ulceration as prognostic factors in case of interferon-alpha (IFN)-treated melanoma patients. We followed 357 IFN-treated melanoma patients retrospectively, investigating progression-free survival (PFS) and overall survival (OS) depending on the presence of ulceration and regression. A Kaplan-Meier analysis was performed, and we used a Cox regression analysis to relate risk factors. The survival function of the Cox regression was used to measure the effect of regression and ulceration on PFS and OS depending on the Breslow thickness (T1-T4) of the primary tumour. Regression was significantly positively related to PFS ( P = 0.0018, HR = 0.352) and OS ( P = 0.0112, HR = 0.380), while ulceration showed a negative effect (PFS: P = 0.0001, HR = 2.629; OS: P = 0.0003, HR = 2.388). They influence survival independently. The most favourable outcome was measured in the regressed/non-ulcerated group, whereas the worse was in the non-regressed/ulcerated one. Of risk factors, Breslow thickness is the most significant predictor. The efficacy of regression is regardless of Breslow thickness, though the more favourable the impact of regression was in the thicker primary lesions. Our results indicate that regression is associated with a more favourable outcome for IFN-treated melanoma patients, whereas ulceration shows an inverse relation. Further studies are needed to analyse the survival benefit of regression in relation to innovative immune checkpoint inhibitors.

HRS mediates tumor immune evasion by regulating proteostasis-associated interferon pathway activation

By sorting receptor tyrosine kinases into endolysosomes, the endosomal sorting complexes required for transport (ESCRTs) are thought to attenuate oncogenic signaling in tumor cells. Paradoxically, ESCRT members are upregulated in tumors. Here, we show that disruption of hepatocyte growth factor-regulated tyrosine kinase substrate (HRS), a pivotal ESCRT component, inhibited tumor growth by promoting CD8+ Tcell infiltration in melanoma and colon cancer mouse models. HRS ablation led to misfolded protein accumulation and triggered endoplasmic reticulum (ER) stress, resulting in the activation of the type I interferon pathway in an inositol-requiring enzyme-1α (IRE1α)/X-box binding protein 1 (XBP1)-dependent manner. HRS was upregulated in tumor cells with high tumor mutational burden (TMB). HRS expression associates with the response to PD-L1/PD-1 blockade therapy in melanoma patients with high TMB tumors. HRS ablation sensitized anti-PD-1 treatment in mouse melanoma models. Our study shows a mechanism by which tumor cells with high TMB evade immune surveillance and suggests HRS as a promising target to improve immunotherapy.

Response to checkpoint inhibition and targeted therapy in melanoma patients with concurrent haematological malignancies

BackgroundPatients diagnosed with haematologic malignancies (HMs) have a higher risk of developing subsequent solid tumours, such as melanoma. Patients with HM were mostly excluded from clinical trials but potentially derive less benefit from immune checkpoint inhibitors (ICIs) due to disease- or treatment-related T- or B-cell dysfunction. MethodsAll advanced melanoma patients treated with anti-PD-1-based treatment or targeted therapy between 2015 and 2021 were included from the prospective nationwide Dutch Melanoma Treatment Registry. Progression-free survival (PFS) and melanoma-specific survival (MSS) were analysed for patients with HM (HM+) and without HM (HM−). A cox model was used to account for confounders associated with PFS and MSS. ResultsIn total, 4638 advanced melanoma patients received first-line anti-PD-1 monotherapy (n = 1763), ipilimumab-nivolumab (n = 800), or BRAF(/MEK) inhibitors (n = 2075). Concurrent HMs were present for 46 anti-PD1-treated patients, 11 ipilimumab-nivolumab-treated patients and 43 BRAF(/MEK)-inhibitor-treated patients. In anti-PD-1-treated patients, the median PFS was 2.8 months for HM+ and 9.9 months for HM− (p = 0.01). MSS was 41.2 months for HM+ and 58.1 months for HM− (p = 0.00086). In multivariable analysis, the presence of an HM was significantly associated with higher risk of melanoma progression (HRadj 1.62; 95% confidence interval [95% CI] 1.15–2.29; p = 0.006) and melanoma-related death (HRadj 1.74; 95% CI 1.09–2.78; p = 0.020). Median PFS and MSS for first-line BRAF(/MEK-) inhibitor-treated HM+ and HM− patients were not significantly different. ConclusionsPatients with HM and advanced melanoma show significantly worse melanoma-related outcomes when treated with ICI, but not targeted therapy, compared to patients without HM. Clinicians should be aware of potentially altered effectiveness of ICI in patients with active HM.

