The emergence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has caused a devastating pandemic. Although most people infected with SARS-CoV-2 develop a mild to moderate disease with virus replication restricted mainly to the upper airways, some progress to having a life-threatening pneumonia. In this Review, we explore recent clinical and experimental advances regarding SARS-CoV-2 pathophysiology and discuss potential mechanisms behind SARS-CoV-2-associated acute respiratory distress syndrome (ARDS), specifically focusing on new insights obtained using novel technologies such as single-cell omics, organoid infection models and CRISPR screens. We describe how SARS-CoV-2 may infect the lower respiratory tract and cause alveolar damage as a result of dysfunctional immune responses. We discuss how this may lead to the induction of a 'leaky state' of both the epithelium and the endothelium, promoting inflammation and coagulation, while an influx of immune cells leads to overexuberant inflammatory responses and immunopathology. Finally, we highlight how these findings may aid the development of new therapeutic interventions against COVID-19. 

/pdf/sars-cov-2-pathogenesis-1tieifc2.pdf

SARS-CoV-2 pathogenesis

Immune dysregulation is an important component of the pathophysiology of COVID-19. A large body of literature has reported the effect of immune-based therapies in patients with COVID-19, with some remarkable successes such as the use of steroids or anti-cytokine therapies. However, challenges in clinical decision-making arise from the complexity of the disease phenotypes and patient heterogeneity, as well as the variable quality of evidence from immunotherapy studies. This Review aims to support clinical decision-making by providing an overview of the evidence generated by major clinical trials of host-directed therapy. We discuss patient stratification and propose an algorithm to guide the use of immunotherapy strategies in the clinic. This will not only help guide treatment decisions, but may also help to design future trials that investigate immunotherapy in other severe infections. This Review aims to support clinical decision-making by providing an overview of the evidence for immunotherapy strategies in patients with COVID-19. 

/pdf/a-guide-to-immunotherapy-for-covid-19-1524g892.pdf

A guide to immunotherapy for COVID-19

To provide guidance on the management of Multisystem Inflammatory Syndrome in Children (MIS‐C), a condition characterized by fever, inflammation, and multiorgan dysfunction that manifests late in the course of SARS–CoV‐2 infection. Recommendations are also provided for children with hyperinflammation during COVID‐19, the acute, infectious phase of SARS–CoV‐2 infection.

/pdf/american-college-of-rheumatology-clinical-guidance-for-1gcjtzqa.pdf

American College of Rheumatology Clinical Guidance for Multisystem Inflammatory Syndrome in Children Associated With SARS–CoV‐2 and Hyperinflammation in Pediatric COVID‐19: Version 3

http://www.thelancet.com/article/S0140673622011096/pdf

Baricitinib in patients admitted to hospital with COVID-19 (RECOVERY): a randomised, controlled, open-label, platform trial and updated meta-analysis

Host genetic factors determining COVID-19 susceptibility and severity.

Efficacy and safety of baricitinib for the treatment of hospitalised adults with COVID-19 (COV-BARRIER): a randomised, double-blind, parallel-group, placebo-controlled phase 3 trial.

