Abogen Biosciences Reports Favorable Phase I Clinical Trial Results for ARCoV mRNA Vaccine in The Lancet Microbe

On January 24, the Phase I clinical trial (ChiCTR2000039212) data of the COVID-19 mRNA vaccine ARCoVaX (ARCoV), jointly developed by Abogen, the Academy of Military Medical Sciences, and Walvax, was published in The Lancet Microbe. This single-center, double-blind, randomized, placebo-controlled, dose-escalation Phase I trial evaluated the preliminary safety, tolerability, and immunogenicity of the mRNA vaccine ARCoV, which encodes the receptor-binding domain (RBD) of the SARS-CoV-2 spike protein.

Source: The Lancet Microbe

The trial was conducted at Shulan (Hangzhou) Hospital, recruiting healthy adults aged 18-59 who were negative for SARS-CoV-2 infection. Participants were randomly assigned to receive either the vaccine or a placebo via intramuscular injection. The vaccine doses were 5 μg, 10 μg, 15 μg, 20 μg, and 25 μg.

Trial Overview (Source: The Lancet Microbe)

Baseline Demographic Characteristics (Source: The Lancet Microbe)

Between October 30 and December 2, 2020, 120 eligible participants were randomly assigned to receive ARCoV or placebo at five dose levels (20 participants per group). All participants received the first dose, and 118 received the second dose.

No serious adverse events were reported within 56 days after vaccination, and most adverse events were mild or moderate. Fever was the most common systemic adverse reaction: 5% (1/20) in the 5 μg group, 65% (13/20) in the 10 μg group, 85% (17/20) in the 15 μg group, 95% (19/20) in the 20 μg group, and 100% (16/16) in the 25 μg group.

Adverse Reaction Data (Source: The Lancet Microbe)

The incidence of Grade 3 systemic adverse events was 0% in the 5 μg group, and 15%, 30%, 35%, and 31% in the 10 μg, 15 μg, 20 μg, and 25 μg groups, respectively. The incidence of Grade 3 systemic adverse events was 0% in the placebo group.

As expected, most fevers disappeared within the first 2 days after vaccination in all groups. The incidence of "solicited systemic adverse events" was similar after the first or second dose of ARCoV.

ARCoV Antibodies and Neutralization Response

Humoral immune responses, including anti-RBD IgG and neutralizing antibodies, increased significantly 7 days after the second injection and peaked during days 14–28. Specific T-cell responses reached their peak 7–14 days after full vaccination. Notably, the 15 μg dose induced the highest titers of neutralizing antibodies, approximately twice those observed in convalescent COVID-19 patients.

ARCoV-Induced Specific T-Cell Response

These data indicate that ARCoV is safe and well-tolerated at all five dose levels. The acceptable safety profile, coupled with the induction of robust humoral and cellular immune responses, supports further clinical testing of ARCoV in larger-scale trials.

Abogen Biosciences was founded by Dr. Yingbo in 2019 and is located in Suzhou, focusing on mRNA drug research and development. In October 2020, Abogen completed its Series A financing of 150 million RMB. In 2021, the company completed three rounds of financing: a Series B round of 600 million RMB in April, a Series C round of 720 million USD in August, and a Series C+ round of 300 million USD in November, accumulating over 1.1 billion USD in total financing, ranking first in global biotechnology financing in 2021.

Abogen has established its own intellectual property platform for mRNA and nanodelivery technologies, with a product pipeline covering areas such as infectious disease prevention and cancer immunotherapy. ARCoVaX, the COVID-19 mRNA vaccine co-developed with the Academy of Military Medical Sciences and Walvax, is the first mRNA vaccine in China to be approved for clinical trials and has now entered Phase III clinical trials.

References:

[1] Gui-Ling Chen et al. Safety and immunogenicity of the SARS-CoV-2 ARCoV mRNA vaccinein Chinese adults: a randomised, double-blind, placebo-controlled, phase 1trial. The Lancet Microbe(2022).

[2] Top 10 RNA Therapy Companies to Watch in 2022