Dysregulation of PD-L1 by UFMylation imparts tumor immune evasion and identified as a potential therapeutic target.

Immunotherapy of PD-L1/PD-1 blockage elicited impressive clinical benefits forcancer treatment. However, the relative low response and therapy resistance highlight the need to better understand the molecular regulation of PD-L1 in tumors. Here, we report that PD-L1 is a target of UFMylation. UFMylation of PD-L1 destabilizes PD-L1 by synergizing its ubiquitination. Inhibition of PD-L1 UFMylation via silencing of UFL1 or Ubiquitin-fold modifier 1 (UFM1), or the defective UFMylation of PD-L1, stabilizes the PD-L1 in multiple human and murine cancer cells, and undermines antitumor immunity invitro and mice, respectively. Clinically, UFL1 expression was decreased in multiple cancers and lower expression of UFL1 negatively correlated with the response of anti-PD1 therapy in melanoma patients. Moreover, we identified a covalent inhibitor of UFSP2 that promoted the UFMylation activity and contributed to the combination therapy with PD-1 blockade. Our findings identified a previously unrecognized regulator of PD-L1 and highlighted UFMylation as a potential therapeutic target.

A pathway-based mutation signature to predict the clinical outcomes and response to CTLA-4 inhibitors in melanoma

Immune checkpoint inhibitor (ICI) therapy has become a powerful clinical strategy for treating melanoma. The relationship between somatic mutations and the clinical benefits of immunotherapy has been widely recognized. However, the gene-based predictive biomarkers are less stable due to the heterogeneity of cancer at the individual gene level. Recent studies have suggested that the accumulation of gene mutations in biological pathways may activate antitumor immune responses. Herein, a novel pathway mutation signature (PMS) was constructed to predict the survival and efficacy of ICI therapy. In a dataset of melanoma patients treated with anti-CTLA-4, we mapped the mutated genes into the pathways and then identified seven significant mutation pathways associated with survival and immunotherapy response, which were used to construct the PMS model. According to the PMS model, the patients in the PMS-high group showed better overall survival (hazard ratio (HR) = 0.37; log-rank test, p < 0.0001) and progression-free survival (HR = 0.52; log-rank test, p = 0.014) than those in the PMS-low group. The PMS-high patients also showed a significantly higher objective response rate to anti-CTLA-4 therapy than the PMS-low patients (Fisher’s exact test, p = 0.0055), and the predictive power of the PMS model was superior to that of TMB. Finally, the prognostic and predictive value of the PMS model was validated in two independent validation sets. Our study demonstrated that the PMS model can be considered a potential biomarker to predict the clinical outcomes and response to anti-CTLA-4 therapy in melanoma patients.

5P Tumor microenvironment cellular crosstalk predicts response to adoptive TIL therapy in melanoma patients

Adoptive cell therapy (ACT) using tumor-infiltrating lymphocytes (TILs) has proven efficacious in metastatic melanoma (Mel). Nevertheless, long-term clinical efficacy remains unsatisfactory for the majority of patients. Therefore, understanding TILs and the orchestrated tumor-microenvironment (TME) states associated with clinical response is of paramount importance.

