First-in-human stage III/IV melanoma​ clinical trial of immune priming agent IFx-Hu2.0

IFx-Hu2.0 was designed to encode part of the Emm55 protein contained within a plasmid in a formulation intended for transfection into mammalian cells. IFx-Hu2.0 promotes both adaptive and innate immune responses in animal studies. Furthermore, previous studies have demonstrated safety/efficacy in equine, canine, and murine species. We present the first-in-human study of IFx-Hu2.0, administered by intralesional injection into melanoma tumors of seven patients with stage III/IV unresectable melanoma. No dose-limiting toxicities attributable to IFx-Hu2.0 were observed. Grade 1/2 injection site reactions were observed in five of seven patients. IgG and IgM responses were seen in the peripheral blood to Emm55 peptides and known melanoma antigens, suggesting that IFx-Hu2.0 acts as an individualized "in-situ vaccine." Three of four patients previously refractory to anti-PD1 experienced clinical benefit upon subsequent anti-PD1-based treatment. Therefore, this approach is feasible, and clinical/correlative outcomes warrant further investigation for treating metastatic melanoma patients as an immune priming agent.

Jagged2 targeting in lung cancer activates anti-tumor immunity via Notch-induced functional reprogramming of tumor-associated macrophages

Signaling through Notch receptors intrinsically regulates tumor cell development and growth. Here, we studied the role of the Notch ligand Jagged2 on immune evasion in non-small cell lung cancer (NSCLC). Higher expression of JAG2 in NSCLC negatively correlated with survival. In NSCLC pre-clinical models, deletion of Jag2, but not Jag1, in cancer cells attenuated tumor growth and activated protective anti-tumor T cell responses. Jag2-/- lung tumors exhibited higher frequencies of macrophages that expressed immunostimulatory mediators and triggered T cell-dependent anti-tumor immunity. Mechanistically, Jag2 ablation promoted Nr4a-mediated induction of Notch ligands DLL1/4 on cancer cells. DLL1/4-initiated Notch1/2 signaling in macrophages induced the expression of transcription factor IRF4 and macrophage immunostimulatory functionality. IRF4 expression was required for the anti-tumor effects of Jag2 deletion in lung tumors. Antibody targeting of Jagged2 inhibited tumor growth and activated IRF4-driven macrophage-mediated anti-tumor immunity. Thus, Jagged2 orchestrates immunosuppressive systems in NSCLC that can be overcome to incite macrophage-mediated anti-tumor immunity.

Treatment of Stage III Resectable Melanoma-Adjuvant and Neoadjuvant Approaches

ABSTRACT

Patients with stage III resectable melanoma carry a high risk of melanoma recurrence that ranges from approximately 40% to 90% at 5 years following surgical management alone. Postoperative systemic adjuvant therapy targets residual micrometastatic disease that could be the source of future recurrence and death from melanoma. Randomized phase III adjuvant trials reported significant improvements in overall survival with high-dose interferon α in 2 of 3 studies (compared with observation and GMK ganglioside vaccine) and with anti-cytotoxic T-lymphocyte antigen 4 ipilimumab at 10 mg/kg compared with placebo and ipilimumab 3 mg/kg compared with high-dose interferon α. In the modern era, more recent phase III trials demonstrated significant recurrence-free survival improvements with anti-programmed cell death protein 1, pembrolizumab, and BRAF-MEK inhibitor combination dabrafenib-trametinib (for BRAF mutant melanoma) versus placebo. Furthermore, anti-programmed cell death protein 1, nivolumab and pembrolizumab have both been shown to significantly improve recurrence-free survival as compared with ipilimumab 10 mg/kg. For melanoma patients with clinically or radiologically detectable locoregionally advanced disease, emerging data support an important role for preoperative systemic neoadjuvant therapy. Importantly, a recent cooperative group trial (S1801) reported superior event-free survival rates with neoadjuvant versus adjuvant therapy. Collectively, current data from neoadjuvant immunotherapy and targeted therapy trials support a future change in clinical practice in favor of neoadjuvant therapy for eligible melanoma patients.

A Bioinformatics Tool for Identifying Intratumoral Microbes from the ORIEN Dataset

Evidence supports significant interactions among microbes, immune cells, and tumor cells in at least 10%-20% of human cancers, emphasizing the importance of further investigating these complex relationships. However, the implications and significance of tumor-related microbes remain largely unknown. Studies have demonstrated the critical roles of host microbes in cancer prevention and treatment responses. Understanding interactions between host microbes and cancer can drive cancer diagnosis and microbial therapeutics (bugs as drugs). Computational identification of cancer-specific microbes and their associations is still challenging due to the high dimensionality and high sparsity of intratumoral microbiome data, which requires large datasets containing sufficient event observations to identify relationships, and the interactions within microbial communities, the heterogeneity in microbial composition, and other confounding effects that can lead to spurious associations. To solve these issues, we present a bioinformatics tool, microbial graph attention (MEGA), to identify the microbes most strongly associated with 12 cancer types. We demonstrate its utility on a dataset from a consortium of nine cancer centers in the Oncology Research Information Exchange Network. This package has three unique features: species-sample relations are represented in a heterogeneous graph and learned by a graph attention network; it incorporates metabolic and phylogenetic information to reflect intricate relationships within microbial communities; and it provides multiple functionalities for association interpretations and visualizations. We analyzed 2,704 tumor RNA sequencing samples and MEGA interpreted the tissue-resident microbial signatures of each of 12 cancer types. MEGA can effectively identify cancer-associated microbial signatures and refine their interactions with tumors.

SIGNIFICANCE

Studying the tumor microbiome in high-throughput sequencing data is challenging because of the extremely sparse data matrices, heterogeneity, and high likelihood of contamination. We present a new deep learning tool, MEGA, to refine the organisms that interact with tumors.

Comparing the rate of immunotherapy treatment change due to toxicity by sex

BACKGROUND

Immuno-oncology therapy (IO) is associated with a variety of treatment-related toxicities. However, the impact of toxicity on the treatment discontinuation rate between males and females is unknown. We hypothesized that immune-related adverse events would lead to more frequent treatment changes in females since autoimmune diseases occur more frequently in females.

AIMS

Our aim was to determine if there was a difference in the rate of immunotherapy treatment change due to toxicity between males and females.

METHODS AND RESULTS

The Oncology Research Information Exchange Network Avatar Database collected clinical data from 10 United States cancer centers. Of 1035 patients receiving IO, 447 were analyzed, excluding those who did not have documentation noting if a patient changed treatment (n = 573). Fifteen patients with unknown or gender-specific cancer were excluded. All cancer types and stages were included. The primary endpoint was documented treatment change due to toxicity. Four hundred and forty-seven patients (281 males and 166 females) received IO treatment. The most common cancers treated were kidney, skin, and lung for 99, 84, and 54 patients, respectively. Females had a shorter IO course than males (median 3.7 vs. 5.1 months, respectively, p = .02). Fifty-four patients changed treatment due to toxicity. There was no significant difference between females and males on chi-square test (11.4% vs. 12.5%, respectively, p = 0.75) and multivariable logistic regression (OR 0.924, 95% CI 0.453-1.885, p = .827). Significantly more patients with chronic obstructive pulmonary disease (COPD) changed therapy due to toxicity (OR 2.491, 95% CI 1.025-6.054, p = .044).

CONCLUSION

Females received a shorter course of IO than males. However, there was no significant difference in the treatment discontinuation rate due to toxicity between males and females receiving IO. Toxicity-related treatment change was associated with COPD.

The T Cell Immunoscore as a Reference for Biomarker Development Utilizing Real-World Data from Patients with Advanced Malignancies Treated with Immune Checkpoint Inhibitors

BACKGROUND

We aimed to determine the prognostic value of an immunoscore reflecting CD3+ and CD8+ T cell density estimated from real-world transcriptomic data of a patient cohort with advanced malignancies treated with immune checkpoint inhibitors (ICIs) in an effort to validate a reference for future machine learning-based biomarker development.

METHODS

Transcriptomic data was collected under the Total Cancer Care Protocol (NCT03977402) Avatar® project. The real-world immunoscore for each patient was calculated based on the estimated densities of tumor CD3+ and CD8+ T cells utilizing CIBERSORTx and the LM22 gene signature matrix. Then, the immunoscore association with overall survival (OS) was estimated using Cox regression and analyzed using Kaplan-Meier curves. The OS predictions were assessed using Harrell's concordance index (C-index). The Youden index was used to identify the optimal cut-off point. Statistical significance was assessed using the log-rank test.

RESULTS

Our study encompassed 522 patients with four cancer types. The median duration to death was 10.5 months for the 275 participants who encountered an event. For the entire cohort, the results demonstrated that transcriptomics-based immunoscore could significantly predict patients at risk of death (p-value < 0.001). Notably, patients with an intermediate-high immunoscore achieved better OS than those with a low immunoscore. In subgroup analysis, the prediction of OS was significant for melanoma and head and neck cancer patients but did not reach significance in the non-small cell lung cancer or renal cell carcinoma cohorts.

CONCLUSIONS

Calculating CD3+ and CD8+ T cell immunoscore using real-world transcriptomic data represents a promising signature for estimating OS with ICIs and can be used as a reference for future machine learning-based biomarker development.

Translation of AI into oncology clinical practice

Artificial intelligence (AI) is a transformative technology that is capturing popular imagination and can revolutionize biomedicine. AI and machine learning (ML) algorithms have the potential to break through existing barriers in oncology research and practice such as automating workflow processes, personalizing care, and reducing healthcare disparities. Emerging applications of AI/ML in the literature include screening and early detection of cancer, disease diagnosis, response prediction, prognosis, and accelerated drug discovery. Despite this excitement, only few AI/ML models have been properly validated and fewer have become regulated products for routine clinical use. In this review, we highlight the main challenges impeding AI/ML clinical translation. We present different clinical use cases from the domains of radiology, radiation oncology, immunotherapy, and drug discovery in oncology. We dissect the unique challenges and opportunities associated with each of these cases. Finally, we summarize the general requirements for successful AI/ML implementation in the clinic, highlighting specific examples and points of emphasis including the importance of multidisciplinary collaboration of stakeholders, role of domain experts in AI augmentation, transparency of AI/ML models, and the establishment of a comprehensive quality assurance program to mitigate risks of training bias and data drifts, all culminating toward safer and more beneficial AI/ML applications in oncology labs and clinics.

Clinical updates in neoadjuvant immunotherapy for melanoma before surgery

INTRODUCTION

Locoregionally advanced melanoma represents a large group of high-risk melanoma patients at presentation and poses major challenges in relation to management and the risks of relapse and death.

AREAS COVERED

Melanoma systemic therapy has undergone substantial advancements with the advent of immune checkpoint inhibitors and molecularly targeted therapies, which have been translated to the neoadjuvant setting for the management of locoregionally advanced disease. Notably, PD1 blockade as monotherapy, in combination with CTLA4 blockade or LAG3 inhibition, has demonstrated significant progress in reducing the risk of relapse and mortality, attributed to high pathologic response rates. Likewise, BRAF-MEK inhibition for BRAF mutant melanoma has yielded comparable outcomes, albeit with lower response durability than immunotherapy. Localized intralesional therapies such as Talimogene laherparepvec (T-VEC) and Tavokinogene Telseplasmid (TAVO) electro-gene-transfer combined with anti-PD1 have demonstrated favorable pathologic responses and increased immune activation. Most importantly, the S1801 randomized trial has demonstrated for the first time the advantage of the neoadjuvant approach over standard surgery followed by adjuvant therapy.

EXPERT OPINION

Current evidence supports neoadjuvant therapy as a standard of care for locoregionally advanced melanoma. Ongoing research will define the optimal regimens and the biomarkers of therapeutic predictive and prognostic value.

