Distant Melanoma Research Articles

EXTH-66. ONCOLYTIC ADENOVIRAL INFECTION SYNERGIZES WITH IMMUNE CHECKPOINT INHIBITION TO MEDIATE INTRACRANIAL TUMOR CONTROL IN DISPARATE MODELS OF MELANOMA BRAIN METASTASES

Abstract Amongst all solid cancers, melanoma brain metastases (MBM) have the highest likelihood of metastasizing to the brain. The emergence of immune checkpoint inhibitors (ICI) for metastatic melanoma have demonstrated increasingly promising results; however, intracranial progression remains a challenging obstacle. Oncolytic viral (OV) therapy leverages tumor cell replication machinery to selectively replicate and kill tumor cells and promote anti-tumor immunity. We propose this OV strategy can be applied to MBM through direct tumor infection that simultaneously sustains a distant antitumor immune response. To counteract immunosuppressive features of the tumor microenvironment (TME), a third-generation oncolytic adenovirus (Delta-24-RGDOX) has been developed which expresses the immune stimulatory OX40 ligand (OX40L). We quantified the cytotoxic capacity of Delta-24-RGDOX and its ability to achieve immunogenic cell death (ICD) in vitro along with cerebral organoid co-culture models. Additionally, we used a series of syngeneic murine melanoma models to explore local and systemic antitumor immunity following Delta-24-RGDOX infection. Delta-24-RGDOX inoculation achieved viral infection, OX40L cell surface expression, tumor cell cytotoxicity, and ICD in vitro. Viral oncolysis was recapitulated in a cerebral organoid melanoma co-culture model with concomitant alterations in microglia activation and detection of viral transcripts within microglia using single cell RNA sequencing, suggesting a viral-clearing role of microglia within the TME. Local tumor clearance was achieved in orthotopic intracranial models following direct intracranial viral inoculation alone, and in combination with ICI. Lastly, we demonstrated improvement in overall survival in a synchronous subcutaneous/intracranial B16F10 model where the subcutaneous tumor was treated with Delta-24-RGDOX in combination with ICI. In summary, Delta-24-RGDOX achieves viral infection, oncolysis, and ICD following infection of melanoma cell lines. These findings translated in multiple in vivo models including immune cell activation and systemic antitumor immunity against uninfected MBM. Future studies are needed to explore the role of immune cell trafficking, myeloid cell modulation, T cell priming, and clonal expansion withing locally infected and the distant melanoma TME.

The economic burden of recurrence in elderly patients with completely resected, stage IIB/IIC or III melanoma: an analysis of the Surveillance, Epidemiology, and End Results-Medicare linked database

Aims To compare healthcare resource utilization (HRU) and costs between patients with or without melanoma recurrence and between patients with distant or locoregional melanoma recurrence. Methods Patients aged ≥65 years with completely resected, stage IIB/IIC or III melanoma were identified from Surveillance, Epidemiology, and End Results-Medicare data and stratified based on whether they experienced a recurrence, and whether it was distant or locoregional (separately for each stage). The index date was the date of recurrence (recurrence group) or a randomly assigned date (non-recurrence group). Patients in the recurrence and non-recurrence groups were propensity score-matched 1:1 based on patient characteristics; HRU and healthcare costs were compared between the 2 groups and between patients with distant or locoregional recurrence during the ≤24 months following index. Results After matching, 507 pairs of patients with recurrent or non-recurrent stage IIB/IIC melanoma (236 patients with distant recurrence, 271 with locoregional) and 141 pairs of patients with recurrent or non-recurrent stage III melanoma (50 patients with distant recurrence, 91 with locoregional) were included. During the first year following recurrence, unadjusted HRU was generally higher in patients with versus without recurrence and patients with distant versus locoregional recurrence among both stage IIB/IIC and III cohorts. Patients who experienced recurrence incurred $6,474 (stage IIB/IIC) or $6,112 (stage III) per patient per month (PPPM) more in unadjusted, all-cause, total healthcare costs than patients without recurrence (both p < 0.001). Patients with distant recurrence incurred $7,292 (stage IIB/IIC) or $5,436 (stage III) PPPM more in unadjusted, all-cause, total healthcare costs than patients with locoregional recurrence (both p < 0.05). Limitations Melanoma recurrence was identified using a claims-based algorithm. Conclusions Economic burden is higher in patients with versus without melanoma recurrence and patients with distant versus locoregional recurrence. There is a high unmet need for adjuvant therapies that may help to prevent or delay recurrence.

Trends in Melanoma Incidence, Prevalence, Stage at Diagnosis, and Survival: An Analysis of the United States Cancer Statistics (USCS) Database.

