BRCA1 and BRCA2 carriers with breast, ovarian and prostate cancer demonstrate a different pattern of metastatic disease compared with non-carriers: results from a rapid autopsy programme.

AIM: To catalogue and compare the pattern of metastatic disease in germline BRCA1/2 pathogenic mutation carriers and non-carriers with breast, ovarian and prostate cancer from a rapid autopsy programme. METHODS AND RESULTS: The number of metastases in the major body systems and the proportion of participants with metastases were documented in 50 participants (19 germline mutation carriers). Analysis was conducted on the participants' pattern of disease for the different cancers and mutation subgroups. The four commonly affected organ systems were the digestive (liver only) (82%), respiratory (76%), gastrointestinal (65%) and reticuloendothelial (42%). There were significant differences in the pattern of metastatic breast cancer in BRCA1/2 germline carriers compared with non-carriers. Breast cancer carriers had significantly fewer organ systems involved (median n = 3, range = 1-3) compared with non-carriers (median n = 9, range = 1-7) (P = 0.03). BRCA1/2 carriers with ovarian carcinomas had significantly more organ systems with metastatic carcinoma (median n = 10, range = 3-8) than non-carriers (median n = 5, range = 3-5) (P < 0.001). There were no significant differences in the number of involved systems in BRCA2 carriers compared with non-carriers with prostate cancer (P = 1.0). There was an absence of locoregional disease (6.5%) compared with distant disease (93.5%) among the three cancer subtypes (P < 0.001). The majority of metastatic deposits (97%) collected during the autopsy were identified by recent diagnostic imaging. CONCLUSION: Even though a major limitation of this study is that our numbers are small, especially in the breast cancer carrier group, the metastatic patterns of breast and ovarian cancers may be impacted by BRCA1/2 carrier status, suggesting that tumours derived from patients with these mutations use different mechanisms of dissemination. The findings may focus clinical diagnostic imaging for monitoring metastases where whole-body imaging resources are scant.

Treatment patterns after poly-ADP ribose polymerase (PARP) inhibitors in epithelial ovarian cancer patients.

OBJECTIVES: The primary objective of this study was to describe treatment patterns after poly-ADP ribose polymerase (PARP) inhibitor in patients with epithelial ovarian cancer. Secondary objectives were to evaluate duration of response, time to first subsequent therapy, progression-free survival and overall survival. METHODS: This was a retrospective analysis of patients with epithelial ovarian cancer treated with PARP inhibitor therapy at six Australian gynecological oncology centers. Eligible patients were identified via clinics, trial databases and pharmacy dispensing logs between January 2005 and September 2019. Information regarding clinico-pathological characteristics and treatment outcomes were collated from medical records. RESULTS: A total of 85 patients with epithelial ovarian cancer were identified. Of these, 61% had germline BRCA1/2 mutations, 9% had somatic BRCA1/2 mutations, 5% had confirmed homologous recombination deficiency and 25% were BRCA1/2 wildtype mutations. A total of seventy-seven (91%) patients received chemotherapy after PARP inhibitor, with fifty-six (72.7%) of these patients receiving platinum-based chemotherapy. Four patients (5%) had a complete response, 15 (20%) a partial response, 15 (20%) stable disease and 41 (55%) progressive disease. Median duration of response to chemotherapy was 7.0 months (range 0.2-20.4). Median time to first subsequent therapy was 17.6 and 15.1 months in patients who received a PARP inhibitor as maintenance therapy and treatment, respectively. Median progression-free survival of first line treatment after PARP inhibitor was 9.6, 3.5 and 4.6 months for platinum doublet, single agent platinum and non-platinum chemotherapy, respectively. Adjusting for age and FIGO (Federation of Gynecological Oncologists classification) stage progression-free survival did not differ between treatment groups (p=0.14). Median overall survival for the cohort was 69 months, and patients with platinum sensitive ovarian cancer had improved survival compared with those with platinum refractory or resistant disease. CONCLUSION: Platinum doublet chemotherapy resulted in non-significant improved progression-free survival compared with other regimens, suggesting potential independent mechanisms of resistance between PARP inhibitor and platinum compounds.

Whole-genome characterization of chemoresistant ovarian cancer.