Adjuvant Therapy for High-Risk Melanoma: An In-Depth Examination of the State of the Field

The consideration of systemic adjuvant therapy is recommended for patients with stage IIB-IV melanoma who have undergone surgical resection due to a heightened risk of experiencing melanoma relapse and mortality from melanoma. Adjuvant therapy options tested over the past three decades include high-dose interferon-α, immune checkpoint inhibitors (pembrolizumab, nivolumab), targeted therapy (dabrafenib-trametinib for BRAF mutant melanoma), radiotherapy and chemotherapy. Most of these therapies have been demonstrated to enhance relapse-free survival (RFS) but with limited to no impact on overall survival (OS), as reported in randomized trials. In contemporary clinical practice, the adjuvant treatment approach for surgically resected stage III-IV melanoma has undergone a notable shift towards the utilization of nivolumab, pembrolizumab, and BRAF-MEK inhibitors, such as dabrafenib plus trametinib (specifically for BRAF mutant melanoma) due to the significant enhancements in RFS observed with these treatments. Pembrolizumab has obtained regulatory approval in the United States to treat resected stage IIB-IIC melanoma, while nivolumab is currently under review for the same indication. This review comprehensively analyzes completed phase III adjuvant therapy trials in adjuvant therapy. Additionally, it provides a summary of ongoing trials and an overview of the main challenges and future directions with adjuvant therapy.

Cetuximab for Immunotherapy-Refractory/Ineligible Cutaneous Squamous Cell Carcinoma

Anti-PD1 therapy demonstrated impressive, prolonged responses in advanced cutaneous squamous cell carcinoma (CSCC). Therapy for ICI-refractory/ineligible disease remains unclear. We performed a retrospective analysis in locally-advanced/metastatic CSCC using cetuximab across three cohorts: immediately after ICI failure (A), not immediately following ICI failure (B), or without prior ICI (C). The primary endpoint was the overall response rate (ORR). Secondary endpoints included disease-control rate (DCR), progression-free survival (PFS), overall survival (OS), time-to-response (TTR) and toxicity. Twenty-three patients were included. In cohort A (n = 11), the ORR was 64% and DCR was 91%, with six ongoing responses at data cutoff. In cohort B (n = 2), all patients had progression as the best response. At a median follow-up of 21 months for A and B, TTR and PFS were 2.0 and 17.3 months, respectively. The median OS was not reached. In cohort C (n = 10), the ORR and DCR were 80%, including five ongoing responses at the data cutoff. At a median follow-up of 22.4 months, the TTR, PFS and OS were 2.5, 7.3 and 23.1 months, respectively. Cetuximab was well tolerated in all cohorts. In summary, cetuximab is effective in patients with failure/contraindications to ICI. Cetuximab immediately after ICI failure yielded particularly fast, durable responses. If confirmed, this could be the preferred therapy following ICI failure.

The tumor microbiome as a predictor of outcomes in patients with metastatic melanoma treated with immune checkpoint inhibitors

Emerging evidence supports the important role of the tumor microbiome in oncogenesis, cancer immune phenotype, cancer progression, and treatment outcomes in many malignancies. In this study, we investigated the metastatic melanoma tumor microbiome and potential roles in association with clinical outcomes, such as survival, in patients with metastatic disease treated with immune checkpoint inhibitors (ICIs). Baseline tumor samples were collected from 71 patients with metastatic melanoma before treatment with ICIs. Bulk RNA-seq was conducted on the formalin-fixed paraffin-embedded (FFPE) tumor samples. Durable clinical benefit (primary clinical endpoint) following ICIs was defined as overall survival ≥24 months and no change to the primary drug regimen (responders). We processed RNA-seq reads to carefully identify exogenous sequences using the {exotic} tool. The 71 patients with metastatic melanoma ranged in age from 24 to 83 years, 59% were male, and 55% survived >24 months following the initiation of ICI treatment. Exogenous taxa were identified in the tumor RNA-seq, including bacteria, fungi, and viruses. We found differences in gene expression and microbe abundances in immunotherapy responsive versus non-responsive tumors. Responders showed significant enrichment of several microbes including Fusobacterium nucleatum, and non-responders showed enrichment of fungi, as well as several bacteria. These microbes correlated with immune-related gene expression signatures. Finally, we found that models for predicting prolonged survival with immunotherapy using both microbe abundances and gene expression outperformed models using either dataset alone. Our findings warrant further investigation and potentially support therapeutic strategies to modify the tumor microbiome in order to improve treatment outcomes with ICIs.

A bioinformatics tool for identifying intratumoral microbes from the ORIEN dataset

Evidence supports significant interactions among microbes, immune cells, and tumor cells in at least 10-20% of human cancers, emphasizing the importance of further investigating these complex relationships. However, the implications and significance of tumor-related microbes remain largely unknown. Studies have demonstrated the critical roles of host microbes in cancer prevention and treatment responses. Understanding interactions between host microbes and cancer can drive cancer diagnosis and microbial therapeutics (bugs as drugs). Computational identification of cancer-specific microbes and their associations is still challenging due to the high dimensionality and high sparsity of intratumoral microbiome data, which requires large datasets containing sufficient event observations to identify relationships, and the interactions within microbial communities, the heterogeneity in microbial composition, and other confounding effects that can lead to spurious associations. To solve these issues, we present a bioinformatics tool, MEGA, to identify the microbes most strongly associated with 12 cancer types. We demonstrate its utility on a dataset from a consortium of 9 cancer centers in the Oncology Research Information Exchange Network (ORIEN). This package has 3 unique features: species-sample relations are represented in a heterogeneous graph and learned by a graph attention network; it incorporates metabolic and phylogenetic information to reflect intricate relationships within microbial communities; and it provides multiple functionalities for association interpretations and visualizations. We analyzed 2704 tumor RNA-seq samples and MEGA interpreted the tissue-resident microbial signatures of each of 12 cancer types. MEGA can effectively identify cancer-associated microbial signatures and refine their interactions with tumors.

A Tumor and Immune-Related Micro-RNA Signature Predicts Relapse-Free Survival of Melanoma Patients Treated with Ipilimumab

Despite the unprecedented advances in the treatment of melanoma with immunotherapy, there continues to be a major need for biomarkers of clinical benefits and immune resistance associated with immune checkpoint inhibitors; microRNA could play a vital role in these efforts. This study planned to identify differentially expressed miRNA molecules that may have prognostic value for clinical benefits. Patients with surgically operable regionally advanced melanoma were treated with neoadjuvant ipilimumab (10 mg/kg intravenously every 3 weeks × two doses) bracketing surgery. Tumor biospecimens were obtained at baseline and surgery, and microRNA (miRNA) expression profiling was performed on the tumor biopsies. We found that an expression profile consisting of a 4-miRNA signature was significantly associated with improved relapse-free survival (RFS). The signature consisted of biologically relevant molecules previously reported to have prognostic value in melanoma and other malignancies, including miR-34c, miR-711, miR-641, and miR-22. Functional annotation analysis of target genes for the 4-miRNA signature was significantly enriched for various cancer-related pathways, including cell proliferation regulation, apoptosis, the MAPK signaling pathway, and the positive regulation of T cell activation. Our results presented miRNAs as potential biomarkers that can guide the treatment of melanoma with immune checkpoint inhibitors. These findings warrant further investigation in relation to CTLA4 blockade and other immune checkpoint inhibitors. ClinicalTrials.gov NCT00972933.

Granulomatous and Sarcoid-like Immune-Related Adverse Events following CTLA4 and PD1 Blockade Adjuvant Therapy of Melanoma: A Combined Analysis of ECOG-ACRIN E1609 and SWOG S1404 Phase III Trials and a Literature Review

BACKGROUND

Treatment with immune checkpoint inhibitors (ICIs) has been linked to granulomatous and sarcoid-like lesions (GSLs) affecting different organs. This study sought to evaluate GSL incidence in patients with high-risk melanoma treated with cytotoxic T-lymphocyte antigen 4 (CTLA4) or programmed cell death 1 (PD1) blockade adjuvant therapy in two clinical trials: ECOG-ACRIN E1609 and SWOG S1404. Descriptions and GSL severity ratings were recorded.

METHODS

Data were collected from ECOG-ACRIN E1609 and SWOG S1404. Descriptive statistics along with GSL severity grades were reported. Additionally, a literature review for such cases was summarized.

RESULTS

A total of 11 GSL cases were reported among 2878 patients treated with either ICI or with High-Dose Interferon Alfa-2b (HDI) in ECOG-ACRIN E1609 and SWOG S1404 trials. Cases were numerically more commonly reported with ipi10, followed by pembrolizumab, ipi3, and HDI, respectively. Most of the cases were grade III. Further, organs involved included lung, mediastinal lymph nodes, skin and subcutaneous tissue, and eye. Furthermore, a summary of 62 reports in the literature was described.

CONCLUSIONS

GSLs following anti-CTLA4 and anti-PD1 antibody therapy in patients with melanoma were reported unusually. Reported cases ranged in grade from I to III and appeared manageable. Careful attention to these events and their reporting will be essential to better guide practice and management guidelines.

Abstract 5704: An integrated immune signature predictive of adjuvant immunotherapeutic benefits for high-risk melanoma

Introduction CTLA4 blockade with ipilimumab was more favorable than interferon-α2b (IFN) in high-risk melanoma in phase adjuvant III trial E1609. Characterization of the pretreatment tumor immune biomarkers and clinical covariates may inform the likelihood of response to ipilimumab and other immune checkpoint inhibitors (ICI), and guide future development of this and other modalities in this patient population.

Methods We utilized PATH-SURVEIOR, a bioinformatics framework developed in-house for associating genes and pathway signatures with clinical endpoints, to perform survival analysis of gene expression levels of 31 candidate immune-related biomarkers based on previous preliminary data. We analyzed microarray gene expression data from 471 melanoma patients treated with ipilimumab (ipi) and 248 melanoma patients treated with IFN as part of E1609. We then developed a LASSO Cox regression model and validated our model in 22 patients treated with neoadjuvant ipi in a separate clinical trial.

Results Using PATH-SURVEIOR, we evaluated 31 candidate immune biomarkers and their association with patient outcome by including treatment group (ipi and IFN) as a multiplicative covariate interaction in the Cox hazard model. Our analysis identified CXCL9, CD8A, CXCL10, and INPP5D as Tier 1 biomarkers (HR &gt; 1 and P &lt; 0.05) and IDO1, IGKC, and IL2RB as Tier 2 biomarkers (HR &gt; 1 and P &lt; 0.1). Next, we developed an ipilimumab immune-based risk score using LASSO Cox regression (L-IPI7) based on these 7 aggregate biomarkers. We then split our 471 ipi-treated cohort into training (310, 66%) and testing (161, 33%) cohorts and assessed our model for its ability to predict overall survival (OS) and relapse-free survival (RFS). Our risk score was capable of stratifying ipi-treated patients into High-Risk and Low-Risk populations, which correlated with OS. As a negative control, we assessed our risk score in 248 IFN-treated patients and found no significant association with OS. As validation, we applied our L-IPI7 score to a cohort of 22 patients treated with neoadjuvant ipi and determined that the score was able to predict patients with a high risk of relapse. Interestingly, when we developed an interactive Cox-regression model with colitis status (grade 0-1 vs grade 2+), we found that neoadjuvant ipi patients with low-grade colitis were associated with a higher L-IPI7 risk score for disease relapse. In addition, we determined that: i) higher age and higher L-IPI7 risk score identified patients with the worst OS and RFS And ii) female patients with a low L-IPI7 risk scores had a better OS and RFS.

