Circulating microRNA-155-3p levels predicts response to first line immunotherapy in patients with metastatic renal cell carcinoma.

Predictive biomarkers of response to immune checkpoint-based therapies (ICI) remain a critically unmet need in the management of advanced renal cell carcinoma (RCC). The complex interplay of the tumour microenvironment (TME) and the circulating immune response has proven to be challenging to decipher. MicroRNAs have gained increasing attention for their role in post-transcriptional gene expression regulation, particularly because they can have immunomodulatory properties. We evaluated the presence of immune-specific extracellular vesicle (EV) microRNAs in the plasma of patients with metastatic RCC (mRCC) prior to initiation of ICI. We found significantly lower levels of microRNA155-3p (miR155) in responders to ICI, when compared to non-responders. This microRNA has unique immunomodulatory properties, thus providing potential biological rationale for our findings. Our results support further work in exploring microRNAs as potential biomarkers of response to immunotherapy.

Prediction of plasma ctDNA fraction and prognostic implications of liquid biopsy in advanced prostate cancer.

No consensus strategies exist for prognosticating metastatic castration-resistant prostate cancer (mCRPC). Circulating tumor DNA fraction (ctDNA%) is increasingly reported by commercial and laboratory tests but its utility for risk stratification is unclear. Here, we intersect ctDNA%, treatment outcomes, and clinical characteristics across 738 plasma samples from 491 male mCRPC patients from two randomized multicentre phase II trials and a prospective province-wide blood biobanking program. ctDNA% correlates with serum and radiographic metrics of disease burden and is highest in patients with liver metastases. ctDNA% strongly predicts overall survival, progression-free survival, and treatment response independent of therapeutic context and outperformed established prognostic clinical factors. Recognizing that ctDNA-based biomarker genotyping is limited by low ctDNA% in some patients, we leverage the relationship between clinical prognostic factors and ctDNA% to develop a clinically-interpretable machine-learning tool that predicts whether a patient has sufficient ctDNA% for informative ctDNA genotyping (available online: https://www.ctDNA.org ). Our results affirm ctDNA% as an actionable tool for patient risk stratification and provide a practical framework for optimized biomarker testing.

A generalizable machine learning framework for classifying DNA repair defects using ctDNA exomes.

Specific classes of DNA damage repair (DDR) defect can drive sensitivity to emerging therapies for metastatic prostate cancer. However, biomarker approaches based on DDR gene sequencing do not accurately predict DDR deficiency or treatment benefit. Somatic alteration signatures may identify DDR deficiency but historically require whole-genome sequencing of tumour tissue. We assembled whole-exome sequencing data for 155 high ctDNA fraction plasma cell-free DNA and matched leukocyte DNA samples from patients with metastatic prostate or bladder cancer. Labels for DDR gene alterations were established using deep targeted sequencing. Per sample mutation and copy number features were used to train XGBoost ensemble models. Naive somatic features and trinucleotide signatures were associated with specific DDR gene alterations but insufficient to resolve each class. Conversely, XGBoost-derived models showed strong performance including an area under the curve of 0.99, 0.99 and 1.00 for identifying BRCA2, CDK12, and mismatch repair deficiency in metastatic prostate cancer. Our machine learning approach re-classified several samples exhibiting genomic features inconsistent with original labels, identified a metastatic bladder cancer sample with a homozygous BRCA2 copy loss, and outperformed an existing exome-based classifier for BRCA2 deficiency. We present DARC Sign (DnA Repair Classification SIGNatures); a public machine learning tool leveraging clinically-practical liquid biopsy specimens for simultaneously identifying multiple types of metastatic prostate cancer DDR deficiencies. We posit that it will be useful for understanding differential responses to DDR-directed therapies in ongoing clinical trials and may ultimately enable prospective identification of prostate cancers with phenotypic evidence of DDR deficiency.

The 5-Hydroxymethylcytosine Landscape of Prostate Cancer.