Patients with high-grade serous ovarian cancer (HGSC) have experienced little improvement in overall survival, and standard treatment has not advanced beyond platinum-based combination chemotherapy, during the past 30 years. To understand the drivers of clinical phenotypes better, here we use whole-genome sequencing of tumour and germline DNA samples from 92 patients with primary refractory, resistant, sensitive and matched acquired resistant disease. We show that gene breakage commonly inactivates the tumour suppressors RB1, NF1, RAD51B and PTEN in HGSC, and contributes to acquired chemotherapy resistance. CCNE1 amplification was common in primary resistant and refractory disease. We observed several molecular events associated with acquired resistance, including multiple independent reversions of germline BRCA1 or BRCA2 mutations in individual patients, loss of BRCA1 promoter methylation, an alteration in molecular subtype, and recurrent promoter fusion associated with overexpression of the drug efflux pump MDR1.

FDG PET/CT for tumoral and systemic immune response monitoring of advanced melanoma during first-line combination ipilimumab and nivolumab treatment.

PURPOSE: We aimed to investigate the role of FDG-PET/CT in monitoring of response and immune-related adverse events (irAEs) following first-line combination-immune checkpoint inhibitor (combination-ICI) therapy for advanced melanoma. METHODS: We retrospectively reviewed outcomes in patients who had (1) first-line nivolumab plus ipilimumab; (2) pre- and post-treatment FDG-PET/CT scans (pre-FDG-PET/CT and post-FDG-PET/CT) within 2 and 4 months of starting ICI, respectively; and (3) at least one lesion assessable by PET response criteria in solid tumors (PERCIST). Extracranial response was monitored by 3 monthly FDG-PET/CT. Whole-body metabolic tumor volume (wbMTV) was measured pre- and post-treatment and correlated with outcome. FDG-PET/CT manifestations of irAE were defined as new increased non-tumoral uptake on post-FDG-PET/CT and were correlated with clinical presentation. RESULTS: Thirty-one consecutive patients, median age 60 years (range, 30-78), were identified from 2016 to 2018. The median number of combination-ICI cycles to the first post-FDG-PET/CT response assessment was 3 (interquartile range (IQR), 2-4). The best-overall responses were complete metabolic response (CMR) in 25 (80%), partial metabolic response (PMR) in 3 (10%), and progressive metabolic disease (PMD) in 3 (10%) patients. Patients with PMD had significantly higher pre-treatment wbMTV (p = 0.009). At a median follow-up of 21.5 months, 26 (84%) patients were alive with median progression-free and overall survival not reached. Secondary progression occurred in 9/31 (29%) patients at a median of 8.2 months (IQR, 6.9-15.5), of those majority (78%) was detected by FDG-PET/CT. Of 36 findings on post-FDG-PET/CT suggestive of irAE, 29 (80%) had clinical confirmation. In 3 (7%), the FDG-PET/CT findings preceded clinical presentation. The most common FDG-PET/CT detectable irAEs were endocrinopathies (36%) and enterocolitis (35%). CONCLUSION: FDG-PET/CT response evaluation predicts the long-term outcome of patients treated with first-line combination-ICIs. Long-term treatment response monitoring for detection of extracranial secondary progression is feasible by FDG-PET/CT. Beyond response assessment, FDG-PET/CT frequently detects clinically relevant irAEs, which may involve multiple systems contemporaneously or at various time-points and may precede clinical diagnosis.

19q12 amplified and non-amplified subsets of high grade serous ovarian cancer with overexpression of cyclin E1 differ in their molecular drivers and clinical outcomes.

OBJECTIVES: Readily apparent cyclin E1 expression occurs in 50% of HGSOC, but only half are linked to 19q12 locus amplification. The amplified/cyclin E1hi subset has intact BRCA1/2, unfavorable outcome, and is potentially therapeutically targetable. We studied whether non-amplified/cyclin E1hi HGSOC has similar characteristics. We also assessed the expression of cyclin E1 degradation-associated proteins, FBXW7 and USP28, as potential drivers of high cyclin E1 expression in both subsets. METHODS: 262 HGSOC cases were analyzed by in situ hybridization for 19q12 locus amplification and immunohistochemistry for cyclin E1, URI1 (another protein encoded by the 19q12 locus), FBXW7 and USP28 expression. Tumors were classified by 19q12 amplification status and correlated to cyclin E1 and URI1 expression, BRCA1/2 germline mutation, FBXW7 and USP28 expression, and clinical outcomes. Additionally, we assessed the relative genomic instability of amplified/cyclin E1hi and non-amplified/cyclin E1hi groups of HGSOC datasets from The Cancer Genome Atlas. RESULTS: Of the 82 cyclin E1hi cases, 43 (52%) were amplified and 39 (48%) were non-amplified. Unlike amplified tumors, non-amplified/cyclin E1hi tumor status was not mutually exclusive with gBRCA1/2 mutation. The non-amplified/cyclin E1hi group had significantly increased USP28, while the amplified/cyclin E1hi cancers had significantly lower FBXW7 expression consistent with a role for both in stabilizing cyclin E1. Notably, only the amplified/cyclin E1hi subset was associated with genomic instability and had a worse outcome than non-amplified/cyclin E1hi group. CONCLUSIONS: Amplified/cyclin E1hi and non-amplified/cyclin E1hi tumors have different pathological and biological characteristics and clinical outcomes indicating that they are separate subsets of cyclin E1hi HGSOC.