Conclusions We developed a broadly applicable model based on LASSO Cox Regression predictive of adjuvant ipi treatment outcomes in melanoma. Our L-IPI7 score based on expression of CXCL9, CD8A, CXCL10, INPP5D, IDO1, IGKC, IL2RB effectively predicts survival, with interactions with age, gender and on-treatment development of colitis.

Citation Format: Alyssa N. Obermayer, Timothy I. Shaw, Sandra J. Lee, F. Stephen Hodi, William A. LaFramboise, Walter Storkus, Arivarasan D. Karunamurthy, Patrick Hwu, Howard Streicher, Dung-Tsa Chen, John M. Kirkwood, Ahmad A. Tarhini. An integrated immune signature predictive of adjuvant immunotherapeutic benefits for high-risk melanoma. [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 5704.

Leptomeningeal Disease (LMD) in Patients with Melanoma Metastases

Leptomeningeal disease (LMD) is a devastating complication caused by seeding malignant cells to the cerebrospinal fluid (CSF) and the leptomeningeal membrane. LMD is diagnosed in 5-15% of patients with systemic malignancy. Management of LMD is challenging due to the biological and metabolic tumor microenvironment of LMD being largely unknown. Patients with LMD can present with a wide variety of signs and/or symptoms that could be multifocal and include headache, nausea, vomiting, diplopia, and weakness, among others. The median survival time for patients with LMD is measured in weeks and up to 3-6 months with aggressive management, and death usually occurs due to progressive neurologic dysfunction. In melanoma, LMD is associated with a suppressive immune microenvironment characterized by a high number of apoptotic and exhausted CD4⁺ T-cells, myeloid-derived suppressor cells, and a low number of CD8⁺ T-cells. Proteomics analysis revealed enrichment of complement cascade, which may disrupt the blood-CSF barrier. Clinical management of melanoma LMD consists primarily of radiation therapy, BRAF/MEK inhibitors as targeted therapy, and immunotherapy with anti-PD-1, anti-CTLA-4, and anti-LAG-3 immune checkpoint inhibitors. This review summarizes the biology and anatomic features of melanoma LMD, as well as the current therapeutic approaches.

Circulating tumor DNA-based molecular residual disease detection for treatment monitoring in advanced melanoma patients

BACKGROUND

Immune checkpoint inhibitors (ICIs) have substantially improved overall survival in patients with advanced melanoma; however, the lack of biomarkers to monitor treatment response and relapse remains an important clinical challenge. Thus, a reliable biomarker is needed that can risk-stratify patients for disease recurrence and predict response to treatment.

METHODS

A retrospective analysis using a personalized, tumor-informed circulating tumor DNA (ctDNA) assay on prospectively collected plasma samples (n = 555) from 69 patients with advanced melanoma was performed. Patients were divided into three cohorts: cohort A (N = 30), stage III patients receiving adjuvant ICI/observation; cohort B (N = 29), unresectable stage III/IV patients receiving ICI therapy; and cohort C (N = 10), stage III/IV patients on surveillance after planned completion of ICI therapy for metastatic disease.

RESULTS

In cohort A, compared to molecular residual disease (MRD)-negative patients, MRD-positivity was associated with significantly shorter distant metastasis-free survival (DMFS; hazard ratio [HR], 10.77; p = .01). Increasing ctDNA levels from the post-surgical or pre-treatment time point to after 6 weeks of ICI were predictive of shorter DMFS in cohort A (HR, 34.54; p < .0001) and shorter progression-free survival (PFS) in cohort B (HR, 22; p = .006). In cohort C, all ctDNA-negative patients remained progression-free for a median follow-up of 14.67 months, whereas ctDNA-positive patients experienced disease progression.

CONCLUSION

Personalized and tumor-informed longitudinal ctDNA monitoring is a valuable prognostic and predictive tool that may be used throughout the clinical course of patients with advanced melanoma.

Effectiveness of Adjuvant Pembrolizumab vs High-Dose Interferon or Ipilimumab for Quality-of-Life Outcomes in Patients With Resected Melanoma: A Secondary Analysis of the SWOG S1404 Randomized Clinical Trial

Importance

A key issue for the adjuvant treatment of patients with melanoma is the assessment of the effect of treatment on relapse, survival, and quality of life (QOL).

Objective

To compare QOL in patients with resected melanoma at high risk for relapse who were treated with adjuvant pembrolizumab vs standard of care with either ipilimumab or high-dose interferon α 2b (HDI).

Design, Setting, and Participants

The S1404 phase 3 randomized clinical trial was conducted by the SWOG Cancer Research Network at 211 community/academic sites in the US, Canada, and Ireland. Patients were enrolled from December 2015 to October 2017. Data analysis for this QOL substudy was completed in March 2022. Overall, 832 patients were evaluable for the primary QOL end point.

Interventions

Patients were randomized (1:1) to treatment with adjuvant pembrolizumab vs standard of care with ipilimumab/HDI.

Main Outcomes and Measures

Quality of life was assessed for patients at baseline and cycles 1, 3, 5, 7, and 9 after randomization using the Functional Assessment of Cancer Therapy (FACT) Biological Response Modifiers (FACT-BRM), FACT-General, Functional Assessment of Chronic Illness Therapy-Diarrhea, and European QOL 5-Dimension 3-Level scales. The primary end point was the comparison by arm of cycle 3 FACT-BRM trial outcome index (TOI) scores using linear regression. Linear-mixed models were used to evaluate QOL scores over time. Regression analyses included adjustments for the baseline score, disease stage, and programmed cell death ligand 1 status. A clinically meaningful difference of 5 points was targeted.

Results

Among 1303 eligible patients (median [range] age, 56.7 [18.3-86.0] years; 524 women [40.2%]; 779 men [59.8%]; 10 Asian [0.8%], 7 Black [0.5%], 44 Hispanic [3.4%], and 1243 White [95.4%] individuals), 1188 (91.1%) had baseline FACT-BRM TOI scores, and 832 were evaluable at cycle 3 (ipilimumab/HDI = 267 [32.1%]; pembrolizumab = 565 [67.9%]). Evaluable patients were predominantly younger than 65 years (623 [74.9%]) and male (779 [58.9%]). Estimates of FACT-BRM TOI cycle 3 compliance did not differ by arm (ipilimumab/HDI, 96.0% vs pembrolizumab, 98.3%; P = .25). The adjusted cycle 3 FACT-BRM TOI score was 9.6 points (95% CI, 7.9-11.3; P < .001) higher (better QOL) for pembrolizumab compared with ipilimumab/HDI, exceeding the prespecified clinically meaningful difference. In linear-mixed models, differences by arm exceeded 5 points in favor of pembrolizumab through cycle 7. In post hoc analyses, FACT-BRM TOI scores favored the pembrolizumab arm compared with the subset of patients receiving ipilimumab (difference, 6.0 points; 95% CI, 4.1-7.8; P < .001) or HDI (difference, 17.0 points; 95% CI, 14.6-19.4; P < .001).

Conclusions and Relevance

This secondary analysis of a phase 3 randomized clinical trial found that adjuvant pembrolizumab improved QOL vs treatment with adjuvant ipilimumab or HDI in patients with high-risk resected melanoma.

Trial Registration

ClinicalTrials.gov identifier: NCT02506153.

Combination Dabrafenib and Trametinib Versus Combination Nivolumab and Ipilimumab for Patients With Advanced BRAF-Mutant Melanoma: The DREAMseq Trial-ECOG-ACRIN EA6134

PURPOSE

Combination programmed cell death protein 1/cytotoxic T-cell lymphocyte-4-blockade and dual BRAF/MEK inhibition have each shown significant clinical benefit in patients with BRAFV600-mutant metastatic melanoma, leading to broad regulatory approval. Little prospective data exist to guide the choice of either initial therapy or treatment sequence in this population. This study was conducted to determine which initial treatment or treatment sequence produced the best efficacy.

PATIENTS AND METHODS

In a phase III trial, patients with treatment-naive BRAFV600-mutant metastatic melanoma were randomly assigned to receive either combination nivolumab/ipilimumab (arm A) or dabrafenib/trametinib (arm B) in step 1, and at disease progression were enrolled in step 2 to receive the alternate therapy, dabrafenib/trametinib (arm C) or nivolumab/ipilimumab (arm D). The primary end point was 2-year overall survival (OS). Secondary end points were 3-year OS, objective response rate, response duration, progression-free survival, crossover feasibility, and safety.

RESULTS

A total of 265 patients were enrolled, with 73 going onto step 2 (27 in arm C and 46 in arm D). The study was stopped early by the independent Data Safety Monitoring Committee because of a clinically significant end point being achieved. The 2-year OS for those starting on arm A was 71.8% (95% CI, 62.5 to 79.1) and arm B 51.5% (95% CI, 41.7 to 60.4; log-rank P = .010). Step 1 progression-free survival favored arm A (P = .054). Objective response rates were arm A: 46.0%; arm B: 43.0%; arm C: 47.8%; and arm D: 29.6%. Median duration of response was not reached for arm A and 12.7 months for arm B (P < .001). Crossover occurred in 52% of patients with documented disease progression. Grade ≥ 3 toxicities occurred with similar frequency between arms, and regimen toxicity profiles were as anticipated.

CONCLUSION

Combination nivolumab/ipilimumab followed by BRAF and MEK inhibitor therapy, if necessary, should be the preferred treatment sequence for a large majority of patients.

Systematic evaluation of the predictive gene expression signatures of immune checkpoint inhibitors in metastatic melanoma

Advances in immunotherapy, including immune checkpoint inhibitors (ICIs), have transformed the standard of care for many types of cancer including melanoma. ICIs have improved the overall outcome of melanoma patients; however, a significant proportion of patients suffer from primary or secondary tumor resistance. Therefore, there is an urgent need to develop predictive biomarkers to better select patients for ICI therapy. Numerous biomarkers that predict the response of melanoma to ICIs have been investigated, including biomarker signatures based on genomics or transcriptomics. Most of these predictive biomarkers have not been systematically evaluated across different cohorts to determine the reproducibility of these signatures in metastatic melanoma. We evaluated 28 previously published predictive biomarkers of ICIs based on gene expression signatures in eight previously published studies with available RNA-sequencing data in public repositories. We found that signatures related to IFN-γ-responsive genes, T and B cell markers, and chemokines in the tumor immune microenvironment are generally predictive of response to ICIs in these patients. In addition, we identified that these predictive biomarkers have higher predictive values in on-treatment samples as compared to pretreatment samples in metastatic melanoma. The most frequently overlapping genes among the top 18 predictive signatures were CXCL10, CXCL9, PRF1, RANTES, IFNG, HLA-DRA, GZMB, and CD8A. From gene set enrichment analysis and cell type deconvolution, we estimated that the tumors of responders were enriched with infiltrating cytotoxic T-cells and other immune cells and the upregulation of genes related to interferon-γ signaling. Conversely, the tumors of non-responders were enriched with stromal-related cell types such as fibroblasts and myofibroblasts, as well as enrichment with T helper 17 cell types across all cohorts. In summary, our approach of validating and integrating multi-omics data can help guide future biomarker development in the field of ICIs and serve the quest for a more personalized therapeutic approach for melanoma patients.

Patient-reported tolerability of adjuvant ipilimumab (3 or 10 mg/kg) versus high-dose interferon alfa-2b for resected high-risk stage III-IV melanoma in phase III trial E1609

PURPOSE

Trial E1609 demonstrated superior overall survival with ipilimumab 3 mg/kg (ipi3) compared to high-dose interferon (HDI) for patients with resected high-risk melanoma. To inform treatment tolerability, we compared health-related quality of life (HRQoL), gastrointestinal (GI), and treatment-specific physical and cognitive/emotional symptoms. We also compared treatment-specific concerns between all arms.

