Antibodies raised against aldehyde-fixed antigens improve sensitivity for postembedding electron microscopy

BACKGROUND

Antibodies are one of the most important tools in biological research. High specificity and sensitivity of antibodies are crucial to obtain reliable results. Tissue fixed with glutaraldehyde (GA) is commonly used in electron microscopical investigations. The fixation and embedding routine in preparation of tissue for post-embedding electron microscopy (EM) will mask and structurally alter epitopes, making antibody-antigen interaction inefficient, with low labeling intensities. One of the main factors in this regard is the use of GA as fixative.

NEW METHOD

To alleviate these technical challenges, we immunized rabbits with antigen pre-fixed with GA. We hypothesized that the resulting antibodies would have stronger affinity to antigens that have been conformationally changed and denatured by GA, the way they are in fixed tissue.

COMPARISON WITH EXISTING METHOD AND RESULTS

An initial screening with western blotting (WB) showed results consistent with our hypothesis. In-house antibodies raised against GA-fixed SNARE proteins SNAP-25 and VAMP2, binds more strongly to fixed proteins compared to non-fixed proteins, while the pattern is opposite with the commercially available antibodies raised against non-fixed antigens (standard antibodies). Quantitative post-embedding EM of hippocampal synapses gave higher labeling intensities with anti-GA-SNAP-25 and anti-GA-VAMP2 compared to standard antibodies. Importantly, light microscopy (LM) and EM with our antibodies revealed stronger labeling of GA-fixed than formaldehyde (FH) treated brains.

CONCLUSION

Our results highlight the experimental potential of raising antibodies against GA-treated antigen to improve sensitivity of the antibodies for postembedding immunogold EM.

Efficacy and safety of inhaled anaesthetic for postoperative sedation during mechanical ventilation in adult cardiac surgery patients: a systematic review and meta-analysis

The aim was to evaluate the efficacy and safety of volatile anaesthetic for postoperative sedation in adult cardiac surgery patients through a systematic review and meta-analysis. We retrieved randomized controlled trials from MEDLINE, EMBASE, CENTRAL, Web of Science, clinical trials registries, conference proceedings, and reference lists of included articles. Independent reviewers extracted data, including patient characteristics, type of intraoperative anaesthesia, inhaled anaesthetic used, comparator sedation, and outcomes of interest, using pre-piloted forms. We assessed risk of bias using the Cochrane Tool and evaluated the strength of the evidence using the GRADE approach. Eight studies enrolling 610 patients were included. Seven had a high and one a low risk of bias. The times to extubation after intensive care unit (ICU) admission and sedation discontinuation were, respectively, 76 [95% confidence interval (CI) -150 to - 2, I2=79%] and 74 min (95% CI - 126 to - 23, I2=96%) less in patients who were sedated using volatile anaesthetic. There was no difference in ICU or hospital length of stay. Patients who received volatile anaesthetic sedation had troponin concentrations that were 0.71 ng ml-1 (95% CI 0.23-1.2) lower than control patients. Reporting on other outcomes was varied and not suitable for meta-analysis. Volatile anaesthetic sedation may be associated with a shorter time to extubation after cardiac surgery but no change in ICU or hospital length of stay. It is associated with a significantly lower postoperative troponin concentration, but the impact of this on adverse cardiovascular outcomes is uncertain. Blinded randomized trials using intention-to-treat analysis are required. PROSPERO registry number: 2016:CRD42016033874. Available from http://www.crd.york.ac.uk/PROSPERO/display_record.asp?ID=CRD42016033874.

462. “All Eyes on You”: A Covert Observational Study on Contact Precaution Compliance in Six Hospitals at the Detroit Medical Center

Background

The Center for Disease Control and Prevention recommends strict contact isolation precautions (CP) that include hand hygiene (HH) and barrier (gloves and gown) precautions upon entering and leaving the rooms of patients diagnosed with multidrug-resistant organism or Clostridium difficile infections. Although this policy has been in place for several years, compliance rate among HCW is rarely studied. The aim of our study was to covertly monitor, analyze, and compare the overall bundle compliance (OBC) and individual (HH, glove and gown) component compliance (ICC) among HCWs during routine patient care.