Synthetic lethality between CCNE1 amplification and loss of BRCA1.

High-grade serous ovarian cancers (HGSCs) are characterized by a high frequency of TP53 mutations, BRCA1/2 inactivation, homologous recombination dysfunction, and widespread copy number changes. Cyclin E1 (CCNE1) gene amplification has been reported to occur independently of BRCA1/2 mutation, and it is associated with primary treatment failure and reduced patient survival. Insensitivity of CCNE1-amplified tumors to platinum cross-linking agents may be partly because of an intact BRCA1/2 pathway. Both BRCA1/2 dysfunction and CCNE1 amplification are known to promote genomic instability and tumor progression. These events may be mutually exclusive, because either change provides a path to tumor development, with no selective advantage to having both mutations. Using data from a genome-wide shRNA synthetic lethal screen, we show that BRCA1 and members of the ubiquitin pathway are selectively required in cancers that harbor CCNE1 amplification. Furthermore, we show specific sensitivity of CCNE1-amplified tumor cells to the proteasome inhibitor bortezomib. These findings provide an explanation for the observed mutual exclusivity of CCNE1 amplification and BRCA1/2 loss in HGSC and suggest a unique therapeutic approach for treatment-resistant CCNE1-amplified tumors.

Impact of obesity on chemotherapy dosing for women with advanced stage serous ovarian cancer in the Australian Ovarian Cancer Study (AOCS).

OBJECTIVES: Obesity is an increasing health problem that is reported to influence chemotherapy dosing. The extent to which this occurs and whether this affects outcomes in ovarian cancer was unclear. To describe chemotherapy dosing practices in normal, overweight and obese patients treated for FIGO Stage III/IV serous ovarian cancer in the Australian Ovarian Cancer Study (AOCS). To evaluate the relationship between body mass index (BMI), dose intensity of chemotherapy received, overall survival (OS) and progression free survival (PFS). METHODS: Patient characteristics including age, height, weight, FIGO stage, serum creatinine, primary chemotherapy received and outcome data were extracted from medical records and entered into the AOCS database. Outcomes were analysed against BMI and relative dose intensity (RDI) received, based on calculations derived from a standard regimen (carboplatin AUC 5 and paclitaxel 175mg/m(2)). RESULTS: 333 women were included in the analysis. 27% were overweight and 21% were obese. In cycle 1 66% of obese patients received carboplatin doses more than 5% below their optimal calculated dose, and 32% received sub-optimal paclitaxel doses, compared to 25% and 13% of normal weight patients respectively. Obese women were more likely to have received <85% RDI for carboplatin compared to normal weight women (p<0.001). BMI group and RDI of carboplatin and paclitaxel were not predictors of OS. Women who received less than 85% RDI for carboplatin had a worse PFS (univariate analysis, median PFS 11 versus 15 months; p=0.04). There was no significant association between RDI and OS or PFS in multivariate analysis. CONCLUSIONS: Obesity is common in ovarian cancer patients, and commonly results in lower chemotherapy dosing than recommended. Analysis of chemotherapy dosing from this study suggests that reduced dose intensity of carboplatin, which was more common in obese women, may impact on PFS in patients with advanced serous ovarian cancer.

Homologous recombination proficient subtypes of high-grade serous ovarian cancer: treatment options for a poor prognosis group.

