Eli Lilly has started patient enrolment for a Phase III clinical trial of baricitinib to treat adults hospitalised due to Covid-19 infection.

Oral JAK1/JAK2 inhibitor, baricitinib, is indicated in 70 countries to treat adults with moderately to severely active rheumatoid arthritis (RA). Lilly licensed the drug from Incyte.

Inhibition of JAK1 and JAK2 is expected to mitigate the cytokine storm related to the complications of Covid-19. The drug may block the host cell proteins involved in viral reproduction, decreasing the infected cells’ ability to produce more virus.

The Phase III trial will enrol approximately 400 patients across the US, Europe and Latin America. It will recruit patients who do not require invasive mechanical ventilation at the time of entering the study.

Trial participants will be given 4mg baricitinib daily or placebo for up to 14 days or until discharge from the hospital.

The primary endpoint of the trial is the proportion of patients who die or need non-invasive ventilation/high-flow oxygen or invasive mechanical ventilation by day 28.

Key secondary outcomes include clinical improvement at different time points, time to recovery, duration of hospitalisation, ventilator-free days, and mortality over a 28-day period.

Eli Lilly senior vice-president Patrik Jonsson said: “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.

“This randomised controlled study is an important step in our understanding of baricitinib as a potential Covid-19 treatment.”

The data from this Phase III trial is expected to support results from the study of the drug plus remdesivir in the second phase of the ACTT-2 study conducted by the National Institute of Allergy and Infectious Diseases (NIAID).

Earlier this month, Lilly started dosing participants in the Phase I trial of antibody therapy LY-CoV555 to treat Covid-19. This is said to be the world’s first study to assess an antibody treatment for the disease.