Methods

A prospective observational study was done in six Detroit Medical Centers (July 2017 to February 2018). Trained observers audited both inpatient and intensive care units on random days and time. Components audited (1) HH before donning and after doffing (2) gowning and gloving techniques before entering and after existing the patient room. A mobile application (speedy audit) was used to record all data. A pilot targeted education program (TEP) was also conducted in one of the hospitals where education was focused only on strict HH practice before donning.

Results

A total of 6,274 observations were collected. The OBC was 38%. Common HCWs observed included nurses (registered nurse and nursing student) 47%; physicians (attending’s, residents, fellows) 28%; service workers including Environmental Service, Food service, Patient transporter, Social worker, Pastoral care- 14%; Allied Health Professions including Dietician, Blood Collection, Physiotherapist, Radiology Tech, Respiratory Therapist 4%; The OBC among all HCW were below 50%. For the ICC, HH (49%) was way below the gloving (80%,) and gowning (62%) compliance. HH compliance before donning was strikingly lower (40%) than the compliance after doffing (62%). This trend was similar in all HCW. Within a month of TEP, a drastic increase in both HH [↑ to 75% from 26% (P < 0.001)] and OBC [↑ to 68% from 16% (P < 0.001)] was seen.

Conclusion

Common misconception that gloves are substitute to HH could explain the low HH rates before donning. Recognition of this gap and focused education on HH before donning has led to improved compliance in all HCW.

Disclosures

All authors: No reported disclosures.

A possible postsynaptic role for SNAP-25 in hippocampal synapses

The SNARE protein SNAP-25 is well documented as regulator of presynaptic vesicle exocytosis. Increasing evidence suggests roles for SNARE proteins in postsynaptic trafficking of glutamate receptors as a basic mechanism in synaptic plasticity. Despite these indications, detailed quantitative subsynaptic localization studies of SNAP-25 have never been performed. Here, we provide novel electron microscopic data of SNAP-25 localization in postsynaptic spines. In addition to its expected presynaptic localization, we show that the protein is also present in the postsynaptic density (PSD), the postsynaptic lateral membrane and on small vesicles in the postsynaptic cytoplasm. We further investigated possible changes in synaptic SNAP-25 protein expression after hippocampal long-term potentiation (LTP). Quantitative analysis of immunogold-labeled electron microscopy sections did not show statistically significant changes of SNAP-25 gold particle densities 1 h after LTP induction, indicating that local trafficking of SNAP-25 does not play a role in the early phases of LTP. However, the strong expression of SNAP-25 in postsynaptic plasma membranes suggests a function of the protein in postsynaptic vesicle exocytosis and a possible role in hippocampal synaptic plasticity.

Lung Cancer–Related Clinical and Economic Impacts of Achieving a 5% Smoking Prevalence Rate by 2035 in Canada

Background: Smoking is responsible for nearly 85% of lung cancer cases and 30% of all cancer-related deaths. Canada has set an ambitious target to reduce tobacco use to 5% by 2035 in alignment with a world-wide tobacco endgame initiative. Aim: We project the impact of achieving a national 5% smoking prevalence rate by 2035 on population-level lung cancer outcomes and costs. Methods: OncoSim-Lung (version 2.5), led by the Canadian Partnership Against Cancer with model development by Statistics Canada, is a microsimulation model that incorporates Canadian demographics, risk factors, registry data, resource utilization and other data to project clinical and economic impacts of cancer control measures. Smoking cessation parameters were modified to reduce the current average national smoking prevalence rate of 18% over time to 5% in 2035. Impacts were compared with those in a reference scenario, which maintained the current prevalence rate. Outputs of interest included lung cancer incidence, mortality, treatment costs, and quality-adjusted life-years (QALYs). Costs and QALYs are undiscounted and reported in 2016 CAD. Results: Achieving a 5% smoking rate by 2035 would result in a 2017-2035 cumulative total of 31,000 fewer lung cancer cases, 21,000 fewer lung cancer-related deaths, and 457,000 additional QALYs compared with projections based on a constant smoking prevalence rate of ∼20%. When stratified by sex, there would be 15,600 and 15,700 fewer lung cancer diagnoses and 11,000 and 10,000 fewer lung cancer-related deaths for males and females respectively. Furthermore, treatment-related costs would be reduced by $680 million dollars. On average there would be 4,500 fewer lung cancer cases, 3,500 fewer deaths, and $35 million in cost savings annually. If a 5% smoking rate is sustained until 2050, then there would be a 15% reduction in lung cancer cases and a 13% reduction in deaths from 2017-2050. Conclusion: Reducing Canada's smoking prevalence to 5% by 2035 could result in a significant reduction in lung cancer cases, deaths and treatment costs. Like Canada, other countries with relatively high smoking prevalence could use averted treatment costs to offset costs of aggressive smoking prevention and cessation programs or redirect them to other healthcare services.