Sphingosine kinase 1 promotes tumor immune evasion by regulating the MTA3-PD-L1 axis

Immune checkpoint blockade (ICB) exhibits considerable benefits in malignancies, but its overall response rate is limited. Previous studies have shown that sphingosine kinases (SPHKs) are critical in the tumor microenvironment (TME), but their role in immunotherapy is unclear. We performed integrative analyses including bioinformatics analysis, functional study, and clinical validation to investigate the role of SPHK1 in tumor immunity. Functionally, we demonstrated that the inhibition of SPHK1 significantly suppressed tumor growth by promoting antitumor immunity in immunocompetent melanoma mouse models and tumor T-cell cocultures. A mechanistic analysis revealed that MTA3 functions as the downstream target of SPHK1 in transcriptionally regulating tumor PD-L1. Preclinically, we found that anti-PD-1 monoclonal antibody (mAb) treatment significantly rescued tumor SPHK1 overexpression or tumor MTA3 overexpression-mediated immune evasion. Significantly, we identified SPHK1 and MTA3 as biological markers for predicting the efficacy of anti-PD-1 mAb therapy in melanoma patients. Our findings revealed a novel role for SPHK1 in tumor evasion mediated by regulating the MTA3-PD-L1 axis, identified SPHK1 and MTA3 as predictors for assessing the efficacy of PD-1 mAb treatment, and provided a therapeutic possibility for the treatment of melanoma patients.

Loss of MHC-I antigen presentation correlated with immune checkpoint blockade tolerance in MAPK inhibitor-resistant melanoma.

Immune checkpoint blockade and MAPK-targeted combined therapy is a promising regimen for advanced melanoma patients. However, the clinical benefit from this combo regimen remains limited, especially in patients who acquired resistance to MAPK-targeted therapy. Here, we systematically characterized the immune landscape during MAPK-targeted therapy in patients and mouse melanoma models. We observed that both the abundance of tumor-infiltrated T cells and the expression of immune-related genes were upregulated in the drug-responsive period, but downregulated in the resistance period, implying that acquired drug resistance dampens the antitumor immune response. Further transcriptomic dissection indicated that loss of MHC-I antigen presentation on tumor cells plays a critical role in the reduction of T cell infiltration during drug resistance. Survival analysis demonstrates that loss of antigen presentation and reduction of T-cell infiltration during acquired drug resistance are associated with poorer clinical response and prognosis of anti-PD-1 therapy in melanoma patients. In addition, we identified that alterations in the MAPK inhibitor resistance-related oncogenic signaling pathway closely correlated with deficiency of MHC-I antigen presentation, including activation of the PI3K-mTOR, MAPK, and Wnt pathways. In conclusion, our research illuminates that decreased infiltration of T cells is associated with acquired drug resistance during MAPK-targeted therapy, which may underlie the cross-resistance to immune checkpoint blockade.

Abstract 539: Development of a novel 5-plex copy number ddPCR assay for ctDNA analysis