Background and objectives Melanoma, a major skin cancer, has seen varying trends in incidence, prevalence, stage atdiagnosis, and survival. This study examines these trends using the United States CancerStatistics (USCS) database, covering the period from 1999 to 2021. Methods We extracted data from the USCS database, which integrates the National Cancer Institute's (NCI) Surveillance, Epidemiology, and End Results (SEER) program and the Centers for Disease Control and Prevention's (CDC) National Program of Cancer Registries (NPCR). The analysis included new melanoma cases, prevalence estimates (using a 20-year limited duration), stage at diagnosis, and five-year relative survival rates. Incidence rates were adjusted for age using the 2000 United States standard population. Descriptive and trend analyses were performed using IBM SPSS Statistics software, version 29 (IBM Corp., Armonk, NY). Results The analysis of melanoma trends from 1999 to 2021 reveals a significant increase in the annual age-adjusted incidence rate, rising from 15.1 per 100,000 (95% CI: 14.9- 15.2) in 1999 to 23.0 per 100,000 (95% CI: 22.8- 23.1) in 2021. This upward trend is consistent across gender and racial/ethnic groups. The prevalence of melanoma over a 20-year period was 0.279 (95% CI: 0.276-0.282), with males showing a higher prevalence (0.302, 95% CI: 0.298-0.306) compared to females (0.256, 95% CI: 0.252-0.260). The distribution of melanoma stage at diagnosis indicated that 77% of cases were localized (95% CI: 76.5-77.5%), 9.5% regional (95% CI: 9.2-9.8%), 4.7% distant (95% CI: 4.4-5.0%), and 8.8% unstaged (95% CI: 8.5-9.1%). Survival analysis showed a five-year relative survival rate of 99.4% (95% CI: 99.2-99.6%) for localized melanoma and 35.6% (95% CI: 33.7-37.6%) for distant melanoma, highlighting significant disparities in survival based on stage at diagnosis. Conclusions The study highlights a rising incidence of melanoma and emphasizes the critical role of early detection in improving survival outcomes. The findings underscore the effectiveness of early diagnosis and the necessity for ongoing efforts to improve melanoma outcomes across diverse populations.

Identification of patients at high risk for relapse using the Merlin Assay (CP-GEP) in an independent cohort of 451 patients (pts) with stage I/II melanoma who did not undergo sentinel lymph node biopsy.

9574 Background: Sentinel lymph node biopsy (SLNB) is the gold standard for nodal assessment in staging cutaneous melanoma (CM) according to AJCC v8 guideline. 80-85% of pts are negative for nodal metastasis, but most pts who relapse or die from melanoma are initially diagnosed as ‘low risk’ early-stage. Previously we showed that the clinicopathological-gene expression profiling (CP-GEP) model is able to stratify SLNB negative pts for their risk of recurrence (1). Later we showed in a small cohort (n=80) that CP-GEP also has the potential to stratify pts who did not undergo SLNB in low and high-risk of recurrence (2). Here we investigate CP-GEP ability to stratify pts who did not undergo SLNB for their risk of recurrence in an expanded cohort. Methods: We analysedformalin-fixed paraffin-embedded primary tumor samples of 451 pts with stage I/II CM diagnosed between 2000-2017, included in the Central Malignant Melanoma Registry, who did not receive SLNB. Study hypothesis and protocol were prospectively formulated. Tumors were analyzed blinded to clinical outcome. The CP-GEP model used combines the expression of 8 genes ( SERPINE2, GDF15, ITGB3, CXCL8, LOXL4, TGFBR1, PLAT and MLANA) by quantitative reverse transcription polymerase chain reaction with age and Breslow thickness to obtain a binary output: CP-GEP Low- or High-Risk. Relapse-free survival (RFS), distant metastasis free survival (DMFS) and Melanoma Specific Survival (MSS) were evaluated using Kaplan-Meier curves. Results: We included 451 pts (stage IA-IIC). 40% were females, median age was 63-year-old, median Breslow thickness was 0.5 mm, and the majority were not ulcerated (96%). An interim analysis was performed on samples from 159 pts and showed the following survival: 5-year RFS 85.8%; DMFS 94.1; MSS 95.7%. The median follow-up time of 57 months (RFS). CP-GEP identified 149 pts as Low-Risk and 10 pts as High-Risk. The 5-year RFS rate was 90.5% and 0% (HR 23.85; p &lt; 0.001), 5-year DMFS was 97.2% and 27% (HR 43.14; p &lt; 0.001), respectively for CP-GEP Low-Risk and High-Risk pts. The 5-year MSS was 99.1% for Low-Risk pts and 25.7% for High-Risk patients (HR 112.96; p &lt; 0.001), capturing 4 out of 5 melanoma specific deaths in the CP-GEP High-Risk group. The final survival analysis of the whole cohort will be presented at the congress. Conclusions: This study shows that CP-GEP has the potential to stratify pts with early-stage melanoma who did not undergo SLNB based on their risk of recurrence. Pts with CP-GEP Low-Risk have a good long-term survival. Contrary, pts with CP-GEP High-Risk have a high risk of recurrence. CP-GEP may have the potential to stratify pts beyond SLNB. 1. Amaral et al, ASCO 2022. 2. Amaral et al, EJC 2023.

