Evaluation of convalescent plasma versus standard of care for the treatment of COVID-19 in hospitalized patients: study protocol for a phase 2 randomized, open-label, controlled, multicenter trial.

BACKGROUND: COVID-19 is a respiratory disease caused by a novel coronavirus (SARS-CoV-2) and causes substantial morbidity and mortality. At the time this clinical trial was planned, there were no available vaccine or therapeutic agents with proven efficacy, but the severity of the condition prompted the use of several pharmacological and non-pharmacological interventions. It has long been hypothesized that the use of convalescent plasma (CP) from infected patients who have developed an effective immune response is likely to be an option for the treatment of patients with a variety of severe acute respiratory infections (SARI) of viral etiology. The aim of this study is to assess the efficacy and safety of convalescent plasma in adult patients with severe COVID-19 pneumonia. METHODS/DESIGN: The ConPlas-19 study is a multicenter, randomized, open-label controlled trial. The study has been planned to include 278 adult patients hospitalized with severe COVID-19 infection not requiring mechanical ventilation (invasive or non-invasive). Subjects are randomly assigned in a 1:1 ratio (139 per treatment arm), stratified by center, to receive intravenously administered CP (single infusion) plus SOC or SOC alone, and are to be followed for 30 days. The primary endpoint of the study is the proportion of patients that progress to category 5, 6, or 7 (on the 7-point ordinal scale proposed by the WHO) at day 15. Interim analyses for efficacy and/or futility will be conducted once 20%, 40%, and 60% of the planned sample size are enrolled and complete D15 assessment. DISCUSSION: This clinical trial is designed to evaluate the efficacy and safety of passive immunotherapy with convalescent plasma for the treatment of adult patients hospitalized with COVID-19. The results of this study are expected to contribute to establishing the potential place of CP in the therapeutics for a new viral disease. TRIAL REGISTRATION: ClinicalTrials.gov NCT04345523 . Registered on 30 March, 2020. First posted date: April 14, 2020.

Double-blind, randomized, controlled, trial to assess the efficacy of allogenic mesenchymal stromal cells in patients with acute respiratory distress syndrome due to COVID-19 (COVID-AT): A structured summary of a study protocol for a randomised controlled trial.