METHODS

We assessed HRQoL using the Functional Assessment of Cancer Therapy-General, physical and cognitive/emotional concerns using the FACT-Biologic Response Modifier subscale, and GI symptoms with the Functional Assessment of Chronic Illness Therapy-Diarrhea subscale pre-treatment and every 3 months. The primary outcome was the difference in HRQoL at 3 months between ipi3/ipi10 vs. HDI.

RESULTS

549 patients (n = 158 ipi3; n = 191 ipi10; n = 200 HDI) were analyzed. 3-month completion was 58.7%. Compared to HDI, ipilimumab patients reported better HRQoL (ipi3 = 87.5 ± 14.6 vs. HDI = 74.7 ± 15.4, p < .001; ipi10 = 84.9 ± 16.5 vs. HDI, p < .001) and fewer physical (ipi3 = 22.3 ± 4.6 vs. HDI = 17.1 ± 5.4, p < .001; ipi10 = 21.8 ± 5.0 vs. HDI p < .001) and cognitive/emotional (ipi3 = 18.6 ± 4.4 vs. HDI = 15.0 ± 5.3, p < .001; ipi10 = 17.7 ± 4.8 vs. HDI p < .001) concerns, but worse GI symptoms (ipi3 = 40.8 ± 5.0 vs. HDI = 42.2 ± 2.9, p = .011; ipi10 = 39.5 ± 7.0 vs. HDI, p < .001). Fewer ipilimumab patients reported worsening treatment-specific concerns (e.g., 52% of ipi3 and 58% of ipi10 reported worsening fatigue vs. 82% HDI, p's < .001).

CONCLUSION

PROs demonstrated less toxicity of ipi3 compared to HDI and ipi10. Priorities for symptom management among patients receiving ipilimumab include GI toxicities, fatigue, weakness, appetite loss, arthralgia, and depression.

TRIAL REGISTRATION

NCT01274338, January 11, 2011 (first posted date) https://clinicaltrials.gov/ct2/show/NCT01274338?term=NCT01274338&draw=2&rank=1 .

Case Report: Durable complete pathologic response and organ preservation following ipilimumab and nivolumab for locally advanced primary vaginal mucosal melanoma

Optimal management of locally advanced vaginal mucosal melanoma is poorly understood because of its rarity and unique biology. Patients have a poor prognosis despite aggressive management approaches including pelvic exenteration and adjuvant radiation that carry major morbidities. We report a case of a patient in early 40’s who experienced complete pathologic response and organ preservation following immunotherapy consisting of 3 cycles of ipilimumab and nivolumab. Treatment was complicated by a high-grade immune mediated hepatitis that eventually resolved with immunosuppressive therapy. Immune monitoring studies utilizing vaginal tumor biopsies showed evidence of enhanced infiltration by CD3+/CD8+ cytotoxic T-cells and increased expression of MHC-I/PD-L1 within the tumor microenvironment following immunotherapy. The patient continues to be without evidence of disease recurrence by radiologic and gynecologic examinations with more than 2 years of follow up from the time of immunotherapy initiation. To our knowledge, this is the only case report in the literature of a patient with locally advanced vaginal mucosal melanoma experiencing a durable complete pathologic response and organ preservation following immune checkpoint blockade as the only treatment approach.

Systemic adjuvant therapy for high-risk cutaneous melanoma

Cutaneous melanoma continues to increase in incidence and poses a significant mortality risk. Surgical excision of melanoma in its early stages is often curative. However, patients with resected stages IIB-IV are considered at high risk for relapse and death from melanoma where systemic adjuvant therapy is indicated. The long-studied high-dose interferon-α was shown to improve relapse-free survival (RFS) and overall survival (OS) but is no longer in use. Adjuvant therapy with ipilimumab at 10 mg/kg (ipi10) demonstrated significant RFS and OS improvements but at a high cost in terms of toxicity, while adjuvant ipilimumab 3 mg/kg was shown to be equally effective and less toxic. More recently, the adjuvant therapy for resected stages III-IV melanoma in clinical practice has changed in favor of nivolumab, pembrolizumab, and BRAF-MEK inhibitors dabrafenib plus trametinib (for BRAF mutant melanoma) based on significant improvements in RFS as compared to ipi10 (nivolumab and pembrolizumab) and placebo (dabrafenib plus trametinib). For resected stages IIB-IIC melanoma, pembrolizumab achieved regulatory approval in the United States based on significant RFS benefits. In this article, we review completed and ongoing phase III adjuvant therapy trials. We also briefly discuss neoadjuvant therapy for locoregionally advanced melanoma. Finally, we explore recent studies on predictive and prognostic melanoma biomarkers in the adjuvant setting.

Sentinel Lymph Node Gene Expression Signature Predicts Recurrence-Free Survival in Cutaneous Melanoma

We sought to develop a sentinel lymph node gene expression signature score predictive of disease recurrence in patients with cutaneous melanoma. Gene expression profiling was performed on SLN biopsies using U133A 2.0 Affymetrix gene chips. The top 25 genes associated with recurrence-free survival (RFS) were selected and a penalized regression function was used to select 12 genes with a non-zero coefficient. A proportional hazards regression model was used to evaluate the association between clinical covariates, gene signature score, and RFS. Among the 45 patients evaluated, 23 (51%) had a positive SLN. Twenty-one (46.7%) patients developed disease recurrence. For the top 25 differentially expressed genes (DEG), 12 non-zero penalized coefficients were estimated (CLGN, C1QTNF3, ADORA3, ARHGAP8, DCTN1, ASPSCR1, CHRFAM7A, ZNF223, PDE6G, CXCL3, HEXIM1, HLA-DRB). This 12-gene signature score was significantly associated with RFS (p < 0.0001) and produced a bootstrap C index of 0.888. In univariate analysis, Breslow thickness, presence of primary tumor ulceration, SLN positivity were each significantly associated with RFS. After simultaneously adjusting for these prognostic factors in relation to the gene signature, the 12-gene score remained a significant independent predictor for RFS (p < 0.0001). This SLN 12-gene signature risk score is associated with melanoma recurrence regardless of SLN status and may be used as a prognostic factor for RFS.

Neoadjuvant immunotherapy of locoregionally advanced solid tumors

Definitive management of locoregionally advanced solid tumors presents a major challenge and often consists of a combination of surgical, radiotherapeutic and systemic therapy approaches. Upfront surgical treatment with or without adjuvant radiotherapy carries the risks of significant morbidities and potential complications that could be lasting. In addition, these patients continue to have a high risk of local or distant disease relapse despite the use of standard adjuvant therapy. Preoperative neoadjuvant systemic therapy has the potential to significantly improve clinical outcomes, particularly in this era of expanding immunotherapeutic agents that have transformed the care of patients with metastatic/unresectable malignancies. Tremendous progress has been made with neoadjuvant immunotherapy in the treatment of several locoregionally advanced resectable solid tumors leading to ongoing phase 3 trials and change in clinical practice. The promise of neoadjuvant immunotherapy has been supported by the high pathologic tumor response rates in early trials as well as the durability of these responses making cure a more achievable potential outcome compared with other forms of systemic therapy. Furthermore, neoadjuvant studies allow the assessment of radiologic and pathological responses and the access to biospecimens before and during systemic therapy. Pathological responses may guide future treatment decisions, and biospecimens allow the conduct of mechanistic and biomarker studies that may guide future drug development. On behalf of the National Cancer Institute Early Drug Development Neoadjuvant Immunotherapy Working Group, this article summarizes the current state of neoadjuvant immunotherapy of solid tumors focusing primarily on locoregionally advanced melanoma, gynecologic malignancies, gastrointestinal malignancies, non-small cell lung cancer and head and neck cancer including recent advances and our expert recommendations related to future neoadjuvant trial designs and associated clinical and translational research questions.

Abstract 5169: Sentinel lymph node gene expression signature predicts survival outcome in cutaneous melanoma

Background: Sentinel lymph node status is an important prognostic factor for melanoma progression. We sought to develop a sentinel lymph node gene expression signature score predictive of disease progression in patients with cutaneous melanoma.

Methods: Cases were retrieved from University of Pittsburgh protocol “Sentinel Node and Non-Sentinel Lymph Nodes (SLN and non-SLN) Procurement from Melanoma Subjects for Molecular Profiling.” Gene expression profiling was performed on SLN biopsies using U133A 2.0 Affymetrix gene chips. The top 25 genes associated with progression-free survival (PFS) were selected and a penalized regression function was used to select genes with a non-zero coefficient. A risk score was calculated from a 12 gene signature. A proportional hazards regression model was used to evaluate the association between clinical covariates, gene signature score, and PFS.

Results: In total, 45 patients were included [female=18 (40%), median age (range)= 56 (16-81) years]. The median Breslow thickness (IQR) was 4.1 (3.3-6.0) mm, ulceration was present in 29 (67%) cases, and 25 (56%) lesions had nodular histology. Among patients, 23 (51%) had a positive SLN via H&E. Twenty-one (46.7%) patients developed disease recurrence/progression with a median follow-up of 8.3 years. The median time to progression was 9.6 years. Among the top 25 genes, 12 non-zero penalized coefficients were estimated (CLGN, C1QTNF3, ADORA3, ARHGAP8, ZNF223, PDE6G, CXCL3, CHRFAM7A, HLA-DRB-decreased risk, DCTN1, ASPSCR1, HEXIM1-increased risk). A 12-gene signature score was significantly associated with PFS (p&lt;0.0001) and produced a bootstrap cross-validated C index of 0.888. Stratifying by SLN status the gene signature risk score remained highly significant (p&lt;0.0001). In univariate analysis, Breslow thickness (HR=1.41), presence of ulceration (HR=3.61), SLN positivity (HR=2.50), and acral-lentiginous histology compared to nodular (HR=4.07) were each significantly associated with PFS (all p&lt;0.05). After simultaneously adjusting for all of these factors plus the gene signature, the 12-gene score remained a significant predictor for PFS (p&lt;0.0001).

Conclusion: A SLN 12-gene signature risk score is associated with melanoma progression regardless of SLN status and can be used as a prognostic factor for PFS of patients. External validation of the gene signature is warranted.

Citation Format: Lilit Karapetyan, William Gooding, Xi Yang, Andrew Knight, Aofei Li, Cindy Sander, Monica Panelli, Walter J. Storkus, Ahmad A. Tarhini, John M. Kirkwood. Sentinel lymph node gene expression signature predicts survival outcome in cutaneous melanoma [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 5169.

Enhanced immune activation within the tumor microenvironment and circulation of female high-risk melanoma patients and improved survival with adjuvant CTLA4 blockade compared to males

BACKGROUND

We hypothesized that a gender difference in clinical response may exist to adjuvant CTLA4 blockade with ipilimumab versus high-dose IFNα (HDI). We investigated differences in candidate immune biomarkers in the circulation and tumor microenvironment (TME).

PATIENTS AND METHODS

This gender-based analysis was nested within the E1609 trial that tested adjuvant therapy with ipilimumab 3 mg/kg (ipi3) and 10 mg/kg (ipi10) versus HDI in high risk resected melanoma. We investigated gender differences in treatment efficacy with ipi3 and ipi10 versus HDI while adjusting for age, stage, ECOG performance (PS), ulceration, primary tumor status and lymph node number. Forest plots were created to compare overall survival (OS) and relapse free survival (RFS) between ipi and HDI. Gene expression profiling (GEP) was performed on tumors of 718 (454 male, 264 female) patients. Similarly, serum and peripheral blood mononuclear cells (PBMC) samples were tested for soluble and cellular biomarkers (N = 321 patients; 109 female and 212 male).