Human Papillomavirus (HPV) Infection As an Emerging Risk Factor in Prostate Cancer

Background: Epidemiologic investigations confirm that prostate tissue is prone to sexually transmitted infection and human papilloma virus (HPV) is the most common sexually transmitted infection. Owing to the controversy on the role of HPV infection in prostate carcinogenesis, it is appropriate to determine and validate the prevalence of HPV infection in a controlled prospective study, and its role in prostate carcinogenesis. It is crucial to investigate the prognostic impact of HPV infection in prostate cancer from a clinical point of view. Aim: The overall aim of our research is to address the possibility of using therapeutic interventions against HPV infection in young boys to prevent the development of prostate cancer in their older age. Establishment of clinical importance of HPV infection in prostate cancer and its prognostic impact for overall survival. Methods: The prostate cancer tissue specimens were obtained from Sahlgrenska University Hospital, Sahlgrenska Academy (SA), Gothenburg, Sweden. The exclusion criteria included patients undergoing any preoperative radiation or chemotherapy. Only histopathologically confirmed cases were processed for DNA, protein and RNA extraction. Histopathological grades and clinical staging was evaluated by pathologists using the Gleason scoring system for prostate cancer. The study is approved by the ethics committee of the institute. High molecular-weight genomic DNA was isolated from tumor/control tissue samples and were subjected to PCR genotyping for detection of the viral DNA. Cases and controls was compared using univariate methods. An independent t-test was performed for the comparison of clinicopathological parameters. Results: The pilot study identified HPV infection in advanced grade of prostate cancer cases in Sweden. HPV infection was identified in 57% of the prostate cancer cases with advanced pathologic grade in Swedish men compared with 11% in the normal controls. The investigation comprised of detailed analysis of the correlation between the clinical parameters and HPV genotyping. Conclusion: The research investigation substantiates the clinical significance of HPV infection in prostate carcinogenesis that has been underestimated till date. The research investigation was funded by Swedish Research Council (Vetenskaprådet) Grant no. 2015-06705.

Evaluating Clinical and Cost Impacts of Achieving 90% HPV Vaccination Rate Against Cervical Cancer in Canada Using the OncoSim Cancer Simulation Model

Background: Cervical cancer can be largely prevented through vaccination against the human papillomavirus (HPV). In Canada, HPV vaccination of school-aged girls started in 2008 and has reached an average rate of 67% across the country. However, this rate is below a current national target of 90%. Aim: We project the difference in lifetime clinical outcomes and health system costs of achieving a 90% HPV vaccination rate versus a 67% rate for girls vaccinated in 2015 using the OncoSim-Cervical model. Methods: The OncoSim-Cervical model (version 2.5) is a microsimulation model led by the Canadian Partnership Against Cancer, with model development by Statistics Canada, to evaluate the impacts of cervical cancer interventions in Canada. It has two parts, the first, the HPV Microsimulation Model, simulates the transmission of HPV between males and females including possible modulation by vaccination and herd immunity, and provides projections of HPV infection and prevalence for input to the cervical cancer natural history component in the second part. We simulated two cohorts of 5-10 year old girls in 2015; one receiving HPV vaccination at the rate of 67% and another at 90%. Their relative lifetime cervical cancer outcomes and costs were compared. Assumptions included: 100% efficacy of the HPV vaccine; triennial cytology screening between ages 21 and 65; 90% screening recruitment of age-eligible women with 80% rescreening; and a $500 cost for a 3-dose quadrivalent HPV vaccine regimen. Projected costs were undiscounted and are in 2016 CAD. Results: Compared with the 67%-vaccinated cohort, in the 90%-vaccinated cohort there was a lifetime reduction of 23% in cervical cancer incident cases and 21% in cervical cancer deaths. Lifetime cancer treatment costs decreased by $26 million (23%), and wart treatment costs and precervical cancer costs decreased by $3.2 million (15%) and $45 million (16%) respectively. Lifetime screening costs decreased by $47 million (2%). Conclusion: Achieving a nationally-set target of 90% HPV vaccination in Canadian girls would not only save more lives but would free up funds that could be redirected to other health system needs. Planners could aim for relatively high nation-wide rates of HPV vaccination coverage to enhance their cervical cancer control strategy.