Approximately 50% of tubo-ovarian high-grade serous carcinomas (HGSCs) have functional homologous recombination-mediated (HR) DNA repair, so-called HR-proficient tumors, which are often associated with primary platinum resistance (relapse within six months after completion of first-line therapy), minimal benefit from poly(ADP-ribose) polymerase (PARP) inhibitors, and shorter survival. HR-proficient tumors comprise multiple molecular subtypes including cases with CCNE1 amplification, AKT2 amplification or CDK12 alteration, and are often characterized as "cold" tumors with fewer infiltrating lymphocytes and decreased expression of PD-1/PD-L1. Several new treatment approaches aim to manipulate these negative prognostic features and render HR-proficient tumors more susceptible to treatment. Alterations in multiple different molecules and pathways in the DNA damage response are driving new drug development to target HR-proficient cancer cells, such as inhibitors of the CDK or P13K/AKT pathways, as well as ATR inhibitors. Treatment combinations with chemotherapy or PARP inhibitors and agents targeting DNA replication stress have shown promising preclinical and clinical results. New approaches in immunotherapy are also being explored, including vaccines or antibody drug conjugates. Many approaches are still in the early stages of development and further clinical trials will determine their clinical relevance. There is a need to include HR-proficient tumors in ovarian cancer trials and to analyze them in a more targeted manner to provide further evidence for their specific therapy, as this will be crucial in improving the overall prognosis of HGSC and ovarian cancer in general.

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

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

Phase 1, first-in-human study of TYRP1-TCB (RO7293583), a novel TYRP1-targeting CD3 T-cell engager, in metastatic melanoma: active drug monitoring to assess the impact of immune response on drug exposure.

Introduction: Although checkpoint inhibitors (CPIs) have improved outcomes for patients with metastatic melanoma, those progressing on CPIs have limited therapeutic options. To address this unmet need and overcome CPI resistance mechanisms, novel immunotherapies, such as T-cell engaging agents, are being developed. The use of these agents has sometimes been limited by the immune response mounted against them in the form of anti-drug antibodies (ADAs), which is challenging to predict preclinically and can lead to neutralization of the drug and loss of efficacy. Methods: TYRP1-TCB (RO7293583; RG6232) is a T-cell engaging bispecific (TCB) antibody that targets tyrosinase-related protein 1 (TYRP1), which is expressed in many melanomas, thereby directing T cells to kill TYRP1-expressing tumor cells. Preclinical studies show TYRP1-TCB to have potent anti-tumor activity. This first-in-human (FIH) phase 1 dose-escalation study characterized the safety, tolerability, maximum tolerated dose/optimal biological dose, and pharmacokinetics (PK) of TYRP1-TCB in patients with metastatic melanoma (NCT04551352). Results: Twenty participants with cutaneous, uveal, or mucosal TYRP1-positive melanoma received TYRP1-TCB in escalating doses (0.045 to 0.4 mg). All participants experienced ≥1 treatment-related adverse event (TRAE); two participants experienced grade 3 TRAEs. The most common toxicities were grade 1-2 cytokine release syndrome (CRS) and rash. Fractionated dosing mitigated CRS and was associated with lower levels of interleukin-6 and tumor necrosis factor-alpha. Measurement of active drug (dual TYPR1- and CD3-binding) PK rapidly identified loss of active drug exposure in all participants treated with 0.4 mg in a flat dosing schedule for ≥3 cycles. Loss of exposure was associated with development of ADAs towards both the TYRP1 and CD3 domains. A total drug PK assay, measuring free and ADA-bound forms, demonstrated that TYRP1-TCB-ADA immune complexes were present in participant samples, but showed no drug activity in vitro. Discussion: This study provides important insights into how the use of active drug PK assays, coupled with mechanistic follow-up, can inform and enable ongoing benefit/risk assessment for individuals participating in FIH dose-escalation trials. Translational studies that lead to a better understanding of the underlying biology of cognate T- and B-cell interactions, ultimately resulting in ADA development to novel biotherapeutics, are needed.

Imaging for assessment of cancer treatment response to immune checkpoint inhibitors can be complementary in identifying hypophysitis.