Background The efficacy and safety of baricitinib, an oral selective Janus kinase 1/2 inhibitor, in addition to standard of care (SOC) in hospitalised adults with COVID-19 is unknown. Methods In this phase 3, global, double-blind, randomised, placebo-controlled trial, participants were enrolled from 101 centres across 12 countries in Asia, Europe, North America, and South America (ClinicalTrials.govNCT04421027). Hospitalised adults with COVID-19 receiving SOC were randomly assigned (1:1) to once-daily baricitinib 4-mg or placebo for up to 14 days. SOC included systemic corticosteroids in 79·3% of participants (dexamethasone ∼90%). The composite primary endpoint was the proportion who progressed to high-flow oxygen, non-invasive ventilation, invasive mechanical ventilation, or death by day 28. All-cause mortality by days 28 and 60 were key secondary and exploratory endpoints, respectively. Efficacy and safety analyses included the intent-to-treat and safety populations, respectively. Findings Between June 11, 2020 and January 15, 2021, 1525 participants were randomly assigned to baricitinib 4-mg (n=764) or matched placebo (n=761). Overall, 27·8% of participants receiving baricitinib vs 30·5% receiving placebo progressed (primary endpoint, odds ratio 0·85, 95% CI 0·67-1·08; p=0·18). The 28-day all-cause mortality was 8·1% (n=62) for baricitinib and 13·1% (n=100) for placebo, corresponding to a 38·2% reduction in mortality (hazard ratio [HR] 0·57, 95% CI 0·41-0·78; nominal p=0·0018). The 60-day all-cause mortality was 10·3% (n=79) for baricitinib and 15·2% (n=116) for placebo (HR 0·62, 95% CI 0·47-0·83; p=0·0050). Frequency of serious adverse events (14·7% [n=110] vs 18·0% [n=135]), serious infections (8·5% [n=64] vs 9·8% [n=74]), and venous thromboembolic events (2·7% [n=20] vs 2·5% [n=19]) was similar between baricitinib and placebo, respectively. Interpretation While reduction of disease progression did not achieve statistical significance, treatment with baricitinib in addition to SOC (including dexamethasone) significantly reduced mortality, with a similar safety profile to SOC, in hospitalised COVID-19 participants. Funding Eli Lilly and Company. Research in context Evidence before this study We searched PubMed using the terms “COVID-19”, “SARS-CoV-2”, “treatment”, “baricitinib” and “JAK inhibitor” for articles in English published up to April 31, 2020, regardless of article type. We considered previous and current clinical trials of investigational medications in COVID-19, as well as previous clinical trials of the Janus kinase (JAK)1 and JAK2 inhibitor, baricitinib, before undertaking this study. At the time the COV-BARRIER study was designed, there were no approved therapies for the treatment of COVID-19. Management of COVID-19 was supportive, and limited phase 3 randomised placebo-controlled studies had been completed. Limited phase 2 and 3 data on the antimalarial hydroxychloroquine and protease inhibitor lopinavir/ritonavir were available, and trials investigating the use of the antiviral remdesivir were ongoing. Baricitinib’s mechanism of action as a JAK1 and JAK2 inhibitor was identified as a potential intervention for the treatment of COVID-19 given its known anti-cytokine properties and potential for targeting host proteins for its antiviral mechanism. Additionally, early case series evaluating the efficacy and safety of baricitinib in the hospitalised patient population supported further evaluation of baricitinib as a potential treatment option for hospitalised patients with COVID-19. While COV-BARRIER was enrolling, ACTT-2, a phase 3 study evaluating baricitinib plus remdesivir was completed showing that baricitinib added to remdesivir improved time to recovery and other outcomes. Added value of this study This was the first phase 3 study to evaluate baricitinib in addition to the current standard of care (SOC) and included antivirals, anticoagulants, and corticosteroids. After the earliest publication of the RECOVERY study in June 2020, the treatment of hospitalised patients with COVID-19 changed with the adoption of dexamethasone as SOC. As a result of its design, COV-BARRIER became the first trial to evaluate the benefit/risk of baricitinib when added to the most current SOC (dexamethasone) in these patients. This was a randomised, double-blind, placebo-controlled trial conducted globally in regions with high COVID-19 hospitalisation rates. The reduction in the composite primary endpoint of progression to non-invasive ventilation, high flow oxygen, invasive mechanical ventilation, or death for baricitinib plus SOC (including dexamethasone) compared to placebo plus SOC did not reach statistical significance. However, in a pre-specified key secondary endpoint, treatment with baricitinib reduced 28-day all-cause mortality by 38·2% compared to placebo (HR 0·57, 95% CI 0·41-0·78; nominal p=0·0018); one additional death was prevented per 20 baricitinib-treated participants. The reduction of all-cause mortality with baricitinib was maintained by day 60 in an exploratory analysis. The frequency of serious adverse events, serious infections, and venous thromboembolic events was similar between baricitinib and placebo, respectively. Implications of all the available evidence In this phase 3 trial, baricitinib given in addition to SOC (which predominantly included dexamethasone) did not reduce a composite endpoint of disease progression, but showed a strong effect on reducing mortality by 28 days, an effect which was maintained by 60 days. In the ACTT-2 study, baricitinib further reduced time to recovery above the background use of remdesivir. Taken together, these findings suggest that baricitinib has synergistic effects to other SOC treatment modalities including remdesivir and dexamethasone. Based on all available evidence, baricitinib is a potentially effective oral treatment option to decrease mortality in hospitalised patients with COVID-19.

/pdf/baricitinib-plus-standard-of-care-for-hospitalized-adults-4pk1rfep2c.pdf

Mousumi Som

Papers

Efficacy and safety of baricitinib for the treatment of hospitalised adults with COVID-19 (COV-BARRIER): a randomised, double-blind, parallel-group, placebo-controlled phase 3 trial.

Baricitinib plus Standard of Care for Hospitalized Adults with COVID-19