RESULTS

The subgroups of female, stage IIIC, PS = 1, ulcerated primary, in-transit metastasis demonstrated significant improvement in RFS and/or OS with ipi3 versus HDI. Female gender was significant for both OS and RFS and was further explored. In the RFS comparison, a multivariate Cox regression model including significant variables indicated a significant interaction between gender and treatment (P = 0.024). In peripheral blood, percentages of CD3+ T cells (P = 0.024) and CD3+ CD4+ helper T cells (P = 0.0001) were higher in females compared to males. Trends toward higher circulating levels of IL1β (P = 0.07) and IL6 (P = 0.06) were also found in females. Males had higher percentages of monocytes (P = 0.03) with trends toward higher percentages of regulatory T cells (T-reg). Tumor GEP analysis supported enhanced infiltration with immune cells including gammadelta T cells (P = 0.005), NK cells (P = 0.01), dendritic cells (P = 0.01), CD4+ T cells (P = 0.03), CD8+ T cells (P = 0.03) and T-reg (P = 0.008) in the tumors of females compared to males and a higher T-effector and IFNγ gene signature score (P = 0.0244).

CONCLUSION

Female gender was associated with adjuvant CTLA4 blockade clinical benefits and female patients were more likely to have evidence of type1 immune activation within the TME and the circulation. Trial registration ClinicalTrials.gov NCT01274338. Registered 11 January 2011, https://www.

CLINICALTRIALS

gov/ct2/show/NCT01274338.

An 11-gene expression signature related to tumorigenesis and immunosuppression in primary cutaneous melanoma predicts sentinel lymph node metastatic status

e21579

Background: A biomarker derived from the primary melanoma tumor to predict regional sentinel lymph node (SLN) metastatic status can be valuable in guiding the decision making in planning the SLN surgical procedure for candidate patients. Methods: Gene expression profiling was performed on primary cutaneous melanoma tumor biopsies of 49 (24 known SLN+, 25 SLN-) patients (T3a/b, T4a/b) who underwent SLN for staging using transcriptome profiling analysis. U133A 2.0 Affymetrix gene chips were used. Significance Analysis of Microarrays (SAM) was used to test the association between gene expression level of the primary tumor and SLN status. Genes with fold change > 1.5 and q value < 0.05 were considered differentially expressed. Pathway analysis was performed using Ingenuity Pathway Analysis. Benjamini and Hochberg method was used to adjust for multiple testing in pathway analysis. All statistical analyses were implemented in R. Results: A total of 49 patients with primary cutaneous melanoma were studied, of which, 24 were diagnosed as SLN positive and 25 as SLN negative by routine H&E and immunohistochemistry. Using SLN metastatic status as the outcome, a univariate logistic regression model was fitted with individual probe sets. A total of 251 probe sets were filtered and 11 probe sets were considered as differentially expressed (DE) between SLN-ve and SLN+ve groups, with the selection criterion set at Benjamini- Hochberg method -adjusted p -value below 0.05 and the absolute log fold change above 0.5. As each of the 11 probe sets was matched to a unique known gene, an 11 gene signature was derived and among them, the expression level of 7 genes was significantly reduced in the SLN+ve group compared to the SLN-ve group, while 4 genes were overexpressed in the SLN+ve group. Integrative and interactive heatmaps were produced from hierarchical cluster analysis to show the 11 differentially expressed genes. Selected genes were found to be uniformly related to tumorigenesis, malignant progression, DNA repair, cell cycle regulation, chemoresistance, immunosuppression and/or involvement in multiple cancer-related pathways. Several of the selected genes were previously shown to be prognostic in various malignancies. Conclusions: We present a unique 11-gene expression signature derived from primary melanoma tumor biopsy samples and related to tumorigenesis and immunosuppression that may be useful for the prognostic stratification of melanoma patients. This may allow the optimal selection of patients for SLN biopsy.

IFx-Hu2.0 phase I first in human study for unresectable melanoma for an intralesional “in-situ vaccine” approach

e21542

Background: Many melanoma patients do not respond to anti-PD1 therapy due to lack of antigen specific responses. IFx-Hu2.0 (plasmid DNA encoding the streptococcal membrane protein, Emm55, contained within a cationic polymer) primes innate and antigen dependent responses in murine/equine melanoma models to produce an environment needed for checkpoint inhibitor efficacy. We describe the first in human study utilizing IFx-Hu2.0 in unresectable melanoma - NCT03655756. Methods: Melanoma patients (unresectable stage III/IV) had cutaneous lesions injected with IFx-Hu2.0 to test safety and feasibility. Patients were refractory to standard of care (anti-PD1, BRAF/MEK) or did not wish these treatments. 1-3 lesions (> 3 mm – 0.1 mg/0.2 mL) were injected, pre/post treatment biopsies obtained, and the primary endpoint of 5/6 patients without dose limiting toxicity (DLT) was assessed at 28 days. Retreatment was permitted. ≥2 lesions were needed: one for injection and uninjected lesion for biopsy. Tissue samples were analyzed for mRNA profiles, antigen responses (PEPperPRINT assay), and multiplex immunofluorescence (markers: CD3, CD8, FOXP3, PD1, PDL1, SOX10, DAPI). Results: The primary endpoint was met in 6 evaluable patients out of 7 enrolled. Observed toxicities included: G1-2 Injection site reactions - 5/7; G1 Bleeding - 1/7; G1-2 Pain - 2/7, G1 Lymphopenia - 1/7, G1 Pruritis - 1/7; with no ≥ G3 toxicities related to study drug observed. One G5 toxicity (Clostridium septicum infection 20 days post injection) was deemed unlikely related to study drug. 5/6 patients received 1 cycle prior to post-protocol immune-based therapy. One treatment naïve patient retreated once with IFx-Hu2.0 required no additional therapy > 9 months. Available paired tissue and plasma sampling revealed increased T cell infiltration into treated lesions, increase in IgM and IgG epitope recognition to melanoma associated antigens in the plasma (detected by PEPperPRINT assay), an increase in mRNA associated with innate immune responses in the injected lesion (CXCL13, LAG3, CXCL11, CXCL10, ICOS) and an adaptive immune response (IL-12, HLA-DRB5, WNT4, CD3D, Arg I) in uninjected lesions associated with downregulation of known melanoma antigens. Of 4 anti-PD1 refractory patients, three patients had clinical benefit to post-protocol retreatment with anti-PD1 based therapy (Stable Disease (SD) lasting > 2 years followed by surgical resection, Partial Response (PR) lasting > 9 months, PR subsequently surgical resected and rendered no evidence of disease). Conclusions: In this pilot study, intralesional IFx-Hu2.0 demonstrated a favorable safety profile. These data support encouraging immunological correlative responses and further study of IFx-Hu2.0 as a priming agent to enhance or restore sensitivity to immune checkpoint inhibitor therapy in melanoma. Clinical trial information: NCT03655756.

Predictors of immunotherapeutic benefits in patients with advanced melanoma and other malignancies treated with immune checkpoint inhibitors utilizing ORIEN “real-world” data

2618

Background: Despite the significant improvements in treating cancer with immune checkpoint inhibitors (ICIs), many patients (pts) do not achieve disease control. Using Oncology Research Information Exchange Network (ORIEN) Avatar real-world data conducted under the Total Cancer Care protocol we investigate predictive biomarkers of ICI benefits in pts with advanced malignancies. Methods: Clinical data were normalized as part of ORIEN Avatar. RNA-seq was performed on tumor samples following the RSEM pipeline and gene expressions were quantified as Transcript Per Million (TPM). Gene expressions (GE) were log2(TPM+1) transformed. Mann-Whitney U-test was used to compute differences between groups, and Kaplan-Meier survival analysis was performed. Results: Pts (n=1214) with 27 cancer types treated with ICIs were retrieved from the database, where 1143 and 875 patients were profiled by WES and RNA-seq, respectively. 804 pts had both WES and RNA-seq data. The top six cancer types were renal cell carcinoma (n=206), non-small cell lung cancer (n=173), head and neck cancer (n=157), melanoma (n=154), sarcomas (n=99) and bladder cancer (n=87). The ICI regimens included therapy with atezolizumab (n=87), avelumab (n=12), cemiplimab (n=6), ipilimumab (n=47), nivolumab (n=424), pembrolizumab (n=525) and ipilimumab+nivolumab (n=113). Median overall survival (OS) for the entire cohort was 21.9 months. Patients had significant improvement in OS if ICI was given in the first line ( P<0.0001). Previously published GE signatures were tested in the melanoma cohort. Signatures related to IFNg, effector T cells, chemokines, MHC II and Tertiary Lymphoid Structures were significantly prognostic and predictive of ICI benefits in advanced melanoma (Table). Analyses in the other cancer types are ongoing. Conclusions: GE data analyses validate the predictive value of immune related gene signatures following ICI immunotherapy in melanoma. Ongoing analyses are investigating these signatures in other malignancies and integrating the GE data with data related to TMB, somatic mutations and germline genetic variations.[Table: see text]

Pan-cancer analysis of exogenous (microbial) sequences in tumor transcriptome data from the ORIEN consortium and their association with cancer and tumor microenvironment

3113

Background: The tumor microbiome holds great potential for its ability to characterize various aspects of cancer biology and as a target for rational manipulation. For many cancer types, little is known about the role of microbes and in what contexts they affect clinical outcomes. Non-human (i.e. exogenous) sequences can be observed in low abundance within high throughput sequencing data of tumors. Here, we describe a collaboration among members of The Oncology Research Information Exchange Network (ORIEN) to leverage tumor biopsy RNAseq data collected under a shared protocol and generated at a single site to better understand the tumor microbiome, its association with prognostic features of the tumor microenvironment (TME) such as hypoxia, and how it may be used to improve clinical outcomes. Methods: Tumor RNAseq samples from 10 primary source locations including the tissues colon, lung, pancreas, and skin from ORIEN and similar cancers from The Cancer Genome Atlas (TCGA) were processed through the exoTIC (exogenous sequencing in tumors and immune cells) pipeline to identify and count exogenous sequences, filter contaminants, and normalize across datasets. Gene expression signatures of the TME, such as hypoxia, were calculated using ‘tmesig’. Microbe relative abundances were modeled with primary tumor location and hypoxia score using a gamma-distributed generalized linear regression via the stats package in R. Results: We analyzed RNAseq data of 2892 and 2720 tumors from ORIEN and TCGA, respectively. Patients’ ages were significantly greater in the ORIEN than the TCGA dataset (62 vs 58 yo, t-test p<0.001). The ORIEN data contained more sarcoma samples than TCGA (n = 691 vs 259) with roughly equivalent numbers in other cancer types. Fewer microbes were significantly associated with the hypoxia score than with cancer type (n = 32 vs 210). This trend was observed in both the ORIEN and TCGA datasets. The largest effect sizes were observed between microbes and small cell lung cancer. Conclusions: We found microbial sequences in all ORIEN and TCGA tumor RNAseq samples tested. Cancer type showed more significant associations with microbes than a hypoxia signature. These observations merit further investigation into the interaction between microbes and the TME. [Table: see text]

Early quality of life (QOL) and symptom analysis from the DREAMseq phase III randomized control trial of combination immunotherapy versus targeted therapy in patients (pts) with BRAF-mutant metastatic melanoma (MM) (ECOG-ACRIN EA6134)