Impact of Follow-Up Colonoscopy Quality on Canadian Colorectal Cancer Outcomes and Costs

Background: Most colorectal cancer (CRC) cases develop from precancerous polyps. Screening using fecal testing for occult blood, with follow-up diagnostic colonoscopy to remove polyps, can prevent invasive cancer from occurring. However, there is variation in the quality of colonoscopy, which may result in nonoptimal health outcomes. Aim: We evaluated the impact of follow-up colonoscopy quality on health outcomes, resource utilization and costs using the OncoSim-CRC microsimulation model (version 2.5). Methods: OncoSim is a microsimulation model led by the Canadian Partnership Against Cancer with model development by Statistics Canada. We compared results of high quality follow-up colonoscopy after positive fecal immunochemical testing (FIT) (colonoscopy sensitivity for cancer detection= 95%; compliance to follow-up colonoscopy = 85%) with that of reduced quality colonoscopy. Variations in colonoscopy performance were simulated through plausible overall effectiveness reduction (ER) and incomplete colonoscopy (IC). Screening system/patient follow-up deficiencies were simulated through poor compliance to diagnostic colonoscopy (PC). Modeling assumptions included: Biennial FIT screening of average-risk people aged 50-74; positive FIT followed by diagnostic colonoscopy; ER = 20% reduction in overall sensitivity; IC = zero sensitivity in proximal colon; PC = compliance reduction by 50%. Overall cost was calculated for 2017-2036 in undiscounted 2016 CAD, and included screening, treatment and end-of-life costs. Results: Compared with high quality colonoscopy follow-up, incomplete colonoscopy with poor compliance over 20 years led to as many as 12% new cases of CRC; 23% more CRC deaths; 89% more interval cancers; and 6% increased costs to the health care system, annually. Conclusion: Reduced colonoscopy quality can lead to considerable declines in the predicted effectiveness of screening and to increased costs to the healthcare system. Efforts to increase and maintain colonoscopy performance is a necessary component of CRC control planning.

The OncoSim Cancer Simulation Platform: A Tool to Project the Population Effects of Cancer Control Interventions in Canada

Background: Cancer control interventions exert their effects over multiple decades. To evaluate diverse and competing opportunities to reduce future cancer burden it is desirable to understand long-term effects prior to any new program implementation or significant change. Internationally, modeling is becoming an accepted source of planning information for decision-makers. Aim: We will describe the construction and use of the OncoSim microsimulation model, which was developed to evaluate cancer control strategies in Canada. Methods: OncoSim is a suite of models (cancers of the lung, colorectum, cervix and breast, plus a composite 32-cancer model) used to address key policy questions and support decision-making. It is led by the Canadian Partnership Against Cancer with model development by Statistics Canada. OncoSim incorporates risk factors, cancer natural history, screening, treatment, survival and end-of-life care. Wherever possible it is informed by Canadian data sources. Models are calibrated to reproduce a range of cancer-specific statistics, e.g., current and historical Canadian cancer-specific incidence and mortality, smoking patterns, and results of screening. The site-specific models have undergone further validation by replicating reported short-term effects of cancer prevention and screening interventions. Users may customize interventions through modifying input parameters. Outputs include incidence, mortality, costs, cost-effectiveness, and resource utilization. Users from the public sector have access at no cost to OncoSim and receive extensive support from a multidisciplinary technical team. The model is continually updated to incorporate emerging knowledge. Results: OncoSim has been used to support cancer control decision-making at the national and provincial/territorial levels. Applications include: national guidelines recommendations for colorectal and lung cancer screening; comparison of cytology vs. HPV based cervical cancer screening; and integration of smoking cessation into low-dose CT lung cancer screening. Conclusion: Validated simulation models such as OncoSim can be a versatile and efficient tool for cancer control planners to evaluate and prioritize cancer control strategies.

