Baricitinib plus Standard of Care for Hospitalised Adults with COVID-19 on Invasive Mechanical Ventilation or Extracorporeal Membrane Oxygenation: Results of a Randomised, Placebo-Controlled Trial

Evidence before this study

We evaluated current and prior studies assessing the efficacy and safety of interventions in patients requiring invasive mechanical ventilation (IMV) and searched current PubMed using the terms “COVID-19”, “SARS-CoV-2”, “treatment”, “critical illness”, “invasive mechanical ventilation”, “baricitinib”, and “JAK inhibitor” for articles in English, published until December 1, 2020, regardless of article type. We also reviewed the NIH and IDSA COVID-19 guidelines and reviewed similar terms on clinicaltrials.gov. When the critical illness addendum study to COV-BARRIER study was designed, there was only one open-label study of dexamethasone showing mortality benefit in hospitalised patients with COVID-19 requiring IMV. Small studies of interleukin-6 inhibitors had shown no effect and larger trials were underway. Guidelines recommended use of dexamethasone with or without remdesivir and recommended against the use of interleukin-6 inhibitors, except in a clinical trial. Overall, there were no reported double-blind, placebo-controlled phase 3 trials which included corticosteroids as part of SOC investigating the efficacy and safety of novel treatments in the NIAID-OS 7 population. 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 antiviral mechanism for targeting host proteins mediating viral endocytosis Data from the NIAID sponsored ACTT-2 trial showed that baricitinib when added to remdesivir improved time to recovery and other outcomes including mortality compared to placebo plus remdesivir. A numerically larger proportion of participants who received baricitinib plus remdesivir showed an improvement in ordinal scale compared to those who received placebo plus remdesivir at day 15 in participants requiring IMV (NIAID-OS score of 7) at baseline. We designed COV-BARRIER, a phase 3, global, double-blind, randomised, placebo-controlled trial, to evaluate the efficacy and safety of baricitinib in combination with SOC (including corticosteroids) for the treatment of hospitalised adults with COVID-19 who did not require mechanical ventilation (i.e., NIAID-OS 4-6). A significant reduction in mortality was found after 28 days between baricitinib and placebo (HR 0·57, corresponding to a 43% relative reduction, p=0·0018); one additional death was prevented per 20 baricitinib-treated participants. In the more severely ill NIAID-OS 6 subgroup, one additional death was prevented per nine baricitinib-treated participants (HR 0·52, corresponding to a 48% relative reduction, p=0·0065). We therefore implemented an addendum to the COV-BARRIER trial to evaluate the benefit/risk of baricitinib in the critically ill NIAID-OS 7 population and considered the sample size of 100 participants sufficient for this trial.

Added value of this study

This was the first phase 3 study to evaluate baricitinib in addition to the current standard of care (SOC), including antivirals, anticoagulants, and corticosteroids, in patients who were receiving IMV or extracorporeal membrane oxygenation at enrolment. This was a multinational, randomised, double-blind, placebo-controlled trial in regions with high COVID-19 hospitalisation rates. Treatment with baricitinib reduced 28-day all-cause mortality compared to placebo (HR 0·54, 95% CI 0·31–0·96; nominal p=0·030), corresponding to a 46% relative reduction, and significantly reduced 60-day all-cause mortality (HR 0·56, 95% CI 0·33–0·97; p=0·027); overall, one additional death was prevented per six baricitinib-treated participants. Numerical improvements in endpoints such as number of ventilator-free days, duration of hospitalisation, and time to recovery were demonstrated. The frequency of serious adverse events, serious infections, and venous thromboembolic events was similar between baricitinib and placebo, respectively.

The COV-BARRIER study overall trial results plus these COV-BARRIER addendum study data in mechanically ventilated and ECMO patients provide important information in context of other large, phase 3 randomised trials in participants with invasive mechanical ventilation at baseline. The RECOVERY study reported mortality of 29·3% following treatment with dexamethasone compared to 41·4% for usual care (rate ratio of 0·64, corresponding to a 36% relative reduction) and 49% mortality in participants who received tocilizumab compared to 51% for usual care (rate ratio of 0.93, corresponding to a 7% relative reduction). The ACTT-2 study reported 28-day mortality of 23·1% and 22·6% in the baricitinib plus remdesivir and placebo plus remdesivir groups, respectively, in this critically ill patient population; however, the primary outcome of this trial was time to recovery, so was not powered to detect a change in mortality.

Implications of all the available evidence

In this phase 3 addendum trial, baricitinib given in addition to SOC (which predominantly included corticosteroids) had a significant effect on mortality reduction by 28 days in critically ill patients, an effect which was maintained by 60 days. These data were comparable with those seen in the COV-BARRIER primary study population of hospitalised patients, but which excluded patients who required IMV or extracorporeal membrane oxygenation at enrolment. These findings suggest that baricitinib has synergistic effects to other SOC treatment modalities including remdesivir and dexamethasone. Based on the available evidence, baricitinib is a novel treatment option to decrease mortality in hospitalised, critically ill patients with COVID-19 even when started late in the disease process after steroids, mechanical ventilation, and ECMO have already been implemented.