A phase 1 trial of the MEK inhibitor selumetinib in combination with pembrolizumab for advanced or metastatic solid tumors.

MEK inhibitors have immunomodulatory activity and potential for synergistic activity when combined with PD-1 inhibitors. We evaluated selumetinib (inhibitor of MEK1/2) plus pembrolizumab (anti‒PD-1 antibody) in patients with advanced/metastatic solid tumors. In this phase 1b study, adults with previously treated advanced/metastatic solid tumors received pembrolizumab 200 mg intravenously every 3 weeks plus selumetinib on days 1‒14 per 3-week cycle (2 weeks on/1 week off); selumetinib dosing began at 50 mg orally twice daily with escalation in 25 mg increments for ≤ 35 cycles. Primary endpoints were dose-limiting toxicities (DLTs), adverse events (AEs), and treatment discontinuations due to AEs. Thirty-two patients were enrolled. Dose escalation was completed up to selumetinib 125 mg twice daily. The target DLT rate of 30% was not reached at any dose level. In the selumetinib 100 mg group, 2/11 patients (18.2%) experienced DLTs (n = 1 grade 3 diarrhea, n = 1 grade 3 fatigue). In the selumetinib 125 mg group, 3/14 (21.4%) experienced DLTs (n = 1 grade 2 retinal detachment, n = 1 grade 3 retinopathy, n = 1 grade 3 stomatitis). Dose-related changes in pharmacokinetic exposures were observed for selumetinib and N-desmethyl selumetinib up to 100 mg (saturation at 125 mg). Two patients achieved partial responses (1 each with selumetinib 75 mg and 125 mg) for an objective response rate of 6%. The study was stopped early because of insufficient efficacy. Although the target DLT rate was not reached at any dose level and no new safety signals were identified, selumetinib plus pembrolizumab had limited antitumor activity in this population. Trial registration: ClinicalTrials.gov , NCT03833427.

Cyberlindnera jadinii and Kluyveromyces lactis, two fungi used in food processes, have potential probiotic effects on gut inflammation.

IMPORTANCE: The food industry has always used many strains of microorganisms including fungi in their production processes. These strains have been widely characterized for their biotechnological value, but we still know very little about their interaction capacities with the host at a time when the intestinal microbiota is at the center of many pathologies. In this study, we characterized five yeast strains from food production which allowed us to identify two new strains with high probiotic potential and beneficial effects in a model of intestinal inflammation.

Eastern Canadian Gastrointestinal Cancer Consensus Conference 2023.

The annual Eastern Canadian Gastrointestinal Cancer Consensus Conference 2023 was held in Quebec City, Quebec 2-4 February 2023. The purpose of the conference was to develop consensus statements on emerging and evolving treatment paradigms. Participants included Canadian medical oncologists, radiation oncologists, pathologists and surgical oncologists from across Ontario, Quebec, and the Atlantic provinces. Consensus statements were developed following rapid review presentations and discussion of available literature. The recommendations proposed here represent the consensus opinions of physicians involved in the care of patients with gastrointestinal malignancies who participated in this meeting.

Ceramide analog C2-cer induces a loss in insulin sensitivity in muscle cells through the salvage/recycling pathway.

Ceramides have been shown to play a major role in the onset of skeletal muscle insulin resistance and therefore in the prevalence of type 2 diabetes. However, many of the studies involved in the discovery of deleterious ceramide actions used a nonphysiological, cell-permeable, short-chain ceramide analog, the C2-ceramide (C2-cer). In the present study, we determined how C2-cer promotes insulin resistance in muscle cells. We demonstrate that C2-cer enters the salvage/recycling pathway and becomes deacylated, yielding sphingosine, re-acylation of which depends on the availability of long chain fatty acids provided by the lipogenesis pathway in muscle cells. Importantly, we show these salvaged ceramides are actually responsible for the inhibition of insulin signaling induced by C2-cer. Interestingly, we also show that the exogenous and endogenous monounsaturated fatty acid oleate prevents C2-cer to be recycled into endogenous ceramide species in a diacylglycerol O-acyltransferase 1-dependent mechanism, which forces free fatty acid metabolism towards triacylglyceride production. Altogether, the study highlights for the first time that C2-cer induces a loss in insulin sensitivity through the salvage/recycling pathway in muscle cells. This study also validates C2-cer as a convenient tool to decipher mechanisms by which long-chain ceramides mediate insulin resistance in muscle cells and suggests that in addition to the de novo ceramide synthesis, recycling of ceramide could contribute to muscle insulin resistance observed in obesity and type 2 diabetes.