Microvesicles in hepatic and peripheral vein can predict nonresponse to corticosteroid therapy in severe alcoholic hepatitis

BACKGROUND

Severe alcoholic hepatitis patients have high mortality and limited response to corticosteroids. Microvesicles reflect cellular stress and disease conditions.

AIMS

To investigate whether microvesicles are associated with severity, response to steroid therapy and inflammation in severe alcoholic hepatitis.

METHODS

Microvesicles originating from different cells were studied pre-therapy in 101 patients; (71 responder to corticosteroid therapy and 30 nonresponders) and 20 healthy controls. Microvesicles and cells were determined in peripheral and hepatic vein samples using flow cytometry and correlated with outcomes. Inflammatory signalling pathways and functional alterations of immune cells after stimulation with microvesicles were also investigated.

RESULTS

Microvesicles mean levels were higher in nonresponders for T cells (CD3⁺ CD4⁺ ; 10.1 MV/μL vs 5.4; P = 0.06), macrophages (CD68⁺ CD11b⁺ ; 136.5 vs 121.9 MV/μL; P = 0.01), haematopoietic stem-cells (CD45⁺ CD34⁺ ; 116.8 vs 13.4 MV/μL; P = 0.0001) and hepatocytes (ASGPR⁺ ; 470 vs 361 MV/μL; P = 0.01); the latter two predicting steroid nonresponse in 94% patients at baseline in peripheral plasma. Microvesicle levels correlated with histological and liver disease severity indices. Whereas, in non-responders hepatic vein CD34+ cells were lower (P = 0.02), the CD34+ microvesicles there from were higher (P = 0.04), thus suggesting impaired regeneration. Also, microvesicles of 0.2-0.4 μm size were higher in nonresponders (P < 0.03) at baseline. Microvesicles from patients trigger more (P = 0.04) ROS generation, TNF-α production (P = 0.04) and up-regulate pro-inflammatory cytokine related genes in neutrophils in vitro.

CONCLUSIONS

Pre-therapy peripheral plasma levels of CD34⁺ and ASGPR⁺ microvesicles are reliable non-invasive markers of steroid nonresponse and mortality in patients with severe alcoholic hepatitis.

Therapeutics discovery: From bench to first in-human trials

The 'Therapeutics discovery: From bench to first in-human trials' conference, held at the King Abdullah International Medical Research Center (KAIMRC), Ministry of National Guard Health Affairs (MNGHA), Kingdom of Saudi Arabia (KSA) from October 10-12, 2017, provided a unique opportunity for experts worldwide to discuss advances in drug discovery and development, focusing on phase I clinical trials. It was the first event of its kind to be hosted at the new research center, which was constructed to boost drug discovery and development in the KSA in collaboration with institutions, such as the Academic Drug Discovery Consortium in the United States of America (USA), Structural Genomics Consortium of the University of Oxford in the United Kingdom (UK), and Institute of Materia Medica of the Chinese Academy of Medical Sciences in China. The program was divided into two parts. A pre-symposium day took place on October 10, during which courses were conducted on clinical trials, preclinical drug discovery, molecular biology and nanofiber research. The attendees had the opportunity for one-to-one meetings with international experts to exchange information and foster collaborations. In the second part of the conference, which took place on October 11 and 12, the clinical trials pipeline, design and recruitment of volunteers, and economic impact of clinical trials were discussed. The Saudi Food and Drug Administration presented the regulations governing clinical trials in the KSA. The process of preclinical drug discovery from small molecules, cellular and immunologic therapies, and approaches to identifying new targets were also presented. The recommendation of the conference was that researchers in the KSA must invest more fund, talents and infrastructure to lead the region in phase I clinical trials and preclinical drug discovery. Diseases affecting the local population, such as Middle East Respiratory Syndrome and resistant bacterial infections, represent the optimal starting point.

