PD-L1 is a biomarker of real-world clinical outcomes for anti-CTLA-4 plus anti-PD-1 or anti-PD-1 monotherapy in metastatic melanoma

Predictive Biomarkers for Immune Checkpoint Inhibitor Therapy in Advanced Melanomas

Biomarkers capable of predicting adverse melanoma patient responses to immune checkpoint inhibitor (ICI) therapies are an unmet need. Clinical biomarkers are largely prognostic and current response guidelines do not reflect the complex tumor-immune cell interaction dynamics attributed to ICI therapies. Validation of enhanced predictive biomarkers is dependent upon adoption of novel spatial imaging platforms capable of quantifying immune checkpoint receptor-ligand interactions within the tumor microenvironment. Assessments of these interactions at multiple points during neoadjuvant ICI regimens would inform biomarker selection based on changes in receptor-ligand interactions that best correlate with patient survival.

[Biomarkers in adjuvant and neoadjuvant treatment of melanoma]

BACKGROUND

Personalized treatment of melanoma is becoming increasingly more important. Biomarkers offer the possibility of controlling treatment more precisely and reducing side effects.

OBJECTIVE

The aim of this text is to provide an overview of current tissue-based, blood-based and radiological biomarkers and their clinical application in melanomas.

MATERIAL AND METHODS

A literature research and analysis of current studies on biomarkers in adjuvant and neoadjuvant treatment of melanomas were carried out and relevant congress contributions were additionally included.

RESULTS

Tissue-based programmed cell death 1 ligand 1 (PD-L1) expression, interferon gamma (IFNγ) signature, gene expression profiles (GEP) and tumor mutational burden (TMB) are of prognostic and predictive relevance. Blood-based circulating tumor DNA (ctDNA) in the sense of a liquid biopsy should be emphasized as a personalized biomarker for longitudinal tracking during treatment or aftercare. Positron emission tomography computed tomography (PET-CT) and body composition enable an improved assessment of treatment efficiency. There are currently no data from prospective validation studies on these biomarkers; initial data from the NivoMela study are awaited.

CONCLUSION

The combination of tissue-based, blood-based and radiological biomarkers in terms of multiparametric approaches is promising but further prospective validation is needed for broad clinical use. These are currently not comprehensively implemented in the clinical routine in centers or in remuneration procedures.

Long-term clinical outcome of patients with metastatic melanoma and initial stable disease during anti-PD-1 checkpoint inhibitor immunotherapy with pembrolizumab

BACKGROUND

A substantial number of patients with metastatic melanoma (MM) treated with anti-PD-1 monotherapy have initial stable disease (SD), yet the real-world prognosis of these patients remains unclear.

METHODS

In this nationwide cohort study, we analysed real-world outcomes of patients with MM treated with pembrolizumab in Denmark. Focusing on patients with initial SD, we assessed best overall response (BOR), progression-free survival (PFS), and overall survival (OS) and identified predictors of survival in multivariable analyses.

RESULTS

Out of 1048 included patients, 233 (22.2%) had initial SD with a median PFS and OS of 14.7 and 50.1 months. Subsequent partial response (PR) or complete response (CR) was developed by 44 (18.9%) and 52 (22.3%) patients showing significantly improved PFS compared to patients with continued SD (PR: HR 0.52, 95% CI 0.34-0.81, p = 0.003; CR: HR 0.15, 95% CI 0.07-0.32, p < 0.001) and survival rates comparable to patients with initial PR and CR, respectively. Furthermore, 49 (21.0%) patients showed continued disease control (median follow-up of 82.3 months). For 51.0% of these patients, the last dose of pembrolizumab was administered during SD with a median treatment duration of 12.4 months.

CONCLUSIONS

Of patients with initial SD, 40% developed a subsequent objective response with improved long-term prognosis comparable to patients with initial response. More than 20% exhibited continued disease control.

Impact of assessment-to-treatment interval and metastatic biopsy site on the predictive value of PD-L1 expression at the 1 % cut-off level in melanoma

BACKGROUND

Intratumoral PD-L1 expression at the 1 % cut-off predicts clinical outcomes and may guide first-line immune checkpoint inhibitor (ICI) selection for metastatic melanoma (MM). However, the impact of the interval between PD-L1 assessment and ICI initiation and the metastatic site used for PD-L1 evaluation, remains unclear.