Analysis of DNA methylation is a valuable tool to understand disease progression and is increasingly being used to create diagnostic and prognostic clinical biomarkers. While conversion of cytosine to 5-methylcytosine (5mC) commonly results in transcriptional repression, further conversion to 5-hydroxymethylcytosine (5hmC) is associated with transcriptional activation. Here we perform the first study integrating whole-genome 5hmC with DNA, 5mC, and transcriptome sequencing in clinical samples of benign, localized, and advanced prostate cancer. 5hmC is shown to mark activation of cancer drivers and downstream targets. Furthermore, 5hmC sequencing revealed profoundly altered cell states throughout the disease course, characterized by increased proliferation, oncogenic signaling, dedifferentiation, and lineage plasticity to neuroendocrine and gastrointestinal lineages. Finally, 5hmC sequencing of cell-free DNA from patients with metastatic disease proved useful as a prognostic biomarker able to identify an aggressive subtype of prostate cancer using the genes TOP2A and EZH2, previously only detectable by transcriptomic analysis of solid tumor biopsies. Overall, these findings reveal that 5hmC marks epigenomic activation in prostate cancer and identify hallmarks of prostate cancer progression with potential as biomarkers of aggressive disease. SIGNIFICANCE: In prostate cancer, 5-hydroxymethylcytosine delineates oncogene activation and stage-specific cell states and can be analyzed in liquid biopsies to detect cancer phenotypes. See related article by Wu and Attard, p. 3880.

Tilsotolimod Exploits the TLR9 Pathway to Promote Antigen Presentation and Type 1 IFN Signaling in Solid Tumors: A Multicenter International Phase I/II Trial (ILLUMINATE-101).

PURPOSE: Tilsotolimod is an investigational synthetic Toll-like receptor 9 (TLR9) agonist that has demonstrated antitumor activity in preclinical models. The ILLUMINATE-101 phase I study explored the safety, dose, efficacy, and immune effects of intratumoral (it) tilsotolimod monotherapy in multiple solid tumors. PATIENTS AND METHODS: Patients with a diagnosis of refractory cancer not amenable to curative therapies received tilsotolimod in doses escalating from 8 to 32 mg into a single lesion at weeks 1, 2, 3, 5, 8, and 11. Additional patients with advanced malignant melanoma were enrolled into an expansion cohort at the 8 mg dose. Objectives included characterizing the safety, establishing the dose, efficacy, and immunologic assessment. Blood samples and tumor biopsies of injected and noninjected lesions were obtained at baseline and 24 hours after treatment for immune analyses. RESULTS: Thirty-eight and 16 patients were enrolled into the dose escalation and melanoma expansion cohorts, respectively. Deep visceral injections were conducted in 91% of patients. No dose-limiting toxicities (DLT) or grade 4 treatment-related adverse events were observed. Biopsies 24 hours after treatment demonstrated an increased IFN pathway signature and dendritic cell maturation. Immunologic profiling revealed upregulation of IFN-signaling genes and modulation of genes for checkpoint proteins. In the dose escalation cohort, 12 (34%) of 35 evaluable patients achieved a best overall response rate (ORR) of stable disease (SD), whereas 3 (19%) of 16 evaluable patients in the melanoma cohort achieved stable disease. CONCLUSIONS: Overall, tilsotolimod monotherapy was generally well tolerated and induced rapid, robust alterations in the tumor microenvironment. See related commentary by Punekar and Weber, p. 5007.

Preclinical Characterization and Phase I Trial Results of a Bispecific Antibody Targeting PD-L1 and 4-1BB (GEN1046) in Patients with Advanced Refractory Solid Tumors.

Checkpoint inhibitors (CPI) have revolutionized the treatment paradigm for advanced solid tumors; however, there remains an opportunity to improve response rates and outcomes. In preclinical models, 4-1BB costimulation synergizes with CPIs targeting the programmed cell death protein 1 (PD-1)/programmed cell death ligand 1 (PD-L1) axis by activating cytotoxic T-cell-mediated antitumor immunity. DuoBody-PD-L1×4-1BB (GEN1046) is an investigational, first-in-class bispecific immunotherapy agent designed to act on both pathways by combining simultaneous and complementary PD-L1 blockade and conditional 4-1BB stimulation in one molecule. GEN1046 induced T-cell proliferation, cytokine production, and antigen-specific T-cell-mediated cytotoxicity superior to clinically approved PD-(L)1 antibodies in human T-cell cultures and exerted potent antitumor activity in transplantable mouse tumor models. In dose escalation of the ongoing first-in-human study in heavily pretreated patients with advanced refractory solid tumors (NCT03917381), GEN1046 demonstrated pharmacodynamic immune effects in peripheral blood consistent with its mechanism of action, manageable safety, and early clinical activity [disease control rate: 65.6% (40/61)], including patients resistant to prior PD-(L)1 immunotherapy. SIGNIFICANCE: DuoBody-PD-L1×4-1BB (GEN1046) is a first-in-class bispecific immunotherapy with a manageable safety profile and encouraging preclinical and early clinical activity. With its ability to confer clinical benefit in tumors typically less sensitive to CPIs, GEN1046 may fill a clinical gap in CPI-relapsed or refractory disease or as a combination therapy with CPIs. See related commentary by Li et al., p. 1184. This article is highlighted in the In This Issue feature, p. 1171.