The Molecular Evolution of Melanoma Distant Metastases

The evolution of primary melanoma to lymph node and distant metastasis is incompletely understood. We examined the genomic diversity in melanoma progression in matched primary melanomas, lymph node and distant metastases from 17 patients. Fluorescence in situ hybridization (FISH) analysis revealed cancer cell fractions with monotonic copy number alterations (CNAs), including PHIP gain and PTEN loss, in the metastatic cascade. By contrast, the cancer cell fraction with CNAs for BPTF and MITF was reduced in lymph node metastases but increased in distant metastases. Separately, the cancer cell fraction with NCOA3 CNA was comparable in primary tumors and lymph nodes yet increased in distant metastases. These results suggest enrichment of the PI3K and MITF pathways in the transition through the metastatic cascade. By contrast, next-generation sequencing analysis did not identify a consistent pattern of changes in variant allele frequency (VAF) while revealing several intriguing findings, including decreased VAF in distant metastases and distinct drivers in lymph node versus distant metastases. These results provide evidence that distant melanoma metastasis does not always emanate from lymph node metastasis. These results enhance our understanding of clonal patterns of melanoma metastasis, with possible implications for targeted therapy and metastasis competency.

Can Adapalene Be Repurposed For Melanoma?

Madam, Melanoma, the most lethal skin cancer, accounts for 75% of deaths by skin cancer in the US.1 Nivolumab, Pembrolizumab, and a combination of Nivolumab and ipilimumab are used in adjuvant therapy for distant metastatic melanoma.2 The combination therapy of ipilimumab and nivolumab for melanoma per patient per month was estimated to be USD 71,689.3 Nevertheless, the efficiency of these treatments is limited.4 Furthermore, metastasis can reduce the effectiveness of cancer treatment. With time, cancer cells can also develop resistance to drugs. Hence alternative treatment regimens should be identified.5 The development of new therapies requires a vast amount of time, research, and investment. Drug repurposing provides an alternate approach to this passage. It refers to the new application of previously approved drugs. This process is rapid, potentially safer, and cost-effective.5 Continue...

Long-term Cancer Survival Trends by Updated Summary Stage.

Stage is the most important prognostic factor for understanding cancer survival trends. Summary stage (SS) classifies cancer based on the extent of spread: In situ, Localized, Regional, or Distant. Continual updating of staging systems poses challenges to stage comparisons over time. We use a consistent summary stage classification and present survival trends for 25 cancer sites using the joinpoint survival (JPSurv) model. We developed a modified summary stage variable, Long-Term Site-Specific Summary Stage, based on as consistent a definition as possible and applied it to a maximum number of diagnosis years, 1975-2019. We estimated trends by stage by applying JPSurv to relative survival data for 25 cancer sites in SEER-8, 1975-2018, followed through December 31, 2019. To help interpret survival trends, we report incidence and mortality trends using the joinpoint model. Five-year relative survival improved for nearly all sites and stages. Large improvements were observed for localized pancreatic cancer [4.25 percentage points annually, 2007-2012 (95% confidence interval, 3.40-5.10)], distant skin melanoma [2.15 percentage points annually, 2008-2018 (1.73-2.57)], and localized esophagus cancer [1.18 percentage points annually, 1975-2018 (1.11-1.26)]. This is the first analysis of survival trends by summary stage for multiple cancer sites. The largest survival increases were seen for cancers with a traditionally poor prognosis and no organized screening, which likely reflects clinical management advances. Our study will be particularly useful for understanding the population-level impact of new treatments and identifying emerging trends in health disparities research.

