Tixagevimab-cilgavimab (AZD7442) for the treatment of patients hospitalized with COVID-19 (DisCoVeRy): A phase 3, randomized, double-blind, placebo-controlled trial (preprint)

Background Tixagevimab and cilgavimab (AZD7442) are two monoclonal antibodies developed by AstraZeneca for the pre-exposure prophylaxis and treatment of patients infected by SARS-CoV-2. Its effectiveness and safety in patients hospitalized with COVID-19 was not known at the outset of this trial. Methods DisCoVeRy is a phase 3, adaptive, multicentre, randomized, controlled trial conducted in 63 sites in Europe. Participants were randomly assigned (1:1) to receive placebo or tixagevimab-cilgavimab in addition to standard of care. The primary outcome was the clinical status at day 15 measured by the WHO seven-point ordinal scale. Several clinical, virological, immunological and safety endpoints were also assessed. Findings Due to slow enrolment, recruitment was stopped on July 1st, 2022. The antigen positive modified intention-to-treat population (mITT) was composed of 173 participants randomized to tixagevimab-cilgavimab (n=91) or placebo (n=82), 91.9% (159/173) with supplementary oxygen, and 47.4% (82/173) previously vaccinated at inclusion. There was no significant difference in the distribution of the WHO ordinal scale at day 15 between the two groups (odds ratio (OR) 0.93, 95%CI [0.54-1.61]; p=0.81) nor in any clinical, virological or safety secondary endpoints. In the global mITT (n=226), neutralization antibody titers were significantly higher in the tixagevimab-cilgavimab group/patients compared to placebo at day 3 (Least-square mean differences (LSMD) 1.44, 95% Confidence interval (CI) [1.20-1.68]; p < 10-23) and day 8 (LSMD 0.91, 95%CI [0.64-1.18]; p < 10-8) and it was most important for patients infected with a pre-omicron variant, both at day 3 (LSMD 1.94, 95% CI [1.67-2.20], p < 10-25) and day 8 (LSMD 1.17, 95% CI [0.87-1.47], p < 10-9), with a significant interaction (p < 10-7 and p=0.01 at days 3 and 8, respectively). Interpretation There were no significant differences between tixagevimab-cilgavimab and placebo in clinical endpoints, however the trial lacked power compared to prespecified calculations. Tixagevimab-cilgavimab was well tolerated, with low rates of treatment related events.

Gut microbiota alterations in patients with persistent respiratory dysfunction three months after severe COVID-19 (preprint)

ObjectiveAlthough COVID-19 is primarily a respiratory infection, mounting evidence suggests that the GI tract is involved in the disease, with gut barrier dysfunction and gut microbiota alterations being related to disease severity. Whether these alterations persist and could be related to long-term respiratory dysfunction is unknown. DesignFrom the NOR-Solidarity trial (n=181), plasma was collected during hospital admission and after three months, and analyzed for markers of gut barrier dysfunction and inflammation. At the three-month follow-up, pulmonary function was assessed by measuring diffusing capacity of the lungs for carbon monoxide (DLCO), and rectal swabs for gut microbiota analyses were collected (n= 97) and analysed by sequencing of the 16S rRNA gene. ResultsGut microbiota diversity was reduced in COVID-19 patients with persistent respiratory dysfunction, defined as DLCO below lower limit of normal three months after hospitalization. These patients also had an altered global gut microbiota composition, with reduced abundance of Erysipelotrichaceae UCG-003 and increased abundance of Flavonifractor and Veillonella, the latter potentially being linked to fibrosis. During hospitalization, increased plasma levels of lipopolysaccharide-binding protein (LBP) were strongly associated with respiratory failure, defined as pO2/fiO2-(P/F-ratio)<26.6 kPa. LBP levels remained elevated during and after hospitalization, and was associated with low-grade inflammation and persistent respiratory dysfunction after three months. ConclusionPersistent respiratory dysfunction after COVID-19 is associated with reduced biodiversity and gut microbiota alterations, along with persistently elevated LBP levels. Our results point to a potential gut-lung axis that should be further investigated in relation to long-term pulmonary dysfunction and long COVID. Summary boxO_ST_ABSWhat is already known about this subject?C_ST_ABSO_LIMounting evidence suggests that the gastrointestinal tract is involved in the pathogenesis of COVID-19, with the putative SARS-CoV-2 receptor ACE 2 ubiquitously expressed in the gut. C_LIO_LIIn severe COVID-19, the gut-blood barrier is compromised, and leakage of microbial products, such as lipopolysaccharides (LPS), could affect the hosts response to COVID-19 infection. C_LIO_LICOVID-19 patients exhibit an altered gut microbiota composition, which has been related to disease severity. However, it is currently not known whether dysbiosis or gut barrier dysfunction persist long-term after hospitalization, or whether microbiota-related mechanisms could be related to persistent pulmonary dysfunction. C_LI What are the new findings?O_LICOVID-19 patients with persistent respiratory dysfunction after three months had a lower microbial diversity and an altered gut microbiota composition at the same time point. C_LIO_LIThe microbiota alterations included reduced abundance of Erysipelotrichaceae UCG-003 and increased abundance of Veillonella and Flavonifractor. C_LIO_LIDuring hospitalization, increased plasma levels of LBP were strongly associated with respiratory failure. C_LIO_LILBP levels remained elevated during and after hospitalization, and associated significantly with persistent respiratory dysfunction at three-month follow-up. C_LI How might it impact on clinical practice in the foreseeable future?Our findings point to a potential gut-lung axis in relation not only to respiratory failure during hospitalization, but also to long-term COVID-19 morbidity. Further studies on gut microbiota composition and gut barrier dysfunction as potential treatment targets and/or disease severity biomarkers in relation to long-term pulmonary dysfunction and long COVID are warranted.