Introduction: Hypophysitis is reported in 8.5%-14% of patients receiving combination immune checkpoint inhibition (cICI) but can be a diagnostic challenge. This study aimed to assess the role of routine diagnostic imaging performed during therapeutic monitoring of combination anti-CTLA-4/anti-PD-1 treatment in the identification of hypophysitis and the relationship of imaging findings to clinical diagnostic criteria. Methods: This retrospective cohort study identified patients treated with cICI between January 2016 and January 2019 at a quaternary melanoma service. Medical records were reviewed to identify patients with a documented diagnosis of hypophysitis based on clinical criteria. Available structural brain imaging with magnetic resonance imaging (MRI) or computed tomography (CT) of the brain and 2-deoxy-2-[18F]fluoro-D-glucose positron emission tomography with computed tomography (FDG-PET/CT) were assessed retrospectively. The main radiological outcome measures were a relative change in pituitary size or FDG uptake temporally attributed to cICI. Results: There were 162 patients (median age 60 years, 30% female) included. A total of 100 and 134 had serial CT/MRI of the brain and FDG-PET/CT, respectively. There were 31 patients who had a documented diagnosis of hypophysitis and an additional 20 who had isolated pituitary imaging findings. The pituitary gland enlargement was mild, and the largest absolute gland size was 13 mm, with a relative increase of 7 mm from baseline. There were no cases of optic chiasm compression. Pituitary enlargement and increased FDG uptake were universally transient. High-dose glucocorticoid treatment for concurrent irAEs prevented assessment of the pituitary-adrenal axis in 90% of patients with isolated imaging findings. Conclusion: Careful review of changes in pituitary characteristics on imaging performed for assessment of therapeutic response to iICI may lead to increased identification and more prompt management of cICI-induced hypophysitis.

Multiomic analysis of homologous recombination-deficient end-stage high-grade serous ovarian cancer.

High-grade serous ovarian cancer (HGSC) is frequently characterized by homologous recombination (HR) DNA repair deficiency and, while most such tumors are sensitive to initial treatment, acquired resistance is common. We undertook a multiomics approach to interrogate molecular diversity in end-stage disease, using multiple autopsy samples collected from 15 women with HR-deficient HGSC. Patients had polyclonal disease, and several resistance mechanisms were identified within most patients, including reversion mutations and HR restoration by other means. We also observed frequent whole-genome duplication and global changes in immune composition with evidence of immune escape. This analysis highlights diverse evolutionary changes within HGSC that evade therapy and ultimately overwhelm individual patients.

Tissue-resident memory T cells from a metastatic vaginal melanoma patient are tumor-responsive T cells and increase after anti-PD-1 treatment.

BACKGROUND: Vaginal melanoma (VM) is a rare cancer and has a poor response to immune checkpoint blockade (ICB). CD8+Tissue Resident Memory (TRM) T cells proliferate in response to ICB and correlate with longer survival in metastatic cutaneous melanoma. However, their capacity to respond to VM and their neoantigens is not known. METHODS: Using longitudinal samples, we explored the evolution of VM mutations by whole-exome sequencing and RNAseq, we also defined the immune context using multiplex immunohistochemistry and nanostring pan cancer immune profile. Then using fresh single cell suspensions of the metastatic samples, we explored VM T cells via mass cytometry and single cell RNAseq and T cell receptor sequencing (TCRseq). Finally, we investigated TRM, pre-TRM and exhausted T cell function against melanoma neo-antigens and melanoma differentiation antigens in vitro. RESULTS: Primary VM was non-inflamed and devoid of CD8+ TRM cells. In contrast, both metastases showed proliferating CD8+ TRM were clustered at the tumor margin, with increased numbers in the second ICB-refractory metastasis. The first metastasis showed dense infiltration of CD8+ T cells, the second showed immune exclusion with loss of melanoma cell Major histocompatibility complex (MHC)-I expression associated with downregulation of antigen presentation pathway gene expression. CD8+ TRM from both metastases responded to autologous melanoma cells more robustly than all other CD8+ T cell subsets. In addition, CD8+ TRM shared TCR clones across metastases, suggesting a response to common antigens, which was supported by recognition of the same neoantigen by expanded tumor infiltrating lymphocytes. CONCLUSIONS: In this study, we identified TRM clusters in VM metastases from a patient, but not primary disease. We showed TRM location at the tumor margin, and their superior functional response to autologous tumor cells, predicted neoantigens and melanoma differentiation antigens. These CD8+ TRM exhibited the highest tumor-responsive potential and shared their TCR with tumor-infiltrating effector memory T cells. This suggests VM metastases from this patient retain strong antitumor T cell functional responses; however, this response is suppressed in vivo. The loss of VG MHC-I expression is a common immune escape mechanism which was not addressed by anti-PD-1 monotherapy; rather an additional targeted approach to upregulate MHC-I expression is required.