Causes of death among patients with cutaneous melanoma: a US population-based study

Research on mortality outcomes and non-cancer-related causes of death in patients with cutaneous melanoma (CM) remains limited. This study aimed to identify the prevalence of non-cancer-related deaths following CM diagnosis. The data of 224,624 patients diagnosed with malignant CM in the United States between 2000 and 2019 were extracted from the Surveillance, Epidemiology, and End Results (SEER) database. We stratified our cohort based on their melanoma stage at diagnosis and further calculated standardized mortality ratios (SMRs) for each cause of death, comparing their relative risk to that of the general US population. The total number of fatalities among melanoma patients was 60,110, representing 26.8% of the total cases. The percentage of deaths is directly proportional to the disease stage, reaching 80% in distant melanoma. The highest fatalities among the localized melanoma group (25,332; 60.5%) occurred from non-cancer causes, followed by melanoma-attributable deaths (10,817; 25.8%). Conversely, melanoma is the leading cause of death in regional and distant melanoma cohorts. Cardiovascular and cerebrovascular diseases were the most prevalent non-cancer causes of death among the three disease-stage cohorts. Compared to the general population, we did not observe an increased risk of death due to non-cancer causes in the localized CM cohort, while patients diagnosed with regional and distant CMs had a statistically significant higher risk of death from all the reported major causes of death.

Distant stage melanoma incidence among US adult women.

e21555 Background: To examine trends in distant stage melanoma incidence among U.S. women. Methods: Demographic and clinical data were obtained from the United States Cancer Statistics (USCS) Database from 2001-2019. SEER*Stat 8.3.9.2 and Joinpoint regression program 4.9.0.0 were used to calculate cancer incidences and trends per 100,000. Average annual percentage change (AAPC) was used to describe trends. Age-adjusted incidences were adjusted by the U.S. 2000 standard population. Results: From 2001-2019, 543,051 women were diagnosed with distant stage melanoma. Over this period, incidence rose from 0.37 to 0.59/100,000 with an increasing annual rate of 2.58% per year (p &lt; 0.0001). In 2019, non-Hispanic White women had disproportionately higher incidence rates at 0.76/100,000 compared to Hispanic (0.26/100,000), non-Hispanic Black (0.17/100,000), and non-Hispanic Asian (0.08/100,000) women. Regarding race, the largest increase in distant melanoma incidence was observed in White women with an average annual increase of 2.92% (p &lt; 0.0001). Among age groups, incidence was highest among those aged ≥45 (1.54/100,000) and 40-44 (0.53/100,000) years. However, the largest increases in distant melanoma incidence were found among 30-34-year-olds at a rate of 3.91% per year (p = 0.004) and 40-44-year-olds at 2.78% per year (p = 0.003). When examined by race and age, annual incidence rates were highest among White women aged 40-44 years at 3.68% per year (p &lt; 0.0001). Regarding U.S. state, incidence was highest in Florida (1.34/100,000), West Virginia (1.32/100,000), and Oklahoma (1.20/100,000). The largest annual increases in distant melanoma incidence rates were observed in Nebraska at 8.63% (p = 0.001), Kentucky at 6.18% (p &lt; 0.0001), and West Virginia at 6.06% (p = 0.001). When performing an intersection analysis of race, age, and U.S. stage, White women living in Nebraska aged ≥45 had the largest increase in distant melanoma at a rate of 8.12% annually (p = 0.004). In 2019, White women in Utah had the highest incidence of distant melanoma at 3.45/100,000. Conclusions: Distant stage melanoma is disproportionally increasing among adult women aged 30-44 years, especially among White populations. Further studies are warranted to understand the environmental and socioeconomic implications behind these trends.

Abscopal responses in patients with metastatic melanoma involving skin and subcutaneous tissues treated with intralesional IL2 plus BCG.

Cutaneous melanoma is relatively common with increasing incidence and significant mortality. While the mainstay of therapy is surgical, patients with stage III and IV disease fare poorer than those with early-stage disease and often benefit from adjuvant therapies. While systemic immunotherapy has changed the landscape of melanoma treatment, for some patients systemic toxicities related to these treatments prohibit successful administration or completion of therapy. Moreover, it is becoming increasingly evident that nodal, regional, and in-transit disease appears to be resistant to systemic immunotherapy relative to responses observed in distant metastatic disease sites. In this scenario, intralesional immunotherapies may offer benefit. In this case series, we describe the use of intralesional IL-2 and BCG at our institution in ten patients with in-transit plus or minus distant cutaneous metastatic melanoma over the last twelve years. All patients received intralesional IL2 and BCG. Both treatments were very well tolerated with only grade 1/2 adverse events. In our cohort, complete clinical response was 60% (6/10), progressive disease in 20% (2/10), and no response in 20% (2/10) of patients. The overall response rate (ORR) was 70%. The median overall survival was 35.5 months and mean overall survival 43 months in this cohort. Herein we further highlight the clinical, histopathological, and radiological course of two complete responders, showing evidence of an abscopal effect with resolution of distant untreated metastasis. Together, this limited data supports the safe and effective use of intralesional IL2 and BCG for the treatment of metastatic or in-transit melanoma in this challenging patient cohort. To our knowledge, this is the first formal study to report on this combination therapy for the treatment of melanoma.