OBJECTIVES: 1. To assess the efficacy of Mesenchymal Stromal Cells (MSC) versus a control arm as described in the primary endpoint. 2. To evaluate the effects of MSC on the secondary efficacy endpoints. 3. To evaluate the safety and tolerability profiles of MSC. 4. To study soluble and cellular biomarkers that might be involved in the course of the disease and the response to the investigational product. TRIAL DESIGN: A double-blind, randomized, controlled, trial to evaluate the efficacy and safety of MSC intravenous administration in patients with COVID-induced Acute Respiratory Distress Syndrome (ARDS) compared to a control arm. PARTICIPANTS: The trial is being conducted at a third level hospital, Hospital Universitario Puerta de Hierro, in Majadahonda, Madrid (Spain). Inclusion criteria 1. Informed consent prior to performing study procedures (witnessed oral consent with written consent by representatives will be accepted to avoid paper handling). Written consent by patient or representatives will be obtained whenever possible. 2. Adult patients ≥18 years of age at the time of enrolment. 3. Laboratory-confirmed SARS-CoV-2 infection as determined by Polymerase Chain Reaction (PCR), in oropharyngeal swabs or any other relevant specimen obtained during the course of the disease. Alternative tests (e.g., rapid antigen tests) are also acceptable as laboratory confirmation if their specificity has been accepted by the Sponsor. 4. Moderate to severe ARDS (PaO2/FiO2 ratio equal or less than 200 mmHg) for less than 96 hours at the time of randomization. 5. Patients requiring invasive ventilation are eligible within 72 hours from intubation. 6. Eligible for ICU admission, according to the clinical team. Exclusion criteria 1. Imminent and unavoidable progression to death within 24 hours, irrespective of the provision of treatments (in the opinion of the clinical team). 2. "Do Not Attempt Resuscitation" order in place. 3. Any end-stage organ disease or condition, which in the investigator's opinion, makes the patient an unsuitable candidate for treatment. 4. History of a moderate/severe lung disorder requiring home-based oxygen therapy. 5. Patient requiring Extracorporeal Membrane Oxygenation (ECMO), haemodialysis or hemofiltration at the time of treatment administration. 6. Current diagnosis of pulmonary embolism. 7. Active neoplasm, except carcinoma in situ or basalioma. 8. Known allergy to the products involved in the allogeneic MSC production process. 9. Current pregnancy or lactation (women with childbearing potential should have a negative pregnancy test result at the time of study enrolment). 10. Current participation in a clinical trial with an experimental treatment for COVID-19 (the use of any off-label medicine according to local treatment protocols is not an exclusion criteria). 11. Any circumstances that in the investigator's opinion compromises the patient's ability to participate in the clinical trial. INTERVENTION AND COMPARATOR: - Experimental treatment arm: Allogeneic MSC (approximately 1 x 106 cells/kg). - Control arm: placebo solution (same composition as the experimental treatment, without the MSC). One single intravenous dose of the assigned treatment will be administered on Day 0 of the study. All trial participants will receive standard of care (SOC). In the context of the current worldwide pandemic, SOC can include medicines that are being used in clinical practice (e.g. lopinavir/ritonavir; hydroxy/chloroquine, tocilizumab, etc.), as well as those authorised for COVID (e.g., remdesivir). MAIN OUTCOMES: Primary endpoint: Change in the PaO2/FiO2 ratio from baseline to day 7 of treatment administration, or to the last available PaO2/FiO2 ratio if death occurs before day 7. Secondary endpoints: - All-cause mortality on days 7, 14, and 28 after treatment. - PaO2/FiO2 ratio at baseline and days 2, 4, 7, 14 and 28 after treatment. - Oxygen saturation (by standardized measurement) at baseline, daily until day 14, and on day 28 after treatment. - Time to PaO2/FiO2 ratio greater than 200 mmHg. - Subjects' clinical status on the WHO 7-point ordinal scale at baseline, daily until day 14, and on day 28 after treatment. - Time to an improvement of one category from admission on the WHO 7-point ordinal scale. - Percentage of patients that worsen at least one category on the WHO 7-point ordinal scale. - Percentage of patients that improve at least one category (maintained 48h) on the WHO 7-point ordinal scale. - Sequential Organ Failure Assessment (SOFA) scale at baseline and days 2, 4, 7, 14 and 28 after treatment. - Duration of hospitalization (days). - Duration of ICU stay (days). - Oxygen therapy-free days in the first 28 days after treatment. - Duration of supplemental oxygen. - Incidence of and duration of non-invasive and invasive mechanical ventilation in the first 28 days after treatment. - Mechanical ventilation-free days in the first 28 days after treatment. - Ventilation parameters. - Incidence of new onset pulmonary fibrosis at 3 and 12 months after treatment, based on CT scan and pulmonary function tests. - Survival at 3 and 12 months. - Cumulative incidence of Serious Adverse events (SAEs) and Grade 3 and 4 Adverse Events (AEs). - Cumulative incidence of Adverse Drug Reactions (ADR) in the experimental treatment arm. - Cumulative incidence of AEs of special interest. - Levels of analytical markers (C-Reactive Protein, lymphocyte and neutrophil counts, lymphocyte subpopulations, LDH, ferritin, D-dimer, coagulation tests and cytokines...) at baseline and days 2, 4, 7, 14 and 28 after treatment. - Other soluble and cellular biomarkers that might be involved in the course of the disease and the response to MSC. RANDOMISATION: The assignment to treatment will be carried out randomly and blinded, with a 1:1 allocation. Randomization will be done through a centralized system embedded in the electronic Case Report Form (CRF). BLINDING (MASKING): To ensure blinding, treatments will be prepared for administration at the Cell Production Unit and the administration of the treatment will be masked, not allowing the identification of the Investigational Medicinal Product (IMP). NUMBERS TO BE RANDOMISED (SAMPLE SIZE): A total of 20 participants are planned to be randomized, 10 to each treatment group. TRIAL STATUS: Protocol version: 1.2, dated October 14th, 2020 Start of recruitment: 01/10/2020 End of recruitment (estimated): December 2020. TRIAL REGISTRATION: EudraCT Number: 2020-002193-27 , registered on July 14th, 2020. NCT number: NCT04615429 , registered on November 4th, 2020. FULL PROTOCOL: The full protocol is attached as an additional file, accessible from the Trials website (Additional file 1). In the interest in expediting dissemination of this material, the familiar formatting has been eliminated; this Letter serves as a summary of the key elements of the full protocol.

