Brii Biosciences (Brii Bio) and TSB Therapeutics have reported positive findings from a randomised, single-blind clinical study of its amubarvimab/romlusevimab combination, for Covid-19 in China.

Obtained from convalesced Covid-19 patients, amubarvimab and romlusevimab are non-competing SARS-CoV-2 monoclonal neutralising antibodies. 

The long-acting Covid-19 neutralising antibody therapy was developed in partnership with the 3rd People’s Hospital of Shenzhen and Tsinghua University. 

TSB commenced this study in China in June last year to assess the safety, tolerability and initial clinical efficacy of the combination therapy in 48 Covid-19 patients. 

This study was carried out parallelly with the US National Institutes of Health (NIH)-sponsored international Phase III ACTIV-2 trial of the amubarvimab/romlusevimab combination.

According to the study findings from China, the combination therapy was found to be safe and well-tolerated in severe as well as non-severe Covid-19 patients. 

In addition, no drug-related serious adverse events (SAEs), infusion reactions and dose discontinuation, or reduction, linked to adverse events were reported. 

The viral loads in eight subjects with severe Covid-19, who received the antibody therapy, substantially declined from baseline levels without any patient experiencing exacerbations that needed mechanical ventilation or caused mortality. 

Furthermore, several clinical benefits were reported in 40 non-severe Covid-19 patients who received the treatment.

The benefits were observed in efficacy indicators including median time to symptom resolution, ribonucleic acid (RNA) conversion rate and proportion of disease progression.

The company noted that the latest data were in line with the findings from the Phase III ACTIV-2 trial in 837 participants.

Brii Bio Greater China president and general manager and TSB Therapeutics CEO Rogers Luo said: “We are pleased to see that the study results further enrich the safety and efficacy of the combination therapy, providing important data for its clinical application. 

“These data alongside the real-world data of the nearly 1,000 patients who received emergency treatment in China last year further support the currently approved indications and dosing regimen of the combination therapy in China.”

In May this year, the company reported that amubarvimab and romlusevimab showed to retain neutralising activity against the Omicron BA.2 subvariant of the SARS-CoV-2 virus.