Characterization of the treatment-naive immune microenvironment in melanoma with BRAF mutation.

BACKGROUND: Patients with BRAF-mutant and wild-type melanoma have different response rates to immune checkpoint blockade therapy. However, the reasons for this remain unknown. To address this issue, we investigated the precise immune composition resulting from BRAF mutation in treatment-naive melanoma to determine whether this may be a driver for different response to immunotherapy. METHODS: In this study, we characterized the treatment-naive immune context in patients with BRAF-mutant and BRAF wild-type (BRAF-wt) melanoma using data from single-cell RNA sequencing, bulk RNA sequencing, flow cytometry and immunohistochemistry (IHC). RESULTS: In single-cell data, BRAF-mutant melanoma displayed a significantly reduced infiltration of CD8+ T cells and macrophages but also increased B cells, natural killer (NK) cells and NKT cells. We then validated this finding using bulk RNA-seq data from the skin cutaneous melanoma cohort in The Cancer Genome Atlas and deconvoluted the data using seven different algorithms. Interestingly, BRAF-mutant tumors had more CD4+ T cells than BRAF-wt samples in both primary and metastatic cohorts. In the metastatic cohort, BRAF-mutant melanoma demonstrated more B cells but less CD8+ T cell infiltration when compared with BRAF-wt samples. In addition, we further investigated the immune cell infiltrate using flow cytometry and multiplex IHC techniques. We confirmed that BRAF-mutant melanoma metastases were enriched for CD4+ T cells and B cells and had a co-existing decrease in CD8+ T cells. Furthermore, we then identified B cells were associated with a trend for improved survival (p=0.078) in the BRAF-mutant samples and Th2 cells were associated with prolonged survival in the BRAF-wt samples. CONCLUSIONS: In conclusion, treatment-naive BRAF-mutant melanoma has a distinct immune context compared with BRAF-wt melanoma, with significantly decreased CD8+ T cells and increased B cells and CD4+ T cells in the tumor microenvironment. These findings indicate that further mechanistic studies are warranted to reveal how this difference in immune context leads to improved outcome to combination immune checkpoint blockade in BRAF-mutant melanoma.

The genomic and immune landscape of long-term survivors of high-grade serous ovarian cancer.

Fewer than half of all patients with advanced-stage high-grade serous ovarian cancers (HGSCs) survive more than five years after diagnosis, but those who have an exceptionally long survival could provide insights into tumor biology and therapeutic approaches. We analyzed 60 patients with advanced-stage HGSC who survived more than 10 years after diagnosis using whole-genome sequencing, transcriptome and methylome profiling of their primary tumor samples, comparing this data to 66 short- or moderate-term survivors. Tumors of long-term survivors were more likely to have multiple alterations in genes associated with DNA repair and more frequent somatic variants resulting in an increased predicted neoantigen load. Patients clustered into survival groups based on genomic and immune cell signatures, including three subsets of patients with BRCA1 alterations with distinctly different outcomes. Specific combinations of germline and somatic gene alterations, tumor cell phenotypes and differential immune responses appear to contribute to long-term survival in HGSC.

Noncanonical IL6 Signaling-Mediated Activation of YAP Regulates Cell Migration and Invasion in Ovarian Clear Cell Cancer.

Ovarian clear cell adenocarcinoma (OCCA) is characterized by a particularly poor response to conventional chemotherapy and a short overall survival time in women with established disease. The development of targeted treatments for OCCA relies on a better understanding of its molecular characteristics. IL6 is strongly expressed in OCCA and may therefore provide a novel therapeutic target. Here we use CRISPR/Cas9 and conditional short hairpin interfering RNA to perform loss-of-function studies in human OCCA cell lines to explore the requirement for IL6 in vitro and in vivo. While reduction of IL6 expression exerted limited effects in vitro, its attenuation significantly impaired tumor growth and neovascularization in vivo. In contrast to typical signaling via STAT3, IL6 in OCCA signaled via a noncanonical pathway involving gp130, Src, and the Hippo pathway protein YAP. A high-throughput combination drug screen identified agents that enhanced cell killing following reduction of IL6 signaling. Intersection of screen hits obtained from two cell lines and orthogonal approaches to attenuation of IL6 yielded AKT and EGFR inhibitors as enhancers of the inhibitory monoclonal IL6 receptor antibody tocilizumab. This study defines for the first time the requirements for, and mechanisms of, signaling by IL6 in human OCCA cell lines and identifies potential combinatory therapeutic approaches. Given the molecular diversity of OCCA, further in vitro and in vivo studies are warranted to determine whether such approaches will overcome the limited efficacy of tocilizumab observed in ovarian cancer to date. SIGNIFICANCE: This study defines the requirements for and mechanisms of noncanonical signaling by IL6 in human ovarian clear cell adenocarcinoma cell lines and identifies combinatory therapeutic approaches to be explored clinically.

