Eli Lilly and Company announced today that the first patient has been enrolled in Phase 3 randomized, double-blind, placebo-controlled study to evaluate the efficacy and safety of baricitinib, an oral JAK1/JAK2 inhibitor licensed from Incyte, in hospitalized adults with COVID-19. Baricitinib is approved in 70 countries as a treatment for adults with moderately to severely active rheumatoid arthritis (RA).

Lilly expects to enroll 400 patients in the trial, with data expected in the next few months. The study will be conducted in the U.S., U.K., Europe and Latin America and includes patients hospitalized with SARS-CoV- 2 infections who have at least one elevated marker of inflammation but do not require invasive mechanical ventilation at study entry.

In COVID-19 infection, increased disease severity can be associated with a hyperinflammatory state. It is hypothesized that through JAK1 and JAK2 inhibition, baricitinib may reduce the cytokine storm associated with the complications of this infection. In addition, baricitinib may have a role in inhibiting the host cell proteins that assist in viral reproduction, reducing the ability of infected cells to make more virus. A manuscript detailing this mechanism of action of baricitinib in COVID-19 has been accepted for publication by EMBO Molecular Medicine.

The primary endpoint for Lilly’s study is the proportion of patients who die or require non-invasive ventilation/high-flow oxygen or invasive mechanical ventilation by Day 28 in patients treated with 4 mg of baricitinib daily (with background therapy) compared to placebo (with background therapy).

Patients will receive baricitinib or placebo for up to 14 days or until discharge from the hospital. Key secondary outcomes of this study include the proportion of patients with clinical improvement at different time points, time to recovery, duration of hospitalization, number of ventilator-free days and mortality over a 28-day period.

“Lilly is committed to fighting this global pandemic, and this includes testing whether existing medicines including baricitinib could help treat the complications of COVID-19 in patients,” said Patrik Jonsson, Lilly senior vice president and president of Lilly Bio-Medicines. “This randomized controlled study is an important step in our understanding of baricitinib as a potential COVID-19 treatment.”

“Following upon the success of remdesivir to treat moderate to severe COVID-19, hospitalized patients are still in need of novel approaches to reduce mortality,” said Vincent C. Marconi, M.D., professor of medicine and global health at Emory University School of Medicine and Emory’s Rollins School of Public Health. “Several ongoing studies with baricitinib will provide necessary data about this treatment that may combine antiviral activity with suppression of cytokine storm.”

The data from Lilly’s trial will complement data from the study of baricitinib with remdesivir in the second phase of the Adaptive COVID-19 Treatment Trial (ACTT-2) run by the National Institute of Allergy and Infectious Diseases (NIAID), part of the National Institutes of Health (NIH). This study – which enrolled its first patient last month – assesses the efficacy and safety of the combination of a 4-mg daily dose of baricitinib plus remdesivir, compared to remdesivir.

Lilly is also supporting select ongoing multisite and single-site investigator-initiated trials in Europe and North America for hospitalized patients with COVID-19 infections. These studies by academic and government institutions will provide information on hundreds of additional patients treated with baricitinib and either placebo or active comparators.

Studying baricitinib in controlled trials is important in order to better characterize its potential benefits and understand the safety of its use as a COVID-19 treatment. The U.S. prescribing information for the approved use of baricitinib for RA includes boxed warnings regarding the use of baricitinib, including warnings about risk for developing blood clots and serious infections.