Cytodyn has treated the first subject in the Phase III CD16 clinical trial of its chemokine receptor 5 (CCR5) antagonist, leronlimab, in critically ill Covid-19 patients in Brazil.

An experimental humanised Immunoglobulin G4 monoclonal antibody, leronlimab attaches to CCR5.

CCR5 is a cellular receptor vital in HIV infection, tumour metastases and a variety of other ailments such as nonalcoholic steatohepatitis.

The Phase III trial will enrol Covid-19 patients who are critically ill, admitted to the hospital and need mechanical and invasive ventilation or extracorporeal membrane oxygenation (ECMO).

Being carried out at 29 hospitals, the trial will have 316 subjects who will receive either four intravenous (IV) doses or 700mg leronlimab weekly or a placebo.

Following the recruitment of 127 subjects, an interim analysis will be carried out 28 days later.

Furthermore, the company plans to seek an Emergency Use Authorization on concluding this interim analysis, based on prior robust sub-population assessment in the CD12 trial.

CytoDyn president and CEO Nader Pourhassan said: “We are seeing strong optimism from all of the doctors and individuals involved in this project, especially since the primary endpoint for CD16 is similar to an endpoint in our past CD12 trial, which produced 166% better results in the leronlimab arm versus placebo.

“Importantly, this trial provides for two additional doses and delivery via IV (which allows leronlimab absorption to occur within one-two hours of being administered compared to two-three days when administered via SQ).”

Last month, CytoDyn treated the first subject in another Phase III CD17 trial in Brazil.

An interim assessment in this trial will be carried out 28 days following the enrolment of 245 subjects.

In August, CytoDyn received approval from Brazil’s Agência Nacional de Vigilância Sanitária (ANVISA) to commence patient enrolment in a Phase III CD17 trial of leronlimab in severe Covid-19 patients.