9559

Background: Combinations of either immune checkpoint inhibitors (anti-PD-1/anti-CTLA-4) or BRAF/MEK-targeted therapies have shown significant clinical benefit in pts with BRAFV600 mutant MM. Until recently, little prospective data existed to guide the choice of initial therapy or sequence. Results of the DREAMseq Trial showed that the treatment sequence beginning with nivolumab/ipilimumab (Nivo/Ipi) immunotherapy produced a clinically meaningful 20% improvement in 2-year overall survival (OS) compared to the sequence beginning with dabrafenib/trametinib (Dab/Tram) targeted therapy. The OS and progression-free survival (PFS) curves were biphasic crossing at 10 and 6 months, respectively. Our aim is to characterize QOL trends within and between the initial therapies through 24 weeks (wks). Methods: 265 pts were randomly assigned to Nivo/Ipi for up to 12 wks then Nivo alone (Arm A) or Dab/Tram continuously (Arm B) and at disease progression (PD) received the alternate therapy. QOL was assessed by the PROMIS Profile 29 at baseline, wk 12 (end of cycle (C) 2), and wk 24 (end of C4). Wilcoxon Signed Rank test was used to examine changes over time within treatment arms. OS was estimated by Kaplan-Meier method to compare between pts who stopped treatment for toxicity on Arm A by C2 and who continued on Arm A therapy to C4. A complete case analysis compared QOL domain means for (C2) vs. (C4). Pt-reported adverse events were also collected. Results: Baseline completion rates for the PROMIS-29 for Arm A (n = 108, 81.2%) and Arm B (n = 117, 88.6%) and decreased to 28.6% and 53.8%, respectively at C4. Through C4, the principal reasons for dropout were toxicity (35.2% for Arm A and 11.9% for Arm B) and PD (26.1% for Arm A and 18.6% for Arm B). From Baseline to C2: Arm B reported statistically significant improvements in Pain Interference (-3.45, P = 0.007), Sleep (-2.11, P = 0.014), and Anxiety (-3.74, P < 0.001). By C4, these early differences had dissipated (mean diff. = 0.73 – 1.73, all p = NS). For pts remaining on treatment to C4 (n = 157), a complete case analysis indicates no significant QOL differences between C2 vs C4. Pts stopping for toxicity on Arm A after C2 had similar 2-yr OS to pts who continued on Arm A to C4. QOL at C2 (Arm A: stopping for toxicity vs. on treatment) were meaningful, but underpowered (Physical Health (PH) mean difference = -3.5, p = 0.18). Conclusions: Over the first 12 wks, Dab/Tram is associated with significant improvement in overall function and less disturbance in in sleep, pain, physical function, and PH than Nivo/Ipi as expected by PFS curves and toxicity profiles. These differences dissipate by 24 wks when Arm A therapy has switched to Nivo alone and PFS curves cross. Early QOL and treatment cessation due to Nivo/Ipi toxicity was not associated with differences in 2-yr OS. Clinical trial information: NCT02224781.

A deep learning approach utilizing clinical and molecular data for identifying prognostic biomarkers in patients treated with immune checkpoint inhibitors: An ORIEN pan-cancer study

2619

Background: Immune checkpoint inhibitors (ICIs) have made significant improvements in the treatment of cancer patients (pts), but many continue to experience primary or secondary resistance. Here, we leveraged clinical and genomic data to identify prognostic biomarkers in pts treated with ICIs utilizing a pan-cancer approach. Methods: Pts were enrolled to the Total Cancer Care protocol across 18 cancer centers within the Oncology Research Information Exchange Network (ORIEN). RNA-seq was performed on tumors following the RSEM pipeline and gene expressions were quantified as Transcript Per Million (TPM) and were logarithmically normalized. An Auto-Encoder Survival Deep Network (AE-SDN) architecture was developed that combined the reconstruction loss of AE with Cox regression for modeling time to event. For comparison, immunoscore for each pt was calculated based on the estimated densities of tumor CD3+ and CD8+ T cells (Galon, 2020) utilizing CIBERSORTx. The quality of overall survival (OS) predictions was assessed using Harrell’s concordance index (C-index). Log-rank test was used to assess stratified group differences (by ICI or cancer histology) along with Kaplan-Meier (KM) survival analysis of AE-SDN and immunoscore. Results: Pts (n=522) with 4 cancer types including melanoma (n=125), renal cell carcinoma (n=149), non-small cell lung cancer (n=128) and head and neck cancer (n=120) treated with 6 ICI regimens were included in this analysis. ICI regimens were nivolumab (n=219), pembrolizumab (n=202), ipilimumab+nivolumab (n=69), ipilimumab (n=30), avelumab (n=1) and cemiplimab (n=1). The Table summarizes the overall C-index and associated 95% CIs and log-rank P values for the entire cohort (regardless of histology) resulting from our proposed AE-SDN model and the separate estimated immunoscore categorization. AE-SDN top selected genes were mostly related to immunity, carcinogenesis and tumor suppression. The corresponding KM plots showed significantly wider separations of the survival curves in favor of our proposed AE-SDN model relative to the immunoscore with more than 20% improvement in prediction power. Conclusions: Deep network machine learning analysis is a promising approach to identifying relevant prognostic biomarkers in cancer pts treated with ICI. This may lead to novel therapeutic predictive signatures and identification of mechanisms of ICI resistance. Our AE-SDN gene expression signature was significantly prognostic and outperformed the estimated CD3+, CD8+ T Cell immunoscore. Further refinements to our prediction power are ongoing along with more advanced neural network architectures to elucidate related functional pathways. [Table: see text]

Single-cell Characterization of the Cellular Landscape of Acral Melanoma Identifies Novel Targets for Immunotherapy

PURPOSE

Acral melanoma is a rare subtype of melanoma that arises on the non-hair-bearing skin of the palms, soles, and nail beds. In this study, we used single-cell RNA sequencing (scRNA-seq) to map the transcriptional landscape of acral melanoma and identify novel immunotherapeutic targets.

EXPERIMENTAL DESIGN

We performed scRNA-seq on nine clinical specimens (five primary, four metastases) of acral melanoma. Detailed cell type curation was performed, the immune landscapes were mapped, and key results were validated by analysis of The Cancer Genome Atlas (TCGA) and single-cell datasets. Cell-cell interactions were inferred and compared with those in nonacral cutaneous melanoma.

RESULTS

Multiple phenotypic subsets of T cells, natural killer (NK) cells, B cells, macrophages, and dendritic cells with varying levels of activation/exhaustion were identified. A comparison between primary and metastatic acral melanoma identified gene signatures associated with changes in immune responses and metabolism. Acral melanoma was characterized by a lower overall immune infiltrate, fewer effector CD8 T cells and NK cells, and a near-complete absence of γδ T cells compared with nonacral cutaneous melanomas. Immune cells associated with acral melanoma exhibited expression of multiple checkpoints including PD-1, LAG-3, CTLA-4, V-domain immunoglobin suppressor of T cell activation (VISTA), TIGIT, and the Adenosine A2A receptor (ADORA2). VISTA was expressed in 58.3% of myeloid cells and TIGIT was expressed in 22.3% of T/NK cells.

CONCLUSIONS

Acral melanoma has a suppressed immune environment compared with that of cutaneous melanoma from nonacral skin. Expression of multiple, therapeutically tractable immune checkpoints were observed, offering new options for clinical translation.

Adjuvant Pembrolizumab versus IFNα2b or Ipilimumab in Resected High-Risk Melanoma

We conducted a randomized phase III trial to evaluate whether adjuvant pembrolizumab for one year (647 patients) improved recurrence-free survival (RFS) or overall survival (OS) in comparison with high-dose IFNα-2b for one year or ipilimumab for up to three years (654 patients), the approved standard-of-care adjuvant immunotherapies at the time of enrollment for patients with high-risk resected melanoma. At a median follow-up of 47.5 months, pembrolizumab was associated with significantly longer RFS than prior standard-of-care adjuvant immunotherapies [HR, 0.77; 99.62% confidence interval (CI), 0.59-0.99; P = 0.002]. There was no statistically significant association with OS among all patients (HR, 0.82; 96.3% CI, 0.61-1.09; P = 0.15). Proportions of treatment-related adverse events of grades 3 to 5 were 19.5% with pembrolizumab, 71.2% with IFNα-2b, and 49.2% with ipilimumab. Therefore, adjuvant pembrolizumab significantly improved RFS but not OS compared with the prior standard-of-care immunotherapies for patients with high-risk resected melanoma.

SIGNIFICANCE

Adjuvant PD-1 blockade therapy decreases the rates of recurrence, but not survival, in patients with surgically resectable melanoma, substituting the prior standard-of-care immunotherapies for this cancer. See related commentary by Smithy and Shoushtari, p. 599. This article is highlighted in the In This Issue feature, p. 587.

Improved prognosis and evidence of enhanced immunogenicity in tumor and circulation of high-risk melanoma patients with unknown primary

BACKGROUND

Melanoma of unknown primary (MUP) represents a poorly understood group of patients both clinically and immunologically. We investigated differences in prognosis and candidate immune biomarkers in patients with unknown compared with those with known primary melanoma enrolled in the E1609 adjuvant trial that tested ipilimumab at 3 and 10 mg/kg vs high-dose interferon-alfa (HDI).

PATIENTS AND METHODS

MUP status was defined as initial presentation with cutaneous, nodal or distant metastasis without a known primary. Relapse-free survival (RFS) and overall survival (OS) rates were estimated by the Kaplan-Meier method. Stratified (by stage) log-rank test was used to compare RFS and OS by primary tumor status. Gene expression profiling (GEP) was performed on the tumor biopsies of a subset of patients. Similarly, peripheral blood samples were tested for candidate soluble and cellular immune biomarkers.

RESULTS

MUP cases represented 12.8% of the total population (N=1699) including 11.7% on the ipilimumab arms and 14.7% on the HDI arm. Stratifying by stage, RFS (p=0.001) and overall survival (OS) (p=0.009) showed outcomes significantly better for patients with unknown primary. The primary tumor status remained prognostically significant after adjusting for treatment and stage in multivariate Cox proportional hazards models. Including only ipilimumab-treated patients, RFS (p=0.005) and OS (p=0.023) were significantly better in favor of those with unknown primary. Among patients with GEP data (n=718; 102 MUP, 616 known), GEP identified pathways and genes related to autoimmunity, inflammation, immune cell infiltration and immune activation that were significantly enriched in the MUP tumors compared with known primaries. Further investigation into infiltrating immune cell types estimated significant enrichment with CD8 +and CD4+T cells, B cells and NK cells as well as significantly higher major histocompatibility complex (MHC)-I and MHC-II scores in MUP compared with known primary. Among patients tested for circulating biomarkers (n=321; 66 unknown and 255 known), patients with MUP had significantly higher circulating levels of IL-2R (p=0.04).

CONCLUSION

Patients with MUP and high-risk melanoma had significantly better prognosis and evidence of significantly enhanced immune activation within the TME and the circulation, supporting the designation of MUP as a distinct prognostic marker in patients with high-risk melanoma.