Abstract Background: Analysis of cell-free circulating tumor DNA (ctDNA) from blood provides an opportunity to detect potential mechanisms of resistance to targeted therapies in melanoma patients. Approximately 20% and 17% of patients undergoing BRAF targeted therapy develop resistance associated with copy number increases in either BRAF or cylinD1 (CCND1), respectively. Detection of BRAF or CCND1 copy number gains prior to radiographic tumor progression could potentially prompt a therapeutic switch aimed at treating patients with smaller tumors burdens, which may improve survival. Conventional droplet digital PCR (ddPCR) for copy number analysis uses two probes, one target and one reference gene (2-plex). To improve the accuracy and sensitivity of the copy number analysis and account for possible genetic alterations in the reference gene, we performed a 5-probe multiplex (5-plex) reaction using three reference genes and two targets. Methods: We used cell lines with known copy number gains for the BRAF gene (M395-R) and CCND1 gene (SkMel-187) to identify copy number increases using ddPCR. To estimate the limit of detection of the copy number gains in plasma, high and low concentrations of the cell line DNAs were spiked into healthy plasma and divided into three replicate samples of 3ml each. DNA was extracted from plasma using the Circulating DSP NA Kit (Qiagen). The ddPCR reaction mix used 4X Supermix and five different copy number specific probes targeting: two genes of interest, BRAF (7q34) and CCND1 (11q13.3); and three control genes: FOXI3 (2p11.2), AGO1 (1p34.3) and TTC5 (14q11.2). Each probe was titrated to display a unique cluster location on the 2D plot. Probe concentrations were: BRAF: FAM 2X; CCND1: FAM 1X; FOXI3: HEX 2X; AGO1: HEX 1X; TTC5: FAM 0.7X/HEX 0.4X. Each extraction was divided into 4 replicate wells. Following droplet generation, gene copies were analyzed using the QX Manager 1.2 Standard Edition for advanced analysis. Results: Probe titration resulted in 32 quantifiably distinct ddPCR clusters on a single 2D plot. Copies/ul of the reference genes were used as a benchmark for diploid status. We determined that the M395-R cell line had 45 copies of the BRAF gene and that SKMel-187 had eight copies of the CCND1 gene compared to diploid PBMC DNA (Promega). Based on the spike-in experiments, we estimate that we can detect copy number gains in plasmas with 10% or 20% tumor fraction when tumor cells have approximately 45 or 8 copies of the target gene, respectively. Conclusion: We successfully multiplexed five copy number assays in a single ddPCR reaction, and showed that copy number changes could be identifiable with as little as 10% tumor fraction within plasma when the tumor-associated copy number gains were relatively high. Overall, the 5-plex assay has the potential to be excellent tool for copy number detection in blood, and can be customized as needed for other targets. Citation Format: Jennifer M. Wiggins, Mahrukh Syeda, David Polsky. Development of a novel 5-plex copy number ddPCR assay for ctDNA analysis [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 539.

A Cancer Associated Fibroblasts-Related Six-Gene Panel for Anti-PD-1 Therapy in Melanoma Driven by Weighted Correlation Network Analysis and Supervised Machine Learning.

BackgroundMelanoma is a highly aggressive skin cancer with a poor prognosis and mortality. Immune checkpoint blockade (ICB) therapy (e.g., anti-PD-1 therapy) has opened a new horizon in melanoma treatment, but some patients present a non-responsive state. Cancer-associated fibroblasts (CAFs) make up the majority of stromal cells in the tumor microenvironment (TME) and have an important impact on the response to immunotherapy. There is still a lack of identification of CAFs-related predictors for anti-PD-1 therapy, although the establishment of immunotherapy biomarkers is well underway. This study aims to explore the potential CAFs-related gene panel for predicting the response to anti-PD-1 therapy in melanoma patients and elucidating their potential effect on TME.MethodsThree gene expression datasets from melanoma patients without anti-PD-1 treatment, in a total of 87 samples, were downloaded from Gene Expression Omnibus (GEO) as the discovery sets (GSE91061) and validation sets (GSE78220 and GSE122220). The CAFs-related module genes were identified from the discovery sets by weighted gene co-expression network analysis (WGCNA). Concurrently, we utilized differential gene analysis on the discovery set to obtain differentially expressed genes (DEGs). Then, CAFs-related key genes were screened with the intersection of CAFs-related module genes and DEGs, succeeded by supervised machine learning-based identification. As a consequence of expression analysis, gene set enrichment analysis, survival analysis, staging analysis, TME analysis, and correlation analysis, the multidimensional systematic characterizations of the key genes were uncovered. The diagnostic performance of the CAFs-related gene panel was assessed by receiver operating characteristic (ROC) curves in the validation sets. Eventually, the CAFs-related gene panel was verified by the expression from the single-cell analysis.ResultsThe six-gene panel associated with CAFs were finally identified for predicting the response to anti-PD-1 therapy, including CDK14, SYNPO2, TCF4, GJA1, CPXM1, and TFPI. The multigene panel demonstrated excellent combined diagnostic performance with the area under the curve of ROC reaching 90.5 and 75.4% ~100% in the discovery and validation sets, respectively.ConclusionConfirmed by clinical treatment outcomes, the identified CAFs-related genes can be used as a promising biomarker panel for prediction to anti-PD-1 therapy response, which may serve as new immunotherapeutic targets to improve survival outcomes of melanoma patients.