Rapid sexual and genomic isolation in sympatric Drosophila without reproductive character displacement

The rapid evolution of sexual isolation in sympatry has long been associated with reinforcement (i.e., selection to avoid maladaptive hybridization). However, there are many species pairs in sympatry that have evolved rapid sexual isolation without known costs to hybridization. A major unresolved question is what evolutionary processes are involved in driving rapid speciation in such cases. Here, we focus on one such system; the Drosophila athabasca species complex, which is composed of three partially sympatric and interfertile semispecies: WN, EA, and EB. To study speciation in this species complex, we assayed sexual and genomic isolation within and between these semispecies in both sympatric and allopatric populations. First, we found no evidence of reproductive character displacement (RCD) in sympatric zones compared to distant allopatry. Instead, semispecies were virtually completely sexually isolated from each other across their entire ranges. Moreover, using spatial approaches and coalescent demographic simulations, we detected either zero or only weak heterospecific gene flow in sympatry. In contrast, within each semispecies we found only random mating and little population genetic structure, except between highly geographically distant populations. Finally, we determined that speciation in this system is at least an order of magnitude older than previously assumed, with WN diverging first, around 200K years ago, and EA and EB diverging 100K years ago. In total, these results suggest that these semispecies should be given full species status and we adopt new nomenclature: WN-D. athabasca, EA-D. mahican, and EB-D. lenape. While the lack of RCD in sympatry and interfertility do not support reinforcement, we discuss what additional evidence is needed to further decipher the mechanisms that caused rapid speciation in this species complex.

Atezolizumab versus chemotherapy in patients with platinum-treated locally advanced or metastatic urothelial carcinoma (IMvigor211): a multicentre, open-label, phase 3 randomised controlled trial

BACKGROUND

Few options exist for patients with locally advanced or metastatic urothelial carcinoma after progression with platinum-based chemotherapy. We aimed to assess the safety and efficacy of atezolizumab (anti-programmed death-ligand 1 [PD-L1]) versus chemotherapy in this patient population.

METHODS

We conducted this multicentre, open-label, phase 3 randomised controlled trial (IMvigor211) at 217 academic medical centres and community oncology practices mainly in Europe, North America, and the Asia-Pacific region. Patients (aged ≥18 years) with metastatic urothelial carcinoma who had progressed after platinum-based chemotherapy were randomly assigned (1:1), via an interactive voice and web response system with a permuted block design (block size of four), to receive atezolizumab 1200 mg or chemotherapy (physician's choice: vinflunine 320 mg/m², paclitaxel 175 mg/m², or 75 mg/m² docetaxel) intravenously every 3 weeks. Randomisation was stratified by PD-L1 expression (expression on <1% [IC0] or 1% to <5% [IC1] of tumour-infiltrating immune cells vs ≥5% of tumour-infiltrating immune cells [IC2/3]), chemotherapy type (vinflunine vs taxanes), liver metastases (yes vs no), and number of prognostic factors (none vs one, two, or three). Patients and investigators were aware of group allocation. Patients, investigators, and the sponsor were masked to PD-L1 expression status. The primary endpoint of overall survival was tested hierarchically in prespecified populations: IC2/3, followed by IC1/2/3, followed by the intention-to-treat population. This study, which is ongoing but not recruiting participants, is registered with ClinicalTrials.gov, number NCT02302807.

FINDINGS

Between Jan 13, 2015, and Feb 15, 2016, we randomly assigned 931 patients from 198 sites to receive atezolizumab (n=467) or chemotherapy (n=464). In the IC2/3 population (n=234), overall survival did not differ significantly between patients in the atezolizumab group and those in the chemotherapy group (median 11·1 months [95% CI 8·6-15·5; n=116] vs 10·6 months [8·4-12·2; n=118]; stratified hazard ratio [HR] 0·87, 95% CI 0·63-1·21; p=0·41), thus precluding further formal statistical analysis. Confirmed objective response rates were similar between treatment groups in the IC2/3 population: 26 (23%) of 113 evaluable patients had an objective response in the atezolizumab group compared with 25 (22%) of 116 patients in the chemotherapy group. Duration of response was numerically longer in the atezolizumab group than in the chemotherapy group (median 15·9 months [95% CI 10·4 to not estimable] vs 8·3 months [5·6-13·2]; HR 0·57, 95% CI 0·26-1·26). In the intention-to-treat population, patients receiving atezolizumab had fewer grade 3-4 treatment-related adverse events than did those receiving chemotherapy (91 [20%] of 459 vs 189 [43%] of 443 patients), and fewer adverse events leading to treatment discontinuation (34 [7%] vs 78 [18%] patients).

