Celltrion said Friday that its Covid-19 antibody treatment, Regkirona, has shown efficacy in treating the Delta variant.
The company injected Regkirona in 49 mice infected with the Delta variant. Compared to the control group that did not receive any drugs, researchers confirmed clinical improvement effects, 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. In addition, the survival rate of the Regkirona-administered group was 100 percent while the control group's survival rate was 0 percent," it said.
As a result of its most recent study, Celltrion has confirmed the same efficacy of its treatment in the wild virus from Wuhan and three variant strains of the Covid-19 virus – Gamma, Beta, and Delta.
The company expects that this result will support the company's claims that the treatment can exert sufficient therapeutic efficacy in vivo even if the neutralizing ability of Regkirona is lowered at the cellular level.
"Celltrion will continue to conduct cellular-level neutralizing and animal efficacy tests for variant viruses sporadically prevalent around the world and have the potential to evolve into dominant species in cooperation with local and foreign organizations with public confidence," the company said.
Regarding the Lambda variant, which has become prevalent starting from Peru, the company has already obtained neutralizing results using a pseudovirus and has confirmed that the treatment has a stronger neutralizing ability than the existing Beta, Gamma, and Delta variants, it added.
Celltrion is also accelerating the development of an inhaled version of Regkirona to diversify treatment options for Covid-19.
Inhalation-type Regkirona will use a method that directly delivers antibodies to the respiratory tract mucosa infected with the Covid-19 virus.
According to the company, Celltrion and Inhalon Biopharma, a U.S.-based bio company with related patents and technologies, have recently started developing the inhaled version.
Inhalon submitted data to the Australian Ethics Committee to initiate a phase 1 clinical trial for an inhaled version of Regkirona in June and plans to confirm efficacy in the phase 2 clinical trial.
"In addition to the major variants that have been prevalent so far, the company has demonstrated the efficacy of Regkirona for Delta and Lambda variants as well," a company official said. "In the future, we will continue to evaluate the treatment's ability to neutralize Covid-19 virus and do our best to develop an inhaled Regkirona so that we can provide various treatment options for Covid-19 patients."