METHODS

In this nationwide cohort study we used the Danish Metastatic Melanoma Database (DAMMED) and the Danish Pathology Registry to analyze patients with MM treated with anti-PD-1 or anti-PD-1 plus anti-CTLA-4 from January 2017 to February 2024. Progression-free survival (PFS) and overall survival (OS) were analyzed using Log-rank tests and Cox regression.

RESULTS

Data from 1137 patients were analyzed. Among patients with PD-L1 assessed within 90 days of treatment (n = 964; 55.2 % PD-L1 <1 %, 44.8 % PD-L1 ≥1 %), combination therapy improved outcomes in PD-L1 < 1 % (PFS adjusted (a)HR 0.62; 95 % CI 0.48-0.80; p < 0.001, OS aHR 0.64; 95 % CI 0.48-0.85; p = 0.002), while outcomes were comparable for PD-L1 ≥ 1 % patients (PFS aHR 0.90; 95 % CI 0.62-1.30; p = 0.57, OS aHR 0.97; 95 % CI 0.60-1.57; p = 0.89). For PD-L1 assessed > 90 days prior (n = 173), this pattern was less pronounced. Among 48 paired PD-L1 assessments from the same organ, discordance occurred in 25 %. Combination therapy improved PFS for patients with PD-L1 < 1 % skin/subcutaneous (aHR 0.51; 95 % CI 0.34-0.76; p < 0.001) and visceral metastases (aHR 0.65; 95 % CI 0.42-1.02; p = 0.060) while this association was not evident for lymph node metastases (aHR 0.79; 95 % CI 0.48-1.29; p = 0.35).

CONCLUSIONS

PD-L1 seems a reliable predictive biomarker in MM, when assessed on tissue obtained within 90 days prior to ICI initiation. Non-nodal metastatic sites appear preferable.

The emerging role of lymphocyte-activation gene 3 targeting in the treatment of solid malignancies

PD-(L)1-based immune checkpoint inhibitor therapies have profoundly impacted the treatment of many solid malignancies. Although the addition of CTLA-4 checkpoint inhibitors can enhance anticancer activity, it also significantly increases the rate of immune-related adverse events. Therefore, there has been much interest in identifying additional immune checkpoints to improve the outcomes seen with PD-1-based therapy while minimizing additional side effects. One such target, lymphocyte-activation gene 3 (LAG-3), has long been recognized as an important inhibitor of T-cell function via modulation of the T-cell receptor pathway. Several drugs targeting LAG-3 have been developed, including most prominently the monoclonal antibody relatlimab. To date, the most significant demonstration of efficacy in targeting LAG-3 has been the use of relatlimab with the PD-1 inhibitor nivolumab in the treatment of advanced melanoma. The combination of nivolumab plus relatlimab is more efficacious compared to PD-1 inhibition alone, as has been previously seen with the combination of CTLA-4 inhibitor ipilimumab with nivolumab. However, nivolumab plus relatlimab offers a potentially more favorable toxicity profile. Here, the authors review the mechanism of the LAG-3 pathway and its rationale as a target for anticancer therapy as well as currently available data regarding the use of LAG-3 agents in treating melanoma and other solid tumors. Other investigational agents that target LAG-3 via novel mechanisms are also reviewed.

Combination Immunotherapy With Nivolumab Plus Ipilimumab in Melanoma of Unknown Primary

The Oncology Grand Rounds series is designed to place original reports published in the Journal into clinical context. A case presentation is followed by a description of diagnostic and management challenges, a review of the relevant literature, and a summary of the authors' suggested management approaches. The goal of this series is to help readers better understand how to apply the results of key studies, including those published in Journal of Clinical Oncology, to patients seen in their own clinical practice.

Navigating the landscape of immune checkpoint inhibitors and novel immunotherapies in melanoma: long-term outcomes, progress, and challenges

INTRODUCTION

Melanoma has become the poster child for transformative outcomes in advanced malignancy from the use of immunotherapy over the last 10-15 years with median survival improving from ~ 1 to > 5 years. With the increasing repertoire of immune checkpoint inhibitors (ICI) and other novel immunotherapeutic approaches, integrating and sequencing treatments to create new paradigms has gained prominence, with focus on optimizing toxicity management and complex scenarios such as immunotherapy resistance, brain metastases, fertility, and duration of follow-up.

AREAS COVERED

In this review, we summarize the progress and emerging evidence in melanoma treatments to date and consider management and possible future directions to improve outcomes for above-mentioned specific patient cohorts.

