Celltrion Group’s regdanvimab (CT-P59) has demonstrated a robust neutralising effect in an in vivo efficacy study against the Delta variant (B.1.617.2) of the SARS-CoV-2 virus.
The variant was first detected in India and is now quickly spreading globally. According to the World Health Organization (WHO), B.1.617.2 is the most common variant being identified in 96 countries.
During the pre-clinical in vivo study, regdanvimab, a monoclonal antibody, was analysed for its neutralisation effect against the variant when given at a clinically relevant dose.
The drug candidate showed a 100% survival rate from Covid-19 versus 0% with placebo. Additionally, substantial protection against body weight loss was observed following the viral challenge.
A therapeutic regdanvimab dosage also decreased the viral load and inflammation in the lungs when compared with untreated controls. The therapy led to virus eradication from all treated animals.
On administration together, regdanvimab had in vivo efficacy against the Delta variant after Beta (B.1.351), which was first detected in South Africa, and Gamma variant (P.1) first identified in Brazil.
The efficacy was similar to that seen against wild-type SARS-CoV-2, indicating that even with the decreased in vitro neutralising activity against variants of concern, the drug candidate maintained its therapeutic potency in vivo.
In a cell-based pseudo-virus assay study conducted by the US National Institutes of Health (NIH), regdanvimab had strong neutralising activity against the Lambda variant (C.37) first detected in Peru.
Celltrion Healthcare Medical and Marketing division head Dr HoUng Kim said: “These new data are encouraging and reinforcing our body of both pre-clinical and clinical data.
“The Delta variant is a highly transmissible and contagious variant that could prompt further waves of infection around the world. It is important to expand the arsenal of monoclonal antibody therapies that are hoped to remain effective against the emerging Covid-19 variants.”
Last month, Celltrion reported positive top-line results from the Phase III trial of regdanvimab to treat mild-to-moderate Covid-19 symptoms.