The US National Institutes of Health (NIH) unit the National Institute of Allergy and Infectious Diseases (NIAID) has announced the commencement of Covid-19 patient enrolment in the fourth iteration of the Adaptive COVID-19 Treatment Trial (ACTT-4).

Sponsored by NIAID, the trial will enrol up to 1,500 hospitalised adults with Covid-19 who require supplemental oxygen at about 100 sites in the US and other countries.

A group of participants will receive a corticosteroid available as a generic drug, dexamethasone, and remdesivir.

Discovered and developed by Gilead Sciences, remdesivir is a broad-spectrum antiviral approved by the US Food and Drug Administration (FDA) for treating hospitalised Covid-19 patients aged 12 or above.

The second group will receive remdesivir in combination with baricitinib.

Known as Olumiant, baricitinib is an FDA-approved inflammation modulator for treating certain adult patients with moderate to severe rheumatoid arthritis.

ACTT-4 trial will analyse whether baricitinib or dexamethasone, when given with remdesivir, is more effective at preventing hospitalised adults on supplemental oxygen from progressing to requiring mechanical ventilation or death.

In addition, the difference in the proportion of participants surviving without the need for invasive mechanical ventilation between the two treatment arms will be evaluated.

Overall clinical status at day 15 in each group will form the key secondary goal of the study.

The institute anticipates full enrolment of subjects in about three to four months.

In ACTT-1 trial, remdesivir shortened the time to recovery as compared to placebo.

The ACTT-2 trial, which was conducted on 1,033 hospitalised adult patients, showed that baricitinib plus remdesivir shortened the time to recovery as compared to placebo plus remdesivir.

Furthermore, in the global RECOVERY trial sponsored by the University of Oxford, dexamethasone showed a lower mortality rate compared with patients receiving usual care.

Last week, FDA granted emergency use authorisation (EUA) for baricitinib plus remdesivir to treat suspected or laboratory-confirmed Covid-19 in hospitalised patients aged two years and older who require supplemental oxygen, invasive mechanical ventilation, or extracorporeal membrane oxygenation.