EXPERT OPINION

Personalized care with integration of novel prognostic and predictive biomarkers is the way forward in tailoring not only patient selection and choice of therapy, but also duration of treatment and surveillance to allow for early recurrence detection and access to newer therapies such as tumor infiltrating lymphocytes (TIL) to maximize the curative fraction of melanoma patients. Further research is needed in optimizing ICI and other immunotherapy toxicity management, including reducing steroid exposure for better patient outcomes and preserving quality of life.

Prognostic Biomarkers in Evolving Melanoma Immunotherapy

Melanoma, a highly aggressive form of skin cancer, has seen significant advancements in treatment through the introduction of immunotherapy. However, the variability in patient responses underscores the need for reliable biomarkers to guide treatment decisions. This article reviews key biomarkers in melanoma immunotherapy, such as PD-L1 expression, tumor mutational burden (TMB), and gene expression profiles (GEPs). It also explores emerging biomarkers, including LAG-3 expression, immune cell phenotyping in tissue and blood, gut microbiota, and circulating tumor DNA (ctDNA). Notably, ctDNA may offer valuable insights into the efficacy of T cell-engaging bispecific molecules, such as tebentafusp. The review provides a comprehensive overview of the evolving landscape of melanoma biomarkers, their role in personalizing treatment, and future research directions, including neoadjuvant immune checkpoint inhibition.

Crosstalk Between nNOS/NO and COX-2 Enhances Interferon-Gamma-Stimulated Melanoma Progression

Background/Objectives: Interferon gamma (IFN-γ) in the melanoma tumor microenvironment plays opposing roles, orchestrating both pro-tumorigenic activity and anticancer immune responses. Our previous studies demonstrated the role of neuronal nitric oxide synthase (nNOS) in IFN-γ-stimulated melanoma progression. However, the underlying mechanism has not been well defined. This study determined whether the nNOS/NO and COX-2/PGE2 signaling pathways crosstalk and augment the pro-tumorigenic effects of IFN-γ in melanoma. Methods: Bioinformatic analysis of patient and cellular proteomic data was conducted to identify proteins of interest associated with IFN-γ treatment in melanoma. Changes in protein expression were determined using various analytical techniques including western blot, flow cytometry, and confocal microscopy. The levels of PGE2 and nitric oxide (NO) were analyzed by HPLC chromatography and flow cytometry. In vivo antitumor efficacy was determined utilizing a human melanoma xenograft mouse model. Results: Our omics analyses revealed that the induction of COX-2 was significantly predictive of IFN-γ treatment in melanoma cells. In the presence of IFN-γ, PGE2 further enhanced PD-L1 expression and amplified the induction of nNOS, which increased intracellular NO levels. Cotreatment with celecoxib effectively diminished these changes induced by PGE2. In addition, nNOS blockade using a selective small molecule inhibitor (HH044), efficiently inhibited IFN-γ-induced PGE2 and COX-2 expression levels in melanoma cells. STAT3 inhibitor napabucasin also inhibited COX-2 expression both in the presence and absence of IFN-γ. Furthermore, celecoxib was shown to enhance HH044 cytotoxicity in vitro and effectively inhibit human melanoma tumor growth in vivo. HH044 treatment also significantly reduced tumor PGE2 levels in vivo. Conclusions: Our study demonstrates the positive feedback loop linking nNOS-mediated NO signaling to the COX-2/PGE2 signaling axis in melanoma, which further potentiates the pro-tumorigenic activity of IFN-γ.

European consensus-based interdisciplinary guideline for melanoma. Part 1: Diagnostics - Update 2024

This guideline was developed in close collaboration with multidisciplinary experts from the European Association of Dermato-Oncology (EADO), the European Dermatology Forum (EDF) and the European Organization for Research and Treatment of Cancer (EORTC). Recommendations for the diagnosis and treatment of melanoma were developed on the basis of systematic literature research and consensus conferences. Cutaneous melanoma (CM) is the most dangerous form of skin tumor and accounts for 90 % of skin cancer mortality. The diagnosis of melanoma can be made clinically and must always be confirmed by dermoscopy. If melanoma is suspected, a histopathological examination is always required. Sequential digital dermoscopy and whole-body photography can be used in high-risk patients to improve the detection of early-stage melanoma. If available, confocal reflectance microscopy can also improve the clinical diagnosis in special cases. Melanoma is classified according to the 8th version of the American Joint Committee on Cancer classification. For thin melanomas up to a tumor thickness of 0.8 mm, no further diagnostic imaging is required. From stage IB, lymph node sonography is recommended, but no further imaging examinations. From stage IIB/C, whole-body examinations with computed tomography or positron emission tomography CT in combination with magnetic resonance imaging of the brain are recommended. From stage IIB/C and higher, a mutation test is recommended, especially for the BRAF V600 mutation. It is important to perform a structured follow-up to detect relapses and secondary primary melanomas as early as possible. A stage-based follow-up regimen is proposed, which in the experience of the guideline group covers the optimal requirements, although further studies may be considered. This guideline is valid until the end of 2026.