i-Move, a personalised exercise intervention for patients with advanced melanoma receiving immunotherapy: a randomised feasibility trial protocol.

INTRODUCTION: There is increasing evidence demonstrating the benefits of exercise in counteracting cancer treatment-related fatigue. Immunotherapy is an established treatment for advanced melanoma, and is associated with fatigue in a third of patients. The safety and efficacy of exercise in counteracting treatment-related fatigue in patients with advanced melanoma receiving immunotherapy are yet to be determined. This study aims to assess the safety, adherence to and acceptability of a mixed-methods parallel-group, pilot randomised controlled trial of a personalised, 12-week semi-supervised exercise programme prescribed by an exercise physiologist (iMove) in 30 patients with stage IV melanoma scheduled to commence immunotherapy: single agent ipilimumab, nivolumab or pembrolizumab, or combination ipilimumab and nivolumab. The trial will be used to provide preliminary evidence of the potential efficacy of exercise for managing fatigue. METHODS AND ANALYSIS: Thirty participants will be recruited from a specialist cancer centre between May and September, 2019. Participants will be randomised 1:1 to receive iMove, or usual care (an information booklet about exercise for people with cancer). Feasibility data comprise: eligibility; recruitment and retention rates; adherence to and acceptability of exercise consultations, personalised exercise programme and study measures; and exercise-related adverse events. Patient-reported outcome measures assess potential impact of the exercise intervention on: fatigue, role functioning, symptoms and quality of life. Follow-up will comprise five time points over 24 weeks. Physical assessments measure physical fitness and functioning. ETHICS AND DISSEMINATION: This study was reviewed and approved by the Peter MacCallum Cancer Centre Human Research Ethics Committee (HREC/48927/PMCC-2019). The findings from this trial will be disseminated via conference presentations and publications in peer-reviewed journals, and by engagement with clinicians, media, government and consumers. In particular, we will promote the outcomes of this work among the oncology community should this pilot indicate benefit for patients. TRIAL REGISTRATION NUMBER: ACTRN12619000952145; Pre-results.

A closer look at immune-mediated myocarditis in the era of combined checkpoint blockade and targeted therapies.

Immune checkpoint inhibitors (ICI) and tyrosine kinase inhibitors (TKI) have transformed the management of many malignancies. Although rare, immune-mediated myocarditis presents unique clinical challenges due to heterogenous presentation, potential life-threatening consequences, and the time-critical need to differentiate it from other causes of cardiac dysfunction. Increasingly, TKI are being combined with ICI to promote immune modulation and improve efficacy. However, these combinations are associated with more toxicities. This series describes six patients with advanced melanoma who developed immune-mediated myocarditis while receiving an anti-PD-1 antibody or an anti-PD-L1 antibody plus a mitogen-activated protein kinase inhibitor. It provides a review of their heterogenous clinical presentations, investigational findings and treatment outcomes. Presentations ranged from asymptomatic cardiac enzyme elevation to death due to heart failure. We highlight the role of cardiac MRI (CMRI), a sensitive and non-invasive tool for the early detection and subsequent monitoring of myocardial inflammation. Five of the six patients exhibited CMRI changes characteristic of myocarditis, including mid-wall myocardial oedema and late gadolinium enhancement in a non-coronary distribution. Critically, two of these patients had normal findings on echocardiogram. Of the five patients who received immunosuppression, four recovered from myocarditis and one died of cardiac failure. The sixth patient improved with cardiac failure management alone. Three of the four patients responding to ICI derived long-term benefit. Clinical vigilance, prompt multimodal diagnosis and multidisciplinary management are paramount for the treatment of immune-mediated myocarditis.