The Predictive Value of MAP2K1/2 Mutations on Efficiency of Immunotherapy in Melanoma.

Background MAP2K1/2 genes are mutated in approximately 8% of melanoma patients; however, the impact of MAP2K1/2 gene alterations on the efficiency of immunotherapy has not been clarified. This study focused on the correlation between MAP2K1/2 gene mutations and the treatment response.MethodsSix metastatic melanoma clinical cohorts treated with immune checkpoint inhibitors [anti-cytotoxic T lymphocyte antigen-4 (CTLA-4) or anti-programmed cell death-1 (PD-1)] were recruited in this study. RNA expression profiling results from each of these six cohorts and the Cancer Genome Atlas (TCGA) melanoma cohort were analysed to explore the mechanism related to immune activation.ResultsCompared to patients with wild-type MAP2K1/2, those with MAP2K1/2 mutations in an independent anti-CTLA-4-treated cohort had higher objective response rates, longer progression-free survival, and longer overall survival (OS). These findings were further validated in a pooled anti-CTLA-4-treated cohort in terms of the OS. However, there was no correlation between MAP2K1/2 mutations and OS in the anti-PD-1-treated cohort. Subgroup Cox regression analysis suggested that patients with MAP2K1/2 mutations received fewer benefits from anti-PD-1 monotherapy than from anti-CTLA-4 treatment. Furthermore, transcriptome profiling analysis revealed that melanoma tumours with MAP2K mutation was enriched in CD8+ T cells, B cells, and neutrophil cells, also expressed high levels of CD33 and IL10, implying a potential mechanism underlying the benefit of melanoma patients with MAP2K1/2 mutations from anti-CTLA-4 treatment.Conclusions MAP2K1/2 mutations were identified as an independent predictive factor for anti-CTLA-4 therapy in melanoma patients. Anti-CTLA-4 treatment might be more effective than anti-PD-1 therapy for patients with MAP2K1/2-mutated melanoma.

Late-onset adverse events of anti-PD1 therapy in melanoma patients: An observational study from MELBASE, a nationwide prospective cohort

Late-onset adverse events (AEs) of anti-programmed cell death 1 (anti-PD1) antibodies have not been systematically described. The purpose was to evaluate late-onset AEs in melanoma patients treated with anti-PD1 administered for at least 2years in a real-life setting. Patients were screened from MelBase, a French multicentric biobank dedicated to the prospective follow up of unresectable stage III or IV melanoma. The study included 119 patients who received anti-PD1 during at least 2years from January 2013 to November 2019. Median follow up was 41.7months (range, 25.2-57.5months). Fifty-three patients received nivolumab and 66 patients received pembrolizumab. AEs occurred in 99 patients (83%) with a median time of 13.3months (range, 0-53.9months), including severe AEs (grade 3 or 4) in 30 patients (30%). Late-onset AEs, mostly grades 1 or 2, occurred in 51 (43%) patients and led to 5 (4%) hospitalizations, of which 4 were severe. Factors associated with late-onset AEs in multivariate analysis were early-onset AEs (within the first 2years of treatment) and treatment duration (P=.02 and P=.03, respectively). Our data demonstrate the possibility of late-onset AEs occurring after 2years of anti-PD1 therapy. Late-onset AEs appear frequently and were mostly mild or moderate. Early-onset AEs and prolonged anti-PD1 treatment may increase the risk of late-onset AEs.