DREAMseq (Doublet, Randomized Evaluation in Advanced Melanoma Sequencing): A phase III trial—ECOG-ACRIN EA6134

356154

Background: Combinations of immune checkpoint inhibitors (CPI) blocking PD-1 and CTLA-4 or BRAF/MEK inhibitors have both shown significant antitumor efficacy and overall survival (OS) benefit in patients (pts) with BRAFV600-mutant metastatic melanoma (MM), leading to broad regulatory approval. Little prospective data exists to guide the choice of one over the other as initial therapy or the preferred treatment sequence in this population. The DREAMseq Trial was designed to compare the efficacy and toxicity of the sequence of nivolumab/ipilimumab (N/I) followed by dabrafenib/trametinib (D/T) to the converse sequence. Methods: Eligible pts with treatment-naive BRAFV600-mutant MM were stratified by ECOG Performance Status (PS) 0 or 1 and LDH level and randomized 1:1 to receive Step 1 with either N/I (Arm A) or D/T (Arm B) and at disease progression (PD) were enrolled in Step 2 receiving the alternate therapy, D/T (Arm C) or N/I (Arm D), respectively. Pts received N (1mg/kg)/I (3 mg/kg) q3 wks x 4 doses followed by N 240 IV q2 wks for up to 72 wks (Arms A and D) or D 150 mg po BID and T 2 mg po qD until PD (Arms B and C). In 2019, investigators were given the option to use alternate induction dosing of N (3mg/kg)/I (1 mg/kg) q3 wks x 4 doses for Arms A and D. Cycles were every 6 wks and imaging was obtained at baseline and q12 wks on each arm. Primary endpoint was 2-year OS. At the 4th Interim Analysis with 59% of pts being 2 yrs from enrollment, the DSMC and NCI CTEP recommended halting accrual and releasing the data. Results: Beginning 7/2015, 265 out of a proposed 300 pts were enrolled (133 Arm A and 132 Arm B). Median age was 61 (25-85) and 63% were male. Demographics for Arm A and B were balanced with 67% PS 0 and 60% with normal LDH. As of 7/16/21, at a median follow-up of 27.7 mos, 27 pts had switched to Arm C and 46 to Arm D. Overall Grade 3+ toxicity was 60% in Arm A and 52% in Arm B. Grade 5 treatment-related AEs included 2 on Arm A and 1 on Arm C. ORR to date is: Arm A 46% (52/113), Arm B 43% (49/114), Arm C 48% (11/23) and Arm D 30% (8/27). 37/42 assessed pts in Arm A and 19/37 in Arm B remain in response. Median DOR: Arm A- Not reached; Arm B-12.7 mos (95% CI: 8.2, -) (p <0.001). There were 100 deaths (Arm A to C- 38/Arm B to D- 62). 2-yr OS rate for those starting with Arm A was 72% (95% CI: 62-81%) and for Arm B 52% (95% CI: 42-62%) (log-rank p= 0.0095). PFS showed a trend in favor of Arm A (log-rank p=0.054). Both the PFS and OS curves show a biphasic pattern with Arm B being above Arm A until 6 and 10 mos, respectively. For the 115 pts with documented progression on Step 1 (Arm A-44/Arm B-71), 60 (52%) had registered for Step 2. The principal reason for not enrolling on Step 2 was death from PD within 6 mos (Arm A:15/23; Arm B: 25/32). Conclusions: For pts with advanced BRAFV600-mutant MM, the treatment sequence beginning with the CPI combination of N/I resulted in superior OS, which became evident at 10 mos, with longer Step 1 DOR and more ongoing responses than the treatment sequence beginning with D/T. Clinical trial information: NCT02224781.

Treatment-free survival over extended follow-up of patients with advanced melanoma treated with immune checkpoint inhibitors in CheckMate 067

BACKGROUND

Treatment-free survival (TFS) characterizes disease control after discontinuation of immune checkpoint inhibitors (ICIs) until subsequent therapy or death. We previously evaluated TFS in a pooled analysis of the CheckMate 067 and CheckMate 069 trials of the ICIs nivolumab and ipilimumab, alone or in combination, in patients with advanced melanoma after minimum follow-up of 36 months. This analysis investigated TFS differences between treatments in CheckMate 067 after a minimum follow-up of 60 months, and their relation to overall survival (OS) differences.

METHODS

Data were from 937 patients who initiated treatment (nivolumab plus ipilimumab, nivolumab, or ipilimumab) in CheckMate 067 (NCT01844505). TFS was defined as the area between the Kaplan-Meier curves for time to protocol therapy cessation and time to subsequent systemic therapy initiation or death, each measured from randomization. TFS was partitioned as time with and without toxicity. Toxicity included persistent and late-onset grade ≥2 select treatment-related adverse events (ie, those of potential immunologic etiology). The area between Kaplan-Meier curves was estimated by the difference in 60-month restricted-mean times of the endpoints. Between-group differences were estimated with bootstrapped 95% CIs.

RESULTS

At 60 months from randomization, 39%, 24%, and 11% of patients assigned to treatment with nivolumab plus ipilimumab, nivolumab, and ipilimumab, respectively, had survived and were treatment-free. The 60-month mean TFS was approximately twice as long with the combination (19.7 months) than with nivolumab (9.9 months; absolute difference, 9.8 (95% CI 6.7 to 12.8)) or ipilimumab (11.9 months; absolute difference, 7.8 (95% CI 4.6 to 11.0)). In the respective groups, mean TFS represented 33% (8% with and 25% without toxicity), 17% (2% and 14%), and 20% (3% and 17%) of the 60-month period. Compared with 36-month estimates, mean TFS over the 60-month period represented slightly greater percentages of time in the nivolumab-containing regimen groups and a lesser percentage in the ipilimumab group. TFS differences between the combination and either monotherapy increased with longer follow-up.

CONCLUSIONS

Along with improved long-term OS with the nivolumab-containing regimens versus ipilimumab, TFS without toxicity was sustained with nivolumab plus ipilimumab versus either monotherapy, demonstrating larger between-group differences with extended follow-up.

Surveillance of Sentinel Node-Positive Melanoma Patients Who Receive Adjuvant Therapy Without Undergoing Completion Lymph Node Dissection

INTRODUCTION

Adjuvant therapy trials required completion lymph node dissection (CLND) for sentinel lymph node (SLN)-positive melanoma prior to systemic treatment, but nodal surveillance without CLND is now common. For patients receiving adjuvant therapy without CLND, patterns of recurrence are unknown and the value of regional nodal ultrasound alongside cross-sectional imaging is not well-defined.

METHODS

In a retrospective cohort of SLN-positive melanoma patients managed with nodal surveillance from June 2014 to June 2019, we evaluated the association between adjuvant treatment and location of first recurrence (locoregional, nodal, distant, or multisite) using Chi-square tests. We compared methods of recurrence detection and cost by surveillance intensity using Chi-square and Dunn's tests.

RESULTS

Among 177 nodal surveillance patients, 66 (37%) received adjuvant therapy. Median follow-up was 24 months, during which 48 patients (27%) recurred. Adjuvant treatment did not alter patterns of initial recurrence (p = 0.76). Adjuvant therapy recipients more often had both nodal ultrasound and cross-sectional imaging surveillance (p < 0.01). Among 13 isolated nodal recurrences, 85% were within the first year and 85% were detected by examination and/or ultrasound. Increasing surveillance intensity was not associated with recurrence detection rates but increased overall cost and cost per detected recurrence.

CONCLUSION

Regardless of adjuvant treatment, most nodal recurrences occurred in the first year and were initially detected clinically or by ultrasound. Findings support continued use of examination and nodal basin ultrasound in addition to any planned cross-sectional imaging surveillance.

Sargramostim and immune checkpoint inhibitors: combinatorial therapeutic studies in metastatic melanoma

The use of immune checkpoint inhibitors in patients with metastatic melanoma generates clinical benefit, including improved survival. Yet disease resistance and immune-related adverse events persist as unmet needs. Sargramostim, a yeast-derived recombinant human GM-CSF, has shown clinical activity against diverse solid tumors, including metastatic melanoma. Here we review the use of sargramostim for treatment of advanced melanoma. Potential sargramostim applications in melanoma draw on the unique ability of GM-CSF to link innate and adaptive immune responses. We review preclinical and translational data describing the mechanism of action of sargramostim and synergy with immune checkpoint inhibitors to enhance efficacy and reduce treatment-related toxicity.

Efficacy of cetuximab after immunotherapy (IO) in advanced cutaneous squamous cell carcinoma (CSCC)

9562

Background: Anti-PD1 (aPD1) monotherapy with cemiplimab-rwlc or pembrolizumab is now considered standard of care for first-line management of advanced CSCC not amenable to surgery or curative radiotherapy. Previously chemotherapy or anti-EGFR agents were commonly used for these patients albeit with modest efficacy and limited duration of response. In prospective evaluation, the overall response rate (ORR) to cetuximab was 28% with disease control rate (DCR) of 69% at 6 weeks. The efficacy of second-line treatment following primary or acquired resistance to aPD1 therapy is not known. We investigated the activity of cetuximab in patients who progressed on previous IO therapy. Methods: We performed a single institution retrospective review from 9/28/18 (US approval date of cemiplimab-rwlc for CSCC) through 11/30/20 of patients with locally advanced or metastatic CSCC who received cetuximab after prior IO therapy. We identified patients who received cetuximab either immediately following IO therapy (cohort A) or as a subsequent line not immediately following IO therapy (cohort B). Primary endpoint was ORR with secondary endpoints of DCR, survival and toxicity. Median follow-up and survival times were calculated using the Kaplan-Meier method. Results: Thirteen patients, median age 72 years (62-82), all Caucasian, and 11 males (85%) were included in this study. Eleven pts received cetuximab immediately post-IO progression; two had additional intervening therapy post-IO before receiving cetuximab. Three patients received concurrent radiotherapy (palliative or definitive) with cetuximab. The ORR to cetuximab was 54% (7/13) including 1 complete and 6 partial responses. The cumulative 6-month DCR was 77%. All responses were observed in cohort A; both patients in cohort B had progressive disease as best response. Six of 7 initial responses are ongoing, including 3 in whom cetuximab was discontinued. At a median follow-up of 9.1 months, the median PFS has not been reached for the entire cohort. There were no unanticipated toxicities to cetuximab with rash (77%) and hypomagnesemia (54%) being the most common adverse events. Conclusions: In advanced CSCC, cetuximab used immediately after progression on aPD1 therapy yields notably higher and durable overall response than previously reported in the pre-IO therapy era. If validated in a larger dataset, this should be the preferred therapy for second-line treatment in advanced CSCC. Further exploration into the mechanism of this high efficacy of anti-EGFR therapy post aPD1 therapy is warranted.

Final analysis of overall survival (OS) and relapse-free-survival (RFS) in the intergroup S1404 phase III randomized trial comparing either high-dose interferon (HDI) or ipilimumab to pembrolizumab in patients with high-risk resected melanoma

9501

Background: We assessed whether or not adjuvant pembrolizumab given over 1 year would improve OS and RFS in comparison to high dose ipilimumab (ipi10) or HDI - the two FDA-approved adjuvant treatments for high risk resected melanoma at the time of study design. Methods: Patients age 18 or greater with resected stages IIIA(N2), B, C and IV were eligible. Patients with CNS metastasis were excluded. At entry, patients must have had complete staging and adequate surgery to render them free of melanoma including completion lymph node dissection for those with sentinel node positive disease. Prior therapy with PD-1 blockade, ipilimumab or interferon was not allowed. Two treatment arms were assigned based on stratification by stage, PD-L1 status (positive vs. negative vs. unknown), and intended control arm (HDI vs. Ipi10). Patients enrolled between 10/2015 and 8/2017 were randomized 1:1 to either the control arm [(1) interferon alfa-2b 20 MU/m2 IV days 1-5, weeks 1-4, followed by 10 MU/m2/d SC days 1, 3, and 5, weeks 5-52 (n=190), or (2) ipilimumab 10 mg/kg IV q3w for 4 doses, then q12w for up to 3 years (n=465)], or the experimental arm [pembrolizumab 200 mg IV q3w for 52 weeks (n=648)]. The study had three primary comparisons: 1) RFS among all patients, 2) OS among all patients, 3) OS among patients with PD-L1+ baseline biopsies. Results: 1,426 patients were screened and 1,345 patients were randomized with 11%, 49%, 34%, and 6% AJCC7 stage IIIA(N2), IIIB, IIIC and IV, respectively. This final analysis was performed per-protocol 3.5 years from the date the last patient was randomized, with 512 RFS and 199 OS events. The pembrolizumab group had a statistically significant improvement in RFS compared to the control group (pooled HDI and ipi10) with HR 0.740 (99.618% CI, 0.571 to 0.958). There was no statistically signifcant improvement in OS in the 1,303 eligible randomized overall patient population with HR 0.837 (96.3% CI, 0.622 to 1.297), or among the 1,070 (82%) patients with PD-L1 positive baseline biopsies with HR 0.883 (97.8% CI, 0.604 to 1.291). Gr 3/4/5 event rates were as follows: HDI 69/9/0%, ipi10 43/5/0.5% and pembrolizumab 17/2/0.3%. Conclusions: Pembrolizumab improves RFS but not OS compared to HDI or ipi10 in the adjuvant treatment of patients with high-risk resected melanoma. Pembrolizumab is a better tolerated adjuvant treatment regimen than HDI or Ipi10. Support: NIH/NCI NCTN grants CA180888, CA180819, CA180820, CA180863; and in part by Merck Sharp & Dohme Corp., a subsidiary of Merck & Co., Inc., Kenilworth, NJ, USA. Editorial Acknowledgement: With special thanks to Elad Sharon, MD, MPH, and Larissa Korde, MD, MPH. National Cancer Institute, Investigational Drug Branch, for their contributions to this trial, as well as Nageatte Ibrahim, MD, and Sama Ahsan, MD Merck. Clinical trial information: NCT02506153.

