UK-headquartered EUSA Pharma has enrolled the first patient in a phase III study of siltuximab in patients hospitalised with COVID-19.

The phase III study, dubbed SILVAR, will evaluate the efficacy and safety of standard of care (SOC), both with and without intravenous siltuximab treatment in patients hospitalised with COVID-19.

The selected patients chosen for the SILVAR study will have also been previously treated with corticosteroids or have also had another respiratory infection.

In addition, the SILVAR study will only enrol hospitalised patients suffering from serious viral acute respiratory distress syndrome (ARDS) in a hyperinflammatory state.

Siltuximab is a monoclonal antibody that targets and neutralises interleukin-6 (IL-6), an inflammatory cytokine observed at high levels in a number of inflammatory conditions.

In the previous SISCO study, results from 30 patients treated with siltuximab compared with 30 matched controls found that treatment with the IL-6 inhibitor led to a 54% reduction in the risk of 30-day all-cause mortality.

“We are delighted to have enrolled the first patient in the ‘SILVAR’ study of siltuximab, a monoclonal antibody that binds to and neutralises IL-6, an important mediator of the immune response to infection,” said Lee Morely, chief executive officer of EUSA Pharma.

“This clinical trial represents an important step in finding a solution for hospitalised patients with serious respiratory complications due to an over reactive immune response to Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2) infection that is not fully responsive to corticosteroid therapy, as well as those with any other respiratory virus infection associated with serious ARDS,” he added.

Siltuximab is currently approved by the US Food and Drug Administration (FDA) and the European Commission (EC) and other health regulatory authorities for the treatment of adult patients with Multicentric Castleman Disease (MCD) who are human immunodeficiency virus (HIV) negative and human herpesvirus-8 (HHV-8) negative.