Dual Immune Checkpoint Inhibition in Melanoma and PD-L1 Expression: The Jury Is Still Out

This comment discusses the use of PD-L1 as a biomarker to guide treatment decisions for metastatic melanoma.

Gal-3 blocks the binding between PD-1 and pembrolizumab

INTRODUCTION

Immune checkpoint inhibitors (ICI) have revolutionized the treatment of metastatic malignant melanoma (MM) and improved long-term survival. Despite the impressive results, some patients still have progressive disease, and the search for biomarkers predicting response to ICI treatment is ongoing. In this search, galectin-3 (Gal-3) has been suggested as a molecule of interest, both as a marker of treatment response and as a treatment target to potentiate ICI therapy. We have previously demonstrated the binding between programmed cell death 1 (PD-1) and Gal-3, and here, we investigated the interaction between PD-1, pembrolizumab, and Gal-3 in metastatic MM patients.

METHODS

The binding between PD-1, pembrolizumab and Gal-3 was investigated by surface plasmon resonance (SPR) and cryogenic electron microscopy (cryo-EM). The function was studied in in vitro cultures and soluble levels of both PD-1 and Gal-3 were measured in metastatic MM patients, treated with pembrolizumab.

RESULTS

By SPR, we demonstrated that Gal-3 can block the binding between PD-1 and pembrolizumab, and further visualized a steric inhibition using cryo-EM. T cells cultured with Gal-3 had reduced pro-inflammatory cytokine production, which could not be rescued by pembrolizumab. In patients with metastatic MM, high levels of Gal-3 in plasma were found in patients with a longer progression-free survival in the study period, whereas high Gal-3 expression in the tumor was seen in patients with disease progression. Soluble PD-1 levels in plasma increased after treatment with pembrolizumab and correlated with disease progression.

CONCLUSION

We demonstrate that the interaction between PD-1 and Gal-3 interferes with the binding of pembrolizumab, supporting that an immune suppression induced by Gal-3 in the tumor microenvironment cannot be rescued by pembrolizumab.

A Complete Response in a Metastatic Melanoma Patient After a Single Dose of Dual Checkpoint Inhibitors Blockade Could Be Predictable: A Case Report

Cutaneous malignant melanoma is one of the most aggressive forms of skin cancer and thus, a high mortality has been reported over decades. The prognosis for melanoma varies widely based on several factors, including the stage at which it is diagnosed, the location and thickness of the tumor, the patient's age and overall health, and specific genetic factors associated with melanoma. Therapeutic options include checkpoint inhibitors, regardless of V-Raf Murine Sarcoma Viral Oncogene Homolog B status (BRAF), and targeted therapy (anti-BRAF) in the adjuvant or metastatic setting. Immune checkpoint inhibitors (ICIs) have revolutionized cancer treatment but predicting which patients will benefit from these therapies remains challenging. Biomarkers like leukocytes, neutrophils, eosinophils, basophils, platelets, and other peripheral blood biomarkers have been investigated for their potential to predict responses to ICIs. Tumor mutational burden (TMB), circulating tumor DNA (ctDNA), and soluble PD-L1 (sPD-L1) have emerged as potential biomarkers for predicting responses to ICIs. Elevated baseline levels of ctDNA and elevated sPD-L1 levels have been associated with worse prognosis in melanoma patients. High TMB is often associated with better responses to ICIs in melanoma. Here we present a case from our department, of a 57-year-old patient, diagnosed in 2019 with stage IV - pT4cNx cM1 (lymph nodes metastases) and suspicion of lung metastases, BRAF wild-type right hallux malignant melanoma. Due to impressive results, first-line treatment with ICIs nivolumab and ipilimumab was the preferred treatment of choice, which showed a favorable response, with regression of oncological disease after the first cycle, and achieving complete response afterward. Unfortunately, the treatment was discontinued due to severe hepatic and pancreatic toxicity, but the favorable response to immunotherapy has been maintained for four years and is ongoing. Identifying predictive biomarkers is important to achieve the best response for the patient, with minimal adverse events, especially if long-term clinical benefit can be reached.