A Phase I Dose-escalation Study of AZD3965, an Oral Monocarboxylate Transporter 1 Inhibitor, in Patients with Advanced Cancer.

PURPOSE: Inhibition of monocarboxylate transporter (MCT) 1-mediated lactate transport may have cytostatic and/or cytotoxic effects on tumor cells. We report results from the dose-escalation part of a first-in-human trial of AZD3965, a first-in-class MCT1 inhibitor, in advanced cancer. PATIENTS AND METHODS: This multicentre, phase I, dose-escalation and dose-expansion trial enrolled patients with advanced solid tumors or lymphoma and no standard therapy options. Exclusion criteria included history of retinal and/or cardiac disease, due to MCT1 expression in the eye and heart. Patients received daily oral AZD3965 according to a 3+3 then rolling six design. Primary objectives were to assess safety and determine the MTD and/or recommended phase II dose (RP2D). Secondary objectives for dose escalation included measurement of pharmacokinetic and pharmacodynamic activity. Exploratory biomarkers included tumor expression of MCT1 and MCT4, functional imaging of biological impact, and metabolomics. RESULTS: During dose escalation, 40 patients received AZD3965 at 5-30 mg once daily or 10 or 15 mg twice daily. Treatment-emergent adverse events were primarily grade 1 and/or 2, most commonly electroretinogram changes (retinopathy), fatigue, anorexia, and constipation. Seven patients receiving ≥20 mg daily experienced dose-limiting toxicities (DLT): grade 3 cardiac troponin rise (n = 1), asymptomatic ocular DLTs (n = 5), and grade 3 acidosis (n = 1). Plasma pharmacokinetics demonstrated attainment of target concentrations; pharmacodynamic measurements indicated on-target activity. CONCLUSIONS: AZD3965 is tolerated at doses that produce target engagement. DLTs were on-target and primarily dose-dependent, asymptomatic, reversible ocular changes. An RP2D of 10 mg twice daily was established for use in dose expansion in cancers that generally express high MCT1/low MCT4).

Rewiring the altered tryptophan metabolism as a novel therapeutic strategy in inflammatory bowel diseases.

OBJECTIVE: The extent to which tryptophan (Trp) metabolism alterations explain or influence the outcome of inflammatory bowel diseases (IBDs) is still unclear. However, several Trp metabolism end-products are essential to intestinal homeostasis. Here, we investigated the role of metabolites from the kynurenine pathway. DESIGN: Targeted quantitative metabolomics was performed in two large human IBD cohorts (1069 patients with IBD). Dextran sodium sulphate-induced colitis experiments in mice were used to evaluate effects of identified metabolites. In vitro, ex vivo and in vivo experiments were used to decipher mechanisms involved. Effects on energy metabolism were evaluated by different methods including Single Cell mEtabolism by profiling Translation inHibition. RESULTS: In mice and humans, intestinal inflammation severity negatively correlates with the amount of xanthurenic (XANA) and kynurenic (KYNA) acids. Supplementation with XANA or KYNA decreases colitis severity through effects on intestinal epithelial cells and T cells, involving Aryl hydrocarbon Receptor (AhR) activation and the rewiring of cellular energy metabolism. Furthermore, direct modulation of the endogenous tryptophan metabolism, using the recombinant enzyme aminoadipate aminotransferase (AADAT), responsible for the generation of XANA and KYNA, was protective in rodent colitis models. CONCLUSION: Our study identified a new mechanism linking Trp metabolism to intestinal inflammation and IBD. Bringing back XANA and KYNA has protective effects involving AhR and the rewiring of the energy metabolism in intestinal epithelial cells and CD4+ T cells. This study paves the way for new therapeutic strategies aiming at pharmacologically correcting its alterations in IBD by manipulating the endogenous metabolic pathway with AADAT.