MRNAs encoding IL-12 and a decoy-resistant variant of IL-18 synergize to engineer T cells for efficacious intratumoral adoptive immunotherapy

Interleukin-12 (IL-12) gene transfer enhances the therapeutic potency of adoptive Tcell therapies. We previously reported that transient engineering of tumor-specific CD8 Tcells with IL-12 mRNA enhanced their systemic therapeutic efficacy when delivered intratumorally. Here, we mix Tcells engineered with mRNAs to express either single-chain IL-12 (scIL-12) or an IL-18 decoy-resistant variant (DRIL18) that is not functionally hampered by IL-18 binding protein (IL-18BP). These mRNA-engineered Tcell mixtures are repeatedly injected into mouse tumors. Pmel-1 Tcell receptor (TCR)-transgenic Tcells electroporated with scIL-12 or DRIL18 mRNAs exert powerful therapeutic effects in local and distant melanoma lesions. These effects are associated with Tcell metabolic fitness, enhanced miR-155 control on immunosuppressive target genes, enhanced expression of various cytokines, and changes in the glycosylation profile of surface proteins, enabling adhesiveness to E-selectin. Efficacy of this intratumoral immunotherapeutic strategy is recapitulated in cultures of tumor-infiltrating lymphocytes (TILs) and chimeric antigen receptor (CAR) Tcells on IL-12 and DRIL18 mRNA electroporation.

Physical- and Chemical-Dually ROS-Responsive Nano-in-Gel Platforms with Sequential Release of OX40 Agonist and PD-1 Inhibitor for Augmented Combination Immunotherapy.

Combination immunotherapy synergizing the PD-1 blockade with OX40 agonism has become a research hotspot, due to its enormous potential to overcome the restricted clinical objective response suffered by monotherapy. Questions of timing and sequence have been important aspects of immunotherapies when considering immunologic mechanisms; however, most of the time the straightforward additive approach was taken. Herein, our work is the first to investigate an alternative timing of aOX40 and aPD-1 treatment in melanoma-bearing mice, and it demonstrates that sequential administration (aOX40 first, then aPD-1 following) provided superior antitumor benefits than concurrent treatment. Based on that, to further avoid the limits suffered by solution forms, we adopted pharmaceutical technologies to construct an in situ-formed physical- and chemical-dually ROS-responsive nano-in-gel platform to implement sequential and prolonged release of aPD-1 and aOX40. Equipped with these advantages, the as-prepared (aPD-1NCs&aOX40)@Gels elicited augmented combination immunity and achieved great eradication of both primary and distant melanoma tumors in vivo.

876P An observational retrospective study on microsatellite instability (MSI) in metastatic melanoma

Microsatellite instability (MSI) has been reported in skin melanoma and is thought to be a progression dependent phenomenon seen predominantly on metastases. However, a paucity of data is available about frequency, predictive and prognostic value of MSI in melanoma, in particular using the pentaplex panel of markers approved for colon cancer. Primary aim of this study was to provide a descriptive analysis of the presence of MSI in distant melanoma metastases, regardless of BRAF status and type of first-line treatment.

EPAC Regulates Melanoma Growth by Stimulating mTORC1 Signaling and Loss of EPAC Signaling Dependence Correlates with Melanoma Progression.

This study establishes loss of dependency on EPAC-mTORC1 signaling as hallmark of primary melanoma evolution and targeting this escape mechanism is a promising strategy for metastatic melanoma.

Abstract 2433: Targeting tGLI1 pharmacologically as a new therapeutic strategy for breast cancer brain metastases

