Celltrion said that an animal efficacy test for Regkirona, its Covid-19 antibody treatment, showed efficacy in treating the Gamma variant originating in Brazil.

In the study, the company injected Regkirona in 55 laboratory mice infected with Gamma variant.

Compared to the control group that did not receive any drugs, the company confirmed the clinical improvement effect, including a significant decrease in virus titer and reduced weight loss in the group treated with Regkirona, according to Celltrion.

"We confirmed virus removal efficacy even when administering Regkirona at a lower dose than the human therapeutic dose, and the survival rate of the Regkirona-administered group was 100 percent, while the control group's survival rate was 0 percent," it said. This result is consistent with the previous experiments conducted on ferrets and mice to test the South African Beta variant."

Although the tests lowered the cellular-level neutralizing ability for Beta variants, the study is very meaningful as the drug showed sufficient therapeutic efficacy in vivo even at a dose 16 times lower than that applied in clinical practice, it added.

Celltrion said it plans to continue conducting cellular-level neutralizing and animal efficacy tests of Regkirona against various variants in cooperation with local and foreign organizations and plans to secure an animal efficacy test for the Delta variant by the end of July.

"We are proving the therapeutic effect of Regkirona against various variants one after another through animal tests," a company official said. "Celltrion also expects positive animal test results for the Delta variant, which has recently been a growing concern."

Celltrion will do its best to prevent the global spread of Covid-19 using Regkirona by actively responding to variant viruses, the official added.