First-in-Class Anti-immunoglobulin-like Transcript 4 Myeloid-Specific Antibody MK-4830 Abrogates a PD-1 Resistance Mechanism in Patients with Advanced Solid Tumors.

PURPOSE: In this first-in-human study (NCT03564691) in advanced solid tumors, we investigated a novel first-in-class human IgG4 monoclonal antibody targeting the immunoglobulin-like transcript 4 (ILT4) receptor, MK-4830, as monotherapy and in combination with pembrolizumab. PATIENTS AND METHODS: Patients with histologically/cytologically confirmed advanced solid tumors, measurable disease by RECIST v1.1, and evaluable baseline tumor sample received escalating doses of intravenous MK-4830 every 3 weeks as monotherapy (parts A and B) and in combination with pembrolizumab (part C). Safety and tolerability were the primary objectives. Pharmacokinetics, objective response rate per RECIST v1.1, and molecular biomarkers were also evaluated. RESULTS: Of 84 patients, 50 received monotherapy and 34 received combination therapy. No dose-limiting toxicities were observed; maximum tolerated dose was not reached. MK-4830 showed dose-related target engagement. Eleven of 34 patients in the dose-escalation phase who received combination therapy achieved objective responses; 5 previously had progressive disease on anti-PD-1/PD-L1 therapies. Exploratory evaluation of the association between response and pretreatment gene expression related to interferon-gamma signaling in tumors suggested higher sensitivity to T-cell inflammation with combination therapy than historically expected with pembrolizumab monotherapy, with greater response at more moderate levels of inflammation. CONCLUSIONS: This first-in-class MK-4830 antibody dosed as monotherapy and in combination with pembrolizumab was well tolerated with no unexpected toxicities, and demonstrated dose-related evidence of target engagement and antitumor activity. Inflammation intrinsic to the ILT4 mechanism may be facilitated by alleviating the myeloid-suppressive components of the tumor microenvironment, supporting the target of ILT4 as a potential novel immunotherapy in combination with an anti-PD-1/PD-L1 agent.

A phase 1 study to assess the safety, pharmacokinetics, and anti-tumor activity of the androgen receptor n-terminal domain inhibitor epi-506 in patients with metastatic castration-resistant prostate cancer.

BACKGROUND: EPI-506 is the first of a new class of drugs targeting the N-terminal domain (NTD) of the androgen receptor (AR), potentially overcoming known resistance mechanisms to androgen receptor pathway inhibitors (ARPIs) among men with metastatic castration resistant prostate cancer (mCRPC). METHODS: Patients with mCRPC who had progressed on prior ARPI were enrolled in this phase 1 open-label, adaptive 3 + 3 dose escalation study. The primary outcome was safety and tolerability of oral EPI-506. Secondary objectives included determination of the maximal tolerated dose (MTD), pharmacokinetic profile, and antitumor efficacy. RESULTS: 28 mCRPC patients were enrolled into 7 dose cohorts of EPI-506 ranging from 80-3600 mg given once daily and 1800 mg given twice daily. Six DLTs occurred in 4 patients; Grade 4 elevated amylase; Grade 3 abdominal pain; Grade 3 elevated ALT and Grade 3 elevated AST; Grade 2 nausea and Grade 1 vomiting which resulted in study drug intake of < 75% of the expected dose during the DLT assessment period. The most common drug-related adverse events included diarrhea, nausea and fatigue. Six patients had a PSA decline not meeting PSA response criteria. The study was terminated prior to reaching the MTD due to poor oral bioavailability. CONCLUSIONS: This phase 1 trial established the safety of EPI-506 and provides proof of concept for targeting the AR NTD. Next generation compounds with improved bioavailability and potency are in clinical development.

Finding the optimal treatment sequence in metastatic castration-resistant prostate cancer-a narrative review.

