The Celltrion Group (Incheon, Korea) announced preliminary preclinical results for regdanvimab (CT-P59), an anti-COVID-19 monoclonal antibody treatment, with data showing that CT-P59 has a neutralizing effect against the South African variant in an in vivo model. The study demonstrated that treatment with CT-P59, at a clinically relevant dose, results in a significant reduction in SARS-CoV-2 viral load.
CT-P59 was identified as a potential treatment for COVID-19 by detecting candidate antibodies and selecting those that showed the greatest potency to neutralize the SARS-CoV-2 virus. Preclinical in vitro and in vivo studies showed that CT-P59 binds strongly to SARS-CoV-2 RBD and significantly neutralizes wild-type and mutant variants of interest, including the UK variant (B.1.17). In in vivo models, CT-P59 effectively reduced SARS-CoV-2 viral load and inflammation in the lung. Results from the global phase 1 clinical trial of CT-P59 demonstrated a promising profile for safety, tolerability, antiviral effect, and efficacy in patients with mild COVID-19 symptoms. Celltrion’s global phase 3 clinical trial to further evaluate the efficacy and safety of CT-P59 is ongoing in 13 countries, including the US, Spain and Romania, having recently completed enrollment of 1,300 patients.
The preclinical study evaluated the neutralizing effect of CT-P59 against the South African variant, using a clinically relevant dose. CT-P59 demonstrated a reduction in binding affinity against the receptor-binding domain (RBD) in all three mutations (K417N, E484K and N501Y substitutions) of the South African variant. Furthermore, CT-P59 showed reduced susceptibility to the South African variant in an in vitro live virus and pseudovirus assay. However, no significant differences were observed in upper and lower respiratory viral infection when exposed to wild-type SARS-CoV-2 and the South African variants in the study. Taken together, the reduced effect on in vitro neutralization of CT-P59 is unlikely to compromise in vivo therapeutic potency against the variant in the respiratory tract, especially at a clinical dose.
“We are encouraged by the new data, which reinforces that Celltrion CT-P59 treatment could be effective against the South African variant and variant mutations,” said Dr. HoUng Kim, Ph.D., Chief of the Medical and Health Division. Celltrion Healthcare Marketing. “In the face of the rapid spread of COVID-19 variants, global access to effective antibody treatment is critically important in reducing the rate of disease progression to severe COVID-19 and helping outpatients avoid hospitalization and alleviate the burden on the healthcare system. We have begun the development of a neutralizing antibody cocktail with CT-P59 against new emerging strains in the UK and South Africa and will continue to further investigate neutralizing antibodies and other responses to protect against current SARS-CoV-2 strains and emerging variants. ” .