Synergistic Interferon Alpha-based Drug Combinations Inhibit SARS-CoV-2 and other viral Infections in Vitro (preprint)

There is an urgent need for new antivirals with powerful therapeutic potential and tolerable side effects. In the present study, we found that recombinant human interferon-alpha (IFNa) triggered cell intrinsic and extrinsic antiviral responses and reduced replication of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in human lung epithelial Calu-3 cells. However, IFNa alone was insufficient to completely abolish SARS-CoV-2 replication. Combinations of IFNa with camostat, remdesivir, EIDD-2801, cycloheximide or convalescent serum showed strong synergy and effectively inhibited SARS-CoV-2 infection. Additionally, we demonstrated synergistic antiviral activity of IFNa2a with pimodivir against influenza A virus (FluAV) infection in human lung epithelial A549 cells, as well as of IFNa2a with lamivudine against human immunodeficiency virus 1 (HIV-1) infection in human TZM-bl cells. Our results indicate that IFNa2a-based combinational therapies help to reduce drug dose and improve efficacy in comparison with monotherapies, making them attractive targets for further pre-clinical and clinical development.

Rejuveinix Mitigates Sepsis-Associated Oxidative Stress in the Brain of Mice: Clinical Impact Potential in COVID-19 and Nervous System Disorders (preprint)

Here, we demonstrate that our anti-sepsis and COVID-19 drug candidate Rejuveinix (RJX) substantially improves the survival outcome in the LPS-GalN animal model of sepsis and multi-organ failure. One hundred (100) percent (%) of untreated control mice remained alive throughout the experiment. By comparison, 100% of LPS-GalN injected mice died at a median of 4.6 hours. In contrast to the invariably fatal treatment outcome of vehicle-treated control mice, 40% of mice treated with RJX (n=25) remained alive with a 2.4-fold longer median time survival time of 10.9 hours (Log-rank X2=20.60, P<0.0001). Notably, RJX increased the tissue levels of antioxidant enzymes SOD, CAT, and GSH-Px, and reduced oxidative stress in the brain. These findings demonstrate the clinical impact potential of RJX as a neuroprotective COVID-19 and sepsis drug candidate.

Hydroxyzine inhibits SARS-CoV-2 Spike protein binding to ACE2 in a qualitative in vitro assay (preprint)

COVID-19 currently represents a major public health problem. Multiple efforts are being performed to control this disease. Vaccinations are already in progress. However, no effective treatments have been found so far. The disease is caused by the SARS-CoV-2 coronavirus that through the Spike protein interacts with its cell surface receptor ACE2 to enter into the host cells. Therefore, compounds able to block this interaction may help to stop disease progression. In this study, we have analyzed the effect of compounds reported to interact and modify the activity of ACE2 on the binding of the Spike protein. Among the compounds tested, we found that hydroxyzine could inhibit the binding of the receptor-binding domain of Spike protein to ACE2 in a qualitative in vitro assay. This finding supports the reported clinical data showing the benefits of hydroxyzine on COVID-19 patients, raising the need for further investigation into its effectiveness in the treatment of COVID-19 given its well-characterized medical properties and affordable cost.

Interferon alpha-based combinations suppress SARS-CoV-2 infection in vitro and in vivo (preprint)

There is an urgent need for new antivirals with powerful therapeutic potential and tolerable side effects. In the present study, we found that recombinant human interferon-alpha (IFNa) triggers intrinsic and extrinsic cellular antiviral responses, as well as reduces replication of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in vitro. Although IFNa alone was insufficient to completely abolish SARS-CoV-2 replication, combinations of IFNa with remdesivir or other antiviral agents (EIDD-2801, camostat, cycloheximide, or convalescent serum) showed strong synergy and effectively inhibited SARS-CoV-2 infection in human lung epithelial Calu-3 cells. Furthermore, we showed that the IFNa-remdesivir combination suppressed virus replication in human lung organoids, and that its single prophylactic dose attenuated SARS-CoV-2 infection in lungs of Syrian hamsters. Transcriptome and metabolomic analyses showed that the combination of IFNa-remdesivir suppressed virus-mediated changes in infected cells, although it affected the homeostasis of uninfected cells. We also demonstrated synergistic antiviral activity of IFNa2a-based combinations against other virus infections in vitro. Altogether, our results indicate that IFNa2a-based combination therapies can achieve higher efficacy while requiring lower dosage compared to monotherapies, making them attractive targets for further pre-clinical and clinical development.