Theravance Biopharma has dosed the first participants in a Phase II clinical study of TD-0903 being conducted for the treatment of Covid-19.

TD-0903 is a lung-selective, nebulised Janus kinase inhibitor (JAKi) being developed to help address acute lung injury (ALI) in hospitalised Covid-19 patients.

The drug is believed to be able to block the cytokine storm related to ALI and prevent progression to acute respiratory distress syndrome (ARDS).

Prior to the start of the Phase II trial in the UK, Theravance completed the dosing of healthy volunteers in the Phase I study at the same clinical unit in the country.

Theravance Biopharma CEO Rick Winningham said: “The initiation of the Phase II study of TD-0903 is a significant milestone in our ongoing efforts to apply our organ-selective therapies and expertise to treat inflammatory conditions.

“Theravance Biopharma has a long history of developing lung-selective medicines to treat respiratory disease, and we are proud to leverage this experience and expertise to respond to the current pandemic.”

The first part of the two-part Phase II study will evaluate the safety, tolerability and clinical response of TD-0903 in sequential ascending dose cohorts, with each patient being dosed for seven days.

Participants must have shown hypoxia, which is lack of oxygen in the blood and is considered a marker of underlying cytokine storm in the lung.

The second part of the trial is designed as a larger, multi-centre study to be performed at hospital-based clinical sites in the UK. It will also be expanded to other European countries and the US, pending ethics committee and regulatory approvals.

Set to enrol approximately 159 patients, the Phase II trial is expected to be completed in October this year.