Dual Checkpoint Inhibition in Melanoma With ≥1% PD-L1-Time to Reassess the Evidence

This Viewpoint discusses use of anti–PD-1 monotherapy as the primary treatment option for patients with treatment-naive metastatic melanoma staining positive for PD-L1 over dual checkpoint inhibition therapy.

Curing Stage IV Melanoma: Where Have We Been and Where Are We?

Little more than 10 years ago, metastatic melanoma was considered to have one of the poorest cancer outcomes, associated with a median overall survival of 6-8 months. Cytotoxic chemotherapy offered modest response rates of 20%-30%, but no clear survival benefit. Patients were routinely enrolled in clinical trials as their first-line therapy in the search for effective novel therapeutics. Remarkable developments in molecular biology, cancer genomics, immunology, and drug discovery have dominated the early part of the 21st century, and nowhere have the benefits been better realized than in the transformation of outcomes for patients with metastatic melanoma: since 2011, 14 new agents have been approved that significantly increase survival, with long-term remissions and, possibly now, potential for cure. Even so, there is still much work to be done, given that most treated patients still die of their disease. Although most survival gains have so far been realized for cutaneous melanoma, improving treatment options for those 10% of patients with rarer, noncutaneous melanomas is a high priority. Key novel therapeutic approaches aimed at improving outcomes with potential for curing patients with melanoma are considered.

N-Acetylgalactosamine-4-sulfatase (Arylsulfatase B) Regulates PD-L1 Expression in Melanoma by an HDAC3-Mediated Epigenetic Mechanism

The effects of the enzyme N-acetylgalactosamine-4-sulfatase (Arylsulfatase B, ARSB), which removes the 4-sulfate group at the non-reducing end of chondroitin 4-sulfate, on the expression of PD-L1 were determined, and the underlying mechanism of PD-L1 expression was elucidated. Initial experiments in human melanoma cells (A375) showed that PD-L1 expression increased from 357 ± 31 to 796 ± 50 pg/mg protein (p < 10-11) when ARSB was silenced in A375 cells. In subcutaneous B16F10 murine melanomas, PD-L1 declined from 1227 ± 189 to 583 ± 110 pg/mg protein (p = 1.67 × 10-7), a decline of 52%, following treatment with exogenous, bioactive recombinant ARSB. This decline occurred in association with reduced tumor growth and prolongation of survival, as previously reported. The mechanism of regulation of PD-L1 expression by ARSB is attributed to ARSB-mediated alteration in chondroitin 4-sulfation, leading to changes in free galectin-3, c-Jun nuclear localization, HDAC3 expression, and effects of acetyl-H3 on the PD-L1 promoter. These findings indicate that changes in ARSB contribute to the expression of PD-L1 in melanoma and can thereby affect the immune checkpoint response. Exogenous ARSB acted on melanoma cells and normal melanocytes through the IGF2 receptor. The decline in PD-L1 expression by exogenous ARSB may contribute to the impact of ARSB on melanoma progression.

DRG2 is required for surface localization of PD-L1 and the efficacy of anti-PD-1 therapy

More than half of tumor patients with high PD-L1 expression do not respond to anti-PD-1/PD-L1 therapy, and the underlying mechanisms are yet to be clarified. Here we show that developmentally regulated GTP-binding protein 2 (DRG2) is required for response of PD-L1-expressing tumors to anti-PD-1 therapy. DRG2 depletion enhanced IFN-γ signaling and increased the PD-L1 level in melanoma cells. However, it inhibited recycling of endosomal PD-L1 and reduced surface PD-L1 levels, which led to defects in interaction with PD-1. Anti-PD-1 did not expand effector-like T cells within DRG2-depleted tumors and failed to improve the survival of DRG2-depleted tumor-bearing mice. Cohort analysis revealed that patients bearing melanoma with low DRG2 protein levels were resistant to anti-PD-1 therapy. These findings identify DRG2 as a key regulator of recycling of endosomal PD-L1 and response to anti-PD-1 therapy and provide insights into how to increase the correlation between PD-L1 expression and response to anti-PD-1 therapy.