Abstract Breast cancer is the second leading cause of brain metastases in women; patients with breast cancer brain metastasis (BCBM) survive only 6-18 months after diagnosis. Novel agents that act on targetable driver mutations (EGFR, PI3K, etc.) and penetrate the blood-brain barrier (BBB) have shown promise as systemic options for patients with distant lung and melanoma metastases. Nevertheless, brain metastases represent an area of unmet clinical need for which new pathways, novel mechanisms, and innovative therapies are needed. Cancer stem cells are thought to be a driving force behind not only distant metastasis, but also late-stage recurrence. The hedgehog pathway is an important mediator of breast cancer stem cells (BCSC); however, FDA-approved therapies targeting this pathway have demonstrated limited efficacy in breast cancer clinical trials. Despite advances made in understanding BCSC, it remains challenging to effectively target BCSC underscoring the need to identify and inhibit novel mediators of BCSC to treat BCBM. Our laboratory recently reported that truncated glioma-associated oncogene homolog 1 (tGLI1) promotes preferential breast cancer metastasis to the brain by activating BCSC and astrocytes in the tumor microenvironment (Oncogene 39:64-78, 2020). tGLI1 is an alternatively spliced GLI1 variant that functions as a tumor-specific gain-of-function transcription factor and terminal effector of the hedgehog pathway. tGLI1 knockdown abrogated BCBM, providing the rationale to therapeutically target tGLI1. In this study, we conducted cell-based chemical screens followed by validations and found that ketoconazole (KCZ), an FDA-approved antifungal, selectively targets tGLI1-expressing cancer cells, leading to suppression of BCSC in vitro and BCBM in vivo. Modification of KCZ moieties produced derivatives that retained tGLI1-selectivity against both BCSC in vitro and BCBM in vivo with increased BBB penetrance. Mechanistic studies suggest that KCZ-dependent cell kill is mediated through reducing tGLI1’s ability to bind and transactivate its target gene promoters, reducing expression of target genes Nanog, OCT4, and VEGFA. Based on these data, we opened an early Phase I clinical trial to determine if KCZ penetrates the BBB and modulates tGLI1 signaling in BCBM (NCT03796273). Preliminary analysis confirmed KCZ accumulation in collected brain biospecimens. We further investigated structure-activity relationship by synthesizing and testing 22 novel compounds, and identified two tGLI1-selective compounds that no longer inhibit CYP3A4. Since KCZ-mediated CYP3A4 antagonism can result in adrenal insufficiency and drug-drug interactions, these two novel tGLI1 inhibitors could be promising agents superior to KCZ. Collectively, these data establish tGLI1 as an actionable target for BCBM and validate KCZ and its novel derivatives as promising treatment options for patients with BCBM. Citation Format: Daniel Doheny, Sara Manore, Grace L. Wong, Dongqin Zhu, Sherona Sirkisoon, Marlyn Anguelov, Noah R. Augayo, Angelina T. Regua, Anderson Cox, Cristina Furdui, Terrence Smalley, Alexandra Thomas, Adrianna Masters, Roy E. Strowd, Hui-Wen Lo. Targeting tGLI1 pharmacologically as a new therapeutic strategy for breast cancer brain metastases [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 2433.

A phase Ia/Ib study evaluating the safety and efficacy of intratumorally administrated OH2, an oncolytic herpes simplex virus 2, in unresected stage IIIC to IV melanoma patients.

e21537 Background: OH2 is a herpes simplex virus type 2-derived oncolytic virus. It was engineered to selectively replicate within tumors and express granulocyte macrophage colony-stimulating factor (GM-CSF) to enhance tumor-specific immune responses. We conducted a phase Ia/Ib clinical trial to evaluate the safety and preliminary efficacy in unresected stage IIIC to IV melanoma patients (pts). Methods: In this phase Ia/Ib trial, we enrolled pts aged between 18-75 with histologically confirmed unresectable stage III or distant metastatic melanoma failed with prior therapies. In phase Ia, nine pts were in the single-dose group, where 3 dose levels (106, 107, and 108 CCID50/mL) of OH2 were assessed. And six pts were in the multi-dose group testing multiple administration regimens. The recommended doses were then expanded in phase Ib. The primary objective was the safety and tolerability of OH2 injection as defined by the dose-limiting toxicities (DLTs) and the maximum-tolerated dose (MTD) in phase Ia. Antitumor activity was assessed per Response Evaluation Criteria in Solid Tumors (RECIST version 1.1) and immune-RECIST in phase Ib. The clinical trial information: NCT04386967. Results: 35 pts were enrolled between November, 2018 and December, 2021. Among this, 37.1% were stageIVM1b-M1c; 88.6% had received of previous treatments: In the phase Ia study, OH2 was well-tolerated, neither serious AEs (SAEs) nor death were reported. No patient experienced TEAE leading to early withdrawal. Most TRAEs were Grade 1 in severity. There were no Grade 3 or above TRAEs. No DLTs were recorded, and the most frequent TRAEs were pyrexia (80%), Skin depigmentation (26.7), Oedema peripheral (26.7%), which were similar in three different doses of the single-dose group. The one-year survival rate was 93.3 % with median overall survival (mOS) being 20.8 months (still ongoing). In the phase Ib study, five pts achieved immune-partial response/partial response. The overall response rate (ORR) was 25.0 % and the five pts had ongoing responses. Six pts experienced stable disease (SD) with a disease control rate (DCR) being 55 %. The durable response rate (partial or complete response for ≥ 6 months) was 60 %. There were seven III-IV1a pts prior treated with anti-PD-1 antibodies. Three of the seven pts achieved iPR/PR (42.9 %), with DCR being 85.7 %. Conclusions: OH2 oncolytic virotherapy showed a favorable safety profile with no DLTs. And exhibited durable antitumor activity in pts. It warrants further investigation for the treatment of pts with unresectable melanoma. Clinical trial information: NCT04386967.