CARD9 in neutrophils protects from colitis and controls mitochondrial metabolism and cell survival.

OBJECTIVES: Inflammatory bowel disease (IBD) results from a combination of genetic predisposition, dysbiosis of the gut microbiota and environmental factors, leading to alterations in the gastrointestinal immune response and chronic inflammation. Caspase recruitment domain 9 (Card9), one of the IBD susceptibility genes, has been shown to protect against intestinal inflammation and fungal infection. However, the cell types and mechanisms involved in the CARD9 protective role against inflammation remain unknown. DESIGN: We used dextran sulfate sodium (DSS)-induced and adoptive transfer colitis models in total and conditional CARD9 knock-out mice to uncover which cell types play a role in the CARD9 protective phenotype. The impact of Card9 deletion on neutrophil function was assessed by an in vivo model of fungal infection and various functional assays, including endpoint dilution assay, apoptosis assay by flow cytometry, proteomics and real-time bioenergetic profile analysis (Seahorse). RESULTS: Lymphocytes are not intrinsically involved in the CARD9 protective role against colitis. CARD9 expression in neutrophils, but not in epithelial or CD11c+cells, protects against DSS-induced colitis. In the absence of CARD9, mitochondrial dysfunction increases mitochondrial reactive oxygen species production leading to the premature death of neutrophilsthrough apoptosis, especially in oxidative environment. The decreased functional neutrophils in tissues might explain the impaired containment of fungi and increased susceptibility to intestinal inflammation. CONCLUSION: These results provide new insight into the role of CARD9 in neutrophil mitochondrial function and its involvement in intestinal inflammation, paving the way for new therapeutic strategies targeting neutrophils.

Effects of Five Filamentous Fungi Used in Food Processes on In Vitro and In Vivo Gut Inflammation.

Food processes use different microorganisms, from bacteria to fungi. Yeast strains have been extensively studied, especially Saccharomyces cerevisiae. However, to date, very little is known about the potential beneficial effects of molds on gut health as part of gut microbiota. We undertook a comprehensive characterization of five mold strains, Penicillium camemberti, P. nalgiovense, P. roqueforti, Fusarium domesticum, and Geotrichum candidum used in food processes, on their ability to trigger or protect intestinal inflammation using in vitro human cell models and in vivo susceptibility to sodium dextran sulfate-induced colitis. Comparison of spore adhesion to epithelial cells showed a very wide disparity in results, with F. domesticum and P. roqueforti being the two extremes, with almost no adhesion and 20% adhesion, respectively. Interaction with human immune cells showed mild pro-inflammatory properties of all Penicillium strains and no effect of the others. However, the potential anti-inflammatory abilities detected for G. candidum in vitro were not confirmed in vivo after oral gavage to mice before and during induced colitis. According to the different series of experiments carried out in this study, the impact of the spores of these molds used in food production is limited, with no specific beneficial or harmful effect on the gut.

Phase 1, dose-escalation study of guadecitabine (SGI-110) in combination with pembrolizumab in patients with solid tumors.

