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During the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic, clinical trials on antiviral or symptomatic drugs have been conducted very rapidly even for drugs with a poor pharmacological rationale for efficacy on SARS-CoV-2. Despite lacking basic pharmacological information, most of these clinical trials were also extremely redundant. Applying simple rules, (such as identifying a mechanistic rationale, confirming the ability to reach exposure targets at therapeutic dosage and ensuring tests show drug efficacy in appropriate in vitro and animal models before entering clinical trials) might have saved considerable amounts of time and money, and might have avoided useless research. Moreover, combining these simple rules with the implementation of a relevant policy at both an international and a national level, by limiting studies with a poor methodological/scientific approach and aggregating studies with similar design into single clinical trials, is potentially a far more-efficient strategy. [ABSTRACT FROM AUTHOR]

Perioperative nutrition with supplements containingl-arginine, ω3-polyunsaturated fatty acids, and nucleotides could boost liver function recovery, immune response, and resistance to infection after hepatic resection. We conducted a placebo-controlled, randomized, double-blind study to assess the effect of a perioperative nutritional supplementation with Oral Impact® in patients undergoing hepatic surgery for liver cancer. Treatment was given three times daily for 7 days before and 3 days after surgery. Primary outcome was factor V, 3 days after surgery. Thirty-five patients (placebo: 17; Oral Impact: 18) were included. Five patients (placebo: three; Oral Impact: two) were not operated and five (placebo: two; Oral Impact: three) did not undergo hepatic resection. Factor V (mean ± SD) was 70 ± 27% and 79 ± 25% (P= 0.409) 3 days after surgery and 90 ± 30% and 106 ± 16% (P= 0.066) 5 days after surgery, in placebo and Oral Impact groups, respectively. There were no significant differences between groups on other outcomes assessing liver function recovery (bile production, γ-glutamyl transferase, α-fetoprotein), immune response (CD3, CD4, CD8 cells, CD4/CD8 ratio, natural killer cells, B lymphocytes), number of infections, and tolerance. A 10-day perioperative nutritional supplementation with Oral Impact does not improve hepatic function, immune response, and resistance to infection in patients undergoing hepatic surgery for liver cancer. [ABSTRACT FROM AUTHOR]

Imatinib mesylate (IM) is a small molecule inhibitor of protein tyrosine kinases. In addition to its direct effect on malignant cells, it has been suggested IM may activate of natural killer (NK) cells, hence exerting immunomodulatory functions. In preclinical settings, improved antitumor responses have been observed when IM and interleukin-2 (IL-2), a cytokine that enhances NK cells functions, were combined. The goals of this study were to determine the maximum tolerated dose (MTD) of IL-2 combined with IM at a constant dose of 400 mg, the pharmacokinetics of IM and IL-2, as well as toxicity and clinical efficacy of this immunotherapeutic regimen in patients affected by advanced tumors. The treatment consisted in 50 mg/day cyclophosphamide from 21 d before the initiation of IM throughout the first IM cycle (from D-21 to D14), 400 mg/day IM for 14 d (D1 to D14) combined with escalating doses of IL-2 (3, 6, 9 and 12 MIU/day) from days 10 to 14. This treatment was administered at three week intervals to 17 patients. Common side effects of the combination were mild to moderate, including fever, chills, fatigue, nausea and hepatic enzyme elevation. IL-2 dose level II, 6 MIU/day, was determined as the MTD with the following dose-limiting toxicities: systemic capillary leak syndrome, fatigue and anorexia. Pharmacokinetic studies revealed that the area under the curve and the maximum concentration of IM and its main metabolite CGP74588 increased significantly when IM was concomitantly administered with IL-2. In contrast, IM did not modulate IL-2 pharmacokinetics. No objective responses were observed. The best response obtained was stable disease in 8/17 (median duration: 12 weeks). Finally, IL-2 augmented the impregnation of IM and its metabolite. The combination of IM (400 mg/day) and IL-2 (6 MIU/day) in tumors that express IM targets warrants further investigation. [ABSTRACT FROM AUTHOR]