Over the last two decades, there has been significant progress in the treatment of metastatic prostate cancer. Multiple treatments with diverse mechanisms of action have improved clinical outcomes for patients with metastatic castration-resistant prostate cancer (mCRPC) including taxane chemotherapy, immunotherapy, potent androgen receptor pathway inhibitors (ARPI), and radiopharmaceuticals (radium-223). As these treatments have entered standard clinical practise, clinicians have been challenged on how to optimally select and sequence them as the landmark studies establishing their efficacy had control arms with placebo or minimally effective therapy and there is a paucity of prospective trials examining treatment sequencing. More recently, the situation has been further complicated as the earlier up-front use of docetaxel and ARPI with standard gonadal testosterone inhibition has been shown to impart substantial improvements in disease control and survival for patients with castration sensitive prostate cancer. As new therapies enter into clinical practise such as the inhibitors of Poly (ADP-Ribose) Polymerase and Prostate Specific Membrane Antigen (PSMA)-targeted therapy, how to optimally select and sequence available treatments will be a continued dilemma in the absence of validated predictive biomarkers. This review will summarize the literature supporting the use of each active agent in mCRPC. We will propose a framework which will guide the selection of appropriate agents based on prior therapies, disease characteristics and biomarkers.

Anti-cytotoxic T-lymphocyte-associated antigen-4 monoclonal antibody quavonlimab in combination with pembrolizumab: Safety and efficacy from a phase I study in previously treated extensive-stage small cell lung cancer.

OBJECTIVES: This first-in-human phase I study (NCT03179436) investigated anti-cytotoxic T-lymphocyte-associated protein 4 monoclonal antibody quavonlimab and anti-programmed death 1 monoclonal antibody pembrolizumab in patients with advanced solid tumors. The study was conducted in two parts: dose-escalation (part 1) and dose-confirmation (part 2). First-line treatment with quavonlimab + pembrolizumab conferred encouraging antitumor activity (objective response rate [ORR], 28%-40%) and was generally well tolerated (grade ≥ 3 treatment-related adverse events [TRAEs] were lowest with quavonlimab 25 mg every 6 weeks [Q6W] at 30% and highest with quavonlimab 75 mg Q3W at 57%) in non-small cell lung cancer. We present data from patients with extensive-stage small cell lung cancer (SCLC) receiving second-line or later therapy. MATERIALS AND METHODS: Patients with stage III/IV SCLC received quavonlimab 75 mg Q6W plus pembrolizumab 200 mg Q3W for ≤ 2 years. Primary endpoints were safety and tolerability; ORRs as assessed by blinded independent central review per Response Evaluation Criteria In Solid Tumorsv1.1 was a secondary endpoint. Progression-free survival (PFS), overall survival (OS), and the correlation of response with PD-L1 expression were exploratory endpoints. RESULTS: Forty patients with extensive-stage SCLC received treatment; median follow-up was 13 months. Dose-limiting toxicity occurred in 4 patients (10%). TRAEs occurred in 80% of patients; grade 3 events occurred in 33% of patients and no grade 4/5 events were reported. Confirmed ORRs (95% CI) were 18% (7-33) among all patients, 7% (<1-34) for PD-L1-positive tumors (n = 14), and 19% (5-42) for PD-L1-negative tumors (n = 21). Response duration ranged from 2.9 to 19.1+ months. Median PFS was 2.0 months; 6-month PFS rate was 26%. Median OS was 11.0 months; 6-month OS rate was 66%. CONCLUSIONS: Encouraging antitumor activity was observed with quavonlimab + pembrolizumab in patients with extensive-stage SCLC; responses were observed in PD-L1-positive and PD-L1-negative tumors. The combination was tolerable with manageable toxicities.

Next-generation sequencing in thyroid cancers: do targetable alterations lead to a therapeutic advantage?: A multicenter experience.

ABSTRACT: Radioiodine-refractory thyroid cancers (IRTCs) are uncommon and have a poor prognosis. Treatment options for radioiodine-refractory and anaplastic tumors (ATCs) are limited. Although the genomic landscape of thyroid cancer has been studied, there is little evidence on whether next-generation sequencing (NGS) findings translate to tumor control.We analyzed all patients with IRTC and ATC who underwent commercially available NGS in 3 cancer centers.Twenty-two patients were identified, 16 patients with IRTCs and 6 patients with ATCs. Eighteen (82%) had targetable findings in NGS, nine patients were treated accordingly. Median progression-free survival for targeted treatment was 50 months [95% confidence interval (CI95%) 9.8-66.6] and2 months (CI95% 0.2-16.5) for IRTC and ATC, respectively. Of 4 patients who achieved durable responses of 7 to 50 months, 2 are ongoing. The estimated median OS of IRTC receiving targeted treatment was not reached (CI95% 89.7-111.4 months) and was 77.8 months (CI95% 52.5-114.6) for patients treated conventionally (P = .3).NGS may detect clinically significant genetic alterations and benefit patients with advanced thyroid cancers.