BACKGROUND: Data suggest that immunomodulation induced by DNA hypomethylating agents can sensitize tumors to immune checkpoint inhibitors. We conducted a phase 1 dose-escalation trial (NCT02998567) of guadecitabine and pembrolizumab in patients with advanced solid tumors. We hypothesized that guadecitabine will overcome pembrolizumab resistance. METHODS: Patients received guadecitabine (45 mg/m2 or 30 mg/m2, administered subcutaneously on days 1-4), with pembrolizumab (200 mg administered intravenously starting from cycle 2 onwards) every 3 weeks. Primary endpoints were safety, tolerability and maximum tolerated dose; secondary and exploratory endpoints included objective response rate (ORR), changes in methylome, transcriptome, immune contextures in pre-treatment and on-treatment tumor biopsies. RESULTS: Between January 2017 and January 2020, 34 patients were enrolled. The recommended phase II dose was guadecitabine 30 mg/m2, days 1-4, and pembrolizumab 200 mg on day 1 every 3 weeks. Two dose-limiting toxicities (neutropenia, febrile neutropenia) were reported at guadecitabine 45 mg/m2 with none reported at guadecitabine 30 mg/m2. The most common treatment-related adverse events (TRAEs) were neutropenia (58.8%), fatigue (17.6%), febrile neutropenia (11.8%) and nausea (11.8%). Common, grade 3+ TRAEs were neutropaenia (38.2%) and febrile neutropaenia (11.8%). There were no treatment-related deaths. Overall, 30 patients were evaluable for antitumor activity; ORR was 7% with 37% achieving disease control (progression-free survival) for ≥24 weeks. Of 12 evaluable patients with non-small cell lung cancer, 10 had been previously treated with immune checkpoint inhibitors with 5 (42%) having disease control ≥24 weeks (clinical benefit). Reduction in LINE-1 DNA methylation following treatment in blood (peripheral blood mononuclear cells) and tissue samples was demonstrated and methylation at transcriptional start site and 5' untranslated region gene regions showed enriched negative correlation with gene expression. Increases in intra-tumoural effector T-cells were seen in some responding patients. Patients having clinical benefit had high baseline inflammatory signature on RNAseq analyses. CONCLUSIONS: Guadecitabine in combination with pembrolizumab is tolerable with biological and anticancer activity. Reversal of previous resistance to immune checkpoint inhibitors is demonstrated.

Intermittent schedules of the oral RAF-MEK inhibitor CH5126766/VS-6766 in patients with RAS/RAF-mutant solid tumours and multiple myeloma: a single-centre, open-label, phase 1 dose-escalation and basket dose-expansion study.