Abstract: Dendritic cells (DCs) are central to the initiation of tumor-specific immune responses. However, the tumor microenvironment generates immunosuppressive cells and soluble mediators that compromise DC functions and limit the success of DC-based therapies. Progress in understanding DC metabolism in cancer is uncovering novel therapeutic targets that could restore DC capacity to prime T cells and trigger effective anticancer responses. Accumulating evidence also indicates that conventional chemo- and radiotherapy protocols can cause DC activation, enhance antigen cross-presentation, selectively eliminate immunosuppressive cells and revert the immunosuppression state caused by cancer, suggesting that relevant chemoimmunotherapy associations could fully exploit DC capacity to trigger anticancer responses. Here, we discuss recent strategies that harness DC against cancer. [Copyright &y& Elsevier]

The concept of immunogenic chemotherapy that has recently emerged relies upon the capacity of a cytotoxic compound to trigger a cell-death modality. This modality elicits cross-priming by dendritic cells of tumor antigen-specific T cells that will contribute to the tumoricidal activity of the compound and protect the host against relapse. In contrast, most anticancer drugs elicit nonimmunogenic apoptosis that is not accompanied with an immunizing property. This review will discuss some molecular and metabolic changes required at the level of the tumor that must engage key pathways at the level of the host for the induction of Tc1 polarized-protective T cell responses during chemotherapy. We will summarize the immune adjuvants that can boost the immunogenicity of cell death to augment the efficacy of chemotherapy. [ABSTRACT FROM AUTHOR]

Conventional cancer treatments mediate their effects via the direct elimination of tumor cells. Nonetheless, recent evidence indicates that radiotherapy and some chemotherapeutic agents can also induce specific immune responses that contribute to therapeutic outcomes. Two major tumor-intrinsic changes that determine the immune response against tumors have been identified: the translocation of calreticulin to the plasma membrane and the release of high-mobility group box 1 protein. Together, these changes improve engulfment and processing of apoptotic bodies by dendritic cells, which are involved in the cross-priming of antitumor T lymphocytes in vivo. We review these two molecular mechanisms that dictate the radio/chemotherapy-elicited antitumor immune response and discuss how this knowledge can be clinically exploited to predict and also ameliorate the success of chemo/radiotherapy. [ABSTRACT FROM AUTHOR]

Background: The dissemination of clinical trial results is an important scientific and ethical endeavour. This survey of completed interventional studies in a French academic center describes their reporting status. Methods: We explored all interventional studies sponsored by Rennes University Hospital identified on the French Open Science Monitor which tracks trials registered on EUCTR or clinicaltrials.gov, and provides an automatic assessment of the reporting of results. For each study, we ascertained the actual reporting of results using systematic searches on the hospital internal database, bibliographic databases (Google Scholar, PubMed), and by contacting all principal investigators (PIs). We describe several features (including total budget and numbers of trial participants) of the studies that did not report any results. Results: The French Open Science Monitor identified 93 interventional studies, among which 10 (11%) reported results. In contrast, our survey identified 36 studies (39%) reporting primary analysis results and an additional 18 (19%) reporting results for secondary analyses (without results for their primary analysis). The overall budget for studies that did not report any results was estimated to be €5,051,253 for a total of 6,735 trial participants. The most frequent reasons for the absence of results reported by PIs were lack of time for 18 (42%), and logistic difficulties (e.g. delay in obtaining results or another blocking factor) for 12 (28%). An association was found between non-publication and negative results (adjusted Odds Ratio = 4.70, 95% Confidence Interval [1.67;14.11]). Conclusions: Even allowing for the fact that automatic searches underestimate the number of studies with published results, the level of reporting was disappointingly low. This amounts to a waste of trial participants' implication and money. Corrective actions are needed. Trial registration: https://osf.io/q5hcs [ABSTRACT FROM AUTHOR]