Is adjuvant treatment for melanoma in clinical practice comparable to trials? The first population-based results.

e21523 Background: Little is known about the outcome of adjuvant therapy in melanoma patients beyond the clinical trial setting. The Dutch Melanoma treatment Registry (DMTR) is a population-based registry, set up in July 2013 to monitor the safety and quality of melanoma care. Since 2019, adjuvant treated melanoma patients have also been registered in the DMTR, following approval and reimbursement of adjuvant treatment in the Netherlands in December 2018. Methods: Analyses were performed on melanoma patients treated with adjuvant anti-PD1 therapy included in the DMTR between 01-07-2018 and 31-12-2019. Descriptive statistics were used to analyze patient-, and treatment characteristics, and death as well as relapse rates. Results: Six hundred and fifty-seven patients treated with adjuvant systemic therapy were included in the DMTR. The majority (94%) of these patients was treated with anti-PD1. Twenty percent of the anti-PD1-treated patients developed grade ≥3 toxicity. Of the 279 patients with a minimum follow-up of one year after start of anti-PD1, 170 (61%) prematurely discontinued therapy. Relapse and death occurred in respectively, 38% and 12% of patients within one year of follow-up. Relapse was significantly more frequent in older patients, with high Breslow thickness and ulcerated melanomas. Conclusions: These data show more frequent premature discontinuation of adjuvant anti-PD1 in daily clinical practice than reported in the registration trials. Moreover, incidence of severe toxicity, relapse and death during adjuvant treatment appears higher in the real-world setting.

The predictive value of MAP2K1/2 mutations for efficiency of immunotherapy in melanoma.

e21587 Background: Immunotherapies targeting immune checkpoint receptors have become the cornerstone of systemic treatment options for malignant melanoma. The response to these immunotherapies may correlate with driver mutations. MAP2K1/2 genes are mutated in approximately 10% of melanomas, however, the impact of MAP2K1/2 gene alterations on the efficiency of immunotherapy has not been clarified. Methods: Six metastatic melanoma clinical cohorts treated with ICIs were included to investigate the association between clinical efficacy of immunotherapy and MAP2K1/2 mutations. Survival analyses were conducted in cohorts receiving two kinds of ICB agents, namely anti-CTLA-4 or anti-PD-1. RNA expression profiling from these cohorts and from the TCGA melanoma cohort were used to explore the potential mechanism related to immune activation. Results: In an independent anti-CTLA-4-treated cohort (n = 110), we found that MAP2K1/2 mutations are predictive of high objective response rate (17.6% vs 1.3%, p = 0.0185) and long progression-free survival [median OS, 49.2 months vs 8.3 months; hazard ratio (HR) = 0.37; 95% CI, 0.15–0.91; p = 0.0307] and overall survival (median PFS, 19.4 months vs 2.8 months; HR = 0.2; 95% CI, 0.05–0.83; p = 0.0262). This predictive value was further validated in a pooled anti-CTLA-4-treated cohort (n = 235) in terms of overall survival (median OS, 49.3 months vs 22.0 months; HR = 0.44; 95% CI, 0.22–0.91; p = 0.0255). However, no correlation between MAP2K1/2 mutations and overall survival was observed in the anti-PD-1-treated cohort (n = 285). Subgroup Cox regression analysis indicated that MAP2K-mutated patients receive less benefit from the anti-PD-1 monotherapy than from the anti-CTLA-4 treatment (median OS, 27.0 months vs 49.3 months; HR = 3.26; 95% CI, 1.18–9.02; p = 0.0225), which was contrary to the result obtained for the total population. Furthermore, transcriptome profiling analysis revealed that MAP2K-mutated tumors are enriched in CD8+ T cells, B cells, and neutrophil cells and also express high levels of CD33 and IL10, which might be the underlying mechanism for melanoma patients with MAP2K1/2-mutated benefit more from anti-CTLA-4 treatment. Conclusions: We identified mutations in MAP2K1/2 genes as the independent predictive factors for anti-CTLA-4 therapy in melanoma patients and found that anti-CTLA-4 treatment in patient harbouring MAP2K1/2 mutations might be more effective than the anti-PD-1 therapy.