Metastatic melanoma of the gallbladder in a patient with acute cholecystitis: a case report and review of the literature

Melanoma is an aggressive type of cancer that has significant metastatic potential. Most commonly, distant melanoma metastases are identified in the lung, liver and brain. Metastatic melanoma of the gallbladder is extremely rare and is usually associated with widespread gastrointestinal deposits which purports a poor prognosis. Whilst an uncommon site of melanoma metastases, it accounts for 50% of all tumour metastases to the gallbladder. There are a small number of case reports and case series that describe different manifestations of melanoma metastases to the gallbladder. We report the case of a patient who presented with acute cholecystitis on a background of cholelithiasis and underwent a laparoscopic cholecystectomy with histopathology identifying gallbladder metastasis from malignant melanoma.

319 The tumor-intrinsic NLRP3 inflammasome establishes a pulmonary metastatic niche via type II epithelial HSP70/TLR4 signaling and facilitates disease hyperprogression in response to immunotherapy

BackgroundOur understanding of those underlying mechanisms that contribute to metastatic progression in melanoma remains limited. While uncommon, melanoma hyperprogression in response to immunotherapy is likely to be an extreme form of acquired resistance. Therefore, studies that define the underlying mechanisms of these processes are expected to provide insight into the discovery of novel therapeutic targets and predictive biomarkers. We previously demonstrated that tumor-intrinsic NLRP3 drives adaptive resistance to anti-PD-1 immunotherapy (anti-PD-1) by inducing the recruitment of polymorphonuclear myeloid-derived suppressor cells (PMN-MDSCs) via the upregulation of CXCL5. Gain-of-function polymorphisms in the TLR4 gene have been associated with pulmonary metastases in melanoma patients. We have shown HSP70 to promote PMN-MDSC chemotaxis via the stimulation of TLR4 signaling. As a result, we hypothesized that the tumor NLRP3 inflammasome may also contribute to distant metastatic progression and disease hyperprogression during immunotherapy by establishing a long-distance signaling axis mediated by HSP70-TLR4 signaling in the lung.MethodsWe pharmacologically and genetically inhibited the NLRP3 inflammasome and HSP70 in a transgenic BRAFV600E mouse model to examine their role in distant metastatic progression before and during anti-PD-1. An inducible type II pulmonary epithelial cell-specific TLR4 knock-out mouse model was engineered to examine the role of distant HSP70-TLR4 signaling in the recruitment of PMN-MDSCs and subsequent metastatic progression to the lung. Plasma HSP70 levels were monitored in melanoma patients undergoing anti-PD-1ResultsAnti-PD-1 significantly increases CXCL2/CXCL5 expression and PMN-MDSC accumulation in the lungs of the transgenic BRAFV600E model. This effect is reversed by 1) tumor-targeted ablation and pharmacologic inhibition of NLRP3 but not systemic host knock-out of NLRP3, 2) Pharmacologic Wnt5a ligand inhibition, 3) tumor-specific ablation and inhibition of HSP70. Inducible knock-out of TLR4 in type II epithelial cells suppressed Wnt5a and CXCL5 expression and inhibited the recruitment of PMN-MDSCs to the lung in response to anti-PD-1. Tumor-specific inhibition of NLRP3/HSP70 and lung-specific ablation of TLR4 suppressed metastatic progression following anti-PD-1 in the BRAFV600E melanoma model. Combination anti-PD-1 and NLRP3 inhibition suppressed primary melanoma progression and distant melanoma metastases versus anti-PD-1 monotherapy. Elevated plasma levels of HSP70 were associated with disease hyperprogression in metastatic melanoma patients undergoing anti-PD-1Abstract 319 Figure 1Tumor-intrinsic NLRP3 inflammasome and metastasisConclusionsTogether, these results describe a novel cross-talk mechanism between the primary tumor and the lung that mediates distant metastatic progression that is accentuated following anti-PD-1 (figure 1). Future clinical studies are needed to evaluate the pharmacologic inhibition of this tumor-lung NLRP3/HSP70/TLR4/Wnt5a/CXCL5 axis on melanoma metastasis and disease hyperprogression during checkpoint inhibitor immunotherapy

Characterizing Trends in Cancer Patients' Survival Using the JPSurv Software.