Abstract Purpose Tacrolimus (TAC) is the main immunosuppressive drug in liver transplantation. Despite intensive therapeutic drug monitoring (TDM) that relies on whole blood trough concentration (TAC blood), patients still present with acute cellular rejection or TAC-related toxic effects with concentrations within the therapeutic range. TAC concentration in peripheral blood mononuclear cells (TAC PBMC) is considered as an efficient surrogate marker of TAC efficacy. However, it is still not applicable in daily practice. New TDM methods are therefore needed, especially during the early postoperative period. TAC is metabolized in the liver and eliminated through biliary excretion. We therefore hypothesised that TAC concentration measured in excreted bile (TAC bileC) could be a relevant surrogate marker of its efficacy. Methods The Therapeutic Drug Monitoring of Tacrolimus Biliary Concentrations for Liver-Transplanted Patients (STABILE) study is a prospective monocentric trial. During the 7 first days after TAC therapy initiation, TAC bileC was measured. The correlation between TAC bileC and TAC PBMC as well as between TAC blood and TAC PBMC was assessed. The correlations between TAC bileC and liver graft function parameter or with occurrence of neurologic toxic effects were also evaluated. Findings Between May 2016 and April 2017, 41 patients were analyzed. TAC bileC was significantly correlated with TAC PBMC (r = 0.25, P = 0.007). However, a better correlation was found between TAC PBMC and TAC blood (r = 0.53, P < 0.001) and was confirmed in multivariate analysis. However, only TAC bileC was significantly correlated with liver graft function, such as factor V (r = 0.40, P = 0.009) or bilirubin level (r = 0.21, P = 0.01), and significantly lower in patients presenting with neurologic toxic effects (P < 0.001). Receiver operating characteristic curve analysis found that a TAC bileC level lower than 0.20 ng/mL on day 2 after TAC therapy initiation was a good predictive marker of occurrence of neurotoxic effects (AUC = 0.81). Implications TAC bileC is not a better surrogate maker of TAC activity than TAC blood. However, TAC bileC could help predict the occurrence of TAC toxic effects when a T-tube is inserted. ClinicalTrials.gov identifier: NCT02820259. [ABSTRACT FROM AUTHOR]

Background: Transparency and reproducibility are expected to be normative practices in clinical trials used for decision-making on marketing authorisations for new medicines. This registered report introduces a cross-sectional study aiming to assess inferential reproducibility for main trials assessed by the European Medicines Agency.Methods: Two researchers independently identified all studies on new medicines, biosimilars and orphan medicines given approval by the European Commission between January 2017 and December 2019, categorised as 'main studies' in the European Public Assessment Reports (EPARs). Sixty-two of these studies were randomly sampled. One researcher retrieved the individual patient data (IPD) for these studies and prepared a dossier for each study, containing the IPD, the protocol and information on the conduct of the study. A second researcher who had no access to study reports used the dossier to run an independent re-analysis of each trial. All results of these re-analyses were reported in terms of each study's conclusions, p-values, effect sizes and changes from the initial protocol. A team of two researchers not involved in the re-analysis compared results of the re-analyses with published results of the trial.Results: Two hundred ninety-two main studies in 173 EPARs were identified. Among the 62 studies randomly sampled, we received IPD for 10 trials. The median number of days between data request and data receipt was 253 [interquartile range 182-469]. For these ten trials, we identified 23 distinct primary outcomes for which the conclusions were reproduced in all re-analyses. Therefore, 10/62 trials (16% [95% confidence interval 8% to 28%]) were reproduced, as the 52 studies without available data were considered non-reproducible. There was no change from the original study protocol regarding the primary outcome in any of these ten studies. Spin was observed in the report of one study.Conclusions: Despite their results supporting decisions that affect millions of people's health across the European Union, most main studies used in EPARs lack transparency and their results are not reproducible for external researchers. Re-analyses of the few trials with available data showed very good inferential reproducibility.Trial Registration: https://osf.io/mcw3t/. [ABSTRACT FROM AUTHOR]