BACKGROUND: CH5126766 (also known as VS-6766, and previously named RO5126766), a novel MEK-pan-RAF inhibitor, has shown antitumour activity across various solid tumours; however, its initial development was limited by toxicity. We aimed to investigate the safety and toxicity profile of intermittent dosing schedules of CH5126766, and the antitumour activity of this drug in patients with solid tumours and multiple myeloma harbouring RAS-RAF-MEK pathway mutations. METHODS: We did a single-centre, open-label, phase 1 dose-escalation and basket dose-expansion study at the Royal Marsden National Health Service Foundation Trust (London, UK). Patients were eligible for the study if they were aged 18 years or older, had cancers that were refractory to conventional treatment or for which no conventional therapy existed, and if they had a WHO performance status score of 0 or 1. For the dose-escalation phase, eligible patients had histologically or cytologically confirmed advanced or metastatic solid tumours. For the basket dose-expansion phase, eligible patients had advanced or metastatic solid tumours or multiple myeloma harbouring RAS-RAF-MEK pathway mutations. During the dose-escalation phase, we evaluated three intermittent oral schedules (28-day cycles) in patients with solid tumours: (1) 4·0 mg or 3·2 mg CH5126766 three times per week; (2) 4·0 mg CH5126766 twice per week; and (3) toxicity-guided dose interruption schedule, in which treatment at the recommended phase 2 dose (4·0 mg CH5126766 twice per week) was de-escalated to 3 weeks on followed by 1 week off if patients had prespecified toxic effects (grade 2 or worse diarrhoea, rash, or creatinine phosphokinase elevation). In the basket dose-expansion phase, we evaluated antitumour activity at the recommended phase 2 dose, determined from the dose-escalation phase, in biomarker-selected patients. The primary endpoints were the recommended phase 2 dose at which no more than one out of six patients had a treatment-related dose-limiting toxicity, and the safety and toxicity profile of each dosing schedule. The key secondary endpoint was investigator-assessed response rate in the dose-expansion phase. Patients who received at least one dose of the study drug were evaluable for safety and patients who received one cycle of the study drug and underwent baseline disease assessment were evaluable for response. This trial is registered with ClinicalTrials.gov, NCT02407509. FINDINGS: Between June 5, 2013, and Jan 10, 2019, 58 eligible patients were enrolled to the study: 29 patients with solid tumours were included in the dose-escalation cohort and 29 patients with solid tumours or multiple myeloma were included in the basket dose-expansion cohort (12 non-small-cell lung cancer, five gynaecological malignancy, four colorectal cancer, one melanoma, and seven multiple myeloma). Median follow-up at the time of data cutoff was 2·3 months (IQR 1·6-3·5). Dose-limiting toxicities included grade 3 bilateral retinal pigment epithelial detachment in one patient who received 4·0 mg CH5126766 three times per week, and grade 3 rash (in two patients) and grade 3 creatinine phosphokinase elevation (in one patient) in those who received 3·2 mg CH5126766 three times per week. 4·0 mg CH5126766 twice per week (on Monday and Thursday or Tuesday and Friday) was established as the recommended phase 2 dose. The most common grade 3-4 treatment-related adverse events were rash (11 [19%] patients), creatinine phosphokinase elevation (six [11%]), hypoalbuminaemia (six [11%]), and fatigue (four [7%]). Five (9%) patients had serious treatment-related adverse events. There were no treatment-related deaths. Eight (14%) of 57 patients died during the trial due to disease progression. Seven (27% [95% CI 11·6-47·8]) of 26 response-evaluable patients in the basket expansion achieved objective responses. INTERPRETATION: To our knowledge, this is the first study to show that highly intermittent schedules of a RAF-MEK inhibitor has antitumour activity across various cancers with RAF-RAS-MEK pathway mutations, and that this inhibitor is tolerable. CH5126766 used as a monotherapy and in combination regimens warrants further evaluation. FUNDING: Chugai Pharmaceutical.

Immune Checkpoint Inhibitors in the Treatment of Gastroesophageal Cancer.

Immune checkpoint blockade has revolutionised the treatment of multiple cancers including melanoma, non-small cell lung cancer, urothelial and renal cell cancers. For patients with chemorefractory gastroesophageal cancer, treatment with anti-PD-1 therapy results in modest benefits in overall survival; nivolumab and pembrolizumab have been licenced in Japan and the USA, respectively, for this indication. However, initial enthusiasm has been tempered by the results of several large negative trials; immune checkpoint blockade is not superior to chemotherapy in the second-line setting or beyond in unselected or low PD-L1-expressing patients. Microsatellite instability is uncommon in patients with metastatic gastric cancer; however, it is associated with response rates of more than 50% and long-term survival benefit. Combining anti-PD-1 with cytotoxic chemotherapy and targeted therapies also shows promise to extend the benefit of immune checkpoint blockade to a larger proportion of gastroesophageal cancer patients. In this review we discuss recently reported and ongoing clinical research in immunotherapy for gastroesophageal cancer, and consider molecular biology associated with sensitivity and resistance to immune checkpoint blockade in gastroesophageal cancer patients.

A study of 1088 consecutive cases of electrolyte abnormalities in oncology phase I trials.