Peroxynitrite-Mediated Dimerization of 3-Nitrotyrosine: Unique Chemistry along the Spectrum of Peroxynitrite-Mediated Nitration of Tyrosine.

Peroxynitrite (ONOO-, PN) has long been considered a potent nitrating agent implicated in numerous inflammation-mediated diseases. The current work highlights an unexplored oxidation chemistry initiated under conditions of sustained PN exposure. Impetus for this investigation developed from mass spectral results that suggested dimerization of a model peptide with a single tyrosine residue that was first nitrated following extended exposure to PN generated in situ. In attempts to substantiate this dimerization event and divulge the possible mode of linkage between the tyrosine derivatives of the peptide monomers, 3-nitrotyrosine (3-NT) was exposed to sustained fluxes of PN in a two-component PN-generating platform developed in this laboratory. Such exposure afforded products with tandem mass spectrometry and fluorescence spectroscopy profiles indicative of C-O coupling between 3-NT moieties. Synthesis and comparative analysis of the C-C coupled 3-NT isomer corroborated these findings. Most notably, the mass spectral data of the C-C coupled 3-NT dimer displayed a 226.80 m/z peak following exposure to high collision energy, corresponding to symmetric cleavage of the parent dimer peak (m/z = 453) along with a fragmentation product at m/z = 180.04 (-NO2 species). This fragmentation profile was distinct from the C-O coupled 3-NT dimer that exhibited a predominant 209.14 m/z peak with a small secondary 226.15 m/z peak indicative of asymmetric cleavage of the parent dimer. Results of this study indicate that formation of C-O coupled 3-NT dimer is promoted by elevated levels of 3-NT formed under high and sustained flux of PN.

Rare Variant Analysis of Human and Rodent Obesity Genes in Individuals with Severe Childhood Obesity.

Obesity is a genetically heterogeneous disorder. Using targeted and whole-exome sequencing, we studied 32 human and 87 rodent obesity genes in 2,548 severely obese children and 1,117 controls. We identified 52 variants contributing to obesity in 2% of cases including multiple novel variants in GNAS, which were sometimes found with accelerated growth rather than short stature as described previously. Nominally significant associations were found for rare functional variants in BBS1, BBS9, GNAS, MKKS, CLOCK and ANGPTL6. The p.S284X variant in ANGPTL6 drives the association signal (rs201622589, MAF~0.1%, odds ratio = 10.13, p-value = 0.042) and results in complete loss of secretion in cells. Further analysis including additional case-control studies and population controls (N = 260,642) did not support association of this variant with obesity (odds ratio = 2.34, p-value = 2.59 × 10-3), highlighting the challenges of testing rare variant associations and the need for very large sample sizes. Further validation in cohorts with severe obesity and engineering the variants in model organisms will be needed to explore whether human variants in ANGPTL6 and other genes that lead to obesity when deleted in mice, do contribute to obesity. Such studies may yield druggable targets for weight loss therapies.

The agouti-related peptide binds heparan sulfate through segments critical for its orexigenic effects.

Syndecans potently modulate agouti-related peptide (AgRP) signaling in the central melanocortin system. Through heparan sulfate moieties, syndecans are thought to anchor AgRP near its receptor, enhancing its orexigenic effects. Original work proposed that the N-terminal domain of AgRP facilitates this interaction. However, this is not compatible with evidence that this domain is posttranslationally cleaved. Addressing this long-standing incongruity, we used calorimetry and magnetic resonance to probe interactions of AgRP peptides with glycosaminoglycans, including heparan sulfate. We show that mature, cleaved, C-terminal AgRP, not the N-terminal domain, binds heparan sulfate. NMR shows that the binding site consists of regions distinct from the melanocortin receptor-binding site. Using a library of designed AgRP variants, we find that the strength of the syndecan interaction perfectly tracks orexigenic action. Our data provide compelling evidence that AgRP is a heparan sulfate-binding protein and localizes critical regions in the AgRP structure required for this interaction.

Electrostatic Similarity Analysis of Human ß-Defensin Binding in the Melanocortin System.