Background: Tivozanib (Fotivda) is an anti-angiogenic tyrosine kinase inhibitor that was denied access to the US market by the Food and Drug Administration (FDA). In contrast, it was granted approval by the European Medicines Agency (EMA) for the treatment of Renal Cell Carcinoma in adults. Given the conflicting decisions from these regulatory agencies, the objectives of the following study are (i) to critically review the evidence supporting the approval of tivozanib; (ii) to analyse the dissemination of this evidence in the literature by way of a citation analysis.Methods: Pivotal trials were searched by two independent reviewers using Medline, Cochrane Library, ClinicalTrials.gov and the European Public Assessment Report. The risk of bias for each trial was then inductively assessed. Articles citing any of these trials were identified using Web of Sciences. Finally, the quality of the citations was evaluated by two independent reviewers according to standard data extraction methods.Results: The search for primary evidence identified two pivotal studies: TIVO-1 upon which the FDA and the EMA decisions were based, and TIVO-3 which was conducted after the agencies' decisions had been issued. The TIVO-1 trial presented several limitations that compromised causal inference, in relation to (i) design (absence of blinding, inappropriate comparator, and one-way crossover), (ii) poor internal consistency in the results for the primary endpoint, (iii) a discrepancy between a benefit observed for progression-free survival (HR: 0.80, 95% CI [0.64-0.99]) and the absence of difference for overall survival (HR: 1.25, 95% CI [0.95 - 1.62]). Our citation search protocol identified 229 articles that cited TIVO-1 in the 7 years following its publication, among which 151 (65.9%) citing articles discussing efficacy. Presence of spin was identified in 64 (42.4%) of these 151 citing articles, and 39 (25.8%) additional articles citing results without providing enough elements to interpret the TIVO-1 results.Conclusion: EMA's approval was based on a single pivotal trial presenting critical limitations, rendering the results from the trial potentially inconclusive. The broad dissemination of TIVO-1 results in the scientific literature may have been affected by spin or results were presented in an inadequate critical manner. [ABSTRACT FROM AUTHOR]

Alongside the growing concerns regarding predatory journal growth, other questionable editorial practices have gained visibility recently. Among them, we explored the usefulness of the Percentage of Papers by the Most Prolific author (PPMP) and the Gini index (level of inequality in the distribution of authorship among authors) as tools to identify journals that may show favoritism in accepting articles by specific authors. We examined whether the PPMP, complemented by the Gini index, could be useful for identifying cases of potential editorial bias, using all articles in a sample of 5,468 biomedical journals indexed in the National Library of Medicine. For articles published between 2015 and 2019, the median PPMP was 2.9%, and 5% of journal exhibited a PPMP of 10.6% or more. Among the journals with the highest PPMP or Gini index values, where a few authors were responsible for a disproportionate number of publications, a random sample was manually examined, revealing that the most prolific author was part of the editorial board in 60 cases (61%). The papers by the most prolific authors were more likely to be accepted for publication within 3 weeks of their submission. Results of analysis on a subset of articles, excluding nonresearch articles, were consistent with those of the principal analysis. In most journals, publications are distributed across a large number of authors. Our results reveal a subset of journals where a few authors, often members of the editorial board, were responsible for a disproportionate number of publications. To enhance trust in their practices, journals need to be transparent about their editorial and peer review practices. Alongside the growing concerns regarding predatory journal growth, other questionable editorial practices have gained visibility recently. This study explores the relationship between hyper-prolific authors and a journal's editorial team, finding a subset of journals where a few authors, often members of the editorial board, were responsible for a disproportionate number of publications. [ABSTRACT FROM AUTHOR]