Improvements in cancer survival are usually assessed by comparing survival in grouped years of diagnosis. To enhance analyses of survival trends, we present the joinpoint survival model webtool (JPSurv) that analyzes survival data by single year of diagnosis and estimates changes in survival trends and year-over-year trend measures. We apply JPSurv to relative survival data for individuals diagnosed with female breast cancer, melanoma cancer, non-Hodgkin lymphoma (NHL), and chronic myeloid leukemia (CML) between 1975 and 2015 in the Surveillance, Epidemiology, and End Results Program. We estimate the number and location of joinpoints and the trend measures and provide interpretation. In general, relative survival has substantially improved at least since the mid-1990s for all cancer sites. The largest improvements in 5-year relative survival were observed for distant-stage melanoma after 2009, which increased by almost 3 survival percentage points for each subsequent year of diagnosis, followed by CML in 1995-2010, and NHL in 1995-2003. The modeling also showed that for patients diagnosed with CML after 1995 (compared with before), there was a greater decrease in the probability of dying of the disease in the 4th and 5th years after diagnosis compared with the initial years since diagnosis. The greatest increases in trends for distant melanoma, NHL, and CML coincided with the introduction of novel treatments, demonstrating the value of JPSurv for estimating and interpreting cancer survival trends. The JPSurv webtool provides a suite of estimates for analyzing trends in cancer survival that complement traditional descriptive survival analyses.

Abstract 2866: Truncated glioma-associated oncogene homolog 1 (tGLI1) is an actionable therapeutic target in breast cancer brain metastases

Abstract Breast cancer is the second leading cause of brain metastases in women; patients with breast cancer brain metastasis (BCBM) survive only 6-18 months following diagnosis. Current standard of care options for BCBM include stereotactic radiosurgery, whole-brain radiotherapy, and surgical resection. Novel agents that act on targetable driver mutations (EGFR, ALK, PI3K, etc) and penetrate the blood-brain barrier have recently shown increasing promise as systemic options for patients with distant lung and melanoma metastases. Nevertheless, brain metastases represent an area of unmet clinical need for which new pathways, novel mechanisms, and innovative therapies are needed. Cancer stem cells are thought to be one of the driving forces behind not only distant metastasis, but also late-stage recurrence. The hedgehog pathway has been identified as an important mediator of breast cancer stem cells (BCSC); however, FDA-approved therapies targeting this pathway have demonstrated limited efficacy in breast cancer clinical trials. Despite advances made in understanding BCSC, it is still challenging to effectively target BCSC underscoring the need to identify and inhibit novel mediators of BCSC for treating BCBM patients. Our laboratory recently reported that truncated glioma-associated oncogene homolog 1 (tGLI1) promotes preferential metastasis to the brain in breast cancer by activating BCSC and astrocytes in the tumor microenvironment (Oncogene 39:64-78, 2020). tGLI1 is an alternatively spliced GLI1 variant that functions as a tumor-specific gain-of-function transcription factor and terminal effector of the hedgehog pathway. We found that tGLI1 knockdown abrogated BCBM, providing the rationale to therapeutically target tGLI1. Cell-based chemical screens followed by validations demonstrated that ketoconazole, an FDA-approved azole antifungal, specifically inhibits tGLI1 leading to suppression of BCSC in vitro and BCBM in vivo. Modification of KCZ side chains produced derivative compounds that retained tGLI1-selectivity in both in vitro models of BCSC and in vivo models of BCBM with increased blood-brain barrier penetrance. Mechanistic studies suggest that KCZ-dependent cell kill is, in part, mediated through downregulation of tGLI1 target genes OCT4, Nanog, and VEGFA. Based on these data, we opened a window-of-opportunity study in patients with BCBM to determine if ketoconazole penetrates the blood-brain barrier and alters tGLI1 signaling in humans (NCT03796273). Preliminary sample analysis has confirmed tGLI1 expression in collected BCBM and glioma samples. To help identify more effective tGLI1 inhibitors, we screened 63 azole compounds for tGLI1-selectivity and identified four additional compounds as potential tGLI1 inhibitors. Collectively, these data establish tGLI1 as an actionable target for BCBM. Citation Format: Daniel L. Doheny, Sherona R. Sirkisoon, Tadas Rimkus, Dongqin Zhu, Noah R. Aguayo, Marlyn Anguelov, Sara Manore, Fei Xing, Linda Metheny-Barlow, Kounosuke Watabe, Alexandra Thomas, Adrianna Henson Masters, Roy E. Strowd, Hui-Wen Lo. Truncated glioma-associated oncogene homolog 1 (tGLI1) is an actionable therapeutic target in breast cancer brain metastases [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 2866.