Circulating heparan sulfate chains and body weight contribute to anti-Xa levels in cancer patients using the prophylactic dose of enoxaparin.

Hospitalized cancer patients are at increased risk of thrombosis and prophylaxis with heparin is recommended. Heparanase is a protein capable of degrading heparan sulfate (HS) chains. The first objective of the study was to examine the effects of weight on anti-Xa levels in cancer patients treated with a fixed dose of enoxaparin as thromboprophylaxis. The second aim was to assess a potential correlation between plasma pre-treatment coagulation parameters and anti-Xa levels in an assumption that heparanase degradation activity towards heparins and HS chains could affect anti-Xa levels. Two blood samples (prior to and 3 h after drug injection) of 76 cancer patients with an indication for prophylaxis with enoxaparin (40 mg) were evaluated for coagulation markers. Sub-prophylactic levels of anti-Xa (< 0.2 U/ml) were found in 16/76 (21%) patients; in 13/76 (13%) patients the values were supra-prophylactic (> 0.5 U/ml). In the subgroup of patients weighing > 80 kg, 7/14 (50%) individuals had a sub-prophylactic level. Overall, anti-Xa levels appeared to correlate with patient's weight (r = - 0.48, p < 0.0001), pre-treatment partial thromboplastin time (PTT), D-dimer, HS, heparanase levels and procoagulant activity. We concluded that plasma anti-Xa levels correlated with patient's weight. A substantial portion of cancer patients receiving enoxaparin prophylaxis was undertreated. For patients > 80 kg, a weight-adjusted prophylactic dose of enoxaparin could be considered. Elevated enoxaparin anti-Xa levels correlated with pre-treatment parameters of coagulation system activation. High pre-treatment HS and elevated plasma anti-Xa levels may potentially serve as biomarkers for the identification of patients at increased thrombosis risk.

Next-generation sequencing in salivary gland carcinoma: Targetable alterations lead to a therapeutic advantage-Multicenter experience.

BACKGROUND: Salivary gland cancers (SGCs) are rare. The approach to metastatic patients is histology-dependent. There is little evidence on whether next-generation sequencing (NGS) findings translate to tumor control in SGCs. METHODS: We analyzed all patients with histologically confirmed SGC who underwent NGS. RESULTS: Twenty-seven patients were identified, 14 (51.8%) had targetable findings in NGS: 5 ERBB2 amplifications, 3 PIK3CA mutations, 2 RUNX1 mutations, 1 TRIM33-RET fusion, 1 FGFR3-TACC3 fusion, 1 microsatellite instability-high, and 2 high mutational burden. Ten patients were treated accordingly. Median progression-free survival for targeted treatment was 8.4 months. Of five patients who achieved durable responses of 8.4 to 31.3 months, two are ongoing. The overall median survival was not reached for patients receiving targeted treatment and was 40.4 months for patients treated conventionally (P = .18). CONCLUSIONS: In the absence of a well-established therapeutic approach, NGS may detect clinically significant genetic alterations and benefit patients with advanced SGC.

Glucocorticoids as an adjunct to oncologic treatment in solid malignancies - Not an innocent bystander.

Glucocorticoids are steroidal hormones which exert their action via genomic and non-genomic mechanisms. In the clinical setting, glucocorticoids are utilized for their anti-inflammatory, anti-allergenic and immunomodulatory effects and for their well-established, pro-apoptotic effects on hematological malignancies. In the treatment of solid tumors, glucocorticoids serve primarily for alleviation of tumor- and treatment-related symptoms and in most cases are not considered to have a direct effect on tumor growth and spread. However, significant pre-clinical data suggest that glucocorticoids have diverse effects on tumor progression, both pro- and anti- tumorigenic. In contrast, the clinical data regarding the pro- and anti-tumorigenic effects of glucocorticoids on solid tumors is scarce, and summarized in this review. The following review presents the suggested glucocorticoids mechanism of action and the effects of glucocorticoids on tumor cells, on the tumor microenvironment and on tumor response to cytotoxic therapy, in the pre-clinical and clinical settings.