We performed a Phase I clinical trial from October 2007 to October 2009, enrolling patients affected by refractory solid tumors, to determine the maximum tolerated dose (MTD) of interleukin (IL)-2 combined with low dose cyclophosphamide (CTX) and imatinib mesylate (IM). In a companion paper published in this issue of OncoImmunology, we show that the MTD of IL-2 is 6 MIU/day for 5 consecutive days, and that IL-2 increases the impregnation of both IM and of its main metabolite, CGP74588. Among the secondary objectives, we wanted to determine immunological markers that might be associated with progression-free survival (PFS) and/or overall survival (OS). The combination therapy markedly reduced the absolute counts of B, CD4+ T and CD8+ T cells in a manner that was proportional to IL-2 dose. There was a slight (less than 2-fold) increase in the proportion of regulatory T cells (Tregs) among CD4+ T cells in response to IM plus IL-2. The natural killer (NK)-cell compartment was activated, exhibiting a significant upregulation of HLA-DR, tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) and CD56. The abundance of HLA-DR+ NK cells after one course of combination therapy positively correlated with both PFS and OS. The IL-2-induced rise of the CD4+:CD8+ T-cell ratio calculated after the first cycle of treatment was also positively associated with OS. Overall, the combination of IM and IL-2 promoted the rapid expansion of HLA-DR+ NK cells and increased the CD4+:CD8+ T-cell ratio, both being associated with clinical benefits. This combinatorial regimen warrants further investigation in Phase II clinical trials, possibly in patients affected by gastrointestinal stromal tumors, a setting in which T and NK cells may play an important therapeutic role. [ABSTRACT FROM AUTHOR]

The question as to whether the tumor grows because of or despite the host immune system is being progressively addressed with refined technology, gene targeting in mice and human translational research. The productive interplay between major actors of the antitumor immunity is actively compromised by the tumor microenvironment subverting the links between innate and cognate immunity and/or generating devastating new players. The complexity of the host–tumor equilibrium could be dissected at the reduced level of the dialogue between professional antigen presenting cells (APC), more precisely dendritic cells, and tumor cells that may profoundly dictate the outcome of the neoplasma. This review will summarize the novel mechanisms by which tumor cells regulate DC recruitment, differentiation, activation and cross-presenting functions in tumor beds and how innate players might counterbalance these interactions. Finally, we will highlight interesting strategies that harness the DC potential to fight against cancer. [Copyright &y& Elsevier]

Summary: Morphological features of eosinophils in patients with reactive eosinophilia (28 patients) and clonal eosinophilia (26 patients) have been compared with each other and with the eosinophil characteristics of healthy volunteers (three subjects) and of patients with the idiopathic hypereosinophilic syndrome (three patients). Morphological features, assessed in isolation from other haematological abnormalities, were found to have poor specificity for a myeloid neoplasm. The most useful feature was the presence of basophilic granules in mature eosinophils, which was associated particularly with acute myeloid leukaemia with inv(16). Marked reduction in granules occurred more often in some subsets of the myeloid neoplasm group but nevertheless was lacking in specificity since it was not infrequently seen in reactive eosinophilia. Although experienced morphologists more often considered that a myeloid neoplasm was likely in patients in whom this was the diagnosis (69%), myeloid neoplasia was also considered likely in a considerable proportion (39%) of patients with reactive eosinophilia. Morphological abnormalities of eosinophils therefore cannot be assessed in isolation in seeking to make a diagnosis of a myeloid neoplasm. Morphology is, however, needed and should be integrated with the results of other investigations. [ABSTRACT FROM AUTHOR]