Somatic mutations predict immune-related adverse events (irAEs) and survival following CTLA4 blockade in melanoma patients

e21584

Background: Predicting immune-related adverse events (irAEs) resulting from immune checkpoint inhibitors (ICIs) as well as the likelihood of clinical benefit is an area of great interest. irAEs have been associated with clinical outcome measures and we were interested in examining somatic mutations that may correlate with irAEs and subsequently with relapse free survival (RFS) and overall survival (OS). Methods: Our irAEs of interest for this analysis were rash and colitis based on prior data and these were tested for association with RFS and overall OS. Nonsynonymous somatic mutations were identified utilizing tumor and matched blood samples from 22 metastatic melanoma patients treated with neoadjuvant ipilimumab. Whole exome sequencing was performed using the SOLiD 5500 Next-Generation Sequencing platform. Somatic mutations were identified by subtraction of germline variants. Total mutational burden was assessed, and individual mutations were correlated with irAEs and with clinical outcome. Results: MUC16 was the most commonly mutated gene (82%). Of notable known oncogenic mutations, BRAF was the most common (50%) followed by NRAS (23%). Among known oncogenic signaling pathways, enrichment was most common in RTK-RAS (58%), followed by NOTCH and WNT. Development of colitis showed a strong trend in association with RFS. Development of rash indicated a similar trend. 20 different statistically significant mutations (p < 0.05) were identified among patients with colitis and these were also associated with OS and RFS. Notably, PTPRO mutation status (known to antagonize PDL1 expression) appeared protective against colitis and associated with worse RFS and OS. Similarly, ADGB mutation was significantly associated with developing rash and also associated with improved RFS and OS. Correcting for TMB in a multivariate model confirmed the associations. Conclusions: Somatic mutations were found to be associated with the irAEs of rash and colitis and with clinical outcome following ipilimumab treatment of melanoma. Our findings warrant further investigation and validation in independent cohorts.

Granulomatous and sarcoid-like immune related adverse events (irAEs) in melanoma patients following CTLA4 blockade adjuvant therapy: An analysis of 1670 high-risk patients

9582

Background: Granulomatous and sarcoid-like lesions (GSL) affecting the skin, lungs, thoracic lymph nodes, eyes and other organs following treatment with immune checkpoint inhibitors (ICIs) have been described in sporadic reports in the literature but the true incidence is unknown. Methods: We sought to estimate the incidence of GSL in the context of prospectively conducted ECOG-ACRIN E1609 phase III adjuvant trial in high-risk resected melanoma (N=1670 patients) testing ipilimumab 3 mg/kg (ipi3) and 10 mg/kg (ipi10) versus high-dose interferon-α (HDI). Descriptive statistics were used to calculate the incidence. Results: Among 1670 total patients treated with ICIs or with HDI in E1609, 1034 were treated with ipilimumab and 636 with HDI. Six GSL cases were reported among 1670 total patients treated with ipilimumab or with HDI as summarized in the table along with the corresponding CTCAE grades. More cases were observed with ipi10, followed by ipi3 and HDI, respectively. Organs involved included skin and subcutaneous tissue (granuloma annulare, granulomatous dermatitis), eye (ocular sarcoidosis), lymph nodes (noncaseating granulomatous lymphadenitis), lung and mediastinal lymph nodes (sarcoidosis, granulomatous inflammation). Conclusions: The incidence of granulomatous and sarcoid-like lesions (GSL) with adjuvant ipilimumab therapy in high-risk melanoma is rare. Reported cases ranged in grade from 1-3 and appeared manageable. Since most cases are asymptomatic, it is possible that GSLs are under-recognized and therefore, under-reported. A larger analysis including patients treated with anti-PD1 antibodies is currently underway. Clinical trial information: NCT01274338. [Table: see text]

Immune adverse events (irAEs) with adjuvant ipilimumab in melanoma, use of immunosuppressants and association with outcome: ECOG-ACRIN E1609 study analysis

Background

The impact of immune-related adverse events (irAEs) occurring from adjuvant use of immunotherapy and of their management on relapse-free survival (RFS) and overall survival (OS) outcomes is currently not well understood.

Patients and methods

E1609 enrolled 1673 patients with resected high-risk melanoma and evaluated adjuvant ipilimumab 3 mg/kg (ipi3) and 10 mg/kg (ipi10) versus interferon-α. We investigated the association of irAEs and of use of immunosuppressants with RFS and OS for patients treated with ipilimumab (n=1034).

Results

Occurrence of grades 1–2 irAEs was associated with RFS (5 years: 52% (95% CI 47% to 56%) vs 41% (95% CI 31% to 50%) with no AE; p=0.006) and a trend toward improved OS (5 years: 75% (95% CI 71% to 79%) compared with 67% (95% CI 56% to 75%) with no AE; p=0.064). Among specific irAEs, grades 1–2 rash was most significantly associated with RFS (p=0.002) and OS (p=0.003). In multivariate models adjusting for prognostic factors, the most significant associations were seen for grades 1–2 rash with RFS (p<0.001, HR=0.70) and OS (p=0.01, HR=0.71) and for grades 1–2 endocrine+rash with RFS (p<0.001, HR=0.66) and OS (p=0.008, HR=0.7). Overall, grades 1–2 irAEs had the best prognosis in terms of RFS and OS and those with grades 3–4 had less RFS benefits and no OS advantage over no irAE. Patients experiencing grades 3–4 irAE had significantly higher exposure to corticosteroids and immunosuppressants than those with grades 1–2 (92% vs 60%; p<0.001), but no significant associations were found between corticosteroid and immunosuppressant use and RFS or OS. In investigating the impact of non-corticosteroid immunosuppressants, although there were trends toward better RFS and OS favoring cases who were not exposed, no significant associations were found.

Conclusions

Rash and endocrine irAEs were independent prognostic factors of RFS and OS in patients treated with adjuvant ipilimumab. Patients experiencing lower grade irAEs derived the most benefit, but we found no significant evidence supporting a negative impact of high dose corticosteroids and immunosuppressants more commonly used to manage grades 3–4 irAEs.

Safety and Efficacy of the Combination of Nivolumab Plus Ipilimumab in Patients With Melanoma and Asymptomatic or Symptomatic Brain Metastases (CheckMate 204)

Background

In patients with melanoma and asymptomatic brain metastases (MBM), nivolumab plus ipilimumab provided an intracranial response rate of 55%. Here, we present the first report for patients who were symptomatic and/or required corticosteroids and updated data for asymptomatic patients.

Methods

Patients with measurable MBM, 0.5-3.0 cm, were enrolled into Cohort A (asymptomatic) or Cohort B (stable neurologic symptoms and/or receiving corticosteroids). Nivolumab, 1 mg/kg, and ipilimumab, 3 mg/kg, were given intravenously every 3 weeks ×4, followed by nivolumab, 3 mg/kg, every 2 weeks until progression, unacceptable toxicity, or 24 months. The primary endpoint was intracranial clinical benefit rate (CBR; complete response [CR], partial response [PR], or stable disease ≥6 months).

Results

Symptomatic patients (N = 18) received a median of one nivolumab and ipilimumab combination dose and had an intracranial CBR of 22.2%. Two of 12 patients on corticosteroids had CR; 2 responded among the 6 not on corticosteroids. Median intracranial progression-free survival (PFS) and overall survival (OS) were 1.2 and 8.7 months, respectively. In contrast, with 20.6 months of follow-up, we confirmed an intracranial CBR of 58.4% in asymptomatic patients (N = 101); median duration of response, PFS, and OS were not reached. No new safety signals were observed.

Conclusions

Nivolumab plus ipilimumab provides durable clinical benefit for asymptomatic patients with MBM and should be considered for first-line therapy. This regimen has limited activity in MBM patients with neurologic symptoms and/or requiring corticosteroids, supporting the need for alternative approaches and methods to reduce the dependency on corticosteroids.

Clinical trial registration. ClinicalTrials.gov, NCT02320058.

Adjuvant Therapy of Melanoma

as adjuvant therapy for high-risk melanoma was extensively studied in regimens that varied by dosage, route of administration, formulation, and therapy duration. The high-dose regimen (HDI) showed significant improvements in relapse-free survival (RFS) in 3 trials and overall survival (OS) in 2. Ipilimumab at 3 mg/kg demonstrated significant OS benefits compared with HDI and less toxicity compared with ipilimumab at 10 mg/kg. More recently, the standard of care has changed in favor of nivolumab and pembrolizumab and BRAF-MEK inhibitors dabrafenib plus trametinib (for BRAF mutated melanoma), based on significant RFS benefits and more favorable toxicity profiles.

Neoadjuvant Pembrolizumab and High-Dose IFNα-2b in Resectable Regionally Advanced Melanoma

PURPOSE

Neoadjuvant immunotherapy may improve the clinical outcome of regionally advanced operable melanoma and allows for rapid clinical and pathologic assessment of response. We examined neoadjuvant pembrolizumab and high-dose IFNα-2b (HDI) therapy in patients with resectable advanced melanoma.

PATIENTS AND METHODS

Patients with resectable stage III/IV melanoma were treated with concurrent pembrolizumab 200 mg i.v. every 3 weeks and HDI 20 MU/m²/day i.v., 5 days per week for 4 weeks, then 10 MU/m²/day subcutaneously 3 days per week for 2 weeks. Definitive surgery followed, as did adjuvant combination immunotherapy, completing a year of treatment. Primary endpoint was safety of the combination. Secondary endpoints included overall response rate (ORR), pathologic complete response (pCR), recurrence-free survival (RFS), and overall survival (OS). Blood samples for correlative studies were collected throughout. Tumor tissue was assessed by IHC and flow cytometry at baseline and at surgery.

RESULTS

A total of 31 patients were enrolled, and 30 were evaluable. At data cutoff (October 2, 2019), median follow-up for OS was 37.87 months (range, 33.2-43.47). Median OS and RFS were not reached. Radiographic ORR was 73.3% [95% confidence interval (CI): 55.5-85.8], with a 43% (95% CI: 27.3-60.1) pCR rate. None of the patients with a pCR have had a recurrence. HDI and pembrolizumab were discontinued in 73% and 43% of patients, respectively. Correlative analyses suggested that intratumoral PD-1/PD-L1 interaction and HLA-DR expression are associated with pCR (P = 0.002 and P = 0.008, respectively).

CONCLUSIONS

Neoadjuvant concurrent HDI and pembrolizumab demonstrated promising clinical activity despite high rates of treatment discontinuation. pCR is a prognostic indicator.See related commentary by Menzies et al., p. 4133.