Celltrion’s monoclonal antibody treatment for COVID-19, regdanvimab (CT-P59), demonstrates strong neutralising activity against Delta variant

Celltrion’s monoclonal antibody treatment for COVID-19, regdanvimab (CT-P59), demonstrates strong neutralising activity against Delta variant

·          Pre-clinical data for regdanvimab (CT-P59) demonstrates strong neutralising activity against the Delta variant (B.1.617.2, first identified in India); results show 100% survival rate with virus eradication from all animals treated with therapeutic dosage of CT-P59

·          Regdanvimab (CT-P59) also retained its neutralisation potency against the Lambda variant (C.37, first identified in Peru) using a pseudo-virus neutralisation assay

·          Celltrion announces results from the global Phase III clinical trial of regdanvimab (CT-P59) at ECCMID 2021; met all primary and key secondary endpoints

July 16 2021, INCHEON, KOREA – Celltrion Group today announced new results from an in vivo efficacy study showing that regdanvimab (CT-P59) has a strong neutralising effect against the rapidly spreading Delta variant (B.1.617.2, first identified in India).

According to the World Health Organization (WHO), the Delta variant has been reported in 96 countries becoming the most common variant.^[i]

The pre-clinical in vivo study assessed the neutralisation effect of CT-P59 against the Delta variant, using a clinically relevant dose. The study demonstrated that CT-P59 treatment results in a 100% survival rate from COVID-19 compared to 0% for the placebo group, with significant protection against body weight loss shown after viral challenge also seen. In addition, a therapeutic dosage of CT-P59 significantly reduced the viral load of SARS-CoV-2 and inflammation in the lungs compared to non-treated controls with virus eradication from all animals treated with CT-P59.

Taken together, CT-P59 has shown in vivo efficacy against Delta variant following Beta (B.1.351, first identified in South Africa)^[ii] and Gamma variant (P.1, first identified in Brazil)^[iii], which was comparable to that against wild type SARS-CoV-2, thus demonstrating that despite the reduced in vitro neutralising activity against Variants of Concern (VOC), CT-P59 retained its therapeutic potency in in vivo setting.

The monoclonal antibody CT-P59 also demonstrated strong neutralising capability against the Lambda variant (C.37, first identified in Peru) in a cell-based pseudo- virus assay study performed by the National Institutes of Health (NIH), US.

“These new data are encouraging and reinforcing our body of both preclinical and clinical data,” said Dr. HoUng Kim, Ph.D., Head of Medical and Marketing Division at Celltrion Healthcare. “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.”

Celltrion announced its full Phase III data at the 31^st European Congress of Clinical Microbiology & Infectious Diseases (ECCMID) which took place online from 9 -12 July 2021. During the oral session, data showed regdanvimab (CT-P59) significantly reduced the risk of COVID-19 related hospitalisation or death by 72% for patients at high- risk of progressing to severe COVID-19 and 70% for all patients. In addition, patients who were treated with regdanvimab (CT-P59) reported a significantly shortened time to clinical recovery by at least 4.7 days for patients at high- risk of progressing to severe COVID-19 and by 4.9 days compared to placebo for all patients

[i] https://www.who.int/emergencies/diseases/novel-coronavirus-2019/media-resources/science-in-5/episode-45---delta-variant

[ii] Ryu DK., et al. Therapeutic effect of CT-P59 against SARS-CoV-2 South African variant. Biochemical and Biophysical Research Communications, Volume 566, 2021, Pages 135-140, https://doi.org/10.1016/j.bbrc.2021.06.016. [Last accessed July 2021]

[iii] Ryu DK., et al. Therapeutic efficacy of CT-P59 against P.1 variant of SARS-CoV-2. bioRxiv 2021.07.08.451696; doi: https://doi.org/10.1101/2021.07.08.451696