Abstract: Background and Aims: Pharmacologically controlled drinking in the treatment of alcohol dependence or alcohol use disorders (AUDs) is an emerging concept. Our objective was to explore the comparative effectiveness of drugs used in this indication. Design: Systematic review with direct and network meta‐analysis of double‐blind randomized controlled trials (RCTs) assessing the efficacy of nalmefene, naltrexone, acamprosate, baclofen or topiramate in non‐abstinent adults diagnosed with alcohol dependence or AUDs. Two independent reviewers selected published and unpublished studies on Medline, the Cochrane Library, Embase, ClinicalTrials.gov, contacted pharmaceutical companies, the European Medicines Agency and the Food and Drug Administration, and extracted data. Setting: Thirty‐two RCTs. Participants: A total of 6036 patients. Measurements: The primary outcome was total alcohol consumption (TAC). Other consumption outcomes and health outcomes were considered as secondary outcomes. Findings: No study provided direct comparisons between drugs. A risk of incomplete outcome data was identified in 26 studies (81%) and risk of selective outcome reporting in 17 (53%). Nalmefene [standardized mean difference (SMD) = −0.19, 95% confidence interval (CI) = −0.29, –0.10; I2 = 0%], baclofen (SMD = −1.00, 95% CI = −1.80, −0.19; one study) and topiramate (SMD = −0.77, 95% CI = −1.12, –0.42; I2 = 0%) showed superiority over placebo on TAC. No efficacy was observed for naltrexone or acamprosate. Similar results were observed for other consumption outcomes, except for baclofen (the favourable outcome on TAC was not reproduced). The number of withdrawals for safety reasons increased under nalmefene and naltrexone. No treatment demonstrated any harm reduction (no study was powered to explore health outcomes). Indirect comparisons suggested that topiramate was superior to nalmefene, naltrexone and acamprosate on consumption outcomes, but its safety profile is known to be poor. Conclusions: There is currently no high‐grade evidence for pharmacological treatment to control drinking using nalmefene, naltrexone, acamprosate, baclofen or topiramate in patients with alcohol dependence or alcohol use disorder. Some treatments show low to medium efficacy in reducing drinking across a range of studies with a high risk of bias. None demonstrates any benefit on health outcomes. [ABSTRACT FROM AUTHOR]

Significance: Accumulating evidence indicates that the success of some anticancer treatments (select chemotherapies or radiotherapy or trastuzumab) could be related to the stimulation of an anticancer immune response through the induction of an immunogenic tumor cell death (ICD). Recent Advances: Preclinical data revealed that dying tumor cells can emit a series of danger signals (so-called 'cell-death-associated molecular patterns' (CDAMP)) that will dictate the recruitment and activation of specific inflammatory phagocytes. Hence, tumor cells succumbing to ICD are characterized by specific metabolic and molecular changes that will trigger a hierarchy of polarizing cytokine-producing cells, culminating in the recruitment and reactivation of antitumor interferon-γ-producing effector T cells which contribute to the success of cytotoxic treatments. Critical Issues: In this review, we summarize the molecular and cellular bases of this ICD, underscoring the crucial role of high mobility group box 1 protein (HMGB1) and adenosine tri-phosphate, both of which are released from dying tumor cells during ICD and are implicated in the chemotherapy-elicited anticancer immune response. Future Directions: We discuss here how such CDAMP could serve as predictive biomarkers that could discriminate immunogenic from nonimmunogenic anti-cancer compounds, and, in case of deficiency, could be compensated by surrogate products to ameliorate the success rate of conventional anticancer treatment modalities. Antioxid. Redox Signal. 20, 1098-1116. [ABSTRACT FROM AUTHOR]

Abstract: Preclinical and clinical findings suggest that tumor-specific immune responses may be responsible – at least in part – for the clinical success of therapeutic regimens that rely on immunogenic cell death (ICD) inducers, including anthracyclines and oxaliplatin. The molecular pathways whereby some, but not all, cytotoxic agents promote bona fide ICD remain to be fully elucidated. Nevertheless, a central role for the endoplasmic reticulum (ER) stress response has been revealed in all scenarios of ICD described thus far. Hence, components of the ER stress machinery may constitute clinically relevant druggable targets for the induction of ICD. In this review, we will summarize recent findings in the field of ICD research with a special focus on ER stress mechanisms and their implication for cancer therapy. [Copyright &y& Elsevier]