BACKGROUND: The incidence and clinical significance of electrolyte abnormalities (EAs) in phase I clinical trials are unknown. The objective of this study is to evaluate the incidence and severity of EAs, graded according to CTCAE, v4.03, to identify variables associated with EAs and their prognostic significance in a phase I population. METHODS: A retrospective chart review was performed of 1088 cases in 82 phase I clinical trials consecutively treated from 2011 to 2015 at the Drug Development Unit of the Royal Marsden Hospital. Cox regression analysis was performed to examine the relationship between overall survival (OS) and baseline characteristics, treating the occurrence of grade III/IV EAs as a time-varying covariate. RESULTS: The most common emergent EAs (all grades) were as follows: hyponatraemia 62%, hypokalaemia 40%, hypophosphataemia 32%, hypomagnesaemia 17% and hypocalcaemia 12%. Grade III/IV EAs occurred in 19% of cases. Grade III/IV EAs occurred during the dose-limiting toxicity window in 8.46% of cases. Diarrhoea was associated with hypomagnesaemia at all grades (p < 0.001), hyponatraemia at all grades (p = 0.006) and with G3/G4 hypokalaemia (p = 0.02). Baseline hypoalbuminaemia and hyponatraemia were associated with a higher risk of developing other EAs during the trial in the univariate analysis. Patients who developed grade III/IV EAs during follow-up had an inferior median OS (26 weeks vs 37 weeks, hazard ratio = 1.61; p < 0.001). CONCLUSION: This is the first study to demonstrate the clinical significance of baseline hypoalbuminaemia and hyponatraemia, which are predictors of development of other EAs in phase I patients. Grade III/IV EAs are adverse prognostic factors of OS independent of serum albumin levels.

Clinical outcomes of adolescents and young adults with advanced solid tumours participating in phase I trials.

BACKGROUND: Adolescent and young adult (AYA) patients with advanced solid tumours are often considered for phase I clinical trials with novel agents. The outcome of AYAs in these trials have not been described before. AIM: To study the outcome of AYA patients in phase I clinical trials. METHODS: Clinical trial data of AYAs (defined as aged 15-39 years at diagnosis) treated at the Drug Development Unit, Royal Marsden Hospital, between 2002 and 2016, were analysed. RESULTS: From a prospectively maintained database of 2631 patients treated in phase I trials, 219 AYA patients (8%) were identified. Major tumour types included gynaecological cancer (25%) and sarcoma (18%). Twenty-five (11%) had a known hereditary cancer syndrome (most commonly BRCA). Molecular characterisation of tumours (n = 45) identified mutations most commonly in TP53 (33%), PI3KCA (18%) and KRAS (9%). Therapeutic targets of trials included DNA damage repair (16%), phosphoinositide 3-kinase (PI3K) (16%) and angiogenesis (16%). Grade 3/4 toxicities were experienced in 26% of patients. Of the 214 evaluable patients, objective response rate was 12%, with clinical benefit rate at 6 months of 22%. Median overall survival (OS) was 7.5 months (95% confidence interval: 6.3-9.5), and 2-year OS was 11%. Of patients with responses, 36% were matched to phase I trials based on germline or somatic genetic aberrations. CONCLUSION: We describe the outcome of the largest cohort of AYA patients treated in phase I trials. A subgroup of these patients demonstrates benefit, with several durable responses beyond 2 years. A sizeable proportion of AYA patients have cancer syndromes, significant family history or somatic molecular aberrancies which may influence novel therapeutic treatment options.

Ataxia Telangiectasia Mutated Protein Loss and Benefit From Oxaliplatin-based Chemotherapy in Colorectal Cancer.

BACKGROUND: Loss of ataxia telangiectasia mutated (ATM), a key protein regulating DNA repair signaling, has been suggested to increase sensitivity to DNA damaging agents. We conducted a study analyzing the loss of ATM protein expression in colorectal cancer and correlated this with clinical outcomes. MATERIALS AND METHODS: The clinical outcomes data and tumor samples from metastatic colorectal cancer patients referred to the Royal Marsden Hospital Drug Development Unit (United Kingdom) from 2012 to 2016 and providing consent for a molecular characterization study were analyzed. Immunohistochemistry (IHC) slides were assessed by a pathologist for nuclear staining intensity of ATM and semiquantitatively scored. ATM loss was defined as a nuclear H-score of ≤ 10. RESULTS: Of 223 colorectal cancer samples, ATM IHC loss was identified in 17 (8%). ATM loss was independent of the RAS and RAF mutational status. ATM loss was associated with superior overall survival after first-line oxaliplatin-based therapy (49 vs. 32 months; hazard ratio [HR], 2.52) but not with irinotecan-based therapy (24 vs. 33 months; HR, 0.72). ATM loss was not prognostic for survival from the diagnosis (50 vs. 44 months; HR, 1.43). CONCLUSION: ATM could be considered a biomarker for the development of novel DNA repair targeting agents and treatment of colorectal cancer.

