Genexine’s investigational Covid-19 vaccine and Celltrion’s treatment candidate showed antiviral effects in primates in pre-clinical trials.

According to the pharmaceutical industry officials on Wednesday, Genexine’s DNA vaccine candidate GX-19 and Celltrion’s antibody treatment candidate CT-P59 showed defense and resistance efficacy against the Covid-19 virus in two primates modeled with Covid-19 infection at the Korea Research Institute of Bioscience and Biotechnology (KRIBB).

In the primate tests, researchers administered one candidate vaccine and two candidate treatments to three monkeys, respectively, compared with the control group of three other monkeys.

A monkey injected with the treatment candidate CT-P59 did not show any active Covid-19 virus 24 hours after the administration. The second monkey injected with the DNA vaccine GX-19 did not develop fever, as opposed to the control arm with fever. After 48 hours, the researchers did not detect any virus in the upper airway, the main route of infection. The KRIBB did not disclose the result of the third monkey tested with the second treatment candidate.

“The primate infection models, verified by the KBIBB, showed lymphocyte reduction similar to the clinical infection pattern. But the monkey tested with GX-19 showed a slower reduction of lymphocytes than the control group and recovered quickly,” said Kim Sung-joo, CEO of GenNBio, a subsidiary of Genexine.

Genexine’s vaccine candidate and Celltrion’s experimental treatment are undergoing human trials in local hospitals.

The Severance Hospital and Gangnam Severance Hospital in Seoul are conducting phase-1/2a studies on Genexine’s GX-919. On July 21, Genexine won the regulatory nod for the world’s first trial on a jet injector-type Covid-19 vaccine.

Celltrion recently completed recruiting Covid-19 patients and began CT-P59 trials at the Chungnam National University Hospital in Daejeon, 140 kilometers south of Seoul.

The two companies said their tests of vaccine and treatment candidates in primates proved efficacy and safety.

“To prove a vaccine candidate’s efficacy, we induce viral infection after administering the vaccine. We call this ‘a challenge experiment.’ We can’t expose humans to the Covid-19 virus, so we do it to primates instead,” an official at Genexine said. “The latest primate models were designed similar to phase-3 trial conditions.”

The latest primates modeled with Covid-19 infection were the world’s fourth, supported by the government and developed by the KRIBB.

Participants in the consortium of industries, scholars, and researchers working on the primate infection model tests include Genexine, Binex, GenNBio, Korea Advanced Institute of Science and Technology (KAIST), and Pohang University of Science and Technology (POSTECH).

Copyright © KBR Unauthorized reproduction, redistribution prohibited