INTERPRETATION

Atezolizumab was not associated with significantly longer overall survival than chemotherapy in patients with platinum-refractory metastatic urothelial carcinoma overexpressing PD-L1 (IC2/3). However, the safety profile for atezolizumab was favourable compared with chemotherapy, Exploratory analysis of the intention-to-treat population showed well-tolerated, durable responses in line with previous phase 2 data for atezolizumab in this setting.

FUNDING

F Hoffmann-La Roche, Genentech.

Real-world (RW) evidence of vinflunine in metastatic urothelial cancer (mUC): A systematic review of seven European studies

463

Background: Vinflunine is the only chemotherapy agent for which there is a marketing authorisation in Europe for platinum-pretreated patients (pts) with mUC, based on a randomized phase III clinical trial. However, RW data regarding long-term efficacy and safety of vinflunine in unselected populations is needed. We conducted a systematic review gathering RW data from published observational European studies. Methods: Controlled studies and case series were excluded. We systematically explored the following endpoints: Overall Response Rate (ORR), Progression-Free Survival (PFS), Overall Survival (OS) and toxicity. Results: From 2014 to 2017, seven post-marketing studies including 750 pts were published: one was prospective and six were retrospective. Median ORR and median OS ranged from 13% to 29% and 6.3 to 11.9 months (mo) respectively (see Table below). In long-term survivors, OS reached 20.5 mo. Initial doses ranged from 250 to 320 mg/m2 adapted to patient’s conditions. In multivariate analysis, OS was found to be associated with the following risk-factors at baseline: ECOG PS >0, hemoglobin <10 g/dl, and presence of liver metastasis. The favorable safety profile demonstrated in randomized trials was confirmed. Main toxicity was hematological: neutropenia (G 3/4 in 1% to 23%) and anemia (G 3/4 in 4% to 33%). Constipation seemed to be less frequent than previously reported (G 3/4 in 5% to 22%). Conclusions: This is the largest experience of vinflunine use in platinum-pretreated pts with mUC. In our RW evidence, vinflunine shows both efficacy and a safe profile in an unselected patient population with similar criteria as in the pivotal trial. These findings reinforce the role of vinflunine in mUC, particularly if compared to evidence with taxanes or the increasing costs of immunotherapy.[Table: see text]

Interleukin-17A and vascular remodelling in severe asthma; lack of evidence for a direct role

BACKGROUND

Bronchial vascular remodelling may contribute to the severity of airway narrowing through mucosal congestion. Interleukin (IL)-17A is associated with the most severe asthmatic phenotype but whether it might contribute to vascular remodelling is uncertain.

OBJECTIVE

To assess vascular remodelling in severe asthma and whether IL-17A directly or indirectly may cause endothelial cell activation and angiogenesis.

METHODS

Bronchial vascularization was quantified in asthmatic subjects, COPD and healthy subjects together with the number of IL-17A⁺ cells as well as the concentration of angiogenic factors in the sputum. The effect of IL-17A on in vitro angiogenesis, cell migration and endothelial permeability was assessed directly on primary human lung microvascular endothelial cells (HMVEC-L) or indirectly with conditioned medium derived from normal bronchial epithelial cells (NHBEC), fibroblasts (NHBF) and airway smooth muscle cells (ASMC) after IL-17A stimulation.

RESULTS

Severe asthmatics have increased vascularity compared to the other groups, which correlates positively with the concentrations of angiogenic factors in sputum. Interestingly, we demonstrated that increased bronchial vascularity correlates positively with the number of subepithelial IL-17A⁺ cells. However IL-17A had no direct effect on HMVEC-L function but it enhanced endothelial tube formation and cell migration through the production of angiogenic factors by NHBE and ASMC.

CONCLUSIONS & CLINICAL RELEVANCE

Our results shed light on the role of IL-17A in vascular remodelling, most likely through stimulating the synthesis of other angiogenic factors. Knowledge of these pathways may aid in the identification of new therapeutic targets.