The ß-defensins are a class of small cationic proteins that serve as components of numerous systems in vertebrate biology, including the immune and melanocortin systems. Human ß-defensin 3 (HBD3), which is produced in the skin, has been found to bind to melanocortin receptors 1 and 4 through complementary electrostatics, a unique mechanism of ligand-receptor interaction. This finding indicates that electrostatics alone, and not specific amino acid contact points, could be sufficient for function in this ligand-receptor system, and further suggests that other small peptide ligands could interact with these receptors in a similar fashion. Here, we conducted molecular-similarity analyses and functional studies of additional members of the human ß-defensin family, examining their potential as ligands of melanocortin-1 receptor, through selection based on their electrostatic similarity to HBD3. Using Poisson-Boltzmann electrostatic calculations and molecular-similarity analysis, we identified members of the human ß-defensin family that are both similar and dissimilar to HBD3 in terms of electrostatic potential. Synthesis and functional testing of a subset of these ß-defensins showed that peptides with an HBD3-like electrostatic character bound to melanocortin receptors with high affinity, whereas those that were anticorrelated to HBD3 showed no binding affinity. These findings expand on the central role of electrostatics in the control of this ligand-receptor system and further demonstrate the utility of employing molecular-similarity analysis. Additionally, we identified several new potential ligands of melanocortin-1 receptor, which may have implications for our understanding of the role defensins play in melanocortin physiology.

G-protein-independent coupling of MC4R to Kir7.1 in hypothalamic neurons.

The regulated release of anorexigenic α-melanocyte stimulating hormone (α-MSH) and orexigenic Agouti-related protein (AgRP) from discrete hypothalamic arcuate neurons onto common target sites in the central nervous system has a fundamental role in the regulation of energy homeostasis. Both peptides bind with high affinity to the melanocortin-4 receptor (MC4R); existing data show that α-MSH is an agonist that couples the receptor to the Gαs signalling pathway, while AgRP binds competitively to block α-MSH binding and blocks the constitutive activity mediated by the ligand-mimetic amino-terminal domain of the receptor. Here we show that, in mice, regulation of firing activity of neurons from the paraventricular nucleus of the hypothalamus (PVN) by α-MSH and AgRP can be mediated independently of Gαs signalling by ligand-induced coupling of MC4R to closure of inwardly rectifying potassium channel, Kir7.1. Furthermore, AgRP is a biased agonist that hyperpolarizes neurons by binding to MC4R and opening Kir7.1, independently of its inhibition of α-MSH binding. Consequently, Kir7.1 signalling appears to be central to melanocortin-mediated regulation of energy homeostasis within the PVN. Coupling of MC4R to Kir7.1 may explain unusual aspects of the control of energy homeostasis by melanocortin signalling, including the gene dosage effect of MC4R and the sustained effects of AgRP on food intake.

Tyrosine nitration in peptides by peroxynitrite generated in situ in a light-controlled platform: effects of pH and thiols.

Peroxynitrite has been shown to play a critical role in inflammation and affords 3-nitrotyrosine as the hallmark product. The reported methods of generating this reactive nitrogen species in situ often fails to provide a high and steady flux of peroxynitrite resulting in poor yields of 3-nitrotyrosine. Herein we report a two-component peroxynitrite-generating platform in which this anion is produced in a biomimetic fashion and under the control of visible light. Incorporation of the nitric oxide- and superoxide-generating components in polymer matrices allows easy alterations of pH in the reaction wells of this platform. We have demonstrated very efficient nitration of tyrosine by peroxynitrite at different pH values and with varying concentrations of carbonate. In addition to tyrosine, a set of tyrosine-containing peptides was also studied. Presence of glutathione in the reaction wells increases the extent of tyrosine nitration in such peptide substrates presumably by raising the lifetime of nitric oxide in the reaction medium. When a cysteine residue was included in the sequence of the peptide, the extent of nitration of the tyrosine residue was found to depend on the position of the cysteine residue with respect to tyrosine. The extent of tyrosine nitration is strongly attenuated when the cysteine residue is directly adjacent to the tyrosine. This effect has been attributed to an intramolecular radical transfer mechanism. Taken together, results of this study demonstrate the potential of this light-controlled platform as a convenient bioanalytical tool in studying the reactions of peroxynitrite under widely varying conditions.