Ceramide Transporter CERT Is Involved in Muscle Insulin Signaling Defects Under Lipotoxic Conditions.

One main mechanism of insulin resistance (IR), a key feature of type 2 diabetes, is the accumulation of saturated fatty acids (FAs) in the muscles of obese patients with type 2 diabetes. Understanding the mechanism that underlies lipid-induced IR is an important challenge. Saturated FAs are metabolized into lipid derivatives called ceramides, and their accumulation plays a central role in the development of muscle IR. Ceramides are produced in the endoplasmic reticulum (ER) and transported to the Golgi apparatus through a transporter called CERT, where they are converted into various sphingolipid species. We show that CERT protein expression is reduced in all IR models studied because of a caspase-dependent cleavage. Inhibiting CERT activity in vitro potentiates the deleterious action of lipotoxicity on insulin signaling, whereas overexpression of CERT in vitro or in vivo decreases muscle ceramide content and improves insulin signaling. In addition, inhibition of caspase activity prevents ceramide-induced insulin signaling defects in C2C12 muscle cells. Altogether, these results demonstrate the importance of physiological ER-to-Golgi ceramide traffic to preserve muscle cell insulin signaling and identify CERT as a major actor in this process.

Neutrophil-lymphocyte ratio kinetics in patients with advanced solid tumours on phase I trials of PD-1/PD-L1 inhibitors.

BACKGROUND: Although the neutrophil-lymphocyte ratio (NLR) is prognostic in many oncological settings, its significance in the immunotherapy era is unknown. Mechanistically, PD-1/PD-L1 inhibitors may alter NLR. We sought to characterise NLR kinetics in patients with advanced solid tumours treated with PD-1/PD-L1 inhibitors. METHODS: Electronic records of patients treated with PD-1/PD-L1 inhibitors on phase I trials across three sites were reviewed. A high NLR (hNLR) was predefined as >5. Univariate logistic regression models were used for toxicity, response analyses and Cox models for overall survival (OS) and progression-free survival analyses. Landmark analyses were performed (cycle two, three). Longitudinal analysis of NLR was performed utilising a mixed effect regression model. RESULTS: The median OS for patients with hNLR was 8.5 months and 19.4 for patients with low NLR, (hazard ratio [HR] = 1.85, 95% confidence interval [CI] 1.15-2.96, p = 0.01). On landmark analysis, hNLR was significantly associated with inferior OS at all time points with a similar magnitude of effect over time (p < 0.05). On multivariate analysis, NLR was associated with OS (HR 1.06, 95% CI 1.01-1.11, p = 0.01). NLR did not correlate with increased immune toxicity. Longitudinally, NLR correlated with response: NLR decreased by 0.09 (95% CI: -0.15 to -0.02; p = 0.01) per month in responders compared with non-responders. CONCLUSIONS: hNLR at baseline and during treatment is adversely prognostic in patients with advanced malignancies receiving PD-1/PD-L1 blockade. Importantly, NLR reduced over time in responders to immunotherapy. Taken together, these data suggest that baseline and longitudinal NLR may have utility as a unique biomarker to aid clinical decision-making in patients receiving immunotherapy.

The PI3K Pathway at the Crossroads of Cancer and the Immune System: Strategies for Next Generation Immunotherapy Combinations.

Immunotherapy has led to a paradigm shift in the treatment of some malignancies, providing long-term, durable responses for a subset of patients with advanced cancers. Increasingly, research has identified links between the immune system and critical oncogenic growth factor pathways. The phosphoinositide 3-kinase (PI3K)-AKT-mTOR cascade is frequently hyperactivated in cancer, and plays an integral role in many cellular processes including tumour growth and survival and can underlie resistance to therapies. In this review, we first summarize two key learnings from the initial studies of inhibitors of this pathway, including the profile of immune-related adverse events such as colitis, transaminitis and pneumonitis and the increased incidence of infections with the majority of agents that target the PI3K-AKT-mTOR pathway. We then discuss recent advances in our understanding of the role of this pathway in the tumour micro-environment, and in the regulation of innate and adaptive immune responses, and propose synergistic combination strategies with PI3K-network inhibitors and cancer immunotherapy.

Imprecision in the Era of Precision Medicine in Non-Small Cell Lung Cancer.

Over the past decade, major advances have been made in the management of advanced non-small cell lung cancer (NSCLC). There has been a particular focus on the identification and targeting of putative driver aberrations, which has propelled NSCLC to the forefront of precision medicine. Several novel molecularly targeted agents have now achieved regulatory approval, while many others are currently in late-phase clinical trial testing. These antitumor therapies have significantly impacted the clinical outcomes of advanced NSCLC and provided patients with much hope for the future. Despite this, multiple deficiencies still exist in our knowledge of this complex disease, and further research is urgently required to overcome these critical issues. This review traces the path undertaken by the different therapeutics assessed in NSCLC and the impact of precision medicine in this disease. We also discuss the areas of "imprecision" that still exist in NSCLC and the modern hypothesis-testing studies being conducted to address these key challenges.

The influence of gut-decontamination prophylactic antibiotics on acute graft-versus-host disease and survival following allogeneic hematopoietic stem cell transplantation.

The intestinal microbiota plays a key role in the pathogenesis of acute graft-versus-host disease (aGVHD). High-dose conditioning regimens given prior to allogeneic hematopoietic stem cell transplantation (aHSCT) modulate the composition of gut microbiota and damage the gut epithelial barrier, resulting in increased systemic inflammation. We assessed whether gut decontamination with antibiotics (ATB) prior to aHSCT influenced the frequency of aGVHD and mortality in 500 patients from two Canadian centers between 2005 and 2012. The rate of grade II-IV aGVHD was higher in the ATB arm compared with the arm without ATB (42% vs 28%; p < 0.001). This difference was mainly driven by a 2-fold higher rate of grade II-IV gastrointestinal aGVHD (GI-GVHD) in the ATB arm compared with the arm without ATB (20.7% vs 10.8%; p = 0.003). Multivariate analyses adjusted for known aGVHD risk factors revealed that more patients in the ATB group developed clinically significant GI-GVHD and liver aGVHD; adjusted odds ratio (aOR) = 1.83; p = 0.023 and aOR = 3.56; p = 0.047, respectively. Importantly, median overall survival (OS) was significantly lower in the group receiving ATB and the OS at 10 y remained decreased in the ATB group; adjusted hazard ratio (aHR) = 1.61 (p < 0.001). Without undermining the role of ATB prophylaxis to prevent infection in aHSCT, we have shown that the use of ATB that targets intestinal bacteria is associated with a more severe aGVHD that involves the GI organs and impacts OS. Prospective studies that evaluate the contribution of bacterial decontamination to aGVHD are warranted.

Emerging biomarkers for PD-1 pathway cancer therapy.

The field of immuno-oncology has witnessed unprecedented success in recent years, with several PD=1 and PD-L1 inhibitors obtaining US FDA registration and breakthrough drug therapy designation in multiple tumor types. Despite its clear efficacy in certain cancers, treatment with these agents carries a risk of immune-related toxicities and substantial financial burden. It is, therefore, critical to identify patients likely to benefit from such immunotherapies and develop strategies to differentiate responders from nonresponders early during treatment. Here we discuss the development of predictive and treatment response biomarkers for immune checkpoint inhibitors. We first examine the role of PD-L1 expression, the most extensively studied predictive biomarker of response, and further discuss emerging putative predictive biomarkers. We also detail challenges faced in the development of response assessments for immunotherapeutics and propose other biomarkers that may be useful as surrogate intermediate end points of response.