Cancer immunosurveillance relies on effector/memory tumor-infiltrating CD8+ T cells with a T-helper cell 1 (TH1) profile. Evidence for a natural killer (NK) cell-based control of humanmalignancies is still largelymissing. The KIT tyrosine kinase inhibitor imatinib mesylate markedly prolongs the survival of patients with gastrointestinal stromal tumors (GIST) by direct effects on tumor cells as well as by indirect immunostimulatory effects on T and NK cells. Here, we investigated the prognostic value of tumor-infiltrating lymphocytes (TIL) expressing CD3, Foxp3, or NKp46 (NCR1) ina cohort of patients with localized GIST.We found that CD3+ TIL were highly activated in GIST and were especially enriched in areas of the tumor that conserve class IMHC expression despite imatinib mesylate treatment. High densities of CD3+ TIL predicted progression-free survival (PFS) in multivariate analyses. Moreover, GIST were infiltrated by a homogeneous subset of cytokinesecreting CD56bright (NCAM1) NK cells that accumulated in tumor foci after imatinib mesylate treatment. The density of the NK infiltrate independently predicted PFS and added prognostic information to the Miettinen score, as well as to the KIT mutational status. NK and T lymphocytes preferentially distributed to distinct areas of tumor sections and probably contributed independently to GIST immunosurveillance. These findings encourage the prospective validation of immune biomarkers for optimal risk stratification of patients with GIST. [ABSTRACT FROM AUTHOR]

Abstract: An attractive, yet hitherto unproven concept predicts that the promotion of tumor regression should elicit the host''s immune response against residual tumor cells to achieve an optimal therapeutic effect. In a way, chemo- or radiotherapy must trigger “danger signals” emitted from immunogenic cell death and hence elicit “danger associated molecular patterns” to stimulate powerful anticancer immune responses. Here, based on the recent experimental and clinical evidence, we will discuss the molecular identity of the multiple checkpoints that dictate the success of “immunogenic chemotherapy” at the levels of the drug, of the tumor cell and of the host immune system. [Copyright &y& Elsevier]

Patients with lower extremity peripheral artery disease (PAD) frequently experience claudication, a clinical symptom indicative of reduced walking capacity. Recommended care consists of exercise rehabilitation combined with optimal medical treatment and surgery. The effects of a single oral dose of sildenafil, a phosphodiesterase type-5 inhibitor, on patients with claudication are discussed. The aim of this study was to test the efficacy of a single 100 mg dose of sildenafil compared to placebo in terms of maximal walking time (MWT) in patients with claudication. The ARTERIOFIL study is a crossover, double-blind, prospective, randomized, single-center study conducted at Angers University Hospital in France. MWT (primary endpoint) was assessed using a treadmill test (10% incline; 3.2 km/h). Secondary endpoints (pain-free walking time (PFWT), transcutaneous oximetry during exercise and redox cycle parameters and safety) were also studied. Fourteen patients were included of whom two were ultimately excluded. In the 12 remaining patients, the MWT was significantly improved during the sildenafil period compared with the placebo period (300 s [95% CI 172 s–428 s] vs 402 s [95% CI 274 s–529 s] p < 0.01). Sildenafil had no significant effect on pain-free walking time or skin tissue oxygenation during exercise. According to redox cycle parameters, sildenafil significantly reduced blood glucose and pyruvate levels and the 3-hydroxybutyrate/acetoacetate ratio, while there was no significant effect on lactate, 3-hydroxybutyrate, acetoacetate and free fatty acid levels. Symptomatic transient hypotension was observed in two women. The ARTERIOFIL study has shown that a single 100 mg oral dose of sildenafil had a significant effect on increase in MWT but had no significant effects on PFWT and oxygenation parameters in patients with claudication. A double-blind, prospective, randomized, multicenter study (VIRTUOSE©) is ongoing to evaluate the chronic effect of six month-long sildenafil treatment on MWT in PAD patients with claudication. This clinical trial was registered at clinicaltrials.gov , registration. number: NCT02832570 , (https://clinicaltrials.gov/ct2/show/NCT02832570). Central Illustration: PAD with Arterial Claudication: Improving the Maximum Walking Time with Sildenafil. Patients with arterial claudication have their walking capacity decrease. Using a treadmill test, the efficacy of a single 100 mg dose of sildenafil compared to placebo was significant on MWT (+34%) in 12 patients. Unlabelled Image [ABSTRACT FROM AUTHOR]