The in vitro and in vivo efficacy of CT-P59 against Gamma, Delta and its associated variants of SARS-CoV-2

Ryu, Dong-Kyun; Kang, Bobin; Noh, Hanmi; Woo, Sun-Je; Lee, Min-Ho; Nuijten, Patricia M.; Kim, Jong-In; Seo, Ji-Min; Kim, Cheolmin; Kim, Minsoo; Yang, Eunji; Lim, Gippeum; Kim, Seong-Gyu; Eo, Su-Kyeong; Choi, Jung-ah; Song, Manki; Oh, Sang-Seok; Chung, Hyo-Young; Tijsma, Aloys SL.; van Baalen, Carel A.; Kwon, Ki-Sung; Lee, Soo-Young

The SARS-CoV-2 variant is rapidly spreading across the world and causes to resurge infections. We previously reported that CT-P59 presented its in vivo potency against Beta variants, despite its reduced activity in cell experiments. Yet, it remains uncertain to exert the antiviral effect of CT-P59 on Gamma, Delta and its associated variants (L452R). To tackle this question, we carried out cell tests and animal studies. CT-P59 showed neutralization against Gamma, Delta, Epsilon, and Kappa variants in cells, with reduced susceptibility. The mouse challenge experiments with Gamma and Delta variants substantiated in vivo potency of CT-P59 showing symptom remission and virus abrogation in the respiratory tract. Collectively, cell and animal studies showed that CT-P59 is effective against Gamma and Delta variants infection, hinting that CT-P59 has therapeutic potential